Practical Hepatic Pathology: A Diagnostic Approach [2 ed.] 9780323442862, 9780323442855, 9780323428736, 2016056540

Table of contents :
Cover
Serier Page
Practical Hepatic Pathology: A Diagnostic Approach
Copyright
Dedication
Contributors
Series Preface
Preface
Acknowledgments
Pattern-Based Approach to Diagnosis
Virtual Slide Box
Section I: Basic Concepts in Liver Pathology
1 - Microscopic Anatomy, Basic Terms, and Elemental Lesions
Parenchymal Architecture and Tissue Organization
Assessing Parenchymal Architecture in a Biopsy
Absence of Portal Tracts
Fragmentation
Subcapsular Parenchyma
Portal Tracts
Bile Ducts
Hepatic Arteries
Portal Veins
Hepatic Veins
Lobular Parenchyma
Hepatocytes
Intralobular Biliary Channels
Sinusoids
Disse Space
Electron Microscopy
Hepatocytes
Sinusoidal Lining Cells
Disse Space
Utility of Electron Microscopy in Routine Diagnostic Practice
Basic Terms and Elemental Lesions
Structural
Inflammation, Cell Damage, and Necrosis
Intracellular Pathology
Biliary Lesions
Sinusoidal Lesions
References
Section II: Clinical, Laboratory, and Radiologic Features of Liver Disease
2 - Clinical Features of Liver Disease
Definitions and Synonyms
Acute Liver Disease
Etiology
Clinical Manifestations
Treatment and Prognosis
Acute Liver Failure
Subacute Liver Failure
Chronic Liver Disease
Etiology
Assessing the Severity of Cirrhosis
Clinical Signs (Stigmata) of Chronic Liver Disease
Complications of Liver Cirrhosis
Variceal Bleeding
Ascites
Spontaneous Bacterial Peritonitis
Hepatorenal Syndrome
Hepatic Encephalopathy
Hepatopulmonary Syndrome
Portopulmonary Hypertension
References
3 - Laboratory Tests in Liver Disease
Liver Tests
Transaminases
“Biliary” Enzymes
Measures of Coagulation
Other Tests
Approach to Evaluation of Abnormal Liver Tests
Laboratory Investigation of Acute Liver Injury
Laboratory Investigation of Chronic Liver Disease
Laboratory Investigation of Liver Disease in Pregnancy
Laboratory Investigation of Liver Abnormalities in Systemic Diseases and Disease of Other Organs
Connective Tissue Diseases
Endocrine Disorders
Infectious Diseases
Neoplastic Diseases
Cardiac Diseases
Gastrointestinal Diseases
References
4 - Investigative Imaging of the Liver
Commonly Used Imaging Modalities
Imaging of Liver Tumors
Hemangioma
Focal Nodular Hyperplasia
Hepatocellular Adenoma
Hepatocellular Carcinoma
Metastases
Cholangiocarcinoma
Imaging of Diffuse Liver Disease
Hepatic Steatosis
Hepatic Fibrosis and Cirrhosis
Contrast-Enhanced Sonography
Transient Elastography
Magnetic Resonance Elastography
Summary
Section III: Liver Diseases of Childhood
5 - Liver Diseases of Childhood
Neonatal Cholestasis
Incidence and Demographics
Role of Liver Biopsy in Neonatal Cholestasis
Biliary Atresia
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Pathology
Macroscopic Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Neonatal (Giant Cell) Hepatitis
Clinical Manifestations
Pathology
Differential Diagnosis
Treatment and Prognosis
Alagille Syndrome
Incidence and Demographics
Molecular Genetics
Clinical Manifestations
Gross Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Primary Sclerosing Cholangitis
Incidence and Demographics
Clinical Manifestations
Radiologic Findings
Microscopic Pathology
Diagnosis
Treatment and Prognosis
Sclerosing Cholangitis Due to Langerhans Cell Histiocytosis
Microscopic Pathology
Molecular Pathology
Treatment and Prognosis
Neonatal Sclerosing Cholangitis
References
Section IV: Metabolic Diseases of the Liver
6 - Medical Genetics and Biochemistry in Diagnosis and Management
Clinical Approach
Approach to Biochemical and Genetic Investigation
Collection, Storage, and Shipping of Specimens
Methodologies Involved in Biochemical and Genetic Testing
Tandem Mass Spectrometry
Methodologies Used for Specific Biochemical Compounds
Amino Acids
Organic Acids
Proteins
Enzymes
DNA
Very Long Chain Fatty Acids and Related Molecules
Treatment and Management
Newborn Screening–Related Disorders
Other Metabolic Liver Diseases
Mitochondrial Disorders
Genetic Counseling
References
7 - Histologic Patterns of Metabolic Liver Diseases
Handling Liver Biopsy Specimens for Suspected Metabolic Disease
Analysis and Reporting of Liver Biopsy Specimens for Suspected Metabolic Disease
Histologic Patterns of Metabolic Liver Disease
Metabolic Diseases with Normal Liver Histology
Metabolic Diseases with an Inflammatory Pattern
Metabolic Diseases with Prominent Lobular Cholestasis
Bile Ductules Versus Ducts in Metabolic Disease
Metabolic Diseases with a Steatotic Pattern
Pathology
Diagnosis
Pathology
Diagnosis
Reye Syndrome
Urea Cycle Defects
Clinical Manifestations
Pathology
Diagnosis
Citrin Deficiency
Galactosemia
Hereditary Fructose Intolerance
Lysosomal Storage Disorders
Pathology
Diagnosis
Acid Lipase Deficiency
Niemann-Pick Disease, Type C
Cystinosis
Diagnosis
Bile Acid Synthetic Defects
Peroxisomal Diseases
Clinical Manifestations
Pathology
Diagnosis
Pathology
Diagnosis
Genetic Hemolytic Disorders
Genetic Metabolic Diseases of Unknown Etiology
References
8 - Liver in Wilson Disease
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Pathology
Gross Pathology
Microscopic Features
Grading and Staging
Ancillary Diagnostic Studies
Differential Diagnosis
Other Disorders of Hepatic Copper Accumulation
Genetics
Treatment and Prognosis
References
9 - Liver Disease in Alpha-1 Antitrypsin Deficiency
Terminology
Incidence and Demographics
Clinical Manifestations and Natural History of Liver Disease
PiZZ
PiMZ
The “S” Allele
Microscopic Pathology
Intracytoplasmic Globules
Pathology of PiZZ
Pathology of PiMZ
Pathology of the “S” Variant
Ultrastructural Pathology
Differential Diagnosis
Diagnosis
Genetics and Molecular Pathology
Treatment and Prognosis
References
10 - Liver Disease in Cystic Fibrosis
Incidence and Demographics
Genetics
Pathophysiology
Clinical Manifestations of Hepatobiliary Disease
Microscopic Pathology
Steatosis
Neonatal Cholestasis
Focal Biliary Cirrhosis
Multilobular Cirrhosis
Large Bile Duct Disease
Diagnostic Studies
Therapy
References
11 - Liver Disease in Iron Overload
Iron Homeostasis
HFE
Hepcidin and Ferroportin
Hepcidin Deficiency/Hepcidin Resistance
Hepcidin Excess/Ferroportin Deficiency
Microscopic Pathology
Iron Pigment
Patterns of Iron Deposition
Parenchymal Iron Overload
Hereditary Hemochromatosis Types 1, 2A, 2B, and 3
Microscopic Pathology
Hereditary Hemochromatosis Type 4 (Ferroportin Gain-of-Function Mutations)
Hereditary Aceruloplasminemia
Dyserythropoietic Syndromes
Iron Overload Associated with Alpha-1-Antitrypsin Deficiency
Mesenchymal Iron Overload
Hereditary Hemochromatosis Type 4 (Ferroportin Loss-of-Function Mutations)
Miscellaneous Disorders
Microscopic Pathology
Mixed Parenchymal-Mesenchymal Iron Overload
Genetic Causes
African Iron Overload and Hepatic Iron Overload in African Americans
Porphyria Cutanea Tarda
Nongenetic Causes
Dysmetabolic Iron Overload Syndrome
Alcoholic Liver Disease
Nonalcoholic Fatty Liver Disease
Chronic Viral Hepatitis
Differential Diagnosis of Severe Iron Overload in Cirrhosis
Genetic/Hereditary Causes
Advanced Fibrosis/Cirrhosis
Spur Cell Anemia in Cirrhosis
Alcoholic Liver Disease
Role of Liver Biopsy
Differential Diagnosis
Iron-Free Foci
Histologic Grading of Iron Deposition
Histologic Effects of Chelation Therapy
Effect on Stainable Iron
Effect on Fibrosis
Ancillary Diagnostic Studies
Hepatic Iron Concentration
Hepatic Iron Index
References
12 - Nonalcoholic Fatty Liver Disease
Definitions and Synonyms
Incidence and Demographics
Clinical Manifestations
Radiology
Gross Pathology
Microscopic Pathology
Steatosis
Steatohepatitis
Inflammation
Other Features
Fibrosis
Variations in Children
Special Stains
Grading and Staging
Differential Diagnosis
Alcoholic Liver Disease
Nonalcoholic Fatty Liver Disease with Concurrent Liver Disease
Nonalcoholic Fatty Liver Disease Outside the Context of Metabolic Syndrome
Drug-Induced Fatty Liver Disease
Abnormalities of Lipid Metabolism
Nutritional Causes
Total Parenteral Nutrition
Starvation and Dietary Effects
Celiac Disease
Chronic Liver Diseases
Hepatitis C Virus Infection
Wilson Disease
Ancillary Diagnostic Tests
Genetics
Treatment and Prognosis
References
Section V: Infectious Diseases of the Liver
13 - Acute Viral Hepatitis
Histologic Patterns of Injury in Acute Viral Hepatitis
Acute “Lobular” Hepatitis (Prototypical Acute Hepatitis)
Gross Pathology
Microscopic Pathology
Clinicopathologic Course Related to Special Patterns of Hepatic Necrosis and Regeneration
Histologic Clues to the Causative Virus
Hepatitis A
Hepatitis E
Hepatitis B
Hepatitis C
Other Viruses Causing Acute Hepatitis
Hepatitis D (Delta) Virus
Clinical Manifestations and Natural History
Pathology
Herpesviruses
Epstein-Barr Virus
Liver Disease Caused by Epstein-Barr Virus. Primary EBV infection occurring in children is largely asymptomatic or minimally sym...
Pathology. The most remarkable histopathologic feature of EBV-related hepatitis is the presence of a dense lymphocytic inflammat...
Diagnosis. Diagnosis of infectious mononucleosis is established by the detection of heterophilic antibodies to EBV by the Monosp...
Cytomegalovirus
Liver Disease Caused by Cytomegalovirus. CMV is the most common cause of congenital infection and is reported in 0.2% to 2.2% of...
Pathology. Congenital CMV infection may lead to neonatal hepatitis, which is discussed in Chapter 5. Histologically, there is po...
Diagnosis. Diagnosis can be made by histology, viral cultures, or serologic tests that detect antibodies or viral proteins. Sero...
Human Herpesvirus 6
Herpes Zoster
Herpes Simplex Virus Types 1 and 2
Pathology. The histologic findings are distinctive, with randomly distributed, patchy areas of coagulative necrosis that demonst...
Adenovirus
Pathology
Diagnosis
Parvovirus
Icteric Hemorrhagic Fevers
Yellow Fever Virus
Liver Disease Caused by Yellow Fever Virus. After 4 to 5 days of incubation, the patient presents with fever, headache, diffuse ...
Pathology. The major histologic finding is hemorrhagic hepatocyte necrosis, which is predominantly midzonal (zone 2) but may be ...
Diagnosis. Besides epidemiologic and clinical symptoms compatible with yellow fever, serologic enzyme immunoassay must detect Ig...
Vaccination and Viscerotropic Disease. The presence of only one serotype of the yellow fever virus enabled the successful develo...
Dengue Virus
Liver Involvement in Severe Dengue Virus Infections. Severe forms of DENV infection demonstrate high level of viremia leading to...
Pathology. A wide spectrum of hepatic histologic changes has been noted in dengue. This comprises fatty change (microvesicular),...
Diagnosis
Ebola and Marburg Viruses
Arenaviruses
Hantavirus
References
14 - Hepatitis B
Incidence and Demographics
Molecular Virology
Natural History and Clinical Manifestations
Treatment
Role of Liver Biopsy in Management of Hepatitis B
Microscopic Pathology of Chronic Hepatitis B
Portal Changes and Interface Hepatitis
Lobular Inflammation, Apoptosis, and Necrosis
Ground-Glass Cells and Sanded Nuclei
Large Cell and Small Cell Changes
Fibrosis and Architectural Distortion
Immunohistochemical Stains for Viral Antigens in Chronic Hepatitis B
Differential Diagnosis of Chronic Hepatitis B
Chronic Hepatitis C
Other Chronic Hepatitides
Other Chronic Liver Diseases
Ground-Glass Cells
Practical Approach in Evaluating Liver Biopsy Specimens from Patients with Chronic Hepatitis B
References
15 - Hepatitis C
Incidence and Demographics
Molecular Virology
Natural History and Clinical Manifestations
Treatment
Role of Liver Biopsy in Management of Hepatitis C
Microscopic Pathology of Chronic Hepatitis C
Portal Changes and Interface Hepatitis
Lobular Inflammation, Apoptosis, and Necrosis
Steatosis and Other Cytoplasmic Changes of Hepatocytes
Large Cell Change and Small Cell Change
Fibrosis and Architectural Distortion
Differential Diagnosis of Chronic Hepatitis C
Chronic Hepatitides
Hereditary Metabolic Disorders
Chronic Biliary Diseases
Steatohepatitis
Malignant Lymphoma
Practical Approach in Evaluating Liver Biopsy Specimens from Patients with Chronic Hepatitis C
References
16 - Chronic Hepatitis: Grading and Staging
Need for Grading and Staging
General Principles of Grading and Staging
Grading and Staging Systems
Histologic Activity Index
Grading Systems
Scheuer System
Batts and Ludwig System
Ishak System
METAVIR Algorithm
Staging Systems
Scheuer System
Ishak System
METAVIR System
Which Is the Best Grading and Staging System
Limitations of the Liver Biopsy in Grading and Staging: Sampling Error
Limitations of Semiquantitative Scoring: Interobserver Variability
Semiquantitative Scoring versus Morphometric Analysis
Noninvasive Non–Biopsy-Based Staging Systems
References
17 - Human Immunodeficiency Virus Infection of the Liver
Pattern of Reactivity of the Reticuloendothelial System
Basic Liver Reactivity Pattern to Human Immunodeficiency Virus Infection
Visceral Leishmaniasis
Hemophagocytic Lymphohistiocytosis
Cholangiopathy Pattern
Steatosis Pattern
Chronic Hepatitis Pattern
Coinfection With Human Immunodeficiency Virus and Hepatitis C Virus
Coinfection With Human Immunodeficiency Virus and Hepatitis B Virus
Hepatitis Pattern With Multifocal Parenchymal Necrosis
Cytomegalovirus
Herpesvirus
Toxoplasmosis
Pneumocystis Infection
Granulomatous Inflammation Pattern
Mycobacterial Infections
Mycoses
Pattern of Bacterial Infections With Abscess Formation
Fibrogenic Pattern
Vascular Lesions
Peliosis
Bacillary Angiomatosis
Nodular Regenerative Hyperplasia
Mitochondriopathy Pattern
Acute Hepatitis and Cholestatic Hepatitis
Human Immunodeficiency Virus–Associated Neoplasia
Kaposi Sarcoma
Acquired Immunodeficiency Syndrome–Associated Lymphomas
References
18 - Nonviral Infections of the Liver
Bacterial Infections
Liver in Sepsis
Pathology
Pyogenic Abscess
Salmonellosis
Pathogenesis
Liver Disease in Salmonellosis
Diagnosis
Brucellosis
Liver Involvement in Brucellosis
Diagnosis
Legionellosis
Actinomycosis
Liver Involvement in Actinomycosis
Syphilis
Leptospirosis
Clinical Manifestations
Pathogenesis
Pathology
Rickettsial Infections
Rocky Mountain Spotted Fever
Liver Disease in Rocky Mountain Spotted Fever
Q Fever
Liver Involvement in Q Fever
Chlamydial Infection
Mycobacterial and Fungal Infections
Protozoal Infections
Amebiasis
Life Cycle in Relation to Liver Disease
Pathology
Diagnosis
Visceral Leishmaniasis (Kala-azar)
Life Cycle and Pathogenesis in Relation to Liver Disease
Pathology
Diagnosis
Visceral Leishmaniasis in Acquired Immunodeficiency Syndrome
Malaria
Life Cycle and Pathogenesis
Clinical Manifestations
Pathology
Diagnosis
Parasitic Infections
Ascariasis
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
Visceral Larva Migrans/Toxocariasis
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
Capillariasis
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
Strongyloidiasis
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
Schistosomiasis
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
Pentastomiasis
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
Fascioliasis
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
Clonorchiasis and Opisthorchiasis
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
Hydatid Cyst
Life Cycle in Relation to Liver Disease
Clinical Manifestations
Pathology
Diagnosis
References
Section VI: Granulomatous Diseases of the Liver
19 - Hepatic Granulomas: Differential Diagnosis
Histologic Patterns of Hepatic Granulomas
Epithelioid Granulomas
Suppurative Granulomas (Granulomas with Central Microabscess)
Microgranulomas
Lipogranulomas
Foamy Macrophage Aggregates
Fibrin-Ring Granulomas
Specific Granulomatous Diseases
Tuberculosis
Pathology
Diagnosis
Other Mycobacteria
Brucellosis
Pathology
Diagnosis
Q-Fever
Pathology
Diagnosis
Systemic Mycoses
Candidiasis
Pathology
Diagnosis
Histoplasmosis
Pathology
Other Mycoses
Parasitic Infections
Other Infectious Agents
Molecular Methods in Paraffin-Embedded Tissues for Detection of Microorganisms
Sarcoidosis
Pathology
Drug-Induced Granulomas
Pathology
Diagnosis
Neoplasia-Associated Granulomas
Idiopathic Hepatic Granulomas
References
20 - Hepatic Sarcoidosis
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
References
Section VII: Autoimmune Hepatitis
21 - Autoimmune Hepatitis and Overlap Syndromes
Definitions and Synonyms
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Microscopic Pathology
Portal Changes and Interface Hepatitis
Lobular Inflammation and Damage
Cholestasis
Fibrosis
Overlap Syndromes
Overlap with Primary Biliary Cholangitis
Overlap with Primary Sclerosing Cholangitis
Grading and Staging of Autoimmune Hepatitis
Differential Diagnosis
Acute or Chronic Viral Hepatitis
Celiac Disease
Drug-Induced Liver Injury
Hereditary Metabolic Diseases
Primary Biliary Cholangitis
Genetics
Treatment and Prognosis
References
Section VIII: Drug- and Toxin-Induced Liver Injury
22 - Metabolism of Drugs and Xenobiotics
General Considerations in Drug Metabolism
Factors Affecting Bioavailability of Drugs
Enzyme Induction and Inhibition
Enzyme Polymorphisms
Disease States
Clinically Significant Drug-Metabolizing Enzymes and Transporters
Cytochrome P450 Enzymes
CYP1A2
CYP2B6
CYP2C
CYP2D6
CYP3A
Conjugating Enzymes
Drug Transporters/Phase III Enzymes
Role of Drug Metabolism in Drug-Induced Liver Injury
Alcohol Use and Risk of Drug-Induced Liver Injury
References
23 - Liver Injury Due to Drugs and Herbal Agents
Brief Historical Overview
Incidence and Demographics
Clinical Manifestations
Microscopic Pathology
Necroinflammatory Patterns (Figures 23.1 to 23.8)
Cholestatic Patterns (Figures 23.9 to 23.15)
Steatotic Patterns (Figures 23.16 to 23.19)
Vascular Injury Patterns (Figures 23.20 to 23.22)
Pigments and Other Cytoplasmic Changes
Neoplasms
Grading and Staging
Differential Diagnosis
Establishing Causality
Ancillary Diagnostic Studies
Genetics
Treatment and Prognosis
Figure Acknowledgments
References
24 - Alcohol-Induced Liver Disease
Incidence and Demographics
Clinical Manifestations
Noninvasive Assessment of Alcoholic Liver Disease
Blood Tests
Imaging Studies
Gross Pathology
Microscopic Pathology
Alcoholic Fatty Liver
Alcoholic Steatohepatitis
Cirrhosis
Histologic Variants
Portal Tract Changes
Iron Overload
Other Changes in Hepatocytes
Grading and Staging
Role of Liver Biopsy
Focal Liver Lesions in Alcoholic Liver Disease
Hepatocellular Carcinoma
Other Focal Lesions
Differential Diagnosis
Classical Histologic Features of Alcoholic Liver Disease
Other Histologic Variants of Alcoholic Liver Disease
Interactions with Other Liver Diseases
Genetics
Treatment and Prognosis
References
Section IX: Disorders of the Bile Ducts, Bile Formation, and Secretion
25 - Fibrocystic Liver Diseases
Ductal Plate
Ductal Plate Malformation
von Meyenburg Complex (Microhamartoma, Biliary Hamartoma)
Polycystic Liver
Autosomal Dominant Polycystic Kidney Disease
Autosomal Dominant Polycystic Liver Disease
Clinical Manifestations
Macroscopic Pathology
Microscopic Pathology
Treatment
Solitary (Nonparasitic) Bile Duct Cysts
Autosomal Recessive Polycystic Kidney Disease/Congenital Hepatic Fibrosis
Clinical Manifestations
Macroscopic Pathology
Microscopic Pathology
Treatment
Caroli Disease
Clinical Manifestations
Macroscopic Pathology
Microscopic Pathology
Treatment
Choledochal Cysts
Clinical Manifestations
Macroscopic Pathology
Microscopic Pathology
Treatment
References
26 - Primary Biliary Cholangitis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Liver Enzymes and Immunoglobulins
Autoantibodies
Antimitochondrial Antibodies
Antinuclear Antibodies
Other Autoantibodies
Radiologic Features
Pathology
Gross Pathology
Microscopic Pathology
Nonsuppurative Cholangitis. Nonsuppurative cholangitis is the hallmark of PBC.17,18 However, the distribution is heterogeneous e...
Ductular Reaction. Ductular reaction often accompanies the bile duct injury and results from metaplasia of periportal hepatocyte...
Bile Duct Loss and Ductopenia. Bile duct loss and ductopenia occur with disease progression, primarily involving the small intra...
Portal Inflammation
Hepatic Parenchymal Changes
Encroachment of the Limiting Plate. The inflammatory cells often spill over from the portal tract into the adjacent parenchyma (...
Cholate Stasis. This finding becomes more prominent with disease progression but may not be seen in all cases on needle biopsies...
Copper Deposition. Copper is excreted in the bile and copper accumulation occurs in the liver in chronic cholestasis of any etio...
Keratin7 Expression. Periportal hepatocytes may strongly express K7 by immunohistochemistry, reflecting acquisition of a biliary...
Cholestasis. Although biochemical cholestasis is present early in the disease, cholestasis at the morphologic level occurs years...
Fibrosis. Progressive ductular reaction and cholate stasis is accompanied by fibrosis. In early stages, periportal fibrosis may ...
Diagnosis
Staging
Differential Diagnosis
Mechanical Large Bile Duct Obstruction
Primary Sclerosing Cholangitis
Adverse Drug Reaction
Autoimmune Hepatitis
Viral Hepatitis
Granulomatous Inflammation
Treatment and Prognosis
Variants and Special Diagnostic Considerations
Antimitochondrial Antibody–Negative Primary Biliary Cholangitis
Asymptomatic Patients with Positive Antimitochondrial Antibody
Primary Biliary Cholangitis–Autoimmune Hepatitis Overlap Syndrome
Recurrent Primary Biliary Cholangitis in Allograft Liver
Nodular Regenerative Hyperplasia
References
27 - Primary Sclerosing Cholangitis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Large (Hilar/Parahilar) Bile Ducts
Small (Septal/Interlobular) Bile Ducts
Small Peripheral Portal Tracts
Parenchymal Changes
Gallbladder
Grading of Primary Sclerosing Cholangitis
Differential Diagnosis
Primary Biliary Cholangitis
Autoimmune Hepatitis
Immunoglobulin G4–Related Sclerosing Cholangitis
Hepatolithiasis and Recurrent Pyogenic Cholangitis
Secondary Sclerosing Cholangitis
Other Chronic Liver Diseases
Dominant Stricture
Genetics
Treatment and Prognosis
Secondary (Acquired) Sclerosing Cholangitis
References
28 - Loss of Intrahepatic Bile Ducts
Microscopic Pathology of Loss of Intrahepatic Bile Ducts
Pitfalls in Microscopic Diagnosis
Liver Diseases Leading to Loss of Intrahepatic Bile Ducts
Primary Biliary Cholangitis
Microscopic Pathology
Primary Sclerosing Cholangitis
Microscopic Pathology
Secondary Sclerosing Cholangitis
Sarcoidosis
Acute and Chronic Liver Allograft Rejection
Microscopic Pathology
Recurrent Primary Biliary Cholangitis and Primary Sclerosing Cholangitis in Liver Allografts
Graft-versus-Host Disease
Acute Graft-versus-Host Disease
Chronic Graft-versus-Host Disease
Microscopic Pathology
Ischemic Cholangiopathy
Microscopic Pathology
Drug-Induced Loss of Intrahepatic Bile Ducts
Microscopic Pathology
Idiopathic Adulthood Ductopenia
References
29A - Intrahepatic Cholestasis
Transporter Proteins
Basolateral (Sinusoidal) Membrane Transporters
Apical (Canalicular) Membrane Transporters
Bile Salt Export Pump (ABCB11)
Multidrug Resistance 1 (ABCB1)
Multidrug Resistance 3 Phospholipid Transporter (ABCB4)
Multidrug Resistance 2 (ABCC2)
Hepatic Basolateral ABC-Transporter Proteins
Electroneutral Anion Exchanger
Other Hepatocyte Transporters
Bile Acids
Bile Acid Functions
Bile Acid Signaling
Enterohepatic Circulation of Bile
Cholangiocyte Modification of Bile
Ileal Transport of Bile Acids
29B - Intrahepatic Cholestasis
Progressive Familial Intrahepatic Cholestasis
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations (Table 29B.2)
Laboratory Findings
Microscopic Findings
PFIC-1
PFIC-2
PFIC-3
Immunohistochemistry
Electron Microscopy
Treatment (see Table 29B.2)
Miscellaneous Causes of “Low-GGT” Intrahepatic Cholestasis
Miscellaneous Causes of “High-GGT” Intrahepatic Cholestasis
Differential Diagnosis
“Benign” Recurrent Intrahepatic Cholestasis
Etiopathogenesis
Clinical Manifestations
Microscopic Findings
Treatment
Intrahepatic Cholestasis of Pregnancy
Etiopathogenesis
Clinical Manifestations
Microscopic Findings
Treatment
Disorders of Bilirubin Metabolism
Crigler-Najjar and Gilbert Syndromes
Dubin-Johnson Syndrome
Rotor Syndrome
References
Section X: Vascular Disorders of the Liver
30 - Vascular Disorders of the Liver
Differential Diagnosis of Sinusoidal Congestion
Budd-Chiari Syndrome
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Treatment and Prognosis
Congestive Hepatopathy
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Treatment and Prognosis
Sinusoidal Obstruction Syndrome/Veno-occlusive Disease
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Treatment and Prognosis
Sickle Cell Disease
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Treatment and Prognosis
Preeclampsia
Etiopathogenesis
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Hemolysis, Elevated Liver Enzymes and Low Platelets (HELLP) Syndrome
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Portal Vein Thrombosis
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Treatment and Prognosis
Idiopathic Noncirrhotic Portal Hypertension
Obliterative Portal Venopathy
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Treatment and Prognosis
Nodular Regenerative Hyperplasia
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
Treatment and Prognosis
Diseases of the Hepatic Artery
Ischemic Hepatitis
Etiopathogenesis
Incidence and Demographics
Clinical Manifestations
Laboratory Findings
Microscopic Pathology
Treatment and Prognosis
Amyloidosis
Clinical Manifestations
Laboratory Findings
Radiologic Features
Gross Pathology
Microscopic Pathology
References
Section XI: Tumors and Tumor-like Lesions of the Liver
31 - Premalignant and Early Malignant Hepatocellular Lesions in Chronic Hepatitis/Cirrhosis
Clinical Setting and Target Population: Surveillance
Nomenclature
Dysplastic Foci
Dysplastic Nodules
Small Hepatocellular Carcinoma
Dysplastic Nodules as Hepatocellular Carcinoma Precursors
Natural History of Premalignant Lesions
Dysplastic Nodules and Early Hepatocellular Carcinoma: Role of Imaging
Premalignant and Early Malignant Hepatocellular Nodules in Daily Clinical Practice
Basic Histopathologic Features (Elementary Lesions)
Parenchymal Changes
Nonparenchymal Changes
Key Diagnostic Points
Stromal Invasion
Biomarkers
Nodule in Nodule
Liver Biopsy
Diagnostic Criteria in Liver Biopsy
Nodule Management
References
32 - Benign Hepatocellular Tumors
Definitions and Synonyms
Focal Nodular Hyperplasia
Hepatocellular Adenoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Focal Nodular Hyperplasia
Ultrasonography and Contrast-Enhanced Ultrasound
Magnetic Resonance Imaging
Hepatocellular Adenoma
Ultrasonography and Contrast-Enhanced Ultrasound
Magnetic Resonance Imaging
Differential Diagnosis
Gross Pathology
Microscopic Pathology
Focal Nodular Hyperplasia
Hepatocellular Adenoma
Genotype-Phenotype Classification of Hepatocellular Adenoma
HNF1α-Inactivated Hepatocellular Adenoma
β-Catenin–Activated Hepatocellular Adenoma
Inflammatory Hepatocellular Adenoma
Hepatocellular Adenoma, Not Otherwise Specified
Immunohistochemistry
Histologic Variants
Differential Diagnosis
Genetics
HNF1α-Inactivated Hepatocellular Adenoma: HNF1A Gene
β-Catenin–Activated Hepatocellular Adenoma: CTNNB1 Gene
Inflammatory Hepatocellular Adenoma
Telomerase Reverse Transcriptase Promoter
Treatment
Focal Nodular Hyperplasia
Hepatocellular Adenoma
References
33 - Hepatocellular Carcinoma
Epidemiology and Risk Factors
Hepatotropic Viruses
Other Etiologic Factors
Clinical Manifestations
Gross Pathology
Microscopic Pathology
Tumor Cells
Growth Patterns
Immunohistochemistry
Histologic Variants
Fibrolamellar Hepatocellular Carcinoma
Clear Cell Hepatocellular Carcinoma
Steatohepatitic Hepatocellular Carcinoma
Sarcomatoid Hepatocellular Carcinoma
Sclerosing Hepatocellular Carcinoma
Grading and Other Prognostic Factors
Differential Diagnosis
Molecular Genetics
Natural History and Treatment
References
34 - Benign and Malignant Tumors of Bile Ducts
Benign Tumors or Tumor-like Lesions
Solitary Bile Duct Cyst
Clinical Manifestations
Pathology
Differential Diagnosis
Ciliated Hepatic Foregut Cyst
Clinical Manifestations
Pathology
Differential Diagnosis
Bile Duct Hamartoma
Clinical Manifestations
Radiologic Features
Pathology
Gross Pathology. On gross examination, bile duct hamartomas are small, ranging from 2 to 5 mm in diameter. They are usually mult...
Microscopic Pathology. Microscopically, bile duct hamartomas are composed of a variable number of ductal structures embedded in ...
Differential Diagnosis
Adenocarcinoma. Bile duct hamartomas need to be distinguished from malignant neoplasms in the liver such as metastatic adenocarc...
Peribiliary Gland Hamartoma. Benign lesions that can be confused with bile duct hamartomas are peribiliary gland hamartomas (see...
Prognosis
Peribiliary Gland Hamartoma (Bile Duct Adenoma)
Clinical Manifestations
Radiologic Features
Pathology
Gross Pathology. Grossly, peribiliary gland hamartoma is a round or ovoid, well-demarcated but not encapsulated lesion that is u...
Microscopic Pathology. Histologically, peribiliary gland hamartoma is composed of tubules and acini, which are lined by a single...
Differential Diagnosis
Mucinous Cystic Neoplasm
Clinical Manifestations
Radiologic Features
Pathology
Gross Pathology. Grossly, these cystic neoplasms are typically large, ranging in size from several centimeters to more than 20 c...
Microscopic Pathology. Microscopically, the locules are lined by a columnar epithelium that is almost always mucinous (Fig. 34.7...
Differential Diagnosis
Ciliated Hepatic Foregut Cysts and Solitary Bile Duct Cysts. These are usually small, asymptomatic, and incidental findings. The...
Cystic Variant of Intraductal Papillary Neoplasm. It may be challenging to distinguish mucinous cystic neoplasm from a cystic va...
Cystadenocarcinoma and Cystic Cholangiocarcinoma. It may be difficult to determine if a cystadenocarcinoma represents malignant ...
Intraductal Papillary Neoplasm of Bile Duct
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Pathology
Gross Pathology. Grossly, the bile ducts involved are variably dilated. Papillary and fragile tumors are present on the inner su...
Microscopic Pathology. IPNB shares many features with IPMN of the pancreas. Similar to IPMN, the involved ducts are dilated, con...
Differential Diagnosis
Mucinous Cystic Neoplasm. IPNB may mimic mucinous cystic neoplasm, particularly when the former becomes cystic; however, the lac...
Biliary Dysplasia (Biliary Intraepithelial Neoplasia). Caution should be practiced to discriminate IPNB from biliary dysplasia o...
Malignant Tumors
Cholangiocarcinoma
Clinical Manifestations
Radiologic Features
Pathology
Gross Pathology. CCs are generally firm, gray-white to tan tumors (Fig. 34.15). They may present as a single mass with or withou...
Microscopic Pathology. Microscopically, CC may mimic metastatic adenocarcinoma from any site; thus, thorough clinical and imagin...
Differential Diagnosis
Benign Biliary Tumors. Typical features of CC are the complex cribriform glands, nuclear pleomorphism, hyperchromasia, mitotic f...
Hepatocellular Carcinoma. Although mucin is not always present, its presence can help distinguish CC from HCC. Immunohistochemic...
Metastatic Adenocarcinoma. Although to some extent immunohistochemistry may help to distinguish CC from metastatic carcinoma fro...
Epithelioid Hemangioendothelioma. Epithelioid hemangioendothelioma can be misdiagnosed as ICC because its intracytoplasmic vascu...
Combined Hepatocellular-Cholangiocarcinoma. Combined hepatocellular-cholangiocarcinoma (HCC-CC), also known as mixed tumor or he...
References
35 - Liver Tumors of Childhood
Epithelial Tumors
Hepatoblastoma
Incidence and Demographics
Clinical Manifestations
Current Classification
Radiologic Features and Gross Pathology
Microscopic Pathology
Pathology of Treated Hepatoblastoma
Staging of Pediatric Liver Tumors
Variants of Hepatoblastoma and Tumors Probably Related to Hepatoblastoma
Genetics and Molecular Pathology
Treatment and Prognosis
Pleomorphic and Anaplastic Hepatoblastoma, Hepatoblastoma with Hepatocellular Carcinoma–Like Features, and Transitional Liver Ce...
Clinical Manifestations
Radiologic Features and Gross Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Fibrolamellar Hepatocellular Carcinoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features and Gross Pathology
Microscopic Pathology
Differential Diagnosis
Genetics and Molecular Pathology
Treatment and Prognosis
Hepatocellular Carcinoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features and Gross Pathology
Microscopic Pathology
Differential Diagnosis
Genetics and Molecular Pathology
Treatment and Prognosis
Liver Cell Adenoma
Focal Nodular Hyperplasia
Other Rare Malignant Epithelial Tumors
Mesenchymal Tumors
Hamartoma of the Liver
Incidence and Demographics
Clinical Manifestations
Radiologic Features and Gross Pathology
Microscopic Pathology
Differential Diagnosis
Genetics and Molecular Pathology
Treatment and Prognosis
Undifferentiated (Embryonal) Sarcoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features and Gross Pathology
Microscopic Pathology
Differential Diagnosis
Genetics and Molecular Pathology
Treatment and Prognosis
Hepatobiliary Rhabdomyosarcoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features and Gross Pathology
Histopathology
Differential Diagnosis
Treatment and Prognosis
Malignant Extrarenal Rhabdoid Tumor
Incidence and Demographics
Clinical Manifestations
Radiologic Features and Gross Pathology
Microscopic Pathology
Differential Diagnosis
Genetics and Molecular Pathology
Treatment and Prognosis
Vascular Tumors
Infantile Hemangioma
Incidence and Demographics
Clinical Manifestations
Radiologic Features and Gross Pathology
Histopathology
Differential Diagnosis
Treatment and Prognosis
Epithelioid Hemangioendothelioma
Pediatric Angiosarcoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features and Gross Pathology
Microscopic Pathology
Treatment and Prognosis
Tumors of the Perivascular Epithelioid Cell
References
36 - Miscellaneous Liver Tumors and Tumor-like Lesions
Cavernous Hemangioma
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Gross Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Epithelioid Hemangioendothelioma
Brief Historical Overview
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Gross Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Angiosarcoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Gross Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Lymphangioma
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Gross Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Angiomyolipoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Gross Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Focal Fatty Change
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Lymphoma
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Hepatosplenic T-Cell Lymphoma
Incidence and Demographics
Clinical Manifestations
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Hairy Cell Leukemia
Systemic Mastocytosis
Langerhans Cell Histiocytosis
Inflammatory (Myofibroblastic) Pseudotumor
Incidence and Demographics
Clinical Manifestations
Radiologic Features
Gross Pathology
Microscopic Pathology
Differential Diagnosis
Treatment and Prognosis
Miscellaneous Primary Benign Tumors of the Liver
Miscellaneous Primary Malignant Tumors of the Liver
Common Metastatic Tumors
References
Section XII: Concepts in Liver Pathology
37 - Clinical Aspects of Liver Transplantation
History of Liver Transplantation
Current Trends
Indications in Adults
Hepatitis C
Hepatitis B and Hepatitis A
Nonalcoholic Fatty Liver Disease
Alcoholic Liver Disease
Autoimmune Hepatitis
Cholestatic Liver Disease
Primary Biliary Cholangitis
Primary Sclerosing Cholangitis
Hepatocellular Carcinoma
Acute Liver Failure
Indications in Children
Patient Evaluation
Elderly Patients
Obese Patients
Patients with Substance Abuse
Patients with Comorbidities
Retransplantation
Pediatric Patients
Donor and Allograft Evaluation
Extended Criteria Donors
Physiologic Extended Criteria Donors
Medical History Extended Criteria Donors
Partial Liver Allografts
Liver Allograft Allocation
Organ Matching
Donor and Recipient Operation
Organ Procurement from Deceased Donors
Liver Transplant Operation
Preparation of Allograft
Recipient Hepatectomy
Implantation of Allograft
Closure of Abdomen
Anesthesia
Posttransplant Course
Surgical Complications
Primary Nonfunction
Biliary Complications
Hepatic Outflow Obstruction
Rejection
Infections
Long-Term Renal Failure
Malignancy
Complications in Pediatric Recipients
Posttransplant Immunosuppression
Immunosuppression Agents
Cyclosporine
Tacrolimus
Sirolimus/Everolimus
Mycophenolate Mofetil
Azathioprine
Prednisone
Induction Therapy
Rabbit Antithymocyte Globulin
Alemtuzumab
Daclizumab
Posttransplant Prophylaxis and Treatment of Infections
References
38 - Pathology of Liver Transplantation
Evaluation of Donor Biopsies
Preservation–Reperfusion Injury
Clinical Manifestations
Microscopic Pathology
Differential Diagnosis
Rejection
Terminology
Clinical Manifestations
Microscopic Pathology
Hyperacute Rejection. Liver biopsies are not performed in the majority of cases of hyperacute humoral rejection because of rapid...
Acute Antibody-Mediated Rejection. Histologic features associated with acute AMR consist of endothelial cell hypertrophy, promin...
Cellular Rejection. Cellular rejection occurring in the early posttransplant period (acute cellular rejection) demonstrates a cl...
Chronic Rejection. The ischemic/fibrotic process of chronic rejection affects the bile ducts and the arteries of the liver allog...
Chronic Antibody-Mediated Rejection. Although chronic AMR (cAMR) has not been fully characterized, it has been shown that LT rec...
Treatment
Central Perivenulitis
Recurrent Diseases
Recurrent Hepatitis C
Clinical Considerations
Microscopic Pathology
Differential Diagnosis
Acute Cellular Rejection. The most clinically significant differential diagnostic problem is the distinction of acute cellular r...
Other Conditions. Acute hepatitis C in the allograft has to be distinguished from drug-induced hepatitis. This distinction relie...
Recurrent Hepatitis B
Clinical Considerations
Microscopic Pathology
Differential Diagnosis
Recurrent Autoimmune Hepatitis
Clinical Considerations
Microscopic Pathology
Differential Diagnosis
Recurrent Primary Biliary Cholangitis
Clinical Considerations
Microscopic Pathology
Differential Diagnosis
Recurrent Primary Sclerosing Cholangitis
Clinical Considerations
Microscopic Pathology
Differential Diagnosis
Recurrent Nonalcoholic Steatohepatitis
Clinical Considerations
Microscopic Pathology
Recurrent Alcohol-Related Liver Disease
Clinical Considerations
Microscopic Pathology
De Novo Diseases
Plasma Cell Hepatitis (De Novo Autoimmune Hepatitis)
De Novo Viral Hepatitis
De Novo Idiopathic Chronic Hepatitis
De Novo Malignancy
Posttransplant Lymphoproliferative Disease
Surgical Complications
Biliary Strictures
Microscopic Pathology
Hepatic Artery Thrombosis and Ischemic Cholangitis
Gross and Microscopic Pathology
Infections
Human Herpesvirus 6
Cytomegalovirus
Epstein-Barr Virus
Adenovirus
Microscopic Pathology
Changes in Late Protocol Biopsies
Idiopathic Fibrosis
Nodular Regenerative Hyperplasia
References
Section XIII: Evolving Concepts in Liver Pathology
39 - Biphenotypic Primary Liver Carcinoma
Microscopic Pathology: A Group of Heterogeneous Tumors
Epidemiology and Prognosis
References
40 - Regression of Liver Fibrosis: From Myth to Reality
Mechanisms of Fibrogenesis
Morphologic Patterns of Fibrosis
Regression of Fibrosis
Regression of Cirrhosis
Histologic Assessment of Regression of Fibrosis
Conventional Scoring Systems
Image Analysis Systems
Histologic Assessment of Regression of Cirrhosis
Hepatic Repair Complex
References
41 - Cirrhosis: A Term in Need of a Makeover
What Is Wrong with the Current Concept of Cirrhosis
Cirrhosis Is Not a Homogeneous Disease
Variations in Gross Morphology
Variations in Microscopic Pathology
Clinical Staging and Prognostication of Cirrhosis
Pathologic Staging of Cirrhosis
Regression of Cirrhosis
Histologic Assessment of Regression of Cirrhosis
Is Cirrhosis a Primarily Fibrotic Process
References
Index
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z

Citation preview

Pattern Recognition Series Series editors: Kevin O. Leslie and Mark R. Wick

Practical Breast Pathology Kristen A. Atkins and Christina S. Kong Practical Cytopathology Andrew S. Field and Matthew A. Zarka Practical Hepatic Pathology, 2nd Edition Romil Saxena Practical Orthopedic Pathology Andrea T. Deyrup and Gene P. Siegal Practical Pulmonary Pathology, 2nd Edition Kevin O. Leslie and Mark R. Wick Practical Renal Pathology Donna J. Lager and Neil A. Abrahams Practical Skin Pathology James W. Patterson Practical Soft Tissue Pathology Jason L. Hornick Practical Surgical Neuropathology Arie Perry and Daniel J. Brat

Practical Hepatic Pathology A Diagnostic Approach

Second Edition

Romil Saxena, MD, FRCPath

Professor of Pathology and Laboratory Medicine Professor of Medicine, Division of Gastroenterology and Hepatology Indiana University School of Medicine Indianapolis, Indiana

1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899

PRACTICAL HEPATIC PATHOLOGY: A DIAGNOSTIC APPROACH, SECOND EDITION

ISBN: 978-0-323-42873-6

Copyright © 2018 by Elsevier, Inc. All rights reserved. Chapter 23: Liver Injury Due to Drugs and Herbal Agents by David E. Kleiner is in the public domain. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Previous edition copyrighted 2011. Library of Congress Cataloging-in-Publication Data Names: Saxena, Romil, editor. Title: Practical hepatic pathology : a diagnostic approach / [edited by]   Romil Saxena. Other titles: Pattern recognition series. Description: Second edition. | Philadelphia, PA : Elsevier, [2018] | Series:   Pattern recognition series | Includes bibliographical references and index. Identifiers: LCCN 2016056540 | ISBN 9780323428736 (hardcover : alk. paper) Subjects: | MESH: Liver Diseases—pathology | Liver Diseases—diagnosis |  Liver—pathology Classification: LCC RC846.9 | NLM WI 700 | DDC 616.3/6207—dc23 LC record available at https://lccn.loc.gov/2016056540 Content Strategist: Kayla Wolfe Senior Content Development Specialist: Margaret Nelson Publishing Services Manager: Patricia Tannian Senior Project Manager: Claire Kramer Design Direction: Amy Buxton

Printed in China. Last digit is the print number:  9  8 7 6 5 4 3 2 1

Dedicated to my mum I wish I had appreciated you more and understood you better But I blew the chance and now you are gone . . .

Contributors

Edson Abdalla, MD, PhD Assistant Professor Departments of Infectious Disease and Gastroenterology Hospital das Clinicas University of São Paulo School of Medicine São Paulo, Brazil Venancio Avancini Ferreira Alves, MD, PhD Professor Department of Pathology University of São Paulo School of Medicine Director CICAP–Anatomic Pathology Hospital Alemão Oswaldo Cruz São Paulo, Brazil Charles Paul Balabaud, MD Professor, Service d’Hépatologie Gastroentérologie Hôpital Saint André University Victor Segalen Bordeaux, France Pierre Bedossa, MD, PhD Pathlogy Department Beaujon Hospital Paris, France Paulette Bioulac-Sage, MD Professeur Emérite Université de Bordeaux Bordeaux, France Mauro Borzio, MD Gastroenterology Unit Azienda Ospedaliera di Melegnano Vizzolo Predabissi, Milan, Italy

Kevin E. Bove, MD Professor Department of Pathology University of Cincinnati College of Medicine Staff Pathologist Department of Pathology Cincinnati Children’s Hospital Cincinnati, Ohio Naga Chalasani, MD David W. Crabb Professor and Director Division of Gastroenterology and Hepatology Indiana University School of Medicine Indianapolis, Indiana Luca Di Tommaso, MD, FIAC Humanitas University Biomedical Sciences and Humanitas Research Hospital Pathology Unit Rozzano, Milan, Italy Maria Irma Seixas Duarte, MD, PhD Professor of Pathology Departamento de Patologia Faculdade de Medicina da Universidade de São Paulo São Paulo, Brazil M. Isabel Fiel, MD, FAASLD Professor of Pathology The Lillian and Henry M. Stratton-Hans Popper Department of Pathology Icahn School of Medicine at Mount Sinai New York, New York Nora Frulio, MD Department of Diagnostic and Interventional Radiology Saint André and Haut Levèque (Centre Magellan) University Hospitals Bordeaux, France vii

Contributors Marwan Ghabril, MD Associate Professor of Medicine Division of Gastroenterology and Hepatology Department of Medicine Indiana University School of Medicine Indianapolis, Indiana Annette S. H. Gouw, MD, PhD Professor of Pathology Department of Pathology and Medical Biology University Medical Center Groningen University of Groningen Groningen, The Netherlands Christopher Griffith, MD Assistant Professor of Clinical Medical and Molecular Genetics Division of Clinical and Biochemical Genetics Indiana University School of Medicine Indianapolis, Indiana Maria Guido, MD, PhD Associate Professor of Pathology Department of Medicine-Anatomic Pathology Unit University of Padova Padova, Italy Maha Guindi, MD Director, Gastrointestinal and Liver Pathology Fellowship Program Clinical Professor of Pathology Department of Pathology and Laboratory Medicine Cedars Sinai Medical Center Los Angeles, California

viii

David E. Kleiner, MD, PhD Chief, Post-Mortem Section Laboratory of Pathology National Cancer Institute Bethesda, Maryland Paul Y. Kwo, MD Professor of Medicine Director of Hepatology Stanford University School of Medicine Palo Alto, California Carolin Lackner, MD Institute of Pathology Medical University of Graz Graz, Austria Richard S. Mangus, MD, MS, FACS Associate Professor of Surgery Surgical Director of Small Bowel and Multivisceral Transplantation Surgical Director of Pediatric Liver Transplantation Indiana University School of Medicine Indianapolis, Indiana Rebecca A. Marks, MD Staff Pathologist Pathology and Laboratory Medicine Richard L. Roudebush VA Hospital Indianapolis, Indiana

Bryan E. Hainline, MD, PhD Director, Clinical and Biochemical Genetics Medical and Molecular Genetics Indiana University School of Medicine Indianapolis, Indiana

Evandro Sobroza de Mello, MD, PhD Assistant Professor Department of Pathology University of São Paulo School of Medicine Senior Pathologist CICAP–Anatomic Pathology Hospital Alemão Oswaldo Cruz São Paolo, Brazil

Stefan G. Hübscher, MB ChB, FRCPath Leith Professor and Professor of Hepatic Pathology Institute of Immunology and Immunotherapy University of Birmingham Birmingham, United Kingdom

Raffaella A. Morotti, MD Professor of Pathology Department of Pathology Yale School of Medicine New Haven, Connecticut

Prodromos Hytiroglou, MD Professor Department of Pathology Aristotle University Medical School Thessaloniki, Greece

Amaro Nunes Duarte Neto, MD, PhD Infectious Diseases and Pathologist Specialist Departamento de Patologia e Disciplina de Emergências Clínicas Faculdade de Medicina da Universidade de São Paulo São Paulo, Brazil

Sanjay Kakar, MD Professor of Pathology Chief, Gastrointestinal-Hepatobiliary Pathology Service Director, Gastrointestinal-Hepatobiliary Pathology Fellowship Program University of California, San Francisco San Francisco, California

Valérie Paradis, MD, PhD Pathology Department Beaujon Hospital Paris, France Young Nyun Park, MD, PhD Department of Pathology Yonsei University College of Medicine Seoul, South Korea

Contributors Alberto Quaglia, MD, PhD, FRCPath Consultant Histopathologist and Honorary Reader Institute of Liver Studies King’s College Hospital London, United Kingdom Massimo Roncalli, MD, PhD Humanitas University Biomedical Sciences and Humanitas Research Hospital Pathology Unit Rozzano, Milan, Italy Natalia Rush, MD Indiana University School of Medicine Indianapolis, Indiana Pierre Russo, MD Professor of Pathology and Laboratory Medicine University of Pennsylvania School of Medicine Director, Division of Anatomic Pathology Children’s Hospital of Philadelphia Philadelphia, Pennsylvania Kumaresan Sandrasegaran, MD Associate Professor of Radiology Indiana University School of Medicine Indianapolis, Indiana Angelo Sangiovanni, MD Division of Gastroenterology and Hepatology Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico University of Milan Milan, Italy Romil Saxena, MD, FRCPath Professor of Pathology and Laboratory Medicine Professor of Medicine, Division of Gastroenterology and Hepatology Indiana University School of Medicine Indianpolis, Indiana Amedeo Sciarra, MD Department of Pathology Humanitas Clinical and Research Center Humanitas University Rozzano, Milan, Italy Christine Sempoux, MD, PhD Professor of Pathology Service of Clinical Pathology Lausanne University Hospital Institute of Pathology Lausanne, Switzerland

Arief Antonius Suriawinata, MD Section Chief of Anatomic Pathology Department of Pathology and Laboratory Medicine Dartmouth-Hitchcock Medical Center Lebanon, New Hampshire Professor of Pathology and Laboratory Medicine Geisel School of Medicine Hanover, New Hampshire A. Joseph Tector, MD, PhD Professor of Surgery Director, Xenotransplant Program University of Alabama at Birmingham Birmingham, Alabama Temel Tirkes, MD Assistant Professor of Radiology University of Indiana School of Medicine Indianapolis, Indiana Raj Vuppalanchi, MD Associate Professor of Medicine Division of Gastroenterology Department of Medicine Indiana University School of Medicine Indianapolis, Indiana Kay Washington, MD, PhD Professor of Pathology Vanderbilt University Medical Center Nashville, Tennessee Matthew M. Yeh, MD, PhD Professor of Pathology Adjunct Professor of Medicine Director, Gastrointestinal and Hepatic Pathology Program University of Washington School of Medicine Seattle, Washington Lisa M. Yerian, MD Vice Chair, Staff Affairs, and Department of Anatomic Pathology Cleveland Clinic Cleveland, Ohio Arthur Zimmermann, MD Professor of Medicine, Emeritus University of Bern Bern, Switzerland

ix

Series Preface It is often stated that anatomic pathologists come in two forms: “Gestalt”-based individuals, who recognize visual scenes as a whole, matching them unconsciously with memorialized archives, and criterion-oriented people, who work through images systematically in segments, tabulating the results—internally, mentally, and quickly—as they go along in examining a visual target. These approaches can be equally effective, and they are probably not as dissimilar as their descriptions would suggest. In reality, even “Gestaltists” subliminally examine details of an image, and if asked specifically about particular features of it, they are able to say whether one characteristic or another is important diagnostically. In accordance with these concepts, in 2004 we published a textbook entitled Practical Pulmonary Pathology: A Diagnostic Approach (PPPDA). That monograph was designed around a pattern-based method, wherein diseases of the lung were divided into six categories on the basis of their general image profiles. Using that technique, one can successfully segregate pathologic conditions into diagnostically and clinically useful groupings. The merits of such a procedure have been validated empirically by the enthusiastic feedback we have received from users of our book. In addition, following the old adage that “imitation is the sincerest form of flattery,” since our book came out other publications and presentations have appeared in our specialty with the same approach. After publication of the PPPDA text, representatives at Elsevier, most notably William Schmitt, were enthusiastic about building a series of texts around pattern-based diagnosis in pathology. To this end, we have recruited a distinguished group of authors and editors to accomplish

that task. Because a panoply of patterns is difficult to approach mentally from a practical perspective, we have asked our contributors to be complete and yet to discuss only principal interpretative images. Our goal is eventually to provide a series of monographs that, in combination with one another, will allow trainees and practitioners in pathology to use salient morphologic patterns to reach with confidence final diagnoses in all organ systems. As stated in the introduction to the PPPDA text, the evaluation of dominant patterns is aided secondarily by the analysis of cellular composition and other distinctive findings. Therefore, within the context of each pattern, editors have been asked to use such data to refer the reader to appropriate specific chapters in their respective texts. We have also stated previously that some overlap is expected between pathologic patterns in any given anatomic site; in addition, specific disease states may potentially manifest themselves with more than one pattern. At first, those facts may seem to militate against the value of pattern-based interpretation; however, pragmatically they do not. One often can narrow diagnostic possibilities to a few entities using the pattern method, and sometimes a single interpretation will be obvious. Both outcomes are useful to clinical physicians caring for a given patient. It is hoped that the expertise of our authors and editors, together with the high quality of morphologic images they present in this Elsevier series, will be beneficial to our reader-colleagues. Kevin O. Leslie, MD Mark R. Wick, MD

xi

Preface Most organs have a limited repertoire of responses to injury, and recognition of these patterns forms the cornerstone of our daily practice of surgical pathology. It is known that a “good eye” is the defining attribute of a good pathologist. However, the limited morphologic expression of injury means that there is overlap of patterns and histopathologic findings among different diseases and that more than one pattern or feature may exist at any given time. The “good eye,” therefore, does not simply recognize a pattern or finding but seeks out the dominant pattern while simultaneously ignoring distracting secondary features. This process is best exemplified by the ubiquitous eosinophil, which receives a lot of press in drug-induced hepatitis and allograft rejection, but which may be present in a wide variety of other conditions. The bright granules scream for attention and promise a peg to hang one’s hat on, but the astute eye looks past them if they are not pertinent to the underlying pattern. Once the primary pattern is identified, the roving (but still “good”) eye next hunts for additional features that help to formulate the final diagnosis. This seemingly effortless and intuitive approach, honed over years of training and experience, has been recapitulated in the present book, as it is in every other volume of this series. The dominant patterns of injury recognized under low magnification are listed, followed by additional findings that lead to the specific diagnosis. Detailed information on the diagnostic entity is found in the cross-referenced chapter, along with a discussion of differential diagnoses, which further guides the pathologist down the right path. The chapters themselves are not intended to be encyclopedic in their approach but are rather oriented toward those who want to learn enough about liver disease without reaching dizzying heights of scholarship. The text is further embellished with ample tables, boxes, images, and an extensive virtual slide box to make this process as straightforward and rewarding as possible. Section I of this text starts off with a chapter that presents the basic framework for microscopic examination of liver biopsies and elaborates on basic terms and elemental lesions. This is followed by Section II, which comprises three outstanding chapters that provide an overview of clinical features of liver diseases, interpretation of laboratory tests, and radiologic findings in liver diseases. Together, these two sections aim to impart a solid foundation for understanding the essentials of the practice of hepatopathology.

Liver diseases of childhood provide unique diagnostic challenges by constantly raising the specter of those nebulous “metabolic diseases.” Because not all metabolic diseases are common, not all childhood diseases are metabolic in nature, and metabolic diseases may present in adults, this text adopts a pragmatic approach by discussing common childhood diseases in Chapter 5 and the most common metabolic diseases individually in Chapters 8 through 12. The remaining spectrum of metabolic diseases is outlined as a pattern-based diagnostic approach in Chapter 7, which is complemented by Chapter 6, which details biochemical and genetic methodologies that assist in establishing the final diagnosis. With the same principle in mind, the most common liver diseases (eg, inflammatory and biliary) are detailed in their own individual chapters. This book does not dwell on matters pathophysiologic beyond what is necessary to enhance the understanding of liver disease. To this end, metabolism of drugs and xenobiotics (Chapter 22) and the molecular physiology of bile formation and secretion (Chapter 29A) are indispensable to the appreciation of drug-induced liver injury (Chapter 23) and diseases caused by mutations in genes that encode bile canalicular transporters and enzymes involved in bilirubin metabolism (Chapter 29B). Finally, because liver transplantation is performed almost ubiquitously and biopsies from allografts are now routinely encountered in daily practice, this text includes a section detailing the clinical aspects (Chapter 37) and pathology (Chapter 38) of liver transplantation. This second edition includes a new section on evolving concepts to keep readers abreast of changing paradigms in the practice of hepatology. The possibility of regression of fibrosis and its recognition (Chapter 40) heralds a promising era in the fight against liver disease, typified by the introduction of direct-acting antiviral agents against hepatitis C infection. Primary liver cell carcinomas that do not respect the conventional dichotomy of hepatocellular or cholangiocytic differentiation but demonstrate biphenotypic differentiation instead (Chapter 39) are increasingly encountered. Elucidation of their clinical characteristics and prognosis requires, first and foremost, recognition and documentation of these tumors in pathology reports. Finally, there is a strong movement within the clinical and pathology communities for thoughtful reconsideration of the term cirrhosis and its misleading connotation of a uniform, homogenous, and irreversible disease (Chapter 41).

xiii

Preface As with the first edition, I hope that the style and organization of this volume, along with its text, images, and a comprehensive virtual slide box, will assist in unmasking the hepatophile who might be surreptitiously lurking among the readers. For the staunch hepatophobes, however, the aim is to assist in establishing, with minimum distress, an accurate diagnosis of liver biopsies that may surreptitiously creep

xiv

under their microscopes. In these twin goals, I hope we have achieved some measure of success. Romil Saxena, MD, FRCPath Indiana University School of Medicine Indianapolis

Acknowledgments The second edition of this book represents, once again, the collective work of its authors, those tireless individuals who continue to balance, with equanimity and poise, multiple commitments toward their patients, families, and academic endeavor. I remain grateful to each and every one of them for accepting yet another time-consuming commitment and fulfilling it with immense sincerity and utmost scholarship. I remain grateful to those who assisted me in laying the foundation of this textbook by reviewing the tables in the introductory section of the first edition. Insightful comments and suggestions by Drs. Kevin Bove, James Crawford, Paul Musto, Neil Thiese, Christopher Wade, and Kay Washington have ensured that these tables, have stood the test of time and made their way unscathed to the second edition. This edition includes access to more than 250 virtual slides of liver biopsies and resection specimens. The exceptional high quality of these images and easy navigation is a tribute to technologic innovations at many levels and the vision at Elsevier in enabling this educational tool for our readers. Above all, though, the excellent slides are a display of the superlative skills of laboratory professionals who dedicate themselves every day to the art of histotechnology. Our work is impossible without these individuals, and to them, I express my sincere admiration and deepest gratitude.

Working shoulder to shoulder with me and always available with their expertise and quiet assurance were Margaret Nelson, Senior Content Development Specialist, and Claire Kramer, Senior Project Manager at Elsevier. Their exemplary work ethic, meticulous attention to detail, and grace and composure in the face of looming deadlines and mountains of work are truly impressive. Thank you both. In his preface to the neuropathology volume of this series, Daniel Brat mentions that “the editing and writing of a textbook should not be entertained by the impatient or faint of heart.” I thank Drs. Leslie and Wick, series editors, and Bill Schmitt, executive editor at Elsevier, for bringing to the fore qualities that I did not know I possessed. I suspect, however, that rather than being inherent to my nature, these virtues evolved out of necessity over the span of this project. This textbook is once again a tribute to my teachers and mentors who sustain and nourish me, endowing me with the bravado to undertake such work; to family and friends who cherish me, bestowing on me the confidence to take it to completion; and to countless patients who educate me and my coauthors, empowering us with the knowledge that I hope you will find in its pages. Romil Saxena, MD, FRCPath Indiana University School of Medicine Indianapolis

xv

Pattern-Based Approach to Diagnosis Romil Saxena, MD, FRCPath Morphologic patterns of liver injury can be reasonably divided into seven categories. Although not essential in every case, the following algorithm aids in identifying the dominant pattern,

Normal lobular architecture (uniformly distributed portal tracts and central veins)

Yes

Portal tracts expanded

especially in challenging or tricky cases, because it systematically examines architecture, portal tracts, and lobular parenchyma, in that order.

Yes

Cellular infiltrates

Yes

PATTERN 1 Portal cellular infiltrates (The blue portal tract)

No No

Lobular injury No

Ductular reaction

Yes

Yes

PATTERN 2 Ductular reaction (The bilious portal tract) PATTERN 3 Lobular injury (The distressed lobule)

No

Steatosis

Yes

PATTERN 4 Steatosis (The bubbly liver)

No Near-normal appearance

Fibrosis

Yes

Yes

PATTERN 5 Near-normal appearance (Calm but not quiet) PATTERN 6 Fibrosis (The scarred liver)

No Mass lesion

The differential diagnoses for each of the patterns in the preceding algorithm are detailed in individual tables on the subsequent pages. These tables are practical rather than being rigorously academic, and they approach liver diseases from all plausible morphologic perspectives to aid the reader in formulating the correct diagnosis. Some examples follow: l  A biopsy from a hepatocellular adenoma (Pattern 7) consisting of benign hepatocytes may be mistaken on casual examination for near-normal liver (Pattern 5), unless one notices the lack of portal structures by first assessing architecture. However, the tables are

Yes

PATTERN 7 Mass lesion (A pushy kind of guy)

so constructed that should one fail to notice the absence of portal tracts and end up along the path of near-normal liver (Pattern 5), the table for this pattern will still lead the reader to the correct diagnosis because it lists hepatocellular adenoma as a diagnostic consideration. l  The pathognomonic ductal plate remnants of congenital hepatic fibrosis do not strictly represent a ductular reaction but effectively mimic it. It is therefore not difficult for the uninitiated eye to perceive them as a form of ductular reaction, and thus congenital hepatic fibrosis is listed in the table of “ductular reaction.” xix

Pattern-Based Approach to Diagnosis

l  Similarly, because bridging necrosis can sometimes be mistaken for

bridging fibrous septa, it is listed in Pattern 6 (fibrosis) in addition to Pattern 1. l  Fibrotic tumors are listed in tables for both patterns, namely “fibrosis” and “tumors.” l  Although fibrosis is the final consequence of several chronic disease processes, it may be the most prominent finding in a liver biopsy and is therefore included as an independent pattern. The pattern of the underlying disease may or may not always be discernible. The tables are further constructed to facilitate evaluation of biopsy specimens (a major objective of this text) in which changes can be notoriously patchy or nonrepresentative. Thus:

l  Focal nodular hyperplasia finds mention in several tables because

the visualized pattern depends on the area of the lesion that is sampled by the biopsy needle. The tables account for these natural variations in morphology and lead the reader to the correct diagnosis irrespective of the area that is actually sampled. l  The pathognomonic features of certain diseases, such as the granulomatous cholangiodestructive lesion of primary biliary cholangitis (PBC) or the occluded central veins of sinusoidal obstruction syndrome/veno-occlusive disease, may be very focal and not always present in a biopsy sample. However, a biopsy sample from a patient with PBC may show other features, such as lymphocytic cholangitis, ductular reaction, or bile duct loss, that are highly suggestive of the diagnosis. Therefore PBC is listed as a diagnostic consideration under all these features. Finally, some diseases receive mention in several tables because they inherently display divergent patterns of injury. Thus:

l  Injury

due to Wilson disease may appear as chronic hepatitis (pattern of “portal cellular infiltrates”), appear as steatohepatitis (pattern of “steatosis”), or show minimal change (pattern of “nearnormal appearance”).

xx

l  Alpha-1 antitrypsin deficiency may demonstrate chronic hepatitis

(pattern of “portal cellular infiltrates”), ductular reaction (pattern of “ductular reaction”), or steatosis (pattern of “steatosis”).

While using the tables, there are a few important points to keep in mind:

l  More than one disease pattern may be present in a biopsy; in such

cases, it is best to identify and work with the dominant pattern. For instance, a mild degree of ductular reaction may be seen in severely active chronic viral hepatitis along with the dominant pattern of portal cellular infiltrates. Similarly, a mild portal infiltrate may accompany a dominant pattern of lobular injury, and, conversely, mild lobular injury may accompany a dominant pattern of portal cellular infiltrates. l  Although there are diseases common to both children and adults, and to the native and transplanted liver, others are specific to children (eg, biliary atresia) or the allograft (eg, rejection). Information about age and transplantation aids the diagnostic process. l  Diagnostic accuracy will be maximized when the tables are used in conjunction with the cross-referenced chapters because the latter highlight close differential diagnoses as well as atypical features and uncommon clinical situations. In addition, as in all disciplines of surgical pathology, diagnoses should be rendered in the appropriate clinical context. l  Liver injury due to drugs and herbals may mimic almost any known liver disease; therefore drug-induced liver injury remains a differential diagnostic consideration in almost every case. Although establishing causal relationships and excluding competing causes of injury form an important part of the diagnostic algorithm (see Chapter 23), a good histologic clue of drug-induced liver injury is a pattern of injury that does not fit into known patterns or that which shows overlapping patterns.

Pattern-Based Approach to Diagnosis

Pattern

Diseases to Be Considered

Portal cellular infiltrates (The blue portal tract)

Viral hepatitis Hepatotropic viruses Nonhepatotropic viruses Recurrent or de novo viral hepatitides, post-transplantation Nonviral infections Neonatal hepatitis Recurrent or de novo autoimmune hepatitis Recurrent primary biliary cholangitis Sarcoidosis

Wilson disease Alpha-1 antitrypsin deficiency Tyrosinemia Cellular rejection Idiopathic chronic hepatitis, post-transplantation Drug-induced liver injury Extramedullary hemopoiesis Lymphoma/leukemia Post-transplant lymphoproliferative disease

Ductular reaction (The bilious portal tract)

Biliary tract obstruction Biliary stricture Biliary atresia Neonatal hepatitis Alagille syndrome (early) Alpha-1 antitrypsin deficiency Cystic fibrosis Recurrent primary biliary cholangitis Sarcoidosis Primary sclerosing cholangitis Secondary sclerosing cholangitis Recurrent sclerosing cholangitis Ischemic cholangiopathy

Recurrent biliary disease, post-transplantation Fibrosing cholestatic hepatitis B and C Progressive familial intrahepatic cholestasis, 2 and 3 Alcoholic steatohepatitis Budd-Chiari syndrome Systemic infections, sepsis Ascending cholangitis Total parenteral nutrition Drug-induced liver injury Mimics Congenital hepatic fibrosis Caroli disease Focal nodular hyperplasia

Lobular injury (The distressed lobule)

Acute viral hepatitis Nonviral infections Autoimmune hepatitis Wilson disease Alpha-1 antitrypsin deficiency Neonatal hepatitis Tyrosinemia Hereditary fructose intolerance Galactosemia Citrin deficiency Zellweger syndrome Glycogen storage diseases Urea cycle defects Lysosomal storage diseases Cholesterol ester storage disease Mitochondriopathies Progressive familial intrahepatic cholestasis, 1 and 2 Bile acid synthetic defects Reye syndrome, postviral

Diabetes mellitus Hemophagocytic lymphohistiocytosis Malignant infiltration Preservation–reperfusion injury Late cellular rejection (central perivenulitis) Ischemic injury Drug-induced injury Alcoholic steatohepatitis Nonalcoholic steatohepatitis Genetic hemochromatosis Secondary hemosiderosis Perinatal/neonatal hemochromatosis Chronic passive congestion Budd-Chiari syndrome Veno-occlusive disease/sinusoidal obstruction syndrome Sickle cell disease Graft-versus-host disease Chronic rejection

Steatosis (The bubbly liver)

Alcoholic steatohepatitis Nonalcoholic steatohepatitis Alcoholic foamy degeneration Reye syndrome, postviral Fatty acid oxidation defects Acute fatty liver of pregnancy Malnutrition Cystic fibrosis Wilson disease Alpha-1 antitrypsin deficiency Mitochondriopathies Urea cycle defects Niemann-Pick disease Glycogen storage disease I, III, and VI

Hereditary fructose intolerance Tyrosinemia Galactosemia Lysosomal storage disorders Cholesterol ester disease Citrin deficiency Drug-induced liver injury Mass lesions with steatosis Focal steatosis Focal nodular hyperplasia Hepatocellular adenoma Dysplastic nodule Hepatocellular carcinoma

xxi

Pattern-Based Approach to Diagnosis

xxii

Pattern

Diseases to Be Considered

Near-normal appearance (Calm but not quiet)

Gaucher disease Niemann Pick disease, type C Glycogen storage diseases Diabetes mellitus Wilson disease Reye syndrome, postviral Urea cycle defects Lysosomal storage diseases Cholesterol ester storage disease Amyloidosis Light chain disease Dubin-Johnson syndrome Malaria Schistosomiasis Leishmaniasis Toxoplasmosis Human immunodeficiency virus infection Sinusoidal malignant infiltration Cholestasis of pregnancy Cholestasis due to systemic infections Paraneoplastic cholestasis Benign recurrent intrahepatic cholestasis

Progressive familial intrahepatic cholestasis 1 Alagille syndrome Idiopathic adulthood ductopenia Alpha-1 antitrypsin deficiency Congestive heart failure Budd-Chiari syndrome Veno-occlusive disease Sickle cell disease Resolving hepatitis Regressing cirrhosis Compression from adjacent mass lesion Nodular regenerative hyperplasia Phenylketonuria Cystinosis Urea cycle defects Aminoacidopathies Preservation–reperfusion injury Hepatocellular nodules Large regenerative nodule Low-grade dysplastic nodule Hepatocellular adenoma Very well-differentiated (early) hepatocellular carcinoma

Fibrosis (The scarred liver)

Chronic viral hepatitis Autoimmune hepatitis Alcoholic steatohepatitis Nonalcoholic steatohepatitis Genetic hemochromatosis Secondary hemosiderosis Perinatal/ neonatal hemochromatosis Primary biliary cholangitis Sarcoidosis Primary sclerosing cholangitis Secondary sclerosing cholangitis Ischemic cholangiopathy Biliary strictures, long-standing Biliary atresia Alagille syndrome Glycogen storage disorders I, III, IV, and VI Alpha-1 antitrypsin deficiency Cystic fibrosis Wilson disease Indian childhood cirrhosis Tyrosinemia Citrin deficiency Hereditary fructose intolerance Galactosemia Gaucher disease

Niemann-Pick disease Progressive familial intrahepatic cholestasis, 2 and 3 Progressive familial intrahepatic cholestasis 1 (late) Zellweger syndrome Polycystic liver disease Congenital hepatic fibrosis Caroli disease Budd-Chiari syndrome Congestive heart failure Hereditary hemorrhagic telangiectasia Congestive syphilis Leishmaniasis Schistosomiasis Tumors with fibrosis Fibrolamellar carcinoma Sclerosing hepatocellular carcinoma Bile duct adenoma Biliary hamartoma Cholangiocarcinoma Biphenotypic primary liver carcinoma (hepatocholangiocarcinoma) Epithelioid hemangioendothelioma Sclerosing cavernous hemangioma Focal nodular hyperplasia Metastatic carcinoma Mimic: Bridging necrosis/multiacinar collapse

Pattern-Based Approach to Diagnosis

Pattern

Diseases to Be Considered

Mass lesion (A pushy kind of guy)

Hepatocellular lesions Focal nodular hyperplasia Hepatocellular adenoma Large regenerative nodule Dysplastic nodule Hepatocellular carcinoma Fibrolamellar carcinoma Hepatoblastoma Transitional liver cell tumor Gland-forming lesions Bile duct adenoma Biliary hamartoma Cholangiocarcinoma Mixed hepatocellular–glandular lesions Hepatoblastoma Nested stromal epithelial tumors Mixed hepatobiliary carcinoma Mesenchymal lesions Mesenchymal hamartoma Undifferentiated embryonal sarcoma Hepatobiliary rhabdomyosarcoma

Infantile hemangioendothelioma Cavernous hemangioma Epithelioid hemangioendothelioma Angiosarcoma Angioleiomyoma Inflammatory/myofibroblastic tumor Miscellaneous mesenchymal tumors Cystic lesions Solitary (nonparasitic) bile duct cyst Ciliated hepatic foregut cyst Polycystic liver disease Mucinous cystic neoplasm Intraductal papillary neoplasm Pyogenic abscess Parasitic abscess Hydatid cyst Hematopoietic lesions Langerhans cell histiocytosis Lymphoma Hodgkin disease Metastases

xxiii

Pattern-Based Approach to Diagnosis

Pattern 1  Portal Cellular Infiltrates (“The Blue Portal Tract”)

Elements of the pattern: The hallmark of this pattern is expansion of portal tracts by a cellular infiltrate, which thus appear “blue.” The portal inflammation may be accompanied by varying degrees of lobular inflammation and hepatocyte damage (eSlide P.1).

xxiv

Pattern-Based Approach to Diagnosis

Pattern 1  Portal Cellular Infiltrates (“The Blue Portal Tract”) Additional Findings Mature lymphocytes ± lymphoid aggregates

Diagnostic Considerations

Chapter:Page

Mild azonal steatosis, biliary duct epithelial damage

Hepatitis C Recurrent or de novo hepatitis C, post-transplantation

Ch. 15:225 Ch. 38:645, 654

Severe interface and/or ­lobular activity

Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis, post-transplantation Viral hepatitis with immunocompromise Drug-induced injury

Ch. 21:310 Ch. 38:648, 653

Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis, post-transplantation Hepatitis B with superinfection or coinfection of hepatitis D virus Viral hepatitis with immunocompromise Acute flare of hepatitis C Wilson disease Drug-induced injury (alone or superimposed on viral hepatitis)

Ch. 21:311 Ch. 38:648, 653

Ground-glass cells/inclusions

Hepatitis B Recurrent or de novo hepatitis B, post-transplantation Drug-induced injury

Ch. 14:213 Ch. 38:647, 654 Ch. 14:219; Ch. 23:363

Morula cells

Hepatitis D infection

Ch. 13:198

Focal lesions (in few or some portal tracts), damaged bile ducts ± bile duct loss

Primary biliary cholangitis Recurrent primary biliary cholangitis

Ch. 26:410 Ch. 38:649

Lymphocytic cholangitis (lymphocytes within bile ducts) ± duct damage

Primary biliary cholangitis Recurrent biliary cholangitis Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis, post-transplantation Hepatitis C Recurrent or de novo hepatitis C, post-transplantation Drug-induced injury

Ch. 26:410 Ch. 38:649 Ch. 21:311 Ch. 38:645, 654

Concentric periductal inflammation, focal lesions (in few or some portal tracts)

Primary sclerosing cholangitis Recurrent sclerosing cholangitis Secondary sclerosing cholangitis

Ch. 27:425 Ch. 38:650 Ch. 27:430

Punched out areas of necrosis ± nuclear inclusions

Adenovirus hepatitis Herpesvirus hepatitis

Ch. 13:202; Ch. 38:658 Ch. 13:202

Eosinophilic nuclear inclusions

Cytomegalovirus hepatitis

Ch. 13:200; Ch. 38:657

Hepatocytes with many glycogenated nuclei, nuclear pleomorphism, ­binucleation, mild steatosis

Wilson disease

Ch. 8:127

Intracytoplasmic globules in periportal hepatocytes

Alpha-1 antitrypsin deficiency

Ch. 9:136

Marked cholestasis, pseudoacinar change of hepatocytes, pericellular fibrosis

Tyrosinemia

Ch. 6:92; Ch. 7:120

Severe cholestasis, giant cells

Neonatal hepatitis

Ch. 5:77

Steatosis ± microgranular (red granular) hepatocytes

Mitochondriopathies

Ch. 6:98; Ch. 7:106; Ch. 17:259

Bridging necrosis/multiacinar collapse

Ch. 17: 251 Ch. 23:331

Ch. 13:198 Ch. 17:251 Ch. 13:192 Ch. 8:128 Ch. 23:331

Ch. 15:225 Ch. 38:645, 654 Ch. 23:353

Table continues on following page. xxv

Pattern-Based Approach to Diagnosis

Pattern 1  Portal Cellular Infiltrates (“The Blue Portal Tract”)—Cont. Additional Findings Mature lymphocytes ± lymphoid aggregates—cont.

Plasma cell predominant

Diagnostic Considerations

Chapter:Page

Sinusoidal lymphoid infiltrate

Hepatitis C Recurrent or de novo hepatitis C Epstein-Barr virus hepatitis Visceral leishmania Leukemia/lymphoma Drug-induced injury

Ch. 15:225 Ch. 38:643, 654 Ch. 13:199; Ch. 38:658 Ch. 17:249; Ch. 18:272 Ch. 36:592 Ch. 23:353

None of the preceding ­specific patterns

Hepatitis B Recurrent or de novo hepatitis B, post-transplantation Hepatitis C Recurrent or de novo hepatitis C, post-transplantation Autoimmune hepatitis Recurrent autoimmune hepatitis Primary biliary cholangitis Recurrent primary biliary cholangitis Wilson disease Human herpesvirus 6 Sclerosing cholangitis in children Drug-induced hepatitis Late cellular rejection Idiopathic chronic hepatitis, post-transplantation Celiac disease Rheumatoid diseases

Ch. 14:213 Ch. 38:647, 654 Ch. 15:225 Ch. 38:643, 654 Ch. 21:310 Ch. 38:648 Ch. 26:410 Ch. 38:650 Ch. 8:127 Ch. 13:201; Ch. 38:657 Ch. 5:71 Ch. 23:331 Ch. 38:638 Ch. 38:654 Ch. 3:49; Ch. 21:314 Ch. 3:48

Focal lesions (in few or some portal tracts), damaged bile ducts ± bile duct loss

Primary biliary cholangitis Recurrent primary biliary cholangitis

Ch. 26:412 Ch. 38:649

Severe interface and/or ­lobular activity

Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis Drug-induced injury

Ch. 21:310 Ch. 38:648, 653 Ch. 23:331, 352

No specific pattern

Hepatitis A Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis Plasma cell hepatitis Drug-induced hepatitis

Ch. 13:197 Ch. 21:310 Ch. 38:648, 653 Ch. 38:653 Ch. 23:331, 352

Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis Primary biliary cholangitis Recurrent primary biliary cholangitis Drug-induced hepatitis

Ch. 21:310 Ch. 38:648, 653 Ch. 26:410 Ch. 38:649 Ch. 23:331

Endotheliitis, bile duct damage

Acute cellular rejection

Ch. 38:634

Large atypical cells

Hodgkin disease

Ch. 36:593

Immature myeloid and/or erythroid ­precursors

Extramedullary hemopoiesis

Ch. 1:16

None of the preceding ­findings

Drug-induced hepatitis Hodgkin disease Indeterminate rejection

Ch. 23:331 Ch. 36:593 Ch. 38:634

Parasitic infections

Ch. 18:275

Mononuclear cells (lymphocytes, plasma cells) with eosinophils Mixed infiltrate mononuclear, eosinophils ± neutrophils

Predominantly eosinophils

Continued xxvi

Pattern-Based Approach to Diagnosis

Additional Findings Granulomas

Atypical lymphoid cells

Diagnostic Considerations

Chapter:Page

Focal lesions (in few or some portal tracts), damaged bile ducts ± bile duct loss

Primary biliary cholangitis Recurrent primary biliary cholangitis

Ch. 26:410 Ch. 38:650

Large fibrosing granulomas

Sarcoidosis

Ch. 20:302

Necrosis, no fibrosis

Infections

Ch. 19:291

Numerous eosinophils

Parasites Drug-induced injury

Ch. 18:275; Ch. 19:295 Ch. 23:353

Mixed inflammatory infiltrate, large ­atypical cells

Hodgkin disease

Ch. 19:298; Ch. 36:593

None of the preceding ­findings

Infections Hodgkin disease Drug-induced hepatitis Idiopathic

Ch. 19:290 Ch. 36:592 Ch. 23:275 Ch. 19:298

Lymphoma/leukemia Epstein-Barr virus hepatitis Post-transplant lymphoproliferative disease

Ch. 36:592 Ch. 13:199; Ch. 38:658 Ch. 38:655

xxvii

Pattern-Based Approach to Diagnosis

Pattern 2  Ductular Reaction (“The Bilious Portal Tract”)

Elements of the pattern: The hallmark of this pattern is expansion of portal tracts by a ductular reaction composed of variable degrees of edema, fibrosis, bile ductular proliferation, and an inflammatory infiltrate that is composed mainly of neutrophils and/or lymphocytes. Visible cholestasis may or may not be present (eSlide P.2). xxviii

Pattern-Based Approach to Diagnosis

Pattern 2  Ductular Reaction (“The Bilious Portal Tract”) Additional Findings

Diagnostic Considerations

Chapter:Page

Edema ± bile plugs ± cholestasis, no fibrosis

Biliary atresia Biliary stricture Systemic infections, sepsis

Ch. 5:72 Ch. 27:429; Ch. 38:658 Ch. 1:26; Ch. 3: 49; Ch. 18:266

Neutrophils within bile duct epithelium and lumen

Ascending cholangitis Liver fluke infestation, fascioliasis Liver fluke infestation, clonorchiasis Ascariasis

Ch. 18:266 Ch. 18:281 Ch. 18:282 Ch. 18:275

Ductular cholestasis

Sepsis

Ch. 1:26; Ch. 18:266

Concentric periductal inflammation, concentric periductal fibrosis

Primary sclerosing cholangitis Recurrent sclerosing cholangitis Secondary sclerosing cholangitis Ischemic cholangiopathy

Ch. 27:425 Ch. 38:650 Ch. 27:430 Ch. 38:658

Large bile duct casts, parasites

Recurrent pyogenic cholangitis

Ch. 18:282; Ch. 27:429

Periductal granulomas

Primary biliary cholangitis Recurrent primary biliary cholangitis Sarcoidosis Drug-induced injury

Ch. 26:410 Ch. 38:649 Ch. 20:302 Ch. 23:353

Large fibrosing granulomas

Sarcoidosis

Ch. 20:302

Lymphocytic cholangitis

Primary biliary cholangitis Recurrent primary biliary cholangitis Drug-induced injury

Ch. 26:410 Ch. 38:649 Ch. 23:353

Loss of bile ducts

Alagille syndrome 5:4 Alpha-1 antitrypsin deficiency Primary biliary cholangitis Recurrent primary biliary cholangitis Primary sclerosing cholangitis Recurrent sclerosing cholangitis Secondary sclerosing cholangitis Ischemic cholangitis Drug-induced injury Sarcoidosis

Ch. 5:70 Ch. 9:136 Ch. 26:410; Ch. 38:435 Ch. 28:439; Ch. 38:649 Ch. 27:425; Ch. 28:436 Ch. 28:429; Ch. 38:650 Ch. 27:430; Ch. 38:436 Ch. 28:440; Ch. 38:655 Ch. 23:336 Ch. 20:302; Ch. 28:437

Minimal ductular reaction, marked cholestasis, degenerative/senescent biliary epithelial changes

Chronic rejection Graft-versus-host disease

Ch. 38:638 Ch. 28:439

Ballooning change, numerous Mallory hyalin ± steatosis

Alcoholic steatohepatitis

Ch. 24:376

Table continues on following page. xxix

Pattern-Based Approach to Diagnosis

Pattern 2  Ductular Reaction (“The Bilious Portal Tract”)—Cont. Additional Findings

Diagnostic Considerations

Chapter:Page

Intracytoplasmic globules

Alpha-1 antitrypsin deficiency

Ch. 9:136

Inspissated pink or orange material in bile ducts/ductules

Cystic fibrosis

Ch. 10:145

Lobular inflammation and injury (cholestatic hepatitis)

Drug-induced injury Hepatitis A Hepatitis E

Ch. 23:353 Ch. 13:197 Ch. 13:197

Ballooned hepatocytes, cholestasis, perisinusoidal fibrosis

Fibrosing cholestatic hepatitis B Fibrosing cholestatic hepatitis C

Ch. 38:648 Ch. 38:645

Multinucleated hepatocytes (giant cells)

Neonatal hepatitis Biliary atresia Bile acid synthetic defects Progressive familial intrahepatic cholestasis 2

Ch. 5:77 Ch. 5:72 Ch. 7:106; Ch. 29B:460 Ch. 29B:456

Ductal structures with open lumina ± bile plugs ± fibrosis

Congenital hepatic fibrosis Ductal plate malformation

Ch. 25:397 Ch. 25:394

Dilated ducts with ductal plate malformation

Caroli disease

Ch. 25:399

Centrilobular dilatation and congestion

Budd-Chiari syndrome Compression from adjacent mass lesion

Ch. 30:468 Ch. 3:43; Ch. 30:467

Fibrous septa with irregularly thickened vessels

Focal nodular hyperplasia

Ch. 32:512

Continued xxx

Pattern-Based Approach to Diagnosis

Additional Findings

Diagnostic Considerations

Chapter:Page

No additional findings

Biliary atresia Biliary stricture Systemic infections, sepsis

Ch. 5:72 Ch. 27:429; Ch. 38:655 Ch. 1:26; Ch. 3:49; Ch. 18:266 Ch. 29B:497 Ch. 5:80 Ch. 23:353 Ch. 27:425 Ch. 27:430 Ch. 38:650 Ch. 17:250 Ch. 26:410 Ch. 38:649 Ch. 38:635 Ch. 3:50 Ch. 30:468 Ch. 1:26

Progressive familial intrahepatic cholestasis 3 Alagille syndrome Drug-induced injury Primary sclerosing cholangitis Secondary sclerosing cholangitis Recurrent sclerosing cholangitis Human immunodeficiency virus cholangiopathy Primary biliary cholangitis Recurrent primary biliary cholangitis Acute humoral rejection Total parenteral nutrition Budd-Chiari syndrome Nonspecific change

xxxi

Pattern-Based Approach to Diagnosis

Pattern 3  Lobular Injury (“The Distressed Lobule”)

Elements of the pattern: The hallmark of this pattern is lobular injury, which is as prominent as (if not more so) any accompanying portal tract changes. Lobular injury is variably manifested as inflammation, hepatocyte damage, hepatocyte necrosis, congestion, cholestasis, and regeneration. When present, the accompanying portal changes consist of variable degrees and combinations of ductular reaction with or without bile duct damage (eSlide P.3). xxxii

Pattern-Based Approach to Diagnosis

Pattern 3  Lobular Injury (“The Distressed Lobule”) Additional Findings

Diagnostic Considerations

Chapter:Page

Lobular disarray, ballooned hepatocytes, apoptotic bodies

Acute viral hepatitis Drug-induced injury Recurrent or de novo acute hepatitis C, post-transplantation Recurrent or de novo acute hepatitis B, post-transplantation

Ch. 13:192 Ch. 23:351 Ch. 38:643, 654 Ch. 38:647, 654

Ground-glass cells/inclusions

Hepatitis B Glycogen storage disease, type IV Lafora disease Post liver or bone marrow transplantation Total parenteral nutrition Alcohol-related liver disease Drug-induced injury

Ch. 14:214, 219 Ch. 6:94; Ch. 7:115 Ch. 7:116 Ch. 7:116 Ch. 3:50 Ch. 24:381 Ch. 14:219; Ch. 23:363

Morula cells

Hepatitis D virus

Ch. 13:198

Punched out necrosis ± nuclear inclusions

Adenovirus hepatitis Herpesvirus hepatitis

Ch. 13:202; Ch. 38:658 Ch. 13:202

Neutrophilic microabscesses

Cholangitis Syphilis Cytomegalovirus hepatitis

Ch. 18:266 Ch. 18:268 Ch. 13:200; Ch. 38:657

Eosinophilic abscess/infiltrate

Visceral larva migrans Capillariasis Strongyloidosis Other parasitic infections

Ch. 18:276 Ch. 18:277 Ch. 18:277 Ch. 18:275; Ch. 19:295

Granulomas

Infections Sarcoidosis Drug-induced injury Idiopathic

Ch. 18:267; Ch. 19:289 Ch. 20:302 Ch. 23:353 Ch. 19:298

Multinucleated hepatocytes (giant cells)

Neonatal hepatitis Biliary atresia Alagille syndrome Alpha-1 antitrypsin deficiency Progressive familial intrahepatic cholestasis 2 Bile acid synthetic defects Zellweger syndrome Autoimmune hepatitis

Ch. 5:77 Ch. 5:72 Ch. 5:80 Ch. 9:136 Ch. 29B:456 Ch. 7:116; Ch. 29B:460 Ch. 6:93; Ch. 7:120 Ch. 21:312

Multinucleated hepatocytes (giant cells), hemosiderin deposition, cell damage/necrosis

Perinatal/neonatal hemochromatosis Tyrosinemia

Ch. 5:77; Ch. 7:122; Ch. 29B:460 Ch. 6:92; Ch. 7:120

Enlarged, pale hepatocytes

Glycogen storage disease Reye syndrome, postviral Urea cycle defects Diabetes mellitus Lysosomal storage diseases Cholesterol ester storage disease Drug-induced injury

Ch. 6:92; Ch. 7:115 Ch. 7:108 Ch. 7:108 Ch. 3:49 Ch. 7:111 Ch. 7:112 Ch. 23:363

Dyscohesive hepatocytes

Leptospirosis

Ch. 18:268

Microgranular (red granular) hepatocytes

Human immunodeficiency virus mitochondriopathy Mitochondriopathies

Ch. 17:259 Ch. 6:98; Ch. 7:106

Ballooned hepatocytes, cholestasis, no inflammation

Fibrosing cholestatic hepatitis B Fibrosing cholestatic hepatitis C

Ch. 38:648 Ch. 38:645 Table continues on following page. xxxiii

Pattern-Based Approach to Diagnosis

Pattern 3  Lobular Injury (“The Distressed Lobule”)—Cont. Additional Findings

Diagnostic Considerations

Chapter:Page

Ballooned hepatocytes, neutrophils, Mallory hyalin

Alcoholic hepatitis Nonalcoholic steatohepatitis Drug-induced injury

Ch. 24:376 Ch. 12:172 Ch. 23:357

Centrilobular ballooned hepatocytes ± cholestasis

Preservation–reperfusion injury

Ch. 38:633

Pseudoacinar change of hepatocytes

Tyrosinemia Citrin deficiency Galactosemia Hereditary fructose intolerance Biliary atresia Neonatal hepatitis

Ch. 7:120 Ch. 7:110 Ch. 7:110 Ch. 6:98; Ch. 7:111 Ch. 5:72 Ch. 5:77

Deposition of hemosiderin

Genetic hemochromatosis Secondary hemosiderosis Wilson disease Tyrosinemia Perinatal/neonatal hemochromatosis

Ch. 11:156 Ch. 11:158 Ch. 8:127 Ch. 7:120 Ch. 5:77; Ch. 7:122; Ch. 29B:460

Perivenular inflammation, endotheliitis, necrosis

Recurrent autoimmune hepatitis Recurrent primary biliary cholangitis Late cellular rejection (central perivenulitis)

Ch. 38:648 Ch. 38:649 Ch. 38:642

Centrilobular sinusoidal dilatation, congestion

Congestive heart failure Budd-Chiari syndrome Veno-occlusive disease/sinusoidal obstruction syndrome Sickle cell disease Drug-induced injury Compression from adjacent mass lesion

Ch. 30:469 Ch. 30:468 Ch. 30:472 Ch. 30:473 Ch. 23:361 Ch. 3:43; Ch. 30:467

Occluded central veins

Veno-occlusive disease/sinusoidal obstruction syndrome Drug-induced injury

Ch. 30:472 Ch. 23:361

Centrilobular sinusoidal dilatation, congestion + ductular reaction

Compression from adjacent mass lesion Budd-Chiari syndrome

Ch. 3:43; Ch. 30:467 Ch. 30:468

Centrilobular necrosis without inflammation

Vascular ischemia Chronic rejection Drug-induced injury (eg, acetaminophen)

Ch. 30:479; Ch. 38:655 Ch. 38:638 Ch. 1:23; Ch. 23:353

Midzonal necrosis without inflammation

Yellow fever virus

Ch. 13:204

Hemorrhagic necrosis

Viral hemorrhagic fevers Toxemia of pregnancy Hyperacute humoral rejection Portal hyperperfusion syndrome

Ch. 13:203 Ch. 30:474 Ch. 38:635 Ch. 38:636

Bridging necrosis; multiacinar collapse

Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis Hepatitis B with superinfection or coinfection of hepatitis D virus Viral hepatitis with immunocompromise Acute flare of hepatitis C Drug-induced injury (alone or superimposed on viral hepatitis) Wilson disease

Ch. 21:312 Ch. 38:648, 653 Ch. 13:198 Ch. 17:251 Ch. 13:198 Ch. 23:331 Ch. 8:128

Erythrophagocytosis

Leptospirosis Rickettsial infections Hemophagocytic lymphohistiocytosis

Ch. 18:269 Ch. 18:270 Ch. 1:18; Ch. 17:249; Ch. 30:467 Continued

xxxiv

Pattern-Based Approach to Diagnosis

Additional Findings

Diagnostic Considerations

Chapter:Page

Prominent Kupffer cells with particulate material

Malaria Leishmaniasis Human immunodeficiency virus infection Hemophagocytic lymphohistiocytosis

Ch. 18:274 Ch. 17:249; Ch. 18:272 Ch. 17:248 Ch. 1:18; Ch. 17:249; Ch. 30:467

Prominent Kupffer cells with storage material

Niemann-Pick disease, type C Farber disease Gaucher disease Cholesterol ester storage disease

Ch. 6:95; Ch. 7:112 Ch. 7:112 Ch. 6:92; Ch. 7:112 Ch. 7:112

Sinusoidal infiltrate of lymphoid cells

Hepatitis C Recurrent hepatitis C, post-transplantation Epstein-Barr virus hepatitis Visceral leishmaniasis Leukemia/lymphoma Drug-induced injury

Ch. 15:225 Ch. 38:643 Ch. 13:199 Ch. 17:249; Ch. 18:272 Ch. 36:592 Ch. 23:353

Sinusoidal infiltrate by nonlymphoid cells

Metastatic carcinoma (eg, breast carcinoma, melanoma) Angiosarcoma Epithelioid hemangioendothelioma

Ch. 36:597 Ch. 36:587 Ch. 36:585

Bland cholestasis (no inflammation or ductular reaction)

Drug-induced injury Paraneoplastic cholestasis Preservation–reperfusion injury Progressive familial intrahepatic cholestasis 1 Benign recurrent intrahepatic cholestasis Cholestasis of pregnancy Systemic infections, sepsis

Ch. 23:353 Ch. 3:51 Ch. 38:633 Ch. 29B:456 Ch. 29B:460 Ch. 29B:461 Ch. 1:26: Ch. 3:49; Ch. 18:266

Cholestasis with loss of intrahepatic bile ducts

Alagille syndrome Alpha-1 antitrypsin deficiency Idiopathic adulthood ductopenia Drug-induced injury Graft-versus-host disease Chronic rejection

Ch. 5:80 Ch. 9:138 Ch. 28:138 Ch. 23:356 Ch. 28:439 Ch. 38:638

Cholestasis with degenerative/senescent biliary epithelial changes

Chronic rejection Graft-versus-host disease

Ch. 38:638 Ch. 28:439

Pink amorphous material in sinusoids, around vessels, or in nerves

Amyloidosis Light chain deposition disease

Ch. 30:480 Ch. 30:481

xxxv

Pattern-Based Approach to Diagnosis

Pattern 4  Steatosis (“The Bubbly Liver”)

Elements of the pattern: The hallmark of this pattern is lipid accumulation (steatosis) in hepatocytes. The lipid appears as clear vacuoles that may be macrovesicular, microvesicular, or mixed in size. Steatosis may or may not be accompanied by ballooning change, Mallory hyaline, portal inflammation, lobular inflammation, and fibrosis (eSlide P.4). xxxvi

Pattern 4  Steatosis (“The Bubbly Liver”) Additional Findings

Diagnostic Considerations

Chapter:Page

Exclusively microvesicular steatosis

Reye syndrome, postviral Acute fatty liver of pregnancy Fatty acid oxidation defects Niemann-Pick disease, types A and B Alcoholic foamy degeneration Drug-induced injury Alcoholic steatohepatitis Nonalcoholic steatohepatitis Drug-induced injury Wilson disease Wilson disease Methotrexate use Reye syndrome, postviral Glycogen storage disease, types I, III, and VI Urea cycle defects Lysosomal storage diseases Cholesterol ester storage disease Diabetes mellitus Drug-induced injury Mitochondriopathies Human immunodeficiency virus mitochondriopathy Citrin deficiency Hereditary fructose intolerance Galactosemia Preservation–reperfusion damage

Ch. 7:108 Ch. 7:106 Ch. 6:92; Ch. 7:105 Ch. 6:95; Ch. 7:112 Ch. 24:375 Ch. 23:357 Ch. 24:376 Ch. 12:172 Ch. 23:357 Ch. 8:127 Ch. 8:127 Ch. 23:358 Ch. 7:108 Ch. 6:92; Ch. 7:108 Ch. 6:93; Ch. 7:108 Ch. 6:92; Ch. 7:111 Ch. 7:112 Ch. 3:51 Ch. 23:364 Ch. 6:98; Ch. 7:106 Ch. 17:259 Ch. 6:93; Ch. 7:110 Ch. 6:98; Ch. 7:111 Ch. 7:110 Ch. 38:633

Alpha-1 antitrypsin deficiency Total parenteral nutrition Cystic fibrosis Hepatocellular adenoma Focal nodular hyperplasia Dysplastic nodule Hepatocellular carcinoma Large regenerative nodule Low-grade dysplastic nodule Early hepatocellular carcinoma Focal nodular hyperplasia Focal steatosis Focal nodular hyperplasia

Ch. 9:136 Ch. 3:52 Ch. 10:145 Ch. 32:515 Ch. 32:510 Ch. 31:490 Ch. 33:532 Ch. 1:6 Ch. 31:490 Ch. 31:490 Ch. 32:510 Ch. 36:592 Ch. 32:510

Pericellular fibrosis

Nonalcoholic steatohepatitis Alcoholic steatohepatitis Wilson disease Citrin deficiency Hereditary fructose intolerance Galactosemia

Ch. 12:175 Ch. 24:379 Ch. 8:127 Ch. 6:93; Ch. 7:110 Ch. 6:98; Ch. 7:111 Ch. 7:110

Macrovesicular or mixed steatosis without any of the preceding additional findings

Malnutrition Alcohol use Nonalcoholic fatty liver disease Diabetes mellitus Cystic fibrosis Urea cycle defects Lysosomal storage diseases Cholesterol ester storage disease Mitochondriopathies Citrin deficiency Hereditary fructose intolerance 6:10, 7:11 Human immunodeficiency virus infection

Ch. 7:105; Ch. 12:181 Ch. 24:375 Ch. 12:170 Ch. 3:51 Ch. 10:145 Ch. 7:108 Ch. 6:92; Ch. 7:111 Ch. 7:112 Ch. 6:98; Ch. 7:106 Ch. 6:93; Ch. 7:110 Ch. 6:98; Ch. 7:111 Ch. 17:257

Ballooned hepatocytes, Mallory hyalin ± neutrophils

Nuclear pleomorphism, binucleated cells, glycogenated nuclei Enlarged, pale hepatocytes

Microgranular (red granular) hepatocytes Pseudoacinar change of hepatocytes

Lipopeliosis Intracytoplasmic globules in periportal hepatocytes Cholestasis with ductular reaction Inspissated pink or orange material in bile ducts/ductules No portal tracts

Irregularly distributed portal tracts, portal tracts far apart

Focal lesion Fibrous septa with abnormal, thickened vessels

xxxvii

Pattern-Based Approach to Diagnosis

Pattern 5  Near-Normal Appearance (“Calm but Not Quiet”)

Elements of the pattern: The hallmark of this pattern is absence of the most common features of liver disease, namely, inflammation, lobular injury, necrosis, steatosis, duct damage, ductular reaction, and fibrosis. Subtle changes are seen on closer examination at higher magnification (eSlide P.5). xxxviii

Pattern-Based Approach to Diagnosis

Pattern 5  Near-Normal Appearance (“Calm but Not Quiet”) Additional Findings

Diagnostic Considerations

Chapter:Page

Glycogenated nuclei

Normal up to 15 years of age Diabetes mellitus Nonalcoholic fatty liver disease Wilson disease

Ch. 1:14 Ch. 3:51 Ch. 12:173 Ch. 8:127

Ground-glass cells/inclusions

Hepatitis B Glycogen storage disease, type IV Lafora disease Post-liver or bone marrow transplantation Total parenteral nutrition Chronic alcohol consumption Adaptive change to medications

Ch. 14:214, 219 Ch. 6:94, Ch. 7:115 Ch. 7:116 Ch. 7:116 Ch. 3:52 Ch. 24:381 Ch. 14:219; Ch. 23:363

Enlarged, pale hepatocytes

Diabetes mellitus Glycogen storage diseases Reye syndrome, postviral Urea cycle defects Lysosomal storage diseases Cholesterol ester storage disease

Ch. 3:51 Ch. 6:94; Ch. 7:115 Ch. 7:108 Ch. 6:93; Ch. 7:108 Ch. 6:92; Ch. 7:111 Ch. 7:112

Pink amorphous material in sinusoids, around vessels or in nerves

Amyloidosis Light chain deposition disease 30:17

Ch. 30:480 Ch. 30:481

Attenuated portal vein radicals, absence of portal veins

Obliterative portal venopathy Portal vein thrombosis Schistosomiasis

Ch. 30:477 Ch. 30:473 Ch. 18:278

Deep brown/black pigment in hepatocytes

Dubin-Johnson syndrome Drug-induced injury

Ch. 29B:462 Ch. 23:364

Black pigment in Kupffer cells and/or macrophages

Malaria Schistosomiasis Thorotrast Drug-induced injury

Ch. 18:274 Ch. 18:274 Ch. 23:364 Ch. 23:364

Prominent Kupffer cells with particulate material

Malaria Leishmaniasis Human immunodeficiency virus infection

Ch. 18:274 Ch. 17:249; Ch. 18:272 Ch. 17:248

Prominent Kupffer cells with storage material

Gaucher disease Niemann-Pick disease, type C Farber disease Cholesterol ester storage disease

Ch. 6:92; Ch. 7:112 Ch. 6:95; Ch. 7:112 Ch. 7:112 Ch. 7:112

Sinusoidal infiltrate of lymphoid cells

Hepatitis C Epstein-Barr virus hepatitis Visceral leishmaniasis Leukemia/lymphoma Drug-induced injury

Ch. 15:225 Ch. 13:199 Ch. 17:249; Ch. 18:272 Ch. 36:592 Ch. 23:353

Sinusoidal infiltrate by nonlymphoid cells

Metastatic carcinoma (eg, breast carcinoma, melanoma) Angiosarcoma Epithelioid hemangioendothelioma

Ch. 36:597 Ch. 36:587 Ch. 36:585

Table continues on following page. xxxix

Pattern-Based Approach to Diagnosis

Pattern 5  Near-Normal Appearance (“Calm but Not Quiet”)—Cont. Additional Findings

Diagnostic Considerations

Chapter:Page

Bland cholestasis (no inflammation or ductular reaction)

Drug-induced injury Cholestasis of pregnancy Progressive familial intrahepatic cholestasis 1 Preservation–reperfusion injury Systemic infections, sepsis Benign recurrent intrahepatic cholestasis Paraneoplastic cholestasis

Ch. 23:353 Ch. 29B:461 Ch. 29B:456 Ch. 38:633 Ch. 1:26; Ch. 3:51; Ch. 18:266 Ch. 29B:460 Ch. 3:51

Cholestasis with loss of intrahepatic bile ducts

Alagille syndrome Idiopathic adulthood ductopenia Drug-induced injury Alpha-1 antitrypsin deficiency Graft-versus-host disease Chronic rejection

Ch. 5:80 Ch. 28:443 Ch. 23:356 Ch. 9:138 Ch. 28:439 Ch. 38:638

Cholestasis with degenerative/senescent biliary epithelial changes

Chronic rejection Graft-versus-host disease

Ch. 38:638 Ch. 28:439

Sinusoidal dilatation, congestion

Congestive hepatopathy Budd-Chiari syndrome Veno-occlusive disease/sinusoidal obstruction ­syndrome Sickle cell disease Compression from adjacent mass lesion Drug-induced injury

Ch. 30:469 Ch. 30:468

Occluded central veins

Veno-occlusive disease/sinusoidal obstruction syndrome Drug-induced injury

Ch. 30:472 Ch. 23:361

Centrolobular sinusoidal dilatation, congestion + ductular reaction

Compression from an adjacent mass lesion Hepatocellular adenoma, inflammatory type

Ch. 3:51; Ch. 30: 467 Ch. 32:518

Vaguely nodular architecture without fibrosis, alternate plate atrophy and hyperplasia

Nodular regenerative hyperplasia

Ch. 3:50; Ch. 23:362; Ch.30:479; Ch. 38:659

Eggs, parasites

Parasitic infections

Ch. 18:275

Iron deposition

Normal in periportal hepatocytes of neonates Genetic hemochromatosis Secondary hemosiderosis

Ch. 7:123 Ch. 11:156 Ch. 11:158

Scattered spotty necrosis, prominent Kupffer cells, mild portal inflammation

Nonspecific reactive hepatitis Celiac disease Rheumatoid disease Systemic infection, sepsis

Ch. 3:50: Ch. 18:266 Ch. 3:50: Ch. 18:266 Ch. 3:50 Ch. 18:266

Scattered apoptosis, ballooned cells, glycogenated nuclei, mild inflammation, mild steatosis

Wilson disease

Ch. 8:127

Minimal ductular reaction, portal fibrosis

Primary sclerosing cholangitis

Ch. 27:425

Scattered clusters of pigmented macrophages

Resolving hepatitis Drug-induced injury

Ch. 1:18; Ch. 13:193 Ch. 23:355

Ch. 30:472 Ch. 30:473 Ch. 30:467, 473 Ch. 23:361

Continued xl

Pattern-Based Approach to Diagnosis

Additional Findings

Diagnostic Considerations

Chapter:Page

No portal tracts

Hepatocellular adenoma Focal nodular hyperplasia Large regenerative nodule Low-grade dysplastic nodule Early hepatocellular carcinoma

Ch. 32:515 Ch. 32:512 Ch. 1:6 Ch. 31:490 Ch. 31:490

Irregularly distributed portal tracts, portal tracts far apart

Large regenerative nodule Low-grade dysplastic nodule Early hepatocellular carcinoma Focal nodular hyperplasia Regressing cirrhosis Loss of bile ducts

Ch. 1:6 Ch. 31:490 Ch. 31:490 Ch. 32:512 Ch. 40:674 Ch. 28:434

No additional findings

Phenylketonuria Cystinosis Urea cycle defects Aminoacidopathies

Ch. 6:92; Ch. 7:102 Ch. 7:115 Ch. 6:92; Ch 7:104 Ch. 6:92; Ch. 7:104

xli

Pattern-Based Approach to Diagnosis

Pattern 6  Fibrosis (“The Scarred Liver”)

xlii

Elements of the pattern: The hallmark of this pattern is the presence of extensive fibrosis that distorts normal hepatic architecture. A secondary pattern related to the underlying causative disease process may or may not be discernable (eSlide P.6).

Pattern-Based Approach to Diagnosis

Pattern 6  Fibrosis (“The Scarred Liver”) Additional Findings

Diagnostic Considerations

Chapter:Page

Bridging necrosis/multiacinar collapse (mimicking fibrous bands)

Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis, post-transplantation Hepatitis B with superinfection or coinfection of hepatitis D virus Viral hepatitis with immunocompromise Acute flare of hepatitis C Wilson disease Drug-induced injury (alone or superimposed on viral hepatitis

Ch. 21:312 Ch. 38:648, 653 Ch. 13:198 Ch. 17:251 Ch. 13:198 Ch. 8:128 Ch. 23:331

Lymphocytic infiltrate ± plasma cells

Chronic hepatitis C Recurrent or de novo hepatitis C, post-transplantation Autoimmune hepatitis Recurrent or de novo autoimmune hepatitis, post-transplantation Chronic hepatitis B Recurrent or de novo hepatitis B, post-transplantation Idiopathic fibrosis, post-transplantation

Ch. 15:225 Ch. 38:645, 654 Ch. 21:310 Ch. 38:648, 653 Ch. 14:213 Ch. 38:647, 654 Ch. 38:658

Ground-glass cells/inclusions

Hepatitis B Recurrent or de novo hepatitis B, post-transplantation Glycogen storage disorder, type IV Total parenteral nutrition Drug-induced injury

Ch. 14:213 Ch. 38:645, 654 Ch. 6:94; Ch. 7:115 Ch. 3:52 Ch. 14:219; Ch. 23:363

Granulomas

Primary biliary cholangitis Recurrent primary biliary cholangitis Sarcoidosis Schistosomiasis

Ch. 26:410 Ch. 38:649 Ch. 20:302 Ch. 18:278; Ch. 19:295

Marked ballooning of hepatocytes

Wilson disease Indian childhood cirrhosis Tyrosinemia Alcohol-induced liver disease Nonalcoholic steatohepatitis

Ch. 8:127 Ch. 8:130 Ch. 6:92; Ch. 7:120 Ch. 24:376 Ch. 12:172

Multinucleated hepatocytes (giant cells)

Neonatal hepatitis Autoimmune hepatitis Biliary atresia Progressive familial intrahepatic cholestasis 2 Bile acid synthetic defects Galactosemia Zellweger syndrome

Ch. 5:77 Ch. 21:312 Ch. 5:72 Ch. 29B:456 Ch. 7:116; Ch. 29B:460 Ch. 7:110 Ch. 6:93; Ch. 7:120

Multinucleated hepatocytes (giant cells), hemosiderin deposition

Perinatal/neonatal hemochromatosis Tyrosinemia

Ch. 5:77; Ch. 7:122; Ch. 29B:460 Ch. 6:92; Ch. 7:120

Intracytoplasmic globules

Alpha-1 antitrypsin deficiency

Ch. 9:136

Prominent Kupffer cells with storage cells

Niemann-Pick disease Gaucher disease

Ch. 6:95; Ch. 7:112 Ch. 6:92; Ch. 7:111

Steatosis

Hereditary fructose intolerance Galactosemia Nonalcoholic steatohepatitis Alcoholic steatohepatitis Alpha-1 antitrypsin deficiency Wilson disease Cystic fibrosis Citrin deficiency Glycogen storage disease, types I, III, and VI

Ch. 6:98; Ch. 7:111 Ch. 7:110 Ch. 12:170 Ch. 24:375 Ch. 9:136 Ch. 8:127 Ch. 10:145 Ch. 6:93; Ch. 7:110 Ch. 6:92; Ch. 7:115 Table continues on following page. xliii

Pattern 6  Fibrosis (“The Scarred Liver”)—Cont. Additional Findings

Diagnostic Considerations

Chapter:Page

Mallory hyaline

Wilson disease Indian childhood cirrhosis Alcoholic steatohepatitis Nonalcoholic steatohepatitis Chronic biliary diseases Drug-induced injury Genetic hemochromatosis Secondary hemosiderosis Wilson disease Tyrosinemia Perinatal/neonatal hemochromatosis

Ch. 8:127 Ch. 8:130 Ch. 24:376 Ch. 12:172 Ch. 26:410; Ch. 27:425 Ch. 23:357 Ch. 11:156 Ch. 11:158 Ch. 8:127, 128 Ch. 7:120 Ch. 5:77; Ch. 7:120; Ch. 29B:460 Ch. 6:92; Ch. 7:110 Ch. 7:110 Ch. 6:98; Ch. 7:111 Ch. 6:93; Ch. 7:110 Ch. 27:425 Ch. 38:650 Ch. 27:430; Ch. 28:437 Ch. 38:655

Deposition of hemosiderin

Pseudoacinar change of hepatocytes

Tyrosinemia Galactosemia Hereditary fructose intolerance Citrin deficiency Biliary halo, marked ductular Concentric periPrimary sclerosing cholangitis reaction, cholate stasis (biliary Recurrent sclerosing cholangitis ductal fi­ brosis, pattern of fibrosis) concentric p­ eriductal Secondary sclerosing cholangitis Ischemic cholangitis ­inflammation, bile duct scars Loss of ducts Primary biliary cholangitis Primary sclerosing cholangitis Recurrent sclerosing cholangitis Secondary sclerosing cholangitis Ischemic cholangitis Progressive familial intrahepatic cholestasis 3 Alagille syndrome Biliary atresia (late) Inspissated pink or Cystic fibrosis orange material in bile ducts/ductules Intracytoplasmic Alpha-1 antitrypsin deficiency globules

Ductal structures with open lumina at edges of fibrous septa ± bile plugs, ductal plate malformation Dilated ducts with ductal plate malformation Cholestasis without inflammation or prominent ductular reaction (bland cholestasis) Occluded portal veins with portal fibrosis, no regenerative nodules xliv

None of the preceding Primary biliary cholangitis Primary sclerosing cholangitis ­findings Recurrent sclerosing cholangitis Secondary sclerosing cholangitis Ischemic cholangiopathy Cystic fibrosis Biliary atresia Progressive familial intrahepatic cholestasis 3 Biliary strictures Drug-induced injury Congenital hepatic fibrosis

Ch. 26:410 Ch. 27:425 Ch. 38:650 Ch. 27:430; Ch. 28:437 Ch. 38:655 Ch. 29B:456 Ch. 5:80 Ch. 5:72 Ch. 10:145

Ch. 9:136 Ch. 26:410 Ch. 27:427 Ch. 38:650 Ch. 27:430; Ch. 28:437 Ch. 28:440; Ch. 38:655 Ch. 10:145 Ch. 5:72 Ch. 29B:457 Ch. 27:429; Ch. 38:655 Ch. 23:353 Ch. 25:397

Caroli disease

Ch. 25:397

Progressive familial intrahepatic cholestasis 1 (late)

Ch. 29B:456

Schistosomiasis

Ch. 18:278; Ch. 19:295

Continued

Additional Findings Perivenular fibrosis; fibrosis bridging central veins

Pericellular pattern of fibrosis

Large tumor cells

Gland-forming tumor

Diagnostic Considerations Centrilobular congestion and atrophy

Budd-Chiari syndrome Veno-occlusive disease/sinusoidal obstruction syndrome Sickle cell disease Drug-induced injury Ballooning, Mallory Alcohol steatohepatitis hyalin, steatosis Nonalcoholic steatohepatitis Drug-induced injury None of the preceding Congestive hepatopathy findings Alcohol steatohepatitis Nonalcoholic steatohepatitis Budd-Chiari syndrome Veno-occlusive disease/sinusoidal obstruction syndrome Ballooned Nonalcoholic steatohepatitis hepatocytes, Alcoholic steatohepatitis Mallory hyalin Wilson disease Indian childhood cirrhosis Drug-induced injury Multinucleated giant Perinatal/neonatal hemochromatosis cells ± hemosiderin deposition Tyrosinemia Zellweger syndrome Pseudoacinar change Tyrosinemia of hepatocytes Galactosemia Citrin deficiency Hereditary fructose intolerance Kupffer cells with Niemann-Pick disease Gaucher disease ­storage material Sinusoidal infiltrate Congenital syphilis ± prominent Leishmaniasis Kupffer cells Steatosis Nonalcoholic steatohepatitis Alcoholic steatohepatitis Tyrosinemia Hereditary fructose intolerance Galactosemia Citrin deficiency Niemann-Pick disease Zellweger syndrome None of the preceding Nonalcoholic steatohepatitis findings Alcoholic steatohepatitis Wilson disease Leishmaniasis Congenital syphilis Fibrolamellar carcinoma Sclerosing hepatocellular carcinoma Metastatic carcinoma Bile duct adenoma Biliary hamartoma Cholangiocarcinoma Combined hepatocellular-cholangiocarcinoma Metastatic adenocarcinoma Hepatoblastoma (cholangioblastic variants, mixed type)

Chapter:Page Ch. 30:468 Ch. 23:361; Ch. 30:472 Ch. 30:473 Ch. 23:361 Ch. 24:379 Ch. 12:175 Ch. 23:257 Ch. 30:469 Ch. 24:376 Ch. 12:172 Ch. 30:468 Ch. 23:361; Ch. 30:472 Ch. 12:172 Ch. 24:376 Ch. 8:128 Ch. 8:130 Ch. 23:358 Ch. 5:77; Ch. 7:122; Ch. 29B:460 Ch. 6:92; Ch. 7:120 Ch. 6:93; Ch. 7:120 Ch. 6:92; Ch. 7:120 Ch. 7:110 Ch. 6:93; Ch. 7:110 Ch. 6:98; Ch. 7:111 Ch. 6:95; Ch. 7:112 Ch. 6:92; Ch. 7:111 Ch. 18:268 Ch. 17:249; Ch. 18:272 Ch. 12:170 Ch. 24:375 Ch. 6:92; Ch. 7:120 Ch. 6:98; Ch. 7:111 Ch. 7:110 Ch. 6:93; Ch. 7:110 Ch. 6:95; Ch. 7:112 Ch. 6:93; Ch. 7:120 Ch. 12:170 Ch. 24:375 Ch. 8:127 Ch. 17:249; Ch. 18:272 Ch. 18:268 Ch. 33:535; Ch. 35:570 Ch. 33:537 Ch. 36:597 Ch. 34:547 Ch. 25:395; Ch. 34:546 Ch. 34:551 Ch. 39:665 Ch. 36:597 Ch. 35:560, 561

Signet-ring cells containing red blood cells

Epithelioid hemangioendothelioma

Ch. 36:585

Dilated vascular spaces

Hereditary hemorrhagic telangiectasia Sclerosing cavernous hemangioma Focal nodular hyperplasia

Ch. 36:585 Ch. 36:583 Ch. 32:512

Polycystic liver disease

Ch. 25:396

Eccentrically thickened vessels, nodularity Multiple benign cysts, ductal plate malformations

xlv

Pattern-Based Approach to Diagnosis

Pattern 7  Mass Lesion (“A Pushy Kind of Guy”)

Elements of the pattern: The hallmark of this pattern is replacement of normal hepatic parenchyma by a tumor. When the tumor is composed of benign or well-differentiated hepatocytes, its presence is suspected by the absence of uniformly distributed central veins and portal tracts (eSlide P.7).

xlvi

Pattern-Based Approach to Diagnosis

Pattern 7  Mass Lesion (“A Pushy Kind of Guy”) Additional Findings

Diagnostic Considerations

Chapter:Page

Benign-appearing hepatocytes

Hepatocellular adenoma Well-differentiated (early) hepatocellular carcinoma Dysplastic nodule Large regenerative nodule Fetal hepatoblastoma

Ch. 32:515 Ch. 31:490 Ch. 31:490 Ch. 1:6 Ch. 35:557

Fibrous septa with abnormal, thick-walled vessels

Focal nodular hyperplasia

Ch. 32:512

Irregularly distributed portal tracts

Large regenerative nodule Dysplastic nodule Early hepatocellular carcinoma

Ch. 1:6 Ch. 31:490 Ch. 31:490

Epithelioid tumors

Hepatocellular carcinoma Fibrolamellar carcinoma Hepatocellular adenoma Transitional liver cell tumor Hepatoblastoma Metastatic tumors Angiomyolipoma

Ch. 33:532 Ch. 33:535; Ch. 35:570 Ch. 32:515 Ch. 35:570 Ch. 35:557 Ch. 36:597 Ch. 36:590

Clear and dark areas

Hepatoblastoma

Ch. 35:557

Benign-appearing glands

Bile duct adenoma Biliary hamartoma Mesenchymal hamartoma Cholangiolocellular carcinoma

Ch. 34:542 Ch. 25:395; Ch. 34:546 Ch. 35:574 Ch. 39:665

Malignant glands

Metastatic adenocarcinoma Cholangiocarcinoma Combined hepatocellular-cholangiocarcinoma

Ch. 36:597 Ch. 34:551 Ch. 39:665

Mixed epithelioid and glandular elements

Hepatoblastoma (cholangioblastic variants, mixed type) Combined hepatocellular-cholangiocarcinoma

Ch. 35:560 Ch. 39:665

Signet-ring cells with red blood cells

Epithelioid hemangioendothelioma

Ch. 36:585

Fibrotic tumor

Fibrolamellar carcinoma Sclerosing hepatocellular carcinoma Epithelioid hemangioendothelioma Hepatoblastoma, treated Cholangiocarcinoma Metastatic adenocarcinoma Combined hepatocellular-cholangiocarcinoma Sclerosing cavernous hemangioma

Ch. 33:535; Ch. 35:570 Ch. 33:537 Ch. 36:585 Ch. 35:560 Ch. 34:551 Ch. 36:597 Ch. 39:665 Ch. 36:583

Bone, cartilage

Hepatoblastoma, mixed type Hepatoblastoma, treated

Ch. 35:560 Ch. 35:560

Plasma cells, eosinophils

Inflammatory/myofibroblastic tumor Immunoglobulin G4–related sclerosing cholangitis Langerhans histiocytosis Hodgkin disease

Ch. 36:594 Ch. 27:429 Ch. 5:83; Ch. 36:595 Ch. 36:593

Vascular spaces

Cavernous hemangioma Infantile hemangioma Well-differentiated angiosarcoma Peliosis Bacillary angiomatosis Kaposi sarcoma

Ch. 36:583 Ch. 35:579 Ch. 35:559 Ch. 17:258; Ch. 23:362; Ch. 36:585 Table continues on following page. Ch. 17:258 Ch. 17:260; Ch. 36:589 Table continues on following page.

xlvii

Pattern-Based Approach to Diagnosis

Pattern 7  Mass Lesion (“A Pushy Kind of Guy”)—Cont. Additional Findings

Diagnostic Considerations

Chapter:Page

Myxoid background

Hepatoblastoma Mesenchymal hamartoma Undifferentiated embryonal sarcoma

Ch. 35:560 Ch. 35:574 Ch. 35:575

Benign cyst

Mucinous cystic neoplasm Solitary (nonparasitic) bile duct cyst Cystic intraductal papillary neoplasm, benign Polycystic liver disease Ciliated hepatic foregut cyst Hydatid cyst

Ch. 34:548 Ch. 25:397; Ch. 34:545 Ch. 34:550 Ch. 25:396 Ch. 34:546 Ch. 18:283

Malignant cyst

Mucinous cystic neoplasm, malignant Cystic Intraductal papillary neoplasm, malignant Cystic cholangiocarcinoma

Ch. 34:548 Ch. 34:550 Ch. 34:551

Zonal changes with fibrotic center

Epithelioid hemangioendothelioma Sclerosing cavernous hemangioma

Ch. 36:585 Ch. 36:583

Fat

Angiomyolipoma Lipoma Pseudolipoma Hepatocellular adenoma Hepatocellular carcinoma Focal nodular hyperplasia Dysplastic nodule

Ch. 36:590 Ch. 36:597 Ch. 36:592 Ch. 32:515 Ch. 33:532, 537; Ch. 35:572 Ch. 32:512 Ch. 31:490

Spindle cells

Solitary fibrous tumor Fibroma Fibrosarcoma Leiomyoma Leiomyosarcoma Neurofibroma, schwannoma Malignant schwannoma Follicular dendritic cell tumor Kaposi sarcoma Angiosarcoma Angiomyolipoma Hepatoblastoma variants Nested stromal epithelial tumors Pediatric hepatic stromal tumors Gastrointestinal stromal tumor Sarcomatoid hepatocellular carcinoma

Ch. 36:597 Ch. 36:597 Ch. 36:598 Ch. 36:597 Ch. 36:598 Ch. 36:597 Ch. 36:598 Ch. 36:596, 598 Ch. 17:260; Ch. 36:589 Ch. 36:587 Ch. 36:590 Ch. 35:561 Ch. 35:564 Ch. 35:564 Ch. 36:596, 597 Ch. 33:537

Granular cells

Granular cell tumor Angiomyolipoma

Ch. 36:597 Ch. 36:590

Clear cells

Hepatocellular carcinoma Hepatoblastoma Metastatic renal cell carcinoma Metastatic adrenal cortical carcinoma Angiomyolipoma

Ch. 33:537; Ch. 35:572 Ch. 35:557 Ch. 36:597 Ch. 36:591 Ch. 36:590

Small blue or undifferentiated cells

Hepatoblastoma Metastatic tumors Hepatobiliary rhabdomyosarcoma Malignant extrarenal rhabdoid tumor Undifferentiated embryonal sarcoma

Ch. 36:557 Ch. 36:597 Ch. 35:575 Ch. 35:578 Ch. 35:575 Continued

xlviii

Pattern-Based Approach to Diagnosis

Additional Findings

Diagnostic Considerations

Chapter:Page

Multinucleated cells

Hepatocellular carcinoma Angiosarcoma

Ch. 33:548; Ch. 35:572 Ch. 36:387

Infiltration along sinusoids

Angiosarcoma Epithelioid hemangioendothelioma Metastatic tumors Leukemia/lymphoma Hepatosplenic T cell lymphoma

Ch. 36:387 Ch. 36:585 Ch. 36:597 Ch. 36:592 Ch. 36:594

Atypical/malignant lymphoid cells

Leukemia/lymphoma Post-transplant lymphoproliferative disease

Ch. 36:592 Ch. 38:655

Abscess

Actinomycosis Candidiasis Amebic abscess Ascending infections, pyogenic hepatitic abscess

Ch. 18:268 Ch. 19:294 Ch. 18:271 Ch. 18:266

Eosinophilic abscess

Visceral larva migrans Capillariasis Strongyloidiasis Other parasitic infections

Ch. 18:276 Ch. 18:277 Ch. 18:277 Ch. 18:275; Ch. 19:295

Fibrotic or fibrocalcific nodule/granuloma

Histoplasmosis

Ch. 19:295

Granuloma with necrosis

Tuberculosis

Ch. 19:292

Syphilis

Ch. 19:290

xlix

Virtual Slide Box



eSlide P.1 P  attern of portal cellular infiltrates (“The Blue Portal Tract”). Portal tracts are expanded by a cellular infiltrate, thus appearing “blue.”   Virtual Slide: VM03577. eSlide P.2 Pattern of ductular reaction (“The Bilious Portal Tract”). Portal tracts are expanded by a ductular reaction composed of variable combinations and extent of edema, fibrosis, bile ductular proliferation, and inflammatory infiltrate.   Virtual Slide: VM03790. eSlide P.3 Pattern of lobular injury (“The Distressed Lobule”). There is lobular injury in the form of variable combinations and extent of cholestasis, inflammation, hepatocellular inflammation, and foci of necrosis. Portal changes may be present but are not as prominent as lobular changes.   Virtual Slide: VM03730. eSlide P.4  Pattern of steatosis (“The Bubbly Liver”). There is accumulation of lipid that appears as clear vacuoles of varying sizes and that may be accompanied by variable combinations and extent of inflammation, ballooning of hepatocytes, Mallory hyaline, and fibrosis.   Virtual Slide: VM03575. eSlide P.5 Pattern of near-normal appearance (“Calm but Not Quiet”). The liver looks almost normal because of absence of obvious inflammation, lobular injury, necrosis, steatosis, ductular reaction, and fibrosis. Subtle changes are seen on closer examination at higher magnification.   Virtual Slide: VM03576. eSlide P.6 Pattern of fibrosis (“The Scarred Liver”). There is extensive fibrosis distorting normal hepatic architecture. A, Hematoxylin-eosin; B, Masson trichrome stain.   Virtual Slide: VM03580 and VM03581. eSlide P.7 Pattern of mass lesion (“A Pushy Kind of Guy”). Normal hepatic parenchyma is replaced by a tumor.   Virtual Slide: VM03582. eSlide 1.1 Section of normal liver stained with hematoxylin and eosin. There are no septa-defining lobules or acini. Portal tracts and central veins are present at regular intervals. Rows of hepatocytes radiate outward from the central veins. Perivenular hepatocytes contain

varying amounts of lipofuscin. Portal tracts vary in size and contain profiles of portal vein, hepatic artery, and bile duct. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03791. eSlide 1.2 Trichrome stain of normal liver highlights portal tracts and central veins, thus facilitating assessment of normal liver architecture. The amount of fibrous tissue varies with the size of portal tracts; larger portal tracts contain more connective tissue and larger profiles of the portal vein, hepatic artery, and bile duct. Trichrome stain highlights the very small central veins by outlining their fibrous walls. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02127. eSlide 1.3 Reticulin stain of normal liver highlights one-cellthick hepatic trabecula. Rows of hepatocytes radiate outward from the central veins. The trabecula are more compact near the portal tracts. Type III collagen (reticulin fibers), which is present in the Disse space, stains black, whereas collagen I comprising fibrous tissue stains brown. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03766. eSlide 1.4 A, Multiple liver cores, two of which show benign parenchyma with no portal tracts or central veins, suggesting large regenerative nodule(s). Trichrome stain (B) does not show obvious cirrhosis (B), but reticulin stain (C) shows markedly abnormal trabecular pattern with irregularly distributed thickened and compressed trabecula, confirming the presence of cirrhosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03657, VM03795 and VM02428. eSlide 1.5A–C A fragmented biopsy with no significant findings on H&E stain (A) and no fibrous septa or nodularity on trichrome stain (B). A reticulin stain (C) confirms normal trabecular architecture, which verifies that fragmentation is not due to architectural distortion caused by advanced bridging fibrosis or cirrhosis. Compare with eSlides 1.5D–F. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03770, VM03769, and VM03768. eSlide 1.5D–F Another fragmented biopsy with expanded portal tracts and patchy bridging fibrosis on H&E (D) and trichrome stains (E). Reticulin stain highlights marked architectural

Virtual Slide Box distortion in the form of irregularly distributed thickened and compressed trabecula (F), confirming that the fragmentation is a result of advanced fibrosis. Compare with eSlides 1.5A–C. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02430, VM02137, and VM03767. eSlide 1.6 A transgastric liver biopsy obtained through the greater curvature of the stomach under real-time endoscopic ultrasonography. The specimen consists of multiple fragments of liver tissue and blood clot. Hematoxylin and eosin (A), trichrome (B) and reticulin stains (C). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02140, VM02139, and VM02141. eSlide 1.7 Trichrome stain of a wedge liver biopsy shows subcapsular parenchyma with bridging fibrous septa and formation of nodules, findings which may be mistaken for cirrhosis. However, these changes often occur exclusively in 3–5 mm of the subcapsular region and are not generally representative of deeper parenchyma. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02142. eSlide 1.8 Trichrome stain shows large, longitudinally cut portal tracts that contain large portal components. The longitudinal profiles should not be mistaken for bridging fibrous septa. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03771. eSlide 1.9 Immunohistochemical stain for CD10 marks epitopes on the canalicular membrane of hepatocytes producing a pattern (“canalicular pattern”) that is highly characteristic of hepatocellular differentiation. The apical membrane of cholangiocytes lining bile ducts also stains positive. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03772. eSlide 1.10 Immunohistochemical stain for K7, a biliary keratin marks bile ducts in portal tracts, ductules at the periphery of portal tracts, and canals of Hering, which appear as single cells or rows cells within periportal areas of the lobule. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02427. eSlide 1.11 A near-normal liver biopsy from a patient with elevated liver tests on blood tests. There is no portal or lobular inflammation, necrosis, steatosis, or any other apparent disease. The only finding is that of scattered pigmented macrophages in portal tracts and lobules (A), which are highlighted by a period acid–Schiff stain after diastase digestion (B). Their presence suggests resolving mild acute hepatitis and explains the abnormal liver test results. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03579 and VM03578. eSlide 1.12 Hemophagocytic lymphohistiocytosis shows prominent, activated Kupffer cells that contain remnants of red blood cells and lymphocytes. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03409. eSlide 1.13 Coagulative necrosis in acetaminophen overdose is typically zonal and preferentially involves perivenular hepatocytes in zone 3. Inflammation, when present, is only mild and consists of scavenger macrophages with or without neutrophils. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03736. eSlide 1.14 A, A case of hepatitis with extensive parenchymal collapse. B, The areas of collapse may appear as bridging fibrosis on a trichrome stain at low magnification but, lii

on closer examination, are a lighter blue than collagen of portal tracts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03793 and VM03792. eSlide 1.15 Infectious mononucleosis with an inflammatory infiltrate of “activated” lymphocytes in portal tracts and sinusoids. The cells are larger than normal lymphocytes, and some appear atypical. The infiltrate “spills over” into the limiting plate without damaging it. Scattered apoptotic hepatocytes are seen, but there is no hepatocellular damage. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03570. eSlide 3.1 Nonspecific reactive hepatitis showing mild nonspecific findings, including mild portal inflammation, scattered foci of lobular inflammation, spotty necrosis, and apoptosis. This biopsy was performed in a 35-year-old because of abnormal liver test results and nonspecific gastrointestinal symptoms. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03498. eSlide 3.2  Diabetic (glycogen) hepatopathy showing enlarged hepatocytes with a pale cytoplasm and abundant megamitochondria. In places, the cytoplasm has an amorphous, glassy appearance. There is no inflammation, steatosis, Mallory-Denk bodies, or fibrosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02954. eSlide 3.3 “Cholangitis lenta” showing dilated bile ductules containing bile plugs at the periphery of portal tracts in a patient with septic shock. There is also patchy centrilobular necrosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02955. eSlide 3.4 Nonspecific changes, including mild ductular reaction, in patient with Crohn disease and elevated liver tests. Although mild ductular reaction without accompanying concentric inflammation, fibrosis, or bile duct scars may be the only finding of primary sclerosing cholangitis (PSC) in a biopsy, the cholangiogram in this patient did not demonstrate features of PSC. In contrast, eSlide 5.8 demonstrates features of PSC in a patient with ulcerative cholangitis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02956. eSlide 3.5 Marked steatosis in a child who received total parenteral nutrition for short gut syndrome. The portal tracts show a mild ductular reaction. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02957. eSlide 3.6 Prominent ductular reaction and numerous “ground glass” intracytoplasmic inclusions in periportal hepatocytes in a patient receiving total parenteral nutrition for short gut syndrome. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02959. eSlide 3.7 Severe cholestasis and biliary cirrhosis in an 11-yearold with short gut syndrome and long-term total parenteral nutrition. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02960. eSlide 5.1  Liver biopsy specimen from a 4-week-old with biliary atresia shows marked ductular reaction consisting of ductular proliferation, mild inflammatory infiltrate, and fibrosis. Hepatic arterioles appear prominent and thick walled. Enlarged, pale-staining hepatocytes, some with multiple nuclei (giant cells), are present mainly in zone 3. Canalicular bile plugs and foci of extramedullary

Virtual Slide Box hemopoiesis are seen (A). Trichrome stain highlights the marked fibrosis (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02611 and VM02612. eSlide 5.2 Duct remnant excised during a Kasai portoenterostomy shows varying stages of inflammatory destruction at different levels of the extrahepatic biliary tract. Periductal inflammation with denudation of epithelium (A), luminal obliteration (B), and fibrosis with dilatation (C) are all seen in the same patient. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02613, VM02614, and VM02615. eSlide 5.3 A hypoplastic gall bladder excised during a Kasai portoenterostomy for biliary atresia in a 7-week-old child. The entire gall bladder is present on this slide. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02616. eSlide 5.4 Liver removed at transplantation several years after a Kasai portoenterostomy. The liver is cirrhotic with nodules of varying sizes that are surrounded by a typical “biliary halo.” The halo is caused by ductular proliferation and cholate-stasis of periseptal hepatocytes. There is extensive loss of bile ducts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03377. eSlide 5.5 Liver biopsy for neonatal cholestasis in a 7-week-old shows marked canalicular cholestasis, few enlarged multinucleated hepatocytes (giant cells) in zone 3, scattered apoptotic cells, extramedullary hemopoiesis, and mild ductular reaction. No storage cells or viral inclusions are seen. A, Hemosiderin is present in periportal hepatocytes, which is a normal feature in neonates. B, There is no fibrosis on a trichrome stain. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02617 and VM02618. eSlide 5.6 A, Neonatal/perinatal hemochromatosis in a 2-weekold showing marked architectural distortion, severe cholestasis with many biliary rosettes, numerous multinucleated giant hepatocytes, mixed inflammation, and extensive perisinusoidal fibrosis. Trichrome stain highlights fibrosis (B) and Perl iron stain demonstrates extensive hemosiderin deposition in hepatocytes (C). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02619, VM02620, and VM02621. eSlide 5.7 Liver biopsy specimen from a 12-week-old with Alagille syndrome showing severe cellular and canalicular cholestasis and absence of bile ducts in most portal tracts. A, There is no inflammation or ductular reaction. B, Trichrome stain highlights fine strands of perisinusoidal fibrosis in perivenular areas, but there is no portal fibrosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02622 and VM02623. eSlide 5.8 Primary sclerosing cholangitis in a 16-year-old with inflammatory bowel disease. There is extensive periductal fibrosis with biliary epithelial damage, focal cholangitis, and absence of bile ducts in rare portal tracts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02624. eSlide 7.1 Explanted liver from a young adult with type I tyrosinemia (elevated blood succinylacetone) shows diffuse fibrosis with lobular disarray, cholestasis, and extensive hemosiderin deposition. Three nodules are present, two of which appear dysplastic. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03026.



eSlide 7.2 E  xplanted liver from a 5-year-old with ornithine transcarbamylase deficiency shows variably sized clusters of enlarged hepatocytes with clear, wispy cytoplasm. Mild, patchy steatosis is present. There is no fibrosis, and only minimal inflammation is present in some portal tracts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03025. eSlide 7.3  Explanted liver from an 8-month-old with type I citrullinemia shows essentially normal liver histology with no inflammation, necrosis, or fibrosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03024. eSlide 7.4  Hepatocytes in an 18-year-old with mucopolysaccharidosis type III (Sanfilippo syndrome) variably show a finely reticulated cytoplasm or large and small clear vesicles that represent both lipid and storage lysosomes. Apoptotic bodies are scattered throughout the parenchyma. There is no inflammation or fibrosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03023. eSlide 7.5 GM1 gangliosidosis in a 14-month-old shows single and clustered Kupffer cells with a finely reticulated foamy cytoplasm scattered among hepatocytes with diffuse steatosis. The latter is probably an indication of poor nutrition. There is no inflammation or fibrosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03022. eSlide 7.6  Gaucher disease shows clusters of Kupffer cells, which are enlarged and demonstrate a characteristic “crinkled tissue paper” appearance (storage cells). Hepatocytes are not affected. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03017. eSlide 7.7 A, Niemann-Pick disease shows diffuse involvement of hepatocytes, Kupffer cells, and macrophages, which demonstrate a finely vesicular, foamy cytoplasm. There is no inflammation, but extensive perisinusoidal and bridging fibrosis is present (B, trichrome stain). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03021 and VM03020. eSlide 7.8 Nephropathic cystinosis shows Kupffer cells packed with cystine crystals scattered uniformly within the liver parenchyma. Hepatocytes are not affected, and there is no inflammation or fibrosis. (Contributed by Sunil Badve, MD, Professor of Pathology, Indiana University School of Medicine.)   Virtual Slide: VM03019. eSlide 7.9 Glycogen storage disease type 1b (von Gierke disease) shows diffuse enlargement of hepatocytes. The cytoplasm appears pale and in places has an amorphous, glassy appearance. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03018. eSlide 7.10 Explanted noncirrhotic liver from a 21-year-old with glycogen storage disease type 1a shows steatosis, ballooned hepatocytes with Mallory hyaline, and a welldifferentiated hepatocellular carcinoma. The latter demonstrates numerous non-necrotizing granulomas that are not present outside the tumor. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03027. eSlide 8.1 A, Case of Wilson Disease in a 6-year-old boy showing moderate steatosis with scattered glycogenated nuclei and mild spotty hepatocyte necrosis. B, Masson trichrome liii

Virtual Slide Box stain shows delicate fibrous septa bridging portal tracts. (Contributed by Kay Washington, MD, PhD.)   Virtual Slide: VM02149 and VM02150. eSlide 8.2 Case of Wilson disease in a 19-year-old man showing variable portal chronic inflammation with little interface hepatitis, moderate steatosis, and established portal-portal bridging fibrosis with nodularity, which is indicative of cirrhosis. Such cases may be confused with nonalcoholic fatty liver disease. (Contributed by Kay Washington, MD, PhD.)   Virtual Slide: VM02151. eSlide 8.3 Case of Wilson disease liver explant in 48-year-old man, diagnosed at age 42, showing cirrhosis with prominent glycogenated nuclei and lipofuscin accumulation. (Contributed by Kay Washington, MD, PhD.)   Virtual Slide: VM02152. eSlide 8.4 Case of Wilson disease in 33-year-old woman who received an orthotopic liver transplant for fulminant hepatic failure. There are no histologic features that aid in distinguishing Wilson disease from other etiologies of massive hepatic necrosis in this case. (Contributed by Kay Washington, MD, PhD.)   Virtual Slide: VM02153. eSlide 9.1 Chronic hepatitis and cirrhosis in a 59-year-old man with alpha-1 antitrypsin deficiency (PiZZ). The abnormal protein has accumulated within hepatocytes in the form of eosinophilic globules of varying sizes (A), which are highlighted by a period acid–Schiff stain following diastase digestion (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03415 and VM03416. eSlide 9.2  Period acid–Schiff stain following diastase digestion highlights alpha-1 antitrypsin globules in periseptal hepatocytes in this 57-year-old woman. There is extensive (3+/4+) hepatocellular hemosiderin deposition. Genetic testing did not reveal C282Y or H63D mutations in the HFE gene. Features of nonalcoholic steatohepatitis are also seen. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03408. eSlide 10.1 Explanted liver from a 10-year-old boy with cystic fibrosis. There is marked steatosis, proliferating bile ducts containing diffusely inspissated bile, and portal fibrosis with bridging. (Contributed by Pierre Russo, MD.)   Virtual Slide: VM02541. eSlide 10.2 Autopsy liver from a 15-year-old adolescent boy with cystic fibrosis who died of respiratory failure. The liver shows portal fibrosis and focal bridging (“focal biliary cirrhosis”). (Contributed by Pierre Russo, MD.)   Virtual Slide: VM02540. eSlide 11.1 A 50-year-old man with homozygous C282Y mutation (type I hereditary hemochromatosis). There is marked parenchymal hemosiderin deposition. Hemosiderin is also present in Kupffer cells, generating a “mixed” pattern of deposition that may be seen in hereditary hemochromatosis when iron deposition is severe. In addition, hemosiderin is present in biliary epithelium and endothelial cells. (Contributed by Maha Guindi, MD.)   Virtual Slide: VM02587. eSlide 11.2 Patient with dialysis-dependent chronic renal failure showing mesenchymal pattern of hemosiderin deposition within Kupffer cells. (Contributed by Maha Guindi, MD.)   Virtual Slide: VM02589. liv



eSlide 11.3 E xtensive hemosiderin accumulation in hepatocytes, Kupffer cells, portal macrophages, and biliary epithelium (mixed pattern of deposition) in an 86-year-old woman with myelodysplastic syndrome and multiple transfusions. Iron deposits were detectable on magnetic resonance imaging. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02588. eSlide 11.4 Patient with sickle cell anemia, status post transfusion for sickle cell crisis related to sepsis. Mixed pattern of hemosiderin deposition in hepatocytes and Kuppfer cells approaching degree of severity seen in hereditary hemochromatosis. Similar to parenchymal pattern of hemosiderin deposition, a mesenchymal pattern may also evolve into a mixed pattern when there is severe iron overload. (Contributed by Maha Guindi, MD.)   Virtual Slide: VM02590. eSlide 11.5 Cirrhosis and extensive hemosiderin accumulation in hepatocytes, Kupffer cells, portal macrophages, and biliary epithelium (mixed pattern of deposition) in a 55-year-old woman with hereditary hemochromatosis. There is marked ductular reaction and large areas of fibrous attrition in this advanced cirrhosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02591. eSlide 11.6 Explanted liver from a patient with alcohol-related chronic liver disease who did not have mutations in the HFE gene. Moderate hemosiderin deposition is seen mainly in hepatocytes. Hemosiderin is also present in some biliary epithelial cells, which, along with endothelial deposition when present, does not necessarily indicate genetic iron overload. (Contributed by Maha Guindi, MD.)   Virtual Slide: VM02592. eSlide 12.1 Moderate steatosis and focal centrilobular perisinusoidal fibrosis in a patient with risk factors for metabolic syndrome. A, Hematoxylin and eosin stain. B, Chromotrope aniline blue stain. (Contributed by Carolin Lackner, MD.)   Virtual Slide: VM03177 and VM03178. eSlide 12.2 A, Nonalcoholic steatohepatitis with mild steatosis, numerous ballooned hepatocytes with Mallory hyaline, and a portal and lobular inflammatory infiltrate consisting predominantly of lymphocytes and clusters of pigmented macrophages. B, Masson trichrome stain shows centrilobular perisinusoidal and periportal fibrosis with a rare bridging septum. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03728 and VM03574. eSlide 12.3 A, Amiodarone-associated liver injury with numerous ballooned hepatocytes, Mallory-Denk bodies, and a chronic inflammatory infiltrate. B, Immunohistochemical stain for keratins 8/18 highlight the Mallory hyaline and show absence of cytoplasmic staining in ballooned hepatocytes. (Contributed by Carolin Lackner, MD.)   Virtual Slide: VM03181 and VM03180. eSlide 12.4 Irinotecan-associated liver injury shows typical features of steatohepatitis including steatosis, ballooned hepatocytes with Mallory hyaline, chronic lymphocytic inflammatory infiltrate, and associated fibrosis. (Contributed by Carolin Lackner, MD.)   Virtual Slide: VM03179. eSlide 12.5  Patient with chronic hepatitis C shows characteristic lymphoid aggregates in portal tracts. Centrilobular macrovesicular steatosis, scattered ballooned

Virtual Slide Box hepatocytes (A), and perisinusoidal fibrosis (B) on trichrome stain suggest concomitant nonalcoholic steatohepatitis. The lobular inflammation, although mostly associated with ballooned hepatocytes as often seen in nonalcoholic steatohepatitis, cannot be confidently assigned to one or the other disease process. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03573 and VM03571. eSlide 13.1 Acute hepatitis C showing portal lymphocytic inflammation and a prominent lobular component with inflammatory foci, necrotic hepatocytes, prominent Kupffer cells, and sinusoidal lymphocytosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02943. eSlide 13.2 Acute hepatitis B with lobular disarray, diffuse lobular inflammatory infiltrate of lymphocytes and pigmented macrophages, prominent Kupffer cells, and numerous apoptotic bodies. There is also a mild lymphocytic inflammation in portal tracts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03491. eSlide 13.3 Yellow fever showing hemorrhagic necrosis preferentially affecting hepatocytes in acinar zone 2 and extending to zone 1. Viable hepatocytes are seen around the portal tracts and a sparse rim around central veins. There is little inflammation. The necrotic hepatocytes have been referred to as Councilman bodies. (Contributed by Ryan Relich, PhD, Assistant Professor of Pathology, Indiana University School of Medicine.)   Virtual Slide: VM02804. eSlide 13.4 Fulminant hepatitis A showing large areas of panacinar collapse, which are replaced by macrophages and inflammatory cells. Viable hepatocytes are ballooned, and there is extensive cholestasis. A mixed inflammatory infiltrate comprising plasma cells and neutrophils and associated with a ductular reaction is present in portal tracts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03379. eSlide 13.5 Herpes simplex virus infection in a pregnant patient who presented with acute liver failure. Well demarcated (“punched out”) areas of necrosis containing nuclear debris are rimmed by infected hepatocytes, which contain eosinophilic intranuclear viral inclusions. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02944. eSlide 13.6 Dengue virus infection showing extensive coagulative necrosis affecting hepatocytes in zone 3 and extending to zone 2. A rim of viable hepatocytes is seen around the portal tracts in zone 1. There is sparse inflammation. (Contributed by Venancio Alves, MD, PhD.)   Virtual Slide: VM03735. eSlide 13.7  Extensive apoptosis of hepatocytes in Lassa fever. There is sparse inflammation, but karyorrhectic debris is strewn throughout the parenchyma. (Contributed by Ryan Relich, PhD, Assistant Professor of Pathology, Indiana University School of Medicine.)   Virtual Slide: VM03380. eSlide 14.1 Liver biopsy specimen from a 35-year-old patient who has been receiving antiviral treatment for chronic hepatitis B for 2 years. There is minimal chronic inflammatory infiltrate in the portal tracts, accompanied by mild portal fibrosis. No interface hepatitis is seen. In the lobules, there are rare aggregates of inflammatory

cells and few ground-glass cells. (Contributed by Prodromos Hytiroglou, MD.)   Virtual Slide: VM02597. eSlide 14.2 Liver biopsy specimen from a 20-year-old patient with known hepatitis B virus infection for 3 years. There are mild to moderate chronic inflammatory infiltrates in the portal tracts and moderate interface hepatitis. In the lobules, there are scattered necroinflammatory foci and abundant ground-glass cells. No evidence of fibrosis is seen. (Contributed by Prodromos Hytiroglou, MD.)   Virtual Slide: VM02593. eSlide 14.3 Liver biopsy specimen from a 37-year-old patient with known hepatitis B virus infection for 7 years. There are mild to moderate chronic inflammatory infiltrates in the portal tracts and mild interface hepatitis. In the lobules, there are scattered foci of necroinflammatory activity, many ground-glass cells, and mild (incidental) steatosis. There is also fibrosis of portal tracts and formation of occasional thin periportal fibrous septa. (Contributed by Prodromos Hytiroglou, MD.)   Virtual Slide: VM02594. eSlide 14.4 Liver biopsy specimen from a 42-year-old patient with chronic hepatitis B (A). The hepatic architecture is distorted because of fibrosis of portal tracts, formation of many fibrous septa, and partial parenchymal nodularity (B, Masson trichrome). Moderate chronic portal inflammation with moderate interface hepatitis, scattered necroinflammatory foci, many ground-glass cells, and mild (incidental) steatosis are present. There is also large cell change of hepatocytes. (Contributed by Prodromos Hytiroglou, MD.)   Virtual Slide: VM02595 and VM02596. eSlide 15.1 A 63-year-old patient with known hepatitis C virus infection for 3 years and diabetes mellitus for 10 years. There is mild to moderate chronic portal inflammatory infiltrate, including lymphoid follicles. Mild interface hepatitis, mild bile duct damage, and scattered foci of necroinflammatory activity are seen. Moderate steatosis may be attributed to either chronic hepatitis C or diabetes mellitus. Portal fibrosis and thin fibrous septa were seen on trichrome stain. (Contributed by Prodromos Hytiroglou, MD.)   Virtual Slide: VM02598. eSlide 15.2 A 52-year-old patient with chronic hepatitis C. The parenchymal architecture is distorted by portal fibrosis, formation of many fibrous septa, and partial parenchymal nodularity (transition to cirrhosis) (A), best seen on trichome stain (B). There is moderate chronic inflammatory infiltrate, including lymphoid follicles, with moderate interface hepatitis. Mild bile duct damage, scattered necroinflammatory foci activity, and mild steatosis are also seen. (Contributed by Prodromos Hytiroglou, MD.)   Virtual Slide: VM02599 and VM02600. eSlide 15.3  A 71-year-old patient with chronic hepatitis C. The parenchymal architecture is distorted; the parenchyma consists of nodules that are surrounded by fibrous septa (cirrhosis). In the portal tracts and the fibrous septa, there are mild to moderate chronic inflammatory infiltrates. Occasional dense lymphoid aggregates are seen. There is mild interface hepatitis. In the nodules, there are scattered foci of necroinflammatory activity and mild steatosis. (Contributed by Prodromos Hytiroglou, MD.)   Virtual Slide: VM02601. lv

Virtual Slide Box

eSlide 16.1 Ishak stage 2, corresponding to METAVIR F1, in a liver biopsy specimen with more than 11 portal tracts, most of which are fibrotic. Van Gieson stain. (Contributed by Maria Guido, MD, PhD.)   Virtual Slide: VM02625. eSlide 16.2 Ishak stage 2, corresponding to METAVIR F1, in a liver biopsy specimen with a tangentially cut vessel, which mimics a fibrous septum (“false” septum). Trichrome stain. (Contributed by Maria Guido, MD, PhD.)   Virtual Slide: VM02626. eSlide 16.3 Ishak stage 3 (METAVIR F2) in a liver biopsy specimen that includes a small subcapsular fragment. The capsule should not be confused with a long fibrous septum. At higher magnification, mesothelial cells are recognized. Van Gieson stain. (Contributed by Maria Guido, MD, PhD.)   Virtual Slide: VM02627. eSlide 16.4  Severe fibrosis with architectural distortion (Ishak stage 5). Features of hepatic repair complex are also evident: at least one perforated delicate septum, isolated thick collagen fibers, aberrant parenchymal veins, and hepatocytes within portal tracts. This case could be diagnosed as cirrhosis with features of regression/remodeling. van Gieson stain. (Contributed by Maria Guido, MD, PhD.)   Virtual Slide: VM02628. eSlide 17.1 Pneumocystis infection characterized by well-demarcated (“punched out”) areas containing pink foamy amorphous material. Saucer- and boat-shaped spores with a groove were visualized on a silver stain. (Contributed by Sunil Badve, MD, Professor of Pathology, Indiana University School of Medicine.)   Virtual Slide: VM03751. eSlide 17.2  Kaposi sarcoma composed of infiltrative lesions consisting of cleftlike vascular spaces lined by spindle-shaped endothelial cells. Red blood cells are found in the vascular lumen and are extravasated into the interstitium; the latter is a characteristic feature of Kaposi sarcoma. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03442. eSlide 18.1 Hepatic abscesses and thrombophlebitis due to Actinomyces. Colonies of the organism show typical aggregates of long-radiating filamentous forms. These are surrounded by a neutrophilic infiltrate, which in turn is surrounded by a mononuclear infiltrate of plasma cells and lymphocytes. (Contributed by Sunil Badve, MD, Professor of Pathology, Indiana University School of Medicine.)   Virtual Slide: VM03127. eSlide 18.2 Congenital syphilis with diffuse perisinusoidal fibrosis causing compression and atrophy of hepatic trabecula. Inflammation is sparse with small clusters of plasma cells scattered through the parenchyma. (Contributed by Sunil Badve, MD, Professor of Pathology, Indiana University School of Medicine.)   Virtual Slide: VM03782. eSlide 18.3  Numerous syphilitic gumma consisting of necrotic nodules surrounded by palisaded macrophages followed by a lymphoplasmacytic infiltrate and a fibrotic perimeter. (Contributed by Sunil Badve, MD, Professor of Pathology, Indiana University School of Medicine.)   Virtual Slide: VM03789. lvi



eSlide 18.4 L  iver involvement in leptospirosis shows detachment of hepatocytes without necrosis or inflammation. (Contributed by Venancio Alves, MD, PhD.)   Virtual Slide: VM03796. eSlide 18.5  Classic pattern of liver involvement by leishmaniasis shows prominent Kupffer cells, which contain the organisms. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03383. eSlide 18.6  Extensive deposition of a black-brown pigment (“malarial pigment”), corresponding to hemozoin in Kupffer cells in chronic malaria. (Contributed by Prodoromos Hytiroglou, MD.)   Virtual Slide: VM03133. eSlide 18.7 Schistosomiasis showing a mixed portal inflammatory infiltrate rich in eosinophils. Remnant of an egg surrounded by giant cells is seen in one portal tract. There is also extensive deposition of a black “schistosomal” pigment within clusters of macrophages and Kupffer cells. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03132. eSlide 18.8  Oriental cholangiohepatitis with acute and chronic cholangitis. Large hilar bile ducts are dilated and filled with a mixed inflammatory infiltrate. The biliary epithelium is extensively damaged and denuded. Medium and small bile ducts show periductal fibrosis and scarring. Large portal lymphoid aggregates are also present. Eggs or parasites were not present in several sections that were examined. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03742. eSlide 18.9 Hydatid cyst lined by a characteristic laminated wall and containing “hydatid sand” in a liver that is markedly steatotic. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02953. eSlide 19.1 Mycobacterium avium intracellulare infection in a patient with acquired immunodeficiency syndrome characterized by well-formed non-necrotizing granulomas within portal tracts and lobules (A) that contain acid fast bacilli (B, Ziehl-Neelsen stain). Macrovesicular steatosis and several glycogenated nuclei are also present in the background liver. (Contributed by Romil Saxena, MD).   Virtual Slide: VM02945 and VM03788. eSlide 19.2 Tuberculosis showing granulomas with central caseous necrosis surrounded by histiocytes and an outer rim of lymphocytes. (Contributed by Evandro Mello, MD, PhD.)   Virtual Slide: VM03787. eSlide 19.3  Leishmaniasis showing numerous non-necrotizing granulomas consisting of epithelioid cells, lymphocytes, and plasma cells in portal tracts and lobules. Parasites are not easily found. Kupffer cells appear prominent, and lymphocytes are present in sinusoids. (Contributed by Evandro Mello, MD, PhD.)   Virtual Slide: VM03765. eSlide 19.4 Several necroinflammatory foci in portal tracts and lobules of an allografted liver, which contain small spores of Histoplasma (A), which are highlighted by a Grocott methenamine stain (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02947 and VM02948. eSlide 19.5 Large ill-defined non-necrotizing granulomas accompanied by a lymphocytic inflammatory infiltrate in a middle-aged man with rapidly deteriorating liver function. Innumerable fungal spores of Histoplasma are seen

Virtual Slide Box in Kupffer cells and granulomatous macrophages. A, Hematoxylin and eosin stain. B, Grocott methenamine stain. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02949 and VM02950. eSlide 19.6 Cryptococcosis characterized by numerous granulomas containing innumerable spores with a prominent clear space. A, Multinucleated giant cells containing multiple spores are present throughout these granulomas. B, The clear space corresponds to a polysaccharide capsule that stains pink with the mucicarmine stain. (Contributed by Evandro Mello, MD, PhD.)   Virtual Slide: VM03786 and VM03737. eSlide 19.7  Numerous non-necrotizing granulomas along with lymphocytic portal and lobular inflammation. Liver test abnormalities were temporally related with initiation of an antibiotic for treatment of acne, suggesting drug-induced granulomas. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02951. eSlide 19.8 A predominantly granulomatous pattern of inflammation is seen in this patient with Hodgkin disease. The large non-necrotizing granulomas contain scattered Reed-Sternberg cells but not the telltale infiltrate of eosinophils. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02952. eSlide 20.1 Sarcoidosis with numerous large portal granulomas consisting of well-defined aggregates of epithelioid histiocytes surrounded by a rim of lymphocytes. There is no necrosis. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM03669. eSlide 20.2 Liver biopsy in a patient with suspected fatty liver disease confirms steatohepatitis. In addition, there are numerous, coalescent non-necrotizing portal and periportal sarcoid granulomas. Patchy bridging fibrosis is related to fibrosis associated with these granulomas. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM03670. eSlide 21.1 Autoimmune hepatitis under treatment. There is mild portal inflammation with mild interface activity and scattered foci of lobular inflammation. The inflammatory infiltrate consists of lymphocytes and many eosinophils. There is no fibrosis. (Contributed by Lisa Yerian, MD, PhD.)   Virtual Slide: VM02896. eSlide 21.2 Severely active autoimmune hepatitis with a dense lymphoplasmacytic inflammatory infiltrate in portal tracts and severe interface activity. There is also diffuse lobular inflammation accompanied by numerous apoptotic bodies and ballooning of hepatocytes. Eosinophils are scattered within the portal tracts and lobules. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02895. eSlide 21.3 Autoimmune hepatitis with severe interface activity and areas of confluent necrosis. The inflammatory infiltrate consists of lymphocytes and plasma cells with scattered eosinophils and neutrophils. Areas of necrosis are replaced by an intense ductular reaction. (Contributed by Lisa Yerian, MD, PhD.)   Virtual Slide: VM02894. eSlide 23.1 Acute hepatitis due to atorvastatin. There is lobular disarray with diffuse inflammation, numerous apoptotic bodies, and hepatocellular damage. The portal

tracts are expanded by a prominent ductular reaction. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02680. eSlide 23.2 Acute hepatitis due to ipilimumab. There is diffuse lobular inflammation with numerous apoptotic bodies and hepatocellular ballooning. The portal tracts are expanded by a dense lymphoplasmacytic inflammatory infiltrate. Numerous eosinophils are present in both the lobules and portal tracts. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02681. eSlide 23.3 Submassive hepatic necrosis due to isoniazid shows large areas of multiacinar necrosis that contain a mild inflammatory infiltrate of lymphocytes and pigmented macrophages, and proliferating bile ductules with bile plugs. Nodules of surviving parenchyma show marked canalicular cholestasis. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02682. eSlide 23.4 Chronic hepatitis-like injury due to 6-mercaptopurine. There is chronic portal inflammatory infiltrate of lymphocytes and many eosinophils. Scattered foci of inflammation, apoptosis, and sinusoidal lymphocytes are seen in the lobules along with canalicular cholestasis. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02683. eSlide 23.5 Mild zone 3 (perivenular) coagulative necrosis due to mithramycin. There is no portal or lobular inflammation. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02684. eSlide 23.6 Mild cholestatic hepatitis due to azathioprine. There is marked cholestasis with numerous clusters of foamy bile laden macrophages. Mild portal and lobular inflammation is present. The biliary epithelium appears damaged. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02685. eSlide 23.7 Cholestatic hepatitis due to amoxicillin-clavulanate. There is marked canalicular and cellular cholestasis with numerous clusters of foamy, bile-laden macrophages. Hepatocellular damage and many apoptotic bodies are seen. The portal tracts show a mild ductular reaction, and there is marked biliary epithelial damage. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02686. eSlide 23.8 Chronic cholestatic injury and bile duct loss due to temozolomide. There is marked biliary damage with flattening of the epithelium, cytoplasmic eosinophilia, and loss of nuclei. Some portal tracts lack bile ducts. Mild mixed portal inflammation is present. There is marked cholestasis with a sprinkling of lymphocytes in the lobules. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02687. eSlide 23.9 Microvesicular steatosis due to fialuridine showing numerous small vesicles within hepatocytes, imparting a foamy appearance. Some ballooned hepatocytes with ill-formed Mallory hyaline are also seen. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02688. eSlide 23.10  Veno-occlusive disease/sinusoidal obstruction syndrome after hematopoietic stem cell transplantation. There is extensive centrilobular hemorrhagic necrosis. Central veins show intimal edema, extravasation of red blood cells, and reactive fibrosis A, Hematoxylin lvii

Virtual Slide Box and eosin stain. B, Masson trichrome stain. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02689 and VM02690. eSlide 23.11 Nodular regenerative hyperplasia due to oxaliplatin. The hepatic parenchyma appears vaguely nodular because of areas of trabecular compression/atrophy alternating with areas of thickened trabecula (A) in the absence of fibrosis (B, Masson trichrome stain). C, These changes are best seen on a reticulin stain. (Contributed by David Kleiner, MD.)   Virtual Slide: VM02691, VM02692, and VM02693. eSlide 24.1  Alcoholic steatohepatitis with numerous ballooned hepatocytes containing Mallory hyaline, which are present in a predominantly centrilobular localization. There is an associated neutrophilic infiltrate (A). Trichrome stain shows pericellular fibrosis and the central veins cannot be easily identified, suggesting phlebosclerosis (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03541 and VM03504. eSlide 24.2  Alcoholic steatohepatitis with ballooned hepatocytes containing Mallory hyaline, which are present mostly in a centrilobular localization. The acute changes are superimposed on preexisting chronic disease; fibrosis involves the centrilobular regions and appears to have obliterated the central veins. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03403. eSlide 24.3 Severe macrovesicular steatosis intermixed with hepatocytes containing a granular cytoplasm. Some hepatocytes contain Mallory hyaline, and numerous giant mitochondria are seen. There is a prominent ductular reaction comprising proliferating ductules and a predominantly neutrophilic infiltrate (A). Trichrome stain shows extensive pericellular fibrosis with portal and periportal fibrosis (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03501 and VM03499. eSlide 24.4 Trichrome stain shows obliteration of central veins in this patient with chronic alcohol-induced liver disease. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03506. eSlide 24.5 Advanced alcoholic liver disease with extensive pericellular fibrosis breaking up the parenchyma into small groups of steatotic hepatocytes (“micro-micro” nodular cirrhosis). Scattered ballooned cells with Mallory hyaline suggest ongoing damage due to continuing alcohol consumption. There is a prominent ductular reaction and many ductules contain bile plugs. A, Hematoxylin and eosin stain. B, Masson trichrome stain. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03386 and VM03500. eSlide 24.6 Advanced alcoholic liver disease with extensive atrophic changes characterized by broad fibrous septa containing proliferating ductules and separating small nodules of hepatocytes. Ballooned cells with Mallory hyaline suggest ongoing damage. A, Hematoxylin and eosin strain. B, Masson trichrome stain. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03389 and VM03402. eSlide 25.1 This biopsy shows several von Meyenburg complexes. Each consists of benign ducts with open lumina, some of which contain bile, in a configuration reminiscent of the developing ductal plate. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02898. lviii



eSlide 25.2 L  iver explanted for autosomal dominant polycystic liver disease shows cysts lined by flattened epithelium, fibrotic cysts, von Meyenburg complexes, and areas of hemorrhage. The liver parenchyma itself has been reduced to randomly scattered small islands of hepatocytes that show sinusoidal dilatation. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02602. eSlide 25.3 Liver in autosomal recessive polycystic kidney disease in a 1-year-old shows extensive ductal plate malformation. A, Microcystically dilated ducts contain polypoid projections consisting of fibroconnective tissue surrounding hypoplastic veins are seen. B, Enlarged kidney from the same patient shows elongated and cystically dilated collecting ducts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02606 and VM02607. eSlide 25.4 Liver explanted for congenital hepatic fibrosis shows nodular architecture and ductal plate malformation. Ductal structures with open lumina, variably containing bile or eosinophilic material, are present at the interface of the fibrous septa with hepatic parenchyma, in a configuration reminiscent of the developing ductal plate. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02608. eSlide 25.5 Congenital hepatic fibrosis on biopsy may be mistaken for cirrhosis, but on closer inspection, features of ductal plate malformation—small ductal structures with open lumina variably containing bile or eosinophilic material—are seen at the periphery of the fibrous septa. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02609. eSlide 25.6 Caroli disease shows dilatation of intrahepatic bile ducts and ductal plate malformation. The latter is characterized by the presence of ductal structures with open lumina in a configuration reminiscent of the developing ductal plate. There is superimposed acute cholangitis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02610. eSlide 26.1  Primary biliary cholangitis shows lymphocytic and granulomatous cholangitis. Multiple small foci of lobular inflammation, which are thought to target the canals of Hering, are present (Contributed by Sanjay Kakar, MD.)   Virtual Slide: VM02470. eSlide 26.2 Primary biliary cholangitis with lymphocytic cholangitis, prominent plasma cell portal infiltrate, ductular reaction, and ill-defined collections of epithelioid macrophages in the portal tracts. (Contributed by Sanjay Kakar, MD.)   Virtual Slide: VM02471. eSlide 26.3 Primary biliary cholangitis with lymphocytic cholangitis, plasma cell-rich portal inflammation, and a well-formed portal granuloma. The periportal (interface) inflammation and scattered hepatocellular dropout raise the possibility of an autoimmune hepatitis component but were not supported by clinical and laboratory data. (Contributed by Sanjay Kakar, MD)   Virtual Slide: VM02472. eSlide 26.4 Primary biliary cholangitis with cirrhosis. Florid duct lesions are seen in some portal areas. Some of the interlobular bile ducts are lost, whereas the septal bile duct is intact. Occasional nodules are elongated with

Virtual Slide Box irregular (“jigsaw puzzle”) outlines, a feature often seen in biliary disease. (Contributed by Sanjay Kakar, MD.)   Virtual Slide: VM02473. eSlide 27.1 Primary sclerosing cholangitis with marked periductal lymphoplasmacytic infiltrate around large bile ducts, scattered bile duct scars, and extensive concentric periductal fibrosis (“onion skinning”) around small ducts that show biliary epithelial damage. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02652. eSlide 27.2 A liver biopsy specimen from a patient with primary sclerosing cholangitis showing mild ductular reaction in most portal tracts and subtle periductal fibrosis with biliary epithelial damage in some. A large portal tract with obvious periductal inflammation and fibrosis is also seen, but such large tracts are rarely present in a liver biopsy specimen, which largely samples small peripheral bile ducts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02654. eSlide 27.3 Gallbladder from a patient with primary sclerosing cholangitis shows severe mucosal lymphoplasmacytic inflammatory infiltrate, including lymphoid aggregates and lymphoid follicles. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03739. eSlide 27.4  Cholangiocarcinoma arising in a patient with primary sclerosing cholangitis. The latter is characterized by concentric periductal inflammation and fibrosis, ductular reaction, loss of bile ducts, and cholate-stasis of periportal hepatocytes. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02656. eSlide 28.1  Chronic graft-versus-host disease showing entire spectrum of bile duct damage from mild epithelial disruption to withered-looking cholangiocytes (A), damaged basement membranes (B, period acid–Schiff diastase stain), and loss of bile ducts in two portal tracts. Portal inflammation and ductular reaction are sparse. Epithelial damage also affects cholangiocytes of ductules. Immunohistochemistry for K7 (C) and K19 (D) highlights relative absence of ductular reaction and bile ducts. (Contributed by Annette Gouw, MD, PhD.)   Virtual Slide: VM02110, VM02111, VM02119, and VM02118. eSlide 28.2  A case of amoxicillin-clavulanic acid–induced loss of intrahepatic bile ducts. Some portal tracts contain mild inflammation and show bile duct damage, whereas in others, the bile duct is missing and there is no inflammation. There is also centrilobular necrosis. (Contributed by Annette Gouw, MD, PhD.)   Virtual Slide: VM02168. eSlide 28.3 Biopsy taken 2 weeks later from the same patient as eSlide 28.2. A, At this stage, most portal tracts lack a bile duct, the portal inflammation has decreased, and ductular reaction is absent. B, Immunohistochemical stain for K7 highlights the severe loss of bile ducts and the lack of a ductular reaction. (Contributed by Annette Gouw, MD, PhD.)   Virtual Slide: VM02122 and VM02123. eSlide 29B.1 Liver explanted for severe FIC-1 deficiency (progressive familial intrahepatic cholestasis type 1) shows cirrhosis with canalicular cholestasis, mild portal

inflammation, and no necrosis. A, Ducts appear to be lost, and a ductular reaction is not obvious. B, Masson trichrome stain shows bridging fibrosis. C, Immunohistochemical stain for K7 highlights diffuse, aberrant staining of hepatocytes and a ductular reaction around the circumference of the parenchymal nodules. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03035, VM03412, and VM03413. eSlide 29B.2 Severe bile salt export port (BSEP) deficiency (progressive familial intrahepatic cholestasis type 2) showing numerous multinucleated hepatocytes, canalicular cholestasis, and some biliary rosettes. A, There is extensive extramedullary hemopoiesis, and a mild ductular reaction is present in portal tracts. Immunohistochemical stain for BSEP shows lack of staining (B) that is normally present on the canalicular membrane (C). (Contributed by Pierre Russo, MD.)   Virtual Slide: VM02542, VM02544, and VM02543. eSlide 29B.3 Liver explanted for severe bile salt export pump deficiency (progressive familial intrahepatic cholestasis type 2) showing micronodular cirrhosis with numerous multinucleated hepatocytes, many of which are necrotic. There is a marked ductular reaction with a mild mixed lymphocytic and neutrophilic inflammation. There is extensive bile duct loss. (Contributed by Raffaella Morotti, MD.)   Virtual Slide: VM03414. eSlide 29B.4 A, Severe multidrug resistance protein 3 deficiency (progressive familial intrahepatic cholestasis type 3) shows ductular reaction in portal tracts with mild hepatocellular swelling and no significant inflammation or cellular damage. B, Masson trichrome stain shows delicate fibrous strands tracking the ductular reaction. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03029 and VM03028. eSlide 29B.5 A, Dubin-Johnson syndrome shows a brown lipofuscin-like pigment that is present throughout the lobule, not only around the central veins but also around the portal tracts. B, This pigment stains black with the Fontana-Masson stain. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03391 and VM03537. eSlide 30.1  Centrilobular sinusoidal dilatation with congestion with hepatocyte necrosis in a patient with ulcerative colitis who had acute Budd-Chiari syndrome. Two thrombi are noted in small hepatic veins. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03417. eSlide 30.2 Liver explanted from a young patient with essential thrombocythemia (JAK2 V617F mutation) and longstanding Budd-Chiari syndrome shows organizing thrombi in both central and portal vein radicles. There is extensive centrilobular hemorrhage and parenchymal atrophy in areas with vascular occlusion. A regenerative nodule with prominent canalicular cholestasis is seen in better draining parts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03738. eSlide 30.3 Perivenular sinusoidal dilatation and congestion with perisinusoidal fibrosis in a child with Ebstein anomaly (Masson trichrome stain). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03493. lix

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eSlide 30.4 S inusoidal dilatation, congestion, and fibrosis in centrilobular regions in a 26-year-old patient with heterotaxy and double outlet right ventricle status post Fontan procedure. The portal tracts show mild ductular reaction and fibrosis. There is no inflammation. A, Hematoxylin and eosin stain. B, Masson trichrome stain. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03393 and VM03494. eSlide 30.5 Sinusoidal obstruction syndrome with extensive and severe perivenular sinusoidal congestion and hemorrhage. Central veins (dotted) show intimal edema and fibrosis and extravasation of red blood cells A, Hematoxylin and eosin stain. B, Masson trichrome stain. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03749 and VM03420. eSlide 30.6 Dilated and congested sinusoids containing clumps of elongated (“sickled”) red blood cells. The patient also has chronic hepatitis B infection. Mild portal and focal lobular lymphocytic inflammation with rare ground glass hepatocytes is seen. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03505. eSlide 30.7 Cirrhosis in a 26-year-old woman with sickle cell disease showing extensive hemosiderin deposition in hepatocytes, Kupffer cells, and macrophages. There is mild lymphocytic portal inflammation. Screening tests were negative for hepatitis A, B, and C. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03422. eSlide 30.8 Extrahepatic portal vein thrombosis in a noncirrhotic patient shows sinusoidal dilatation with thinning of the hepatic trabecula, with a centrilobular localization. These changes are not evenly distributed. Rare portal veins with muscularized walls (dotted) and narrowed lumina may be seen. There is no inflammation or necrosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03741. eSlide 30.9 Reticulin stain demonstrates marked alteration in the form of thinning and thickening of the hepatic trabecula in a noncirrhotic patient with extrahepatic portal vein thrombosis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03496. eSlide 30.10  Obliterative portal venopathy showing absence and attenuation of portal vein branches in small terminal portal tracts and a mild lymphocytic inflammatory infiltrate representing phlebitis in others. The liver appears near normal in this patient who underwent a transplantation because of portal hypertension and failing liver function. A, Hematoxylin and eosin stain. B, Masson trichrome stain. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03429 and VM03397. eSlide 30.11 Granulomatous arteritis with obliteration of a hepatic artery branch in a patient with Wegener granulomatosis. The adjacent portal vein is patent, but another appears muscularized. There is prominent ductular reaction, and other arterial branches appear thickened. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03398. eSlide 30.12 Ischemic hepatitis showing centrilobular coagulative necrosis superimposed on sinusoidal congestion in this patient who had underlying congestive heart disease. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03396. lx

eSlide 30.13 E xtensive perivascular amyloid deposition in a 74-year-old man who had a hepatic resection for a large benign cyst. The amyloid appears as an amorphous, pale eosinophilic material on H&E stain (A) and stains brick red with the Congo red (B). The patient was lost to follow-up, and the cause of the chronic hepatitis and amyloid deposition remains unknown. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03428 and VM03726. eSlide 31.1 High-grade dysplastic nodule in a 56-year-old man with cirrhosis due to chronic hepatitis B. Compared with surrounding cirrhotic nodules, there is increased cell density with high nucleocytoplasmic ratios (A) and increased sinusoidal capillarization (B, immunohistochemical stain for CD34). Portal tracts are present within this high-grade dysplastic nodule. (Contributed by Young Nyun Park, MD, Ph.D.)   Virtual Slide: VM02632 and VM02633. eSlide 31.2 Early hepatocellular carcinoma, 0.9 × 0.6 cm in size, in a 64-year-old man. This well-differentiated lesion shows a thin trabecular pattern with increased cell density compared with adjacent non-neoplastic liver. Fatty change is noted. There is no tumor capsule. At the periphery, there is gradual replacement of nonneoplastic hepatic cords by tumoral trabecula replacing growth pattern). (Contributed by Young Nyun Park, MD, PhD.)   Virtual Slide: VM02634. eSlide 31.3 Small and progressed hepatocellular carcinoma (1.2 cm) in a 37-year-old man with cirrhosis due to chronic hepatitis B. This moderately differentiated lesion shows expansile growth pattern and a tumor capsule. At the periphery, a smaller, well-differentiated nodule (outer nodule) is present within an inner moderately differentiated nodule (nodule in nodule pattern). (Contributed by Young Nyun Park, MD, PhD.)   Virtual Slide: VM02635. eSlide 32.1 A, Biopsy specimen of focal nodular hyperplasia discovered fortuitously in a 28-year-old woman. There were no characteristic findings on imaging. This 5-mm biopsy fragment shows benign hepatocytes intercepted by two fibrous bands containing mild inflammation, ductular reaction, and an eccentrically thickened arteriole. There is mild sinusoidal dilatation. B, Immunohistochemical stain for glutamine synthetase (same lesion shown in Fig. 32.5A) shows irregularly shaped positive areas, often centered around veins, in a “maplike” pattern characteristic of focal nodular hyperplasia. (Contributed by Paulette Bioulac-Sage, MD.)   Virtual Slide: VM02478 and VM02479. eSlide 32.2 Hepatocyte nuclear factor 1 alpha–inactivated hepatocellular adenoma (9 cm) in a 34-year-old woman composed of nonencapsulated, well-demarcated tumor with lobulated contours made up of well differentiated hepatocytes with severe steatosis and intermingled with nonsteatotic hepatocytes. There are numerous vessels but no bile ducts, inflammation, or cytologic atypia. Diagnosis was confirmed by lack of liver fatty acid binding protein in the tumor that contrasted with normal expression in the surrounding nontumoral parenchyma. (Contributed by Paulette Bioulac-Sage, MD.)   Virtual Slide: VM02524.

Virtual Slide Box eSlide 32.3 β  -Catenin–activated hepatocellular adenoma (HCA) with a nodule of hepatocellular carcinoma (HCC) (“nodule-in-nodule” appearance). The tumor is nonencapsulated. The main nodule shows little cytologic or architectural changes except for few rosettes and marginally thickened hepatic plates. The smaller nodule is malignant, with thickened plates and numerous pseudoglands. Not shown are reticulin (maintained in HCA, decreased in HCC) and glutamine synthetase (diffuse and strong throughout the tumor). (Contributed by Paulette Bioulac-Sage, MD.)   Virtual Slide: VM02488. eSlide 32.4 One of several inflammatory hepatocellular adenomas (0.6–5 cm) in a 43-year-old woman. The tumor consists of benign hepatocytes with sinusoidal dilatation and congestion, inflammatory cells, and mild ductular reaction around arteries. Diffuse expression of C-reactive protein is present within tumor with sharp demarcation from surrounding nontumoral liver (not shown). Mild steatosis is seen in nontumoral liver and focally in tumoral hepatocytes at the periphery. (Contributed by Paulette BioulacSage, MD.)   Virtual Slide: VM02477. eSlide 32.5 Immunohistochemical stain for glutamine synthetase shows a characteristic “maplike” pattern in focal nodular hyperplasia (FNH). Large, anastomosing, positive areas predominate at the periphery of hepatocytic nodules. Recognition of this pattern in a biopsy specimen allows diagnosis of FNH. In the adjacent normal liver, staining is restricted to two or three rows of hepatocytes around central veins. (Contributed by Paulette Bioulac-Sage, MD.)   Virtual Slide: VM02526. eSlide 32.6 A, Biopsy specimen of one of several nodules in a 54-year-old woman showing a typical hepatocyte nuclear factor 1 alpha–inactivated hepatocellular adenoma arising in normal liver. Two fragments are present with no intervening capsule; one corresponds to a proliferation of steatotic hepatocytes without any portal tracts, inflammation, or atypia. The second part is normal liver parenchyma. B, Immunohistochemical stain for liver fatty acid binding protein shows complete lack of staining in the steatotic part compared with normal expression in the nontumoral liver, which is seen as irregular distribution of cytoplasmic positivity within hepatocytes. (Contributed by Paulette Bioulac-Sage, MD.)   Virtual Slide: VM02480 and VM02481. eSlide 32.7 A, Biopsy specimen from one of several nodules in a 48-year-old woman with adenomatosis showing a nonsteatotic hepatocyte nuclear factor 1 alpha–inactivated hepatocellular adenoma. There are two fragments; the 7-mm one corresponds to nontumoral liver parenchyma. The second smaller fragment shows loss of normal lobular architecture with absence of portal tracts. Several small veins are present within a benign hepatocytic proliferation. There is no atypia. The reticulin framework and CD34 immunostaining (not shown) show a normal pattern. B, Immunohistochemical stain for liver fatty acid binding protein shows complete lack of staining in small fragment compared with normal expression in the large fragment

of nontumoral liver. (Contributed by Paulette BioulacSage, MD.)   Virtual Slide: VM02482 and VM02483. eSlide 32.8 A, Biopsy specimen of a typical inflammatory hepatocellular adenoma (2 cm) in a 38-year-old woman. Three fragments consist of tumor with small areas of nontumoral liver at their extremities. The fourth fragment consists entirely of nontumoral liver. The tumor corresponds to a proliferation of benign hepatocytes without portal tracts, intermingled with foci of inflammatory cells, often around arteries, with mild ductular reaction. Large areas of sinusoidal dilatation and congestion are seen. The nontumoral liver is normal. B, Immunohistochemical stain for C-reactive protein (CRP) shows strong and diffuse overexpression by hepatocytes with strict demarcation from the nontumoral liver, which is CRP negative. (Contributed by Paulette Bioulac-Sage, MD.)   Virtual Slide: VM02484 and VM02485. eSlide 33.1 Liver biopsy of a hepatocellular carcinoma composed of large cells with abundant eosinophilic cytoplasm that contain a single nucleus with a prominent eosinophilic nucleolus. The trabecular architecture is barely discernible, giving rise to a compact appearance. The cells contain various intracytoplasmic inclusions, Mallory-Denk bodies, and fat droplets. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03399. eSlide 33.2 Liver biopsy of a well-differentiated hepatocellular carcinoma that shows a predominantly trabecular architecture with focal acinar (pseudogland) formation. The trabeculae are lined by endothelial cells. The tumor cells have abundant eosinophilic cytoplasm with central nuclei containing prominent nucleoli (A). Reticulin stain highlights the thickened trabecula within the tumor (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03746 and VM03743. eSlide 33.3 Biopsy of a well-differentiated hepatocellular carcinoma in a trabecular and acinar growth pattern. Characteristic are small islands of tumor cells covered by endothelial cells that appear to “roll off ” the biopsy (A). Reticulin stain shows one-cell-thick trabecula in the nontumoral liver and thickened trabecula in the tumor (“retic poor” pattern) (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03747 and VM03744. eSlide 33.4  Well-differentiated hepatocellular carcinoma in an explanted liver showing a predominantly acinar pattern. These pseudoglandular structures variously contain bile or faint eosinophilic material. Peliotic vascular lakes are also present. A trabecular architecture is seen focally at the periphery of the nodule. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03750. eSlide 33.5 Clear cell variant of hepatocellular carcinoma closely mimics a renal cell carcinoma. However, markers of hepatocellular differentiation, including arginase-1 and hepatocyte-specific antigen, were positive, whereas PAX-8, a marker of renal cell differentiation, was negative. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03745. eSlide 33.6 Liver biopsy of a steatohepatitic hepatocellular carcinoma showing a compact and trabecular architecture. The presence of steatosis, ballooned hepatocytes, and lxi

Virtual Slide Box Mallory-Denk bodies is reminiscent of steatohepatitis. There are no portal tracts, and many arteries are interspersed throughout the tumor. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03437. eSlide 33.7  Steatohepatitic variant of hepatocellular carcinoma with a trabecular growth pattern and presence of steatosis, ballooned cells, and Mallory-Denk bodies. Foci of conventional hepatocellular carcinoma are also present. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03748. eSlide 34.1 Incidental ciliated hepatic foregut cyst containing a granular, eosinophilic material in a liver explanted for cirrhosis due to chronic hepatitis C. The cyst is lined by a ciliated respiratory-like epithelium and contains smooth muscle in its wall. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02962. eSlide 34.2 Bile duct adenoma consisting of benign bile ducts in a desmoplastic stroma and a von Meyenburg complex comprising slightly dilated ductal structures containing bile in a liver explanted for cirrhosis due to chronic hepatitis C. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02961. eSlide 34.3 An incidental bile duct adenoma sampled in a liver biopsy performed for grading and staging of chronic hepatitis C. Benign bile ducts with open lumina are present in a fibrotic stroma.   Virtual Slide: VM03572. eSlide 34.4 Mucinous cystic neoplasm lined by a single layer of tall columnar mucous cells (A). The wall of the cyst contains endometrial stroma that is immunohistochemically positive for estrogen receptor (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02963 and VM02964. eSlide 34.5 Biliary intraductal papillary neoplasm grows within and dilates bile ducts. The tumor demonstrates a complex papillary architecture and is comprised of epithelium that variably shows biliary (A), foveolar (A and B), intestinal (A and C), or oncocytic (C) differentiation. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02965, VM02966, and VM02967. eSlide 34.6 Low-grade biliary intraepithelial neoplasia in a hilar duct in a patient with primary sclerosing cholangitis. The lesion is characterized by crowding and tufting of the lining biliary epithelium that shows nuclear stratification and hyperchromasia. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02969. eSlide 34.7 Cholangiocarcinoma arising in a patient with primary sclerosing cholangitis (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02968. eSlide 35.1 Fetal hepatoblastoma consisting of medium-sized cells arranged in slender trabecula with intervening sinusoids. A characteristic “clear-and-dark-cell” pattern is present because of cellular cytoplasm that is either clear or eosinophilic. Adjacent liver is noncirrhotic. (Contributed by Arthur Zimmermann, MD.)   Virtual Slide: VM02639. eSlide 35.2 Mixed epithelial mesenchymal hepatoblastoma with teratoid features composed of fetal epithelial component, neuroectodermal components (glial cells, lxii

melanocytes, neuronal cells), endodermal components (glands representing embryonal gut), squamous epithelium, and abundant osteoid. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03400. eSlide 35.3  Treated hepatoblastoma with numerous islands of squamous epithelium, extensive fibrosis, extensive osteoid formation, foreign body giant cells, and hemosiderin laden macrophages. (Contributed by Arthur Zimmermann, MD.)   Virtual Slide: VM02640. eSlide 35.4 Fibrolamellar carcinoma composed of sheets of large, polygonal cells containing abundant eosinophilic cytoplasm and a single central nucleus with prominent eosinophilic nucleolus. The cells are embedded in a characteristic stroma of lamellar fibrosis. Intracytoplasmic globules and pale bodies are present. (Contributed by Arthur Zimmermann, MD.)   Virtual Slide: VM02641. eSlide 35.5 Hepatocellular carcinoma with a trabecular and acinar pattern with abundant bile production. Foci of highgrade tumor with multinucleated pleomorphic tumor cells containing Mallory hyaline are present. (Contributed by Arthur Zimmermann, MD.)   Virtual Slide: VM02642. eSlide 35.6 Mesenchymal hamartoma composed of loose myxoid tissue containing scattered vessels and bile ducts with a concentric collar of fibrous tissue. The periphery is typically ill defined, where lobules of the tumor intermingle with the adjacent nontumoral liver. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03777. eSlide 35.7  Undifferentiated embryonal sarcoma composed of sheets of undifferentiated cells with large hyperchromatic nuclei in a myxoid stroma. Mitotic figures, numerous multinucleated tumor cells with bizarre pleomorphic nuclei, and intracytoplasmic eosinophilic globules are present. There are large areas of necrosis and hemorrhage. Entrapped ducts surrounded by a cuff of tumor are seen at the periphery of the tumor. (Contributed by Arthur Zimmermann, MD.)   Virtual Slide: VM02643. eSlide 35.8 Extrarenal malignant rhabdoid tumor composed of sheets of large pleomorphic cells containing abundant eosinophilic cytoplasm and an eccentric nucleus with a prominent eosinophilic nucleolus. A, A loose myxoid stroma and abundant necrosis are seen. B, Immunohistochemical stain shows loss of INI1 in the tumor nuclei, a pathognomic feature of this tumor. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03432 and VM03495. eSlide 35.9  Infantile hemangioma composed of anastomosing vascular channels of varying sizes lined by plump endothelial cells. A, Bile ducts are entrapped throughout the lesion. The endothelial cells are strongly positive for CD34 (B) and GLUT-1 (C). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02645, VM02648 and VM02717. eSlide 36.1 Cavernous hemangioma composed of vascular channels of varying shapes and sizes. These are lined by flattened endothelial cells. Scattered foci of sclerosis and myxoid change are seen. Dilated vascular channels are seen in portal tracts of the adjacent liver, imparting an

Virtual Slide Box irregular or “spongy” interface. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM02486. eSlide 36.2  Epithelioid hemangioendothelioma consisting of spindle and epithelioid cells in a fibrous and focally, myxoid stroma. Numerous characteristic cells with intracytoplasmic lumina containing red blood cells are seen. Tumor is seen occluding large vessels. There are many entrapped portal tracts that show invasion of portal vessels by tufts of tumor cells. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM02487. eSlide 36.3  Angiomyolipoma composed predominantly of epithelioid smooth muscle cells. There is extensive extramedullary hematopoiesis. Thick-walled blood vessels and collections of adipocytes are present only focally. The adjacent liver shows extensive collections of neutrophils, a consequence of surgery (“surgical hepatitis”), and scattered megakaryocytes as a manifestation of extramedullary hematopoiesis. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM02490. eSlide 36.4 Diffuse large B-cell lymphoma that presented as a liver mass. In addition to forming a tumor mass, monomorphic lymphoma cells are also infiltrating portal tracts and hepatic sinusoids. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM02519. eSlide 36.5 Hepatosplenic γδ T-cell lymphoma shows sinusoidal infiltration by a lymphocytic infiltrate that mimics hepatitis. The diagnosis was confirmed by immunohistochemical and molecular studies. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM02520. eSlide 36.6  Liver involvement by Hodgkin lymphoma shows characteristic Reed-Sternberg cells in a background of lymphocytes and eosinophils. Areas of necrosis are evident. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM02521. eSlide 36.7 Solitary fibrous tumor composed of fusiform spindle cells interspersed with dilated vessels imparting a hemangiopericytoma-like pattern. The adjacent liver shows bile ductular reaction, dilated vessels and focal sinusoidal dilatation, features of compression by the tumor. (Contributed by Arief Suriawinata, MD.)   Virtual Slide: VM02527. eSlide 38.1 Liver explanted for heredofamilial amyloidosis (familial amyloidotic polyneuropathy) shows amyloid deposition within nerves and around blood vessels in an otherwise normal liver. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03401. eSlide 38.2 Preservation–reperfusion injury characterized by ballooning and cholestasis of perivenular hepatocytes, and a mild ductular reaction with proliferating ductules associated with neutrophils and eosinophils. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02899. eSlide 38.3 Lipopeliosis 5 days after transplantation characterized by confluent lipid droplets and congested sinusoids. Some portal tracts show mixed inflammation, but the findings are not sufficient for a diagnosis of rejection. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02900.



eSlide 38.4 S evere acute cellular rejection with a mixed portal inflammatory infiltrate consisting of lymphocytes, eosinophils, and neutrophils. Bile duct damage and endotheliitis are present. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02901. eSlide 38.5 Late cellular rejection occurring 17 years after transplantation. There is prominent central perivenulitis characterized by a mild infiltrate of plasma cells and pigmented macrophages accompanied by hepatocytes necrosis. A mild portal lymphocytic infiltrate is present in some but not all portal tracts; bile duct injury and endotheliitis are not seen. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02902. eSlide 38.6 Chronic rejection with extensive cellular cholestasis and loss of bile ducts. Residual bile ducts are attenuated. There is also perivenular hepatocyte dropout, suggesting a concomitant ischemic arteriopathic component. No inflammation or ductular reaction is seen. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02903. eSlide 38.7  Centrilobular sinusoidal dilatation and congestion with hepatic trabecular atrophy due to kinking of the hepatic vein. There is no inflammation and no evidence of rejection. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02904. eSlide 38.8 Recurrent acute hepatitis C shows numerous apoptotic bodies, foci of lymphocytic lobular inflammation, and mild portal inflammation composed predominantly of lymphocytes with a few eosinophils and neutrophils. There is no interface hepatitis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02905. eSlide 38.9 Recurrent chronic hepatitis C with many portal lymphoid aggregates. Mild interface and lobular hepatitis is present. There is also mild macrovesicular steatosis with no definitive features of steatohepatitis. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02906. eSlide 38.10 Liver allograft 4 years after transplantation with cirrhosis and chronic hepatitis due to recurrent hepatitis C infection. The vascular and biliary radicles appear pristine without evidence of rejection or other posttransplantation disease. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02970. eSlide 38.11 Fibrosing cholestatic hepatitis in an allograft due to recurrent hepatitis C infection. A, There is chronic portal inflammation with interface hepatitis, and ductular reaction. B, Extensive perisinusoidal and bridging fibrosis is seen on trichrome stain. Serum hepatitis C virus RNA was 33.8 million copies. (Contributed by Isabel Fiel, MD.)   Virtual Slide: VM02907 and VM02908. eSlide 38.12 Recurrent hepatitis B shows marked portal lymphocytic inflammation with interface and lobular activity and numerous ground glass hepatocytes. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02909. eSlide 38.13  Recurrent autoimmune hepatitis shows marked inflammation and expansion of portal tracts with severe interface and lobular activity including areas of collapse. The inflammatory infiltrate is composed lxiii

Virtual Slide Box predominantly of plasma cells intermixed with lymphocytes. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02910. eSlide 38.14 Recurrent primary biliary cholangitis with florid duct lesions (granulomatous cholangitis), lymphoplasmacytic cholangitis, bile ductular reaction, and bile duct loss. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02911. eSlide 38.15 Recurrent sclerosing cholangitis shows lymphoplasmacytic inflammation around septal bile ducts, ductular reaction, and loss of bile ducts. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02912. eSlide 38.16 Recurrent nonalcoholic steatohepatitis shows steatosis, many ballooned hepatocytes containing ill-formed Mallory hyaline (A), and perisinusoidal fibrosis (B,  Masson trichrome stain). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02914 and VM02913. eSlide 38.17 De novo alcohol-related liver disease shows steatosis, numerous ballooned hepatocytes with Mallory hyaline, neutrophilic infiltrate, ductular reaction (A), and extensive perisinusoidal fibrosis (B, Masson trichrome stain). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02915 and VM02916. eSlide 38.18  Plasma cell hepatitis characterized by prominent plasma cell infiltrate expanding portal tracts. Interface and lobular activity is also present. (Contributed by Isabel Fiel, MD.)   Virtual Slide: VM02917. eSlide 38.19 Liver allograft 12 years after transplantation for biliary atresia shows patchy mild perivenulitis, patchy mild lymphocytic portal inflammation (A), irregular periportal and perivenular fibrosis (B, Masson trichrome stain), and parenchymal remodelling evidenced as thinned or thickened hepatic trabecula (C, reticulin stain). Biopsy was performed for elevated liver tests to rule out rejection. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02918, VM03725 and VM03724. eSlide 38.20  Post-transplant lymphoproliferative disease consisting of large pleomorphic cells with prominent nucleoli that are positive for CD20 (diffuse large B-cell lymphoma) (A) and EBER (B, in situ hybridization for Epstein-Barr Encoding Region). Patient had undergone transplantation for alcoholic liver disease and hepatocellular carcinoma. This biopsy was performed to rule out a recurrent carcinoma. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02919 and VM02920. eSlide 38.21 Extensive hepatocyte necrosis, ballooning, and cholestasis due to vascular problem in a biopsy taken 7 days after transplantation. (Contributed by Isabel Fiel, MD.)   Virtual Slide: VM03775. eSlide 38.22 Cytomegalovirus hepatitis showing marked portal and lobular mixed inflammation consisting of lymphocytes and neutrophils with a vaguely granulomatous appearance in places. Scattered intranuclear eosinophilic

lxiv

inclusions are seen. There is also fibrin deposition in portal veins. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02922. eSlide 38.23  Adenoviral hepatitis with extensive hemorrhagic necrosis and granulomatous inflammation. Basophilic intranuclear inclusions are present at the edges of the necrotic foci (A). Immunohistochemical stain highlights the infected nuclei (B). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02924 and VM02925. eSlide 39.1 Mixed hepatocholangiocarcinoma in a cirrhotic liver shows an intimate mixture of hepatocytic and ductal elements. Note stromal invasion into an adjacent portal tract. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02971. eSlide 39.2 Mixed hepatocholangiocarcinoma in a biopsy comprising a hepatocellular component (A) with thickened trabecula (B, reticulin) and ductal component (A) positive for polyclonal carcinoembryonic antigen (C, immunohistochemical stain). (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02972, VM02973, and VM02974. eSlide 39.3  Cholangiolocellular carcinoma demonstrates an “antlerlike” configuration of anastomosing ducts and tubules in a desmoplastic stroma. The tumor is invading into a nerve. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM02975. eSlide 41.1 “Biliary” cirrhosis showing bridging of adjacent portal tracts by fibrous septa, which gives rise to a micronodular pattern. The fibrous septa show a prominent ductular reaction with only minimal inflammation. H&E (A) and trichrome (B) stains. (Contributed by Romil Saxena, MD.)   Virtual Slide: VM03583, VM03584. eSlide 41.2 Laennec stage 4A with thin septa and no obvious nodules in a case of chronic hepatitis B and delta agent coinfection. H&E (A), trichrome (B), and reticulin (C) stains. (Contributed by Christine Sempoux, MD, PhD.)   Virtual Slide: VM02990, VM02991, and VM02992. eSlide 41.3 Laennec stage 4B showing broad septa and micronodules occupying less than half the biopsy in chronic hepatitis C. H&E (A), trichrome (B), and reticulin (C) stains. (Contributed by Christine Sempoux, MD, PhD.)   Virtual Slide: VM02993, VM02994, and VM02995. eSlide 41.4 Laennec stage 4C showing many micronodules in a patient with alcoholic cirrhosis. H&E (A), trichrome (B), and reticulin (C) stains. (Contributed by Christine Sempoux, MD, PhD.)   Virtual Slide: VM02996, VM02997, and VM02998. eSlide 41.5 Regressing cirrhosis with features of hepatic repair complex seen in a partial liver resection for hepatocellular carcinoma and chronic hepatitis B. H&E (A), trichrome (B), and reticulin (C) stains. (Contributed by Christine Sempoux, MD, PhD.)   Virtual Slide: VM02987, VM02988, and VM02989.

1 Microscopic Anatomy, Basic Terms, and Elemental Lesions Romil Saxena, MD, FRCPath

Parenchymal Architecture and Tissue Organization  3 Assessing Parenchymal Architecture in a Biopsy  6 Absence of Portal Tracts  6 Fragmentation 6 Subcapsular Parenchyma  8 Portal Tracts  8 Bile Ducts  8 Hepatic Arteries  9 Portal Veins  11 Hepatic Veins  11 Lobular Parenchyma  12 Hepatocytes 12 Intralobular Biliary Channels  15 Sinusoids 16 Disse Space  19 Electron Microscopy  20 Hepatocytes 20 Sinusoidal Lining Cells  20 Disse Space  20 Utility of Electron Microscopy in Routine Diagnostic Practice 22 Basic Terms and Elemental Lesions  22 Structural 22 Inflammation, Cell Damage, and Necrosis  22 Intracellular Pathology  23 Biliary Lesions  26 Sinusoidal Lesions  27

Abbreviations H&E hematoxylin and eosin HMS hepatic microcirculatory subunit K keratin* NADPH nicotinamide adenine dinucleotide phosphate

It would not be misleading to state that the microscopic structure of the liver as visualized in a routine hematoxylin and eosin (H&E)– stained slide is irritatingly bland when compared with its complex and diverse functions. In all truthfulness, when one examines such a section, one is peering down at a sea of monotonous hepatocytes interspersed at reassuring intervals by portal tracts and central veins (Fig. 1.1). Specifically, one fails to notice, even with a healthy dose of imagination, well-demarcated hexagonal lobules, primary or secondary lobules, berry-shaped acini or pyramidal portal units, all so prolifically described in literature (Fig. 1.2). However, it is evident from experimental studies and the zonal distribution of disease processes that there is a definite pattern of functional and metabolic organization to the hepatic parenchyma. Therefore an understanding of our diverse attempts to organize the liver parenchyma into neat functional units is often rewarded by a better insight into liver biopsy material obtained for a variety of indications (Box 1.1).

Parenchymal Architecture and Tissue Organization Although the concept of the hexagonal lobule began with the earliest morphologists such as Malpighi, detailed microscopic characterization was first provided by Kiernan in 1833 who described a roughly hexagonal structure centered around the hepatic vein with portal tracts at its corners.1 This hexagonal lobule is demarcated by fibrous septa in certain species such as the pig (Fig. 1.3). Although no such septa exist in the human liver, the concept of the classic lobule (see Fig. 1.2A) as a structural unit is consistent with portocentral gradients, which exist for numerous metabolic pathways and their encoding genes. Similarly, blood flows along this gradient from portal tracts to central veins, whereas bile and lymph flow in the reverse direction. Other early investigators, particularly Brissaud, Sabourin, and Mall,2,3 described the portal or biliary lobule, emphasizing portal tracts and bile flow as the pivotal points around which hepatic architecture is organized. *Although the prefix CK is widely used in surgical pathology to designate human cytokeratins, consensus nomenclature recommends the replacement of “cytokeratin” with “keratin” and the prefix “CK” with “K.” (Schweizer J, Bowden PE, Coulombe PA, et al. New consensus nomenclature for mammalian keratins. J Cell Biol. 2006;174:169–174).

3

Practical Hepatic Pathology: A Diagnostic Approach

A

B Figure 1.1  On low power, the liver parenchyma appears as a sea of monotonous hepatocytes interspersed at regular intervals by portal tracts and central veins (arrows). There is no clearly demarcated structural unit. H&E stain (A) and Masson trichrome stain (B) (also see eSlides 1.1, 1.2, and 1.3).

Furthermore, Brissaud and Sabourin have been credited with describing septa that link adjacent central veins, thus demarcating portal lobules in the seal liver. Arey, who clarified that the notion of septa demarcating portal lobules arose from a misinterpretation of Brissaud and Sabourin’s original descriptions in French, could not corroborate the presence of these septa by a study of livers from approximately 25 species.2 The study of blood flow by injecting dyed gelatin solutions into the portal vein led Rappaport to a differing perspective of hepatic microarchitecture.4,5 Rappaport observed that blood did not flow directly inward from portal tracts to central veins, but rather flowed first laterally through a thin vessel that extended halfway toward the neighboring portal tract before flowing inward from this vessel into several adjacent hexagonal lobules. Rappaport thus observed that the basic unit of the liver is not the hexagonal lobule, or indeed the portal lobule, but the berry-shaped acinus pivoted around this axial vessel, the portal venule, which arises from the smallest, terminal branch of the portal vein. The parenchyma around the portal venule can be arbitrarily divided into three concentric zones: zone 1 is the closest and receives the maximum amount of oxygen and nutrients, whereas zone 3 is the farthest (see Fig. 1.2A). The acinar concept, which is based on perfusion of the liver parenchyma, explains pathologic lesions that have their basis in parenchymal perfusion, such as perivenular localization 4

of ischemic lesions. The shape of the acinar unit also suggests that zone 3 is star-shaped6 (see Fig. 1.2B). On the other hand, by staining for enzymes expressed in periportal hepatocytes (carbamoyl phosphate synthetase and glucose-6-phosphatase) and those expressed in perivenular hepatocytes (glutamine synthetase and NADPH-cytochrome c), Lamers demonstrated that the perivenular area, corresponding to Rappaport acinar zone 3, is discrete and circular, whereas the periportal areas, corresponding to Rappaport acinar zone 1, are irregular in outline and roughly star-shaped7 (see Fig. 1.2C). This study showed that three dimensionally and in the context of expression of certain enzymes, the periportal “domain” (around portal tracts) follows the branching pattern of the portal veins and envelopes the discrete and circular perivenular “domain” (around central veins), which follows the branching pattern of the hepatic veins. The role of the smallest branch of the portal vein, the portal venule, in lobular architecture was also highlighted by Matsumoto, who called this vessel a vascular septum; the word “septum” was used not to denote a fibrous band but a boundary that demarcates the hexagonal lobule. Each side of the hexagonal lobule is made up of two vascular septa arising from adjacent portal tracts (see Fig. 1.2A and D). Inlet venules arise from the terminal portal vein and portal venule to end in sinusoids. Sinusoids arising from the terminal portal vein and the proximal portion of the portal venule (ie, near the portal tracts, therefore portal sinusoids) spread transversely before turning inward and heading radially toward the central vein, whereas sinusoids that arise from the distal portion of the portal venule (ie, from the vascular septum, therefore, septal sinusoids) travel radially straight toward the central vein.8,9 Metabolic gradients have been described along portal and septal sinusoids, albeit in the rat liver.10,11 The hunt for the functional unit of the liver (the smallest structural unit that can independently subserve all known functions of an organ) led Ekataksin to study and describe the choleohepaton or hepatic microcirculatory subunit (HMS). This structure is even less obvious in surgical pathology material than the lobule or acinus. The HMS is a pyramidal unit with its base at the perimeter of the classic lobule and its apex at the central vein that consists of approximately 19 sinusoids fed by a single inlet venule and drained by a single canal of Hering. The HMS can be highlighted by injection of a fluorescent dye that, after filling up the sinusoids of the pyramidal unit through the inlet venule, accumulates in hepatic plates and then appears a little later as a “chicken wire” pattern of bile canaliculi draining the same area.12,13 Notwithstanding the differing perspectives of the hepatic functional unit in various studies over the course of centuries, a few crucial facts emerge: 1. As with the seven blind men examining an elephant, each study and each concept of hepatic microarchitecture highlights a specific functional, morphologic, or structural aspect of the liver. Rather than being contradictory or exclusive to each other, every concept complements the others and contributes toward a comprehensive whole. 2. The arborization patterns of the hepatic and portal veins relative to each other are fundamentally important in establishing the parenchymal architecture of the liver. Matsumoto’s painstakingly detailed reconstruction of hepatic angioarchitecture demonstrated that the hepatic venous system follows the branching order of the portal system right up to the first-order branches of the distributing portal veins. Thereafter, the first-order branches of the distributing portal veins give rise to eleven second-order branches, whereas the hepatic veins do not follow suit, thus resulting in the positioning of six portal veins around one central vein.8 3. Metabolic zonation is dynamic, and the functional zones are not anatomically rigid or limited by fibrous septa. Their boundaries

Microscopic Anatomy, Basic Terms, and Elemental Lesions

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D Figure 1.2  A, The hexagonal lobule first detailed by Kiernan and shown by dotted lines consists of a polygonal structure with the central vein (CV) at the center and portal tracts (PT) at its corners. The acinus described by Rappaport is centered around the portal venule (PV), a thin-walled, axial vessel that arises from the terminal portal vein in terminal portal tracts. The hepatic parenchyma can be arbitrarily divided into zones 1, 2, and 3 (shown), with zone 1 being closest to the PV and zone 3 being the farthest and centered around the CV. Matsumoto described a primary lobule (detailed further in D) consisting of a sickleshaped zone abutting the PT (dotted area) and a triangular area (horizontal lines). Five to six primary lobules form the secondary lobule, which corresponds to the classic hexagonal lobule. B, The acinar concept organizes hepatic parenchyma into three zones centered around the portal venule (PV). Zone 1 (shown), closest to the PV, receives maximum nutrition and oxygen. Zone 3 (shown) around the central veins (CVs), furthest away from nutrients and oxygen, is most severely affected in conditions of low perfusion. According to the acinar concept, zone 3 is star-shaped (dark areas). PT, portal tract. C, Staining for enzymes expressed in periportal hepatocytes (carbamoyl phosphate synthetase and glucose-6-phosphatase) and for those expressed in perivenular hepatocytes (glutamine synthetase and NADPH–cytochrome c) demonstrates that the perivenular area is discrete and circular (gray), whereas the periportal areas are irregular in outline and roughly star-shaped (black). CV, Central vein; PT, portal tract; PV, portal venule. D, The primary lobule described by Matsumoto is bound by portal venules (PV), which are thin-walled, axial vessels that arise from the terminal portal vein (arrows) in terminal portal tracts. It consists of a sickle-shaped zone (asterisk) made up of transverse sinusoids, which provides an inflow front for blood entering the lobule. The transverse sinusoids drain into radial sinusoids (arrowheads) that empty into the central vein (CV). Five to six primary lobules form the secondary lobule, which corresponds to the classic hexagonal lobule. (Copyright by Rashmil Saxena, BFA, Indiana University School of Medicine.)

shift depending on feeding cycles and functional needs, and are regulated by local nutritional factors, digestive hormones, and oxygen levels. 4. The actual shape of the unit described, irrespective of the one being studied, varies by its physical location within the liver and its relationship to neighboring units. Variations in size and shape have been shown for the hexagonal lobule14 as well as the HMS,13 each of which appears more flattened under the capsule than in the deeper

liver. Teutsch, through three-dimensional reconstruction studies, has demonstrated the modular architecture of the liver units that mold to each other like Lego blocks, thus conforming to the shape of their neighbors and at the periphery, to the overall shape of the organ.14 These observations cast doubt on whether a structurally welldefined functional unit, as embodied by the quintessential nephron in the kidney, exists in the liver. One may safely conclude that the lack 5

Practical Hepatic Pathology: A Diagnostic Approach Box 1.1  Indications for Liver Biopsy Elevation of liver tests Jaundice of unknown cause Ascites and portal hypertension Abnormal tests of iron homeostasis Grading and staging of chronic hepatitis To facilitate therapeutic decisions To evaluate therapeutic efficacy Diagnosis, staging, and grading of fatty liver disease Quantitation of tissue copper or iron Enzyme or metabolite analysis for diagnosis of metabolic diseases Microbiologic cultures for identification of specific infectious agent Diagnosis and characterization of tumors Evaluation of liver allograft following transplantation

centrilobular location (see Fig. 1.4), whereas iron accumulation, which begins in hepatocytes around the portal tracts, indicates a periportal location. The presence of lipofuscin at regular intervals attests to the maintenance of normal architecture and aids in the identification of small or tangentially cut central veins, which may not be otherwise visible on an H&E stain. Trichrome and reticulin stains greatly assist in the assessment of architecture (Table 1.1). Trichrome stain highlights portal tracts and central veins that may not be easily visualized on an H&E stain, either because they have not been sectioned en face or are too small to be easily recognizable (see Fig. 1.4 and eSlide 1.2). Similarly, the trichrome stain highlights portal tracts that lack bile ducts, the absence of which may render portal tracts less prominent. The reticulin stain, a silver impregnation technique that stains collagen III (reticulin) fibers in the Disse space, is most useful for assessing hepatic plate architecture (Fig. 1.5; see also Fig. 1.4B and E) and trabecular thickness, which are seen to advantage with this stain (eSlide 1.3). Thus condensation of reticulin fibers highlights areas of hepatocyte loss, whereas thickened plates highlight areas of regeneration. Markedly thickened plates on a reticulin stain aid in the diagnosis of hepatocellular carcinoma and its distinction from nonmalignant lesions, in which the plates are no more than two or three cells thick. Nodularity on a reticulin stain in the absence of fibrosis indicates nodular regenerative hyperplasia. Patients present with portal hypertension, raising clinical suspicion of cirrhosis; however, bridging fibrosis septa are not seen on trichrome stain. Although reticulin fibers appear black on the silver impregnation stain, collagen I, which constitutes fibrous bands, appears brown (see Fig. 1.5A).

Absence of Portal Tracts

Figure 1.3  In the pig liver, fibrous septa clearly demarcate a polygonal, usually hexagonal, lobule that contains a centrally situated vein (arrows). Masson trichrome stain.

of a morphologically distinct unit is consistent with the lack of a distinct functional unit, the shape of which depends on the metabolic and physiologic function being subserved. The microarchitecture of the liver thus allows for flexibility of function as a hexagon, an acinus, and a portal unit or an enzymatic zone, with each unit being subservient to a precise metabolic function. Therefore, an apparently simple configuration belies a sophisticated microarchitecture that facilitates versatility of function with economy of form. In this, the liver is unique. Furthermore, a modular architecture allows the units to conform to each other, to traversing large portal tracts or hepatic veins, as well as to the overall shape of the organ,14 so that there is no tail or trunk unceremoniously sticking out, as in the analogous elephant alluded to earlier. Finally, it appears that the branching pattern of the hepatic vein relative to that of the portal vein sets the basic framework for the overall microarchitecture.

Assessing Parenchymal Architecture in a Biopsy Liver architecture is best appreciated on low power or scanning magnification. Preservation of normal architecture is indicated by the presence of portal tracts and central veins at regular intervals within the hepatic parenchyma (see Fig. 1.1) (eSlide 1.1). The perivenular areas are further recognized by the presence of hepatic plates that radiate outward from the central veins (Fig. 1.4); hepatic plates appear more compact in the periportal regions. Zonally distributed pigments serve as additional landmarks in the assessment of architecture; thus, lipofuscin, which is present in perivenular hepatocytes, indicates a 6

Long tracts of benign-appearing hepatic parenchyma without regularly appearing portal tracts and central veins raise the suspicion of a hepatocellular adenoma or a well-differentiated hepatocellular carcinoma. Both lesions contain haphazardly distributed arterioles; in addition, hepatocellular adenomas show areas of sinusoidal dilatation and/or hemorrhage (Fig. 1.6 and Table 1.2). High-grade dysplastic nodules and hepatocellular carcinomas that are not well-differentiated also lack portal tracts but are easier to recognize because the hepatocytes do not appear benign, raising suspicion for a dysplastic or malignant lesion. Expanses of hepatic parenchyma that have lost the normal central vein–to–portal tract arrangement but contain irregularly scattered portal tracts may represent a large regenerative nodule in a cirrhotic liver (see Fig. 1.6 and eSlide 1.4). The accompanying clinical information in such cases usually mentions the presence of cirrhosis and a dominant nodule that is being biopsied to rule out a carcinoma. Alternatively, the history may be merely one of cirrhosis, and the needle may have inadvertently sampled a large regenerative nodule. The reticulin pattern in these instances shows irregular thickening of hepatic plates. The presence of portal tracts is thus a reassuring sign of a benign lesion. Sometimes, however, portal tracts may not be easily recognizable even when present; this occurs particularly when the portal tracts lack their most prominent component, the bile ducts. In these instances, portal tracts are highlighted by the trichrome stain. Furthermore, in diseases that cause loss of bile ducts, immunohistochemistry for the biliary keratins K7 and K19 may highlight the presence of duct remnants. In addition, membranous positivity of periportal hepatocytes for K7 (biliary metaplasia of hepatocytes), indicating chronic cholestasis, may be present (see Fig. 1.6).

Fragmentation Fragmentation of a biopsy specimen may result from the procedure itself or reflect the presence of fibrosis (eSlide 1.5); the incidence caused

Microscopic Anatomy, Basic Terms, and Elemental Lesions

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E Figure 1.4  A, In the adult liver, rows of one-cell-thick hepatocytes radiate outward from the central vein (asterisk). Depending on the plane of section, the intervening sinusoids appear as longitudinal or circular spaces, some of which are seen opening into the central vein. Perivenular hepatocytes contain lipofuscin, a light-brown, finely granular pigment (also see eSlide 1.1). B, Reticulin stain shows the hepatic microarchitecture to advantage. The hepatocytes appear more compact near the portal tract (arrow) where the one-cell-thick architecture is not so well-demonstrated (also see eSlide 1.3). C, Trichrome stain highlights the small-caliber central vein (asterisk) (also see eSlide 1.2). D, In infants, variable degrees of hematopoiesis are seen in portal tracts (arrow) and lobules (arrowhead). E, Children younger than 5 years show a two-cell-thick arrangement of hepatocytes (asterisk, central vein).

7

Practical Hepatic Pathology: A Diagnostic Approach Table 1.1  Histochemical Stains in Routine Diagnostic Practice

8

Stain

Diagnostic Use

Trichrome

Staging of fibrosis • Assess stage of disease • Facilitate therapeutic decisions • Assess efficacy of therapy • Compare efficacy of various therapeutic options Highlights the portal tracts and central veins, thus facilitating assessment of architecture

Reticulin

Demonstrates hepatic trabecular architecture Highlights cell loss and necrosis (collapse) Highlights thickened plates, which indicate regeneration Facilitates differentiation of hepatocellular carcinoma from nonmalignant nodules (see Chapter 31)

normally seen in this location; these are not representative of the rest of the liver and give the false impression of fibrosis (Fig. 1.9 and eSlide 1.7).16 Petrelli and Scheuer studied biopsies from the inferior edge of the liver in 72 patients ranging in age from 3 months to 93 years, and they found no variation in the subcapsular and deeper parenchyma in 33 patients. However, in 21 cases, there was crowding of central veins and portal tracts, and slender septa were seen emanating from portal tracts in some of these cases. In the remaining 18 cases, thin septa were seen bridging portal tracts with central veins and isolating islands of parenchyma; these patients ranged in age from 15 to 93 years. A needle biopsy, which often includes deeper tissue, is therefore preferable to a wedge biopsy for estimation of fibrosis.

Portal Tracts

by procedures has decreased significantly with the increasing use of cutting rather than suction biopsy needles. In current practice, procedural fragmentation is most often the result of obtaining biopsies through the transjugular approach. A fragmented biopsy presents unique challenges in interpretation of architecture and estimation of fibrosis. Although fragments with smooth, rounded edges may indicate the presence of fibrous septa and those with straight, frayed edges may point to mechanical fragmentation, these features are not always reliable indicators. A reticulin stain, on the other hand, greatly aids interpretation by facilitating assessment of the hepatic plate architecture, which is abnormal when fragmentation is the result of parenchymal fibrosis (Fig. 1.7 and Table 1.2). The relatively new technique of endoscopic ultrasound–guided transgastric liver biopsies produces specimens that may be markedly fragmented and therefore particularly difficult to assess for fibrosis and stage of disease. These specimens are obtained by highly flexible suction needles rather than cutting needles and often include significant amounts of blood clot15 (Fig 1.8 and eSlide 1.6).

Portal tracts represent cross-sections or tangential sections of a branching system of connective tissue that carries the hepatic arterial and portal venous vessels from the hilum of the liver to the periphery and, in reverse direction, bile ducts from the peripheral hepatic parenchyma to the hilum. As the connective tissue branches and spans outward, the sizes of the portal tracts and their constituent structures decrease, accompanied by a corresponding decrease in the amount of fibrous tissue. The branching tree analogy is relevant to routine diagnostic pathology because it helps explain the variation in size and shape of portal tracts encountered in surgical pathology specimens; this variation reflects the part of the branching tree being sectioned (eg, large versus small tracts, branching points) and the plane of section (cross section versus tangential versus longitudinal). Thus, whereas terminal portal tracts usually have a round or oval profile, larger portal tracts may be triangular or stellate in shape (Fig. 1.10). In addition, the latter contain more fibrous tissue, which should not be mistaken for pathologic fibrosis, an error that can be avoided by correlating the amount of fibrous tissue with the size of the included structures; large portal tracts have large-caliber vessels and may be expected to contain more fibrous tissue. Sectioned at their branching points or cut longitudinally, portal tracts may mimic fibrous septa; this pitfall can be avoided by noting the longitudinal profiles of the portal tract constituents in these “septa” (see Fig. 1.10 and eSlide 1.8). A portal tract contains branches of the hepatic artery and portal vein as well as the tributaries of the bile duct. Although the smallest, terminal portal tracts cut in cross section may show one profile of each as in the classically described portal triad, the number of profiles in larger tracts varies, depending on what the size of the portal tract is, whether they are cut in cross-section or in tangential section, and whether they contain a branching point (see Fig. 1.10). That not all portal tracts are triads was apparent in a study of 16 normal biopsy specimens from adult patients, which found more than one profile of a bile duct or hepatic artery in many portal tracts. Interestingly, there were almost as many portal dyads as portal triads, with most dyads missing a portal vein and a minority that lacked a bile duct or a hepatic artery.17 In addition to the three components mentioned earlier, portal tracts contain lymphatics that collect lymph formed in the Disse space (Fig. 1.11), which flows toward the portal tracts in the direction of bile flow and against that of blood. Portal lymphatics are not discernible on a routine H&E stain but can be highlighted by immunohistochemical stains for markers expressed on lymphatic endothelium such as D2-40 (Fig. 1.12). Portal tracts also contain nerve fibers that can be visualized on an H&E stain in large, but not small, portal tracts, even though the latter possess neural innervation.

Subcapsular Parenchyma

Bile Ducts

The immediate 2 to 3 mm of subcapsular parenchyma is not ideal for evaluation of fibrosis because bridging fibrous septa and nodularity are

The intrahepatic course of the biliary tree consists of 7 to 10 orders of cholangiographically visible bile ducts.18 The smallest bile ducts,

Iron (Prussian blue reaction)

Demonstrates presence, extent, and cellular localization (hepatocytes versus sinusoidal lining cells) of hemosiderin deposition Highlights iron containing macrophages

Periodic acid–Schiff

Demonstrates presence of storage cells in Gaucher disease and NiemannPick disease Demonstrates single or clusters of macrophages as markers of previous hepatocellular damage Demonstrates presence of alpha-1 antitrypsin globules

Rhodamine

Demonstrates copper deposition in Wilson disease and chronic biliary diseases

Orcein

Demonstrates presence of hepatitis B surface antigen Demonstrates copper deposition in Wilson disease and chronic biliary diseases Demonstrates presence of elastic fibers

Victoria blue

Demonstrates presence of hepatitis B surface antigen Demonstrates copper deposition in Wilson disease and chronic biliary diseases Demonstrates presence of elastic fibers

Sirius red

Enhances natural birefringence of collagen under polarized light; useful for digitized morphometric analysis of fibrosis

Aniline blue

Exclusively stains collagen for digitized morphometric analysis of fibrosis

Oil red O

Demonstrates presence of fat in nonfixed tissue

Microscopic Anatomy, Basic Terms, and Elemental Lesions

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D Figure 1.5  Reticulin stain in diagnostic pathology. A, Reticulin fibers (collagen III) in lobules stain black (arrows), and collagen fibers within portal tracts (collagen I) stain brown (arrowheads) with a Gomori reticulin stain. B, Loss of hepatocytes appears as condensation of reticulin fibers (arrows), also known as collapse. C, Areas of regeneration are seen as thickening of liver trabeculae on a reticulin stain. D, Hepatocellular carcinoma with markedly thickened trabeculae and few reticulin fibers, sometimes referred to as the “retic-poor” pattern.

the interlobular bile ducts, which measure less than 100 μm in diameter, are not visualized radiographically. They are lined by cuboidal cholangiocytes, which rest on a delicate basement membrane and contain central, round, evenly spaced nuclei (Fig. 1.13). Interlobular bile ducts drain bile produced by hepatocytes, which reaches them through an intralobular network of bile canaliculi which drain into the canals of Hering that in turn drain into bile ductules (discussed later). Interlobular bile ducts drain into septal ducts, which measure more than 100 μm in diameter, and, which in turn, drain into segmental ducts, which measure 400 to 800 μm in diameter. Cholangiocytes lining the larger bile ducts are columnar, with basally situated round-to-oval nuclei that appear even and regularly spaced. Increasing duct size is accompanied by thicker walls, which correspond histologically to increasing amounts of fibrous tissue (Fig. 1.14). When sampled in a biopsy, this robust collar of fibrous tissue around medium and large bile ducts may be mistaken for the “onion skinning” seen in sclerosing cholangitis. This pitfall can be avoided by noting the large size of the ducts and lack of accompanying epithelial damage or basement membrane thickening that invariably

precedes advanced fibrosis in sclerosing cholangitis. In addition, in the early stages of primary sclerosing cholangitis, the concentric onionskinning fibrosis is accompanied by edema and mild inflammatory infiltrate (see Fig. 1.14). The large ducts at the hilum are associated with peribiliary glands and, less commonly, with exocrine pancreatic tissue, which may be sampled on biopsy material. Biliary epithelium marks immunohistochemically for keratins K7 and K19.

Hepatic Arteries Hepatic artery branches accompany bile ducts in almost all (96%) portal tracts and approximate the bile ducts in size (see Fig. 1.10A and D); the ratio of bile duct size to hepatic artery size is approximately 0.8. This close association between artery and duct reflects the crucial and almost exclusive role of the hepatic artery in perfusion of the biliary tree. Hepatic arterial branches form a rich peribiliary vascular plexus consisting of an inner and outer layer around the large ducts, reducing to a single layer as the ducts decrease in size. The smallest tributaries of the biliary tree are supplied by a few capillaries wrapping around and lying in grooves on the surface of the bile duct. 9

Practical Hepatic Pathology: A Diagnostic Approach

B

A

C Figure 1.6  Long tracts of benign-appearing hepatocytes without regularly occurring portal tracts seen in hepatocellular adenoma (A), which contain scattered arterioles (arrows and inset) that are not accompanied by paired bile ducts (“unpaired arterioles”) and a large regenerative nodule in cirrhosis (B). C, Immunohistochemical stain for K7 helps localize a portal tract lacking a bile duct (arrows) and demonstrates biliary metaplasia of periportal hepatocytes (single arrowhead) and a biliary rosette (between two arrowheads), indicative of chronic cholestasis. Table 1.2  Assessment of Architecture on Liver Biopsy Long Tracts of Benign Parenchyma Without Regularly Occurring Portal Tracts Hepatocellular adenoma

Contains scattered arterioles; areas of sinusoidal dilatation; reticulin stain shows trabeculae that are two or three cells thick

Large regenerative nodule

May contain irregularly distributed portal tracts (also see eSlide 1.4)

Loss of bile ducts, making portal tracts difficult to recognize

Trichrome stain highlights portal tracts; immunohistochemistry for K7 may show duct remnants or membranous staining of periportal hepatocytes

Fragmentation of Biopsy Material Related to procedure

Normal reticulin pattern (also see eSlide 1.5A–C)

Caused by parenchymal fibrosis

Abnormal reticulin pattern showing irregularly distributed thickened trabeculae and nodularity (also see eSlide 1.5D–F)

Subcapsular Tissue May show fibrous septa and nodularity

Do not assess fibrosis on subcapsular tissue because it may not be representative of deeper parenchyma

Overdiagnosis of Fibrosis

10

Large portal tracts

Contain large branches and tributaries of portal vein, hepatic artery, and bile duct

Branching portal tracts

Portal tract constituents run parallel to branching portal tract

Longitudinally cut portal tracts

Portal tract constituents run parallel to direction of portal tract (also see eSlide 1.8)

Areas of confluent necrosis

Reticulin stain shows collapse (also see eSlide 1.14)

Microscopic Anatomy, Basic Terms, and Elemental Lesions

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D Figure 1.7  Fragmentation of a liver biopsy specimen may be either because of procedure (A) or presence of fibrosis in the liver parenchyma (B). Masson trichrome stain. Although fibrosis is seen in B with the Masson trichrome stain, the distinction is best made on a Gomori reticulin stain, which shows normal (C) versus abnormal (D) trabecular architecture (also see eSlide 1.5).

Because the majority of hepatic arteries are accompanied by bile ducts, the finding of hepatic arteries unaccompanied by bile ducts in portal tracts (“isolated” or “unpaired” hepatic arteries) should raise suspicion of diseases characterized by bile duct loss (see Chapter 28). Bile ducts may appear appreciably smaller than their accompanying arteries because of epithelial atrophy preceding eventual loss. Although there is some thickening of hepatic arterioles with age19 and with hypertension,20 these changes are not as marked or as frequent as elsewhere in the body. Hepatic arteries are often involved in systemic amyloidosis, in which they are thickened by the deposition of amorphous eosinophilic material characteristic of amyloid.

Portal Veins The intrahepatic portal venous system consists of two functionally distinct parts: the conducting system and the distributing system. As the names suggest, the former carries or conducts blood to the far reaches of the hepatic parenchyma, whereas the latter ensures even distribution of blood to individual hepatocytes through the vast sinusoidal network. The most terminal branch of the distributing system (portal venule) corresponds to the vessel around which the acinus described by Rappaport is organized and to the “vascular septum” described by Matsumoto. This vessel, which completely lacks connective tissue and has a sinusoidal appearance, is not discernible on a routine H&E stain. Portal veins are the largest structures in the portal tracts, with wide lumina lined by a single layer of flattened endothelial cells (see

Fig. 1.10A and D). The larger branches have thin walls consisting of a narrow rim of fibrous connective tissue, whereas the smaller ones are lined by a single layer of endothelial cells. Portal veins may be absent or obliterated (obliterative portal venopathy), giving rise to noncirrhotic portal hypertension; the extrahepatic portal vein is not infrequently thrombosed in cirrhotic patients. Phlebitis of the portal veins is a common manifestation of immunoglobulin G4 (IgG4) disease.

Hepatic Veins Three main hepatic veins and several smaller veins drain the liver. The latter are surgically significant because they may be of considerable size. The right hepatic vein drains the right lobe of the liver, and after a short extrahepatic course, empties into the anterior surface of the inferior vena cava. The middle hepatic vein drains the middle portion of the left lobe and a variable portion of the right lobe, whereas the left hepatic vein drains the left lobe; these veins often join together after a short extrahepatic course to form a common venous channel that drains into the anterior aspect of the inferior vena cava. Less frequently, they may drain separately into the inferior vena cava. The caudate lobe drains directly into the inferior vena cava, occasionally into its posterior aspect. The central veins, the smallest tributaries of the hepatic venous system, appear as round-to-oval thin-walled channels lined by a single layer of flattened endothelial cells that may hardly be discernible on an H&E stain (see Fig. 1.4). Rows of hepatocytes radiating outward 11

Practical Hepatic Pathology: A Diagnostic Approach

A

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D

Figure 1.8  Representative examples of transgastric liver biopsies obtained under real-time endosonographic guidance by highly flexible suction needles. The specimens are fragmented and contain variable amounts of tissue cores (arrows) and blood clot (arrowheads). A contains scant blood clot, whereas C contains numerous cores of blood clot. The latter, however, also contains a tissue core of sizable length (arrow).

a trichrome stain (Fig. 1.15). The hepatic venules are obliterated in sinusoidal obstruction syndrome/veno-occlusive diseases and, along with the sinusoids, may be dilated in conditions causing obstruction to venous outflow such as congestive cardiac failure or Budd-Chiari syndrome. Perivenular fibrosis is a common feature of alcoholic and nonalcoholic steatohepatitis.

Lobular Parenchyma Hepatocytes

Figure 1.9  Subcapsular parenchyma showing bridging fibrous septa and nodules that are not representative of the rest of the liver, thus giving a false impression of bridging fibrosis and cirrhosis. Masson trichrome stain (also see eSlide 1.7).

and the presence of intracellular lipofuscin in perivenular hepatocytes facilitate identification of the central veins. Depending on the plane of section, sinusoids may be seen opening into the central veins. Larger tributaries such as the sublobular veins are often invested by an easily visible wall of fibrous tissue, which can be further highlighted with 12

The lobular parenchyma is made up of rows of hepatocytes separated by sinusoids, both of which radiate outward from the central vein toward the portal tracts. The hepatic plates are one cell thick in adults and two to three cells thick in children 5 years of age or younger21 (Box 1.2); the one-cell-thick arrangement is more obvious in the perivenular regions but less so in the periportal regions where the plates appear more compact (see Fig. 1.4B). Hepatocytes are large polygonal cells, approximately 25 μm in size that contain abundant, finely granular, eosinophilic cytoplasm, with centrally placed, round nuclei containing one or two prominent nucleoli. Binucleated cells are not uncommon, a feature that increases with age along with nuclear enlargement and pleomorphism22,23 (Fig. 1.16). The nuclear size correlates with nuclear ploidy. Binucleation, nuclear enlargement, and pleomorphism also occur after treatment with methotrexate, a drug that interrupts the mitotic spindle and the nuclear replicative process. Glycogenated nuclei, which appear optically clear on H&E stain are seen in adolescents and young adults in periportal

Microscopic Anatomy, Basic Terms, and Elemental Lesions

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F Figure 1.10  The shape and size of portal tracts depends on the point at which they have been sectioned and the plane of section. A, Small portal tracts, as seen in this image, are either round or oval in shape. Hepatic arteries (arrow) accompany bile ducts (arrowhead) and approximate them in size. Portal veins (asterisk) appear as thin-walled structures with wide lumina (also see eSlide 1.1). B, Large portal tracts, in contrast, may show irregular shapes and sizes, especially when cut at their branching points as in this image. C, A branching portal tract sampled in a biopsy; this does not represent bridging fibrosis. Both large and branching portal tracts may contain more than one profile of the portal vein, hepatic artery, or bile duct. D, A large, longitudinally cut portal tract spans the entire width of the biopsy. It contains correspondingly large constituents and is not a bridging fibrous septum (also see eSlide 1.8). As in part A, a hepatic artery (arrow) accompanies a bile duct (arrowhead) of approximately equal size. The portal vein (asterisk) appears as a thin-walled structure with a wide lumen. E, A portal tract is seen spanning the entire width of the biopsy from a patient with chronic hepatitis C. F, On higher magnification the portal vein (arrows) and bile ducts (arrowheads) show a longitudinal profile, indicating this is a longitudinally cut portal tract rather than a fibrous septum.

13

Practical Hepatic Pathology: A Diagnostic Approach

H

H

DS S RBC KC DS

SC L SC KC

H

Figure 1.12  Immunohistochemical stain with D2-40 antibody demonstrates lymphatics in larger portal tracts. These are not visible on an H&E stain.

A Sinusoidal lumen SEC

KC

DS

L

SC BC

TJ L

B Figure 1.11  A, Disse space (DS) is not visible on an H&E stain but can be seen on electron microscopy as a narrow space lying between sinusoids (S) on one side and hepatocytes (H) on the other. It contains microvilli arising from the sinusoidal domain of the hepatocellular membrane. Stellate cells (SC) reside in the DS, whereas Kupffer cells (KC) lie in sinusoids, in which red blood cells (RBC) can also be seen. KC possess highly ruffled membranes. Stellate cells store lipids (L). B, Schematic representation of hepatic microarchitecture. The hepatocyte is a polarized cell whose sinusoidal domain contains microvilli and faces the DS. The canalicular domain forms the bile canaliculus (BC), whereas the lateral domain (L) lies between the sinusoidal and canalicular domains. The bile canaliculus is sealed by tight junctions (TJ) to prevent efflux of bile. The sinusoids are lined by fenestrated endothelial cells (SEC); the size of the fenestrations regulates passage of macromolecules from the blood into the Disse space. Stellate cells (SC) lie in the DS and KC in the sinusoids. (A, Courtesy Michael Goheen, MS, Department of Pathology, Indiana University School of Medicine. B, Copyright by Rashmil Saxena, BFA, Indiana University School of Medicine.)

hepatocytes24 (see Fig. 1.13). Glycogenated nuclei are also numerous in diabetes and Wilson disease at any age. Scattered hepatocyte apoptosis and mitosis reflecting normal cell turnover are usually present in otherwise normal biopsies; rare foci of inflammation and necrosis (spotty necrosis, described later) may also be apparent. The cytoplasm of hepatocytes contains abundant glycogen that stains intensely with periodic acid–Schiff stain; the staining is lost after digestion of glycogen with diastase (Fig. 1.17). The amount of glycogen varies with relation to feeding cycles and type of diet. Hepatocytes also contain lipofuscin, a finely granular, brown pigment that accumulates around nuclei of perivenular hepatocytes (see Figs. 1.4A and 1.16). Lipofuscin represents oxidized lipids derived from cellular wear and tear, and it is 14

Figure 1.13  A small bile duct (arrowhead) lined by cuboidal cholangiocytes, which contain uniform evenly spaced nuclei. Glycogenated nuclei are seen in periportal hepatocytes (arrows).

sequestered in secondary lysosomes. This pigment is weakly periodic acid–Schiff positive and resistant to digestion by diastase; it is negative for iron with the Prussian blue reaction. Because it is a wear-and-tear pigment, the amount of lipofuscin increases with age (see Fig. 1.16). Hemosiderin, the other brown pigment, is not present in the normal liver but accumulates in hepatocytes and/or Kupffer cells in various pathologic processes. In contrast to lipofuscin, hepatocellular accumulation of hemosiderin begins in periportal hepatocytes. Hemosiderin appears as coarse, highly refractile, golden brown granules on an H&E stain and as dark blue granules on a Perls stain (Fig. 1.18A and B). Similar to hemosiderin, bile does not accumulate in the physiologically normal liver but accumulates in various compartments (canaliculi, hepatocytes, Kupffer cells) in cholestatic diseases. Bile appears as a green, nongranular pigment on H&E stain, which can be seen to advantage in a Perls stain for iron (see Fig. 1.18C and D). Bile stains a dark green with the Hall stain, but this stain is hardly necessary in routine practice. Copper may be visible in an H&E stain as orange granules. However, the visualization of these granules in the otherwise eosinophilic cytoplasm of hepatocytes is challenging; copper

Microscopic Anatomy, Basic Terms, and Elemental Lesions

1

A

B

C

D Figure 1.14  A large bile duct lined by columnar cholangiocytes (A) with a robust collar of fibrous tissue that is highlighted by the trichrome stain (B). In contrast to the normal fibrous tissue seen in A and B, the concentric fibrosis (“onion skinning”) of sclerosing cholangitis is characterized by a combination of edema, inflammatory cells, and fibrosis (C) and is accompanied by epithelial damage manifested as nuclear hyperchromasia, irregularity, overlapping, and pleomorphism (D).

and copper-associated protein are best visualized by rhodamine and the orcein or Victoria blue stains, respectively (see Fig. 1.18E and F). The cytoplasm of hepatocytes stains immunohistochemically for hepatocyte paraffin 1 (HepPar1) (which marks the cytoplasmic urea cycle enzyme, carbamoyl phosphate synthetase-1)25 and cytokeratins K8 and K18. The canalicular membrane marks for proteins present on this membrane domain as discussed in the next section. Membranous staining of hepatocytes for K7 occurs in chronic cholestasis (see Fig. 1.6C) and is sometimes referred to as biliary metaplasia of hepatocytes.

Intralobular Biliary Channels Bile canaliculi are tiny, 1- to 2-μm wide tissue spaces formed by the apical membranes of adjacent hepatocytes. They form a delicate intralobular network of channels that drain bile produced by hepatocytes. Bile canaliculi cannot normally be visualized on H&E stain unless distended by bile or contrasted by pale cytoplasmic staining of hepatocytes, which brings into view the darker-staining canalicular pole (Fig. 1.19A and B) caused presumably by the pericanalicular web of filaments and junctional complexes. Bile canaliculi can also be effectively highlighted by immunohistochemical stains for antigens expressed on the canalicular membrane of hepatocytes. These include polyclonal carcinoembryonic antigen and

CD10, which reveal a delicate framework of linear and branching structures weaving between hepatocytes, creating the so-called canalicular pattern of staining (see Fig. 1.19C and eSlide 1.9). Although these stains have limited utility in non-neoplastic liver diseases, they are invaluable in establishing the hepatocellular lineage of tumors; a canalicular pattern of staining demonstrates bile canalicular and, therefore, hepatocellular differentiation. The canalicular membrane of hepatocytes is also host to a large number of molecules that transport or translocate bile constituents across the membrane (see Fig. 29A.1). Mutations leading to absence or functional impairment of these molecules cause various inherited disorders of cholestasis. At the outer third of the lobule, bile canaliculi drain into the canals of Hering, which are lined on one side by hepatocytes and on the other by cholangiocytes. The canals of Hering may be seen on an H&E stain as small groups or strings of cuboidal cells in the periportal regions, but they are not always visible. However, they are highlighted by immunohistochemical stains for the biliary keratins K7 and K19. The canals of Hering serve as “troughs” for collecting parenchymal bile and conveying it to the interface of the portal tracts; here, they drain into bile ductules, which are larger channels with a circumferential lining of cholangiocytes that, in turn, drain into interlobular bile ducts26 (see Fig. 1.19D and E; eSlide 1.10). 15

Practical Hepatic Pathology: A Diagnostic Approach

A Figure 1.15  A sublobular vein containing discernible fibrous tissue has been sampled in this liver biopsy. Masson trichrome stain. Box 1.2  Age-Related Changes in the Liver Younger Individuals Two-cell-thick trabeculae Extramedullary hemopoiesis Glycogenated nuclei Older Individuals Binucleation, multinucleation, and nuclear polyploidy Increase in lipofuscin in perivenular hepatocytes Collagenized portal tracts

B

*

Figure 1.17  A, Hepatocytes contain an abundant amount of glycogen, which stains an intense magenta color with the periodic acid–Schiff stain. B, The staining is lost after digestion with diastase. Portal tracts (arrows) appear as nonstaining areas.

Sinusoids

Figure 1.16  Liver biopsy sample from an older individual showing nuclear pleomorphism, binucleation, and multinucleation. There is abundant lipofuscin in perivenular hepatocytes around the central vein (asterisk).

The canals of Hering, representing the de facto hepatobiliary interface, are thought to contain the proliferative cellular compartment of the liver27 and may be responsible for the ductular reaction seen in chronic biliary diseases. As the most proximal part of the biliary system with a cholangiocytic component, the canals of Hering are targets of the autoimmune process that primarily attacks and destroys small bile ducts in primary biliary cholangitis28 and of hepatic drug toxicity caused by methotrexate.29 16

Sinusoids are low-pressure vascular channels, 4 to 15 μm in diameter, which lie between rows of hepatocytes, providing these cells with a large interface for exchange of materials with the incoming blood (see Figs. 1.4 and 1.11). Sinusoids appear as slitlike spaces when cut longitudinally and circular when cut in cross-section. Sinusoids usually appear empty or may contain few red blood cells or a sprinkling of inflammatory cells. Rarely, a megakaryocyte may be seen (Fig. 1.20), and as in the lung, this finding is considered normal and nonspecific. However, extensive hemopoiesis is present in infant livers in the portal tracts as well as the lobules (see Fig. 1.4D). Sinusoidal lymphocytosis (see later) occurs in infectious mononucleosis and hepatitis C. Malignancies may involve the liver in a predominantly sinusoidal pattern of infiltration, most frequently with leukemia and rarely with other malignant tumors such as small cell carcinoma. Sinusoidal dilatation and congestion occur in the perivenular region in any condition that impedes venous outflow such as occurs with sinusoidal obstruction syndrome/veno-occlusive disease, Budd-Chiari syndrome, or increased right ventricular pressure. Sinusoids are lined by specialized endothelial cells and contain Kupffer cells. Collectively termed sinusoidal lining cells, these two cell types possess distinctive ultrastructural characteristics but cannot be reliably

Microscopic Anatomy, Basic Terms, and Elemental Lesions

1

A

B

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D

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F Figure 1.18  Hemosiderin deposition in periportal hepatocytes in a patient with genetic hemochromatosis who was homozygous for the C282Y mutation. It appears as dark brown, intensely refractile granules on an H&E stain (A) and as dark blue granules along the canalicular pole of hepatocytes on a Perls iron stain (B). C, Bile appears as a nongranular, dark green pigment, which may accumulate within hepatocytes or in canaliculi (arrows). D, Bile is seen to advantage in the Perls stain for iron (arrows). E, In chronic cholestatic diseases, copper deposition may be seen as orange granules in periportal hepatocytes (arrows) and can be highlighted by the rhodamine stain (F).

17

Practical Hepatic Pathology: A Diagnostic Approach

A

B

C

D Bile ductule Bile canaliculi

Canal of Hering

E

Terminal bile duct

Terminal hepatic venule

Figure 1.19  Bile canaliculi are rarely visualized on an H&E stain unless they stand out (arrows) against pale staining of hepatic cytoplasm (A) or are distended (arrows) by inspissated bile (B). C, They are highlighted by an immunohistochemical stain for CD10, which shows a characteristic canalicular pattern (also see eSlide 1.9). D, Immunohistochemical stain for keratin K7 showing the terminal bile duct (long arrows), bile ductules with a circumferential lining of cholangiocytes lying at the edges of the portal tract (arrowheads) and canals of Hering (short arrows), which appear as single, isolated cells in the lobules (also see eSlide 1.10). E, Schematic representation showing a terminal bile duct with several draining bile ductules. The bile ductules lie at the edges of portal tracts and connect to the trough-like canals of Hering, which lie in the outer third of the lobule and collect bile from bile canaliculi draining hepatocytes within the lobules. (E, Copyright by Rashmil Saxena, BFA, Indiana University School of Medicine.)

distinguished from each other on H&E stain, in which they appear as slender cells with elongated nuclei and nonvisible cytoplasm. Kupffer cells appear prominent when they store or scavenge material such as excess iron, products of cellular breakdown, or products of abnormal metabolism as seen in Gaucher disease or Niemann-Pick disease (see eSlides 7.6 and 7.7). 18

Kupffer cells also appear prominent during episodes of hepatitis, during which they phagocytose cellular debris. Clusters of these cells containing pigment may provide the only evidence of a resolving hepatitis and are visualized to advantage on a periodic acid–Schiff stain after diastase digestion (Fig. 1.21 and eSlide 1.11). Kupffer cells are also prominent in

Microscopic Anatomy, Basic Terms, and Elemental Lesions

1

Figure 1.20  An occasional megakaryocyte (arrow) may be seen in liver biopsies and constitutes a normal finding.

Figure 1.21  Clusters of pigment-laden macrophages, representing ingested cellular debris, provided the only clue to resolving hepatitis in this patient with an otherwise normal biopsy and history of elevated liver tests. Periodic acid–Schiff stain with diastase digestion (also see eSlide 1.11).

Figure 1.22  Immunohistochemical stain for CD34 stains blood vessels within portal tracts and rare endothelial cells in the immediate periportal region (arrows). The endothelial cells lining the sinusoids do not stain with CD34.

A

hemophagocytic lymphohistiocytosis syndrome in which they may contain remnants of red or white blood cells (eSlide 1.12). Unlike vascular endothelium elsewhere in the body, sinusoidal endothelial cells do not express CD34 (Fig. 1.22) or factor VIII–related antigen, and they do not bind the lectin from Ulex europaeus. However, in chronic liver disease, the cells undergo a phenotypic shift to regular vascular endothelium as demonstrated by expression of factor VIII–related antigen, CD34, and binding of U. europaeus; this change is termed capillarization of sinusoids.

Disse Space The Disse space lies between hepatocytes and the sinusoids and is also referred to as the perisinusoidal space. The Disse space cannot be visualized on an H&E slide from a normal liver but is visible as a narrow tissue space in electron micrographs (see Fig. 1.11). The Disse space contains stellate cells, also called Ito cells or lipocytes; these cells contain lipids and are involved in vitamin A metabolism. They are not normally visible on H&E section but can be visualized on methylene blue–stained 1-μm thin sections for electron

B Figure 1.23  A, Stellate cells (arrow) are not easily seen on an H&E stain but can be visualized on a 1-μm section prepared for electron microscopic examination and stained with methylene blue. Stellate cells contain lipid droplets, whereas sinusoidal lining cells (arrowhead) do not. B, Immunohistochemical stain for smooth muscle actin demonstrates positivity along the sinusoids, indicating activation of stellate cells. 19

Practical Hepatic Pathology: A Diagnostic Approach microscopy (Fig. 1.23). Stellate cells play a leading role in fibrogenesis; they are activated in various disease states when they acquire characteristics of myofibroblasts, becoming contractile, marking with smooth muscle antigen, and producing collagen (see Fig. 1.23). The Disse space also contains reticulin fibers (collagen III), which are best visualized by silver impregnation stains such as the Gomori stain.

Electron Microscopy Hepatocytes

Hepatocytes appear as irregular polyhedral cells containing a roughly spherical nucleus that constitutes 5% to 10% of cell volume and contains one or more prominent nucleoli. Hepatocytes range in size from 20 to 30 μm; the size being influenced by a number of factors such as regenerative activity and metabolic state. For instance, influx of solutes such as amino acids or glucose causes transmembrane movement of water into the cells, increasing their volume by 5% to 10%. Hepatocytes possess three specialized membrane domains (see Fig. 1.11B). The basolateral or sinusoidal domain faces the sinusoids and constitutes 70% of the cell surface. It is also referred to as the vascular pole of the hepatocyte. The sinusoidal membrane contains microvilli (Fig. 1.24A; see also Fig. 1.11), which traverse the Disse space to protrude into the sinusoids through fenestrations in the lining endothelial cells. The lateral membrane of the cell is made up of two domains: the canalicular domain and the lateral domain. The canalicular domain, along with the canicular domain of the adjoining hepatocyte, makes up the bile canaliculus and is also called the biliary or apical pole of the hepatocyte. The lateral domain is the part of the lateral membrane that does not make up the biliary canaliculus. It extends from the edge of the canalicular domain to the edge of the sinusoidal domain. The canalicular and lateral domains each constitute 15% of the total cell surface. The bile canaliculus (see Fig. 1.24B), carved out of the surface of adjacent hepatocytes, is bound laterally by junctional complexes that include tight junctions, gap junctions, and desmosomes. Tight junctions constitute the barrier between the canaliculus and the rest of the intercellular space, preventing passage of bile out of the biliary canaliculus. The bile canaliculus is lined by microvilli. The cytoplasm of the hepatocyte immediately underneath the canaliculus is rich in microfilaments that form a pericanalicular web, which imparts contractility to the canaliculus and influences its caliber, thus regulating bile flow. Being one of the most metabolically active cells in the body, the hepatocyte is rich in organelles, the most abundant of which are the endoplasmic reticulum, mitochondria, peroxisomes, and lysosomes (see Fig. 1.24). As in all cells, the endoplasmic reticulum of hepatocytes is involved in translation and post-translational modification of proteins. The cytochrome P450 enzyme system is localized in the endoplasmic reticulum. Hypertrophy of the smooth endoplasmic reticulum is manifested histologically as a ground-glass appearance of the cytoplasm (described later), as seen in chronic hepatitis B infection. Endoplasmic reticulum is also the site of storage of abnormal protein in alpha-1 antitrypsin deficiency, which appears as fibrillar material within dilated cisterna of the endoplasmic reticulum (see Fig. 9.9). Hepatocytes are rich in mitochondria, which are estimated to number approximately 1000 per cell; structural abnormalities of mitochondria may be seen in energy-depletion states or diseases of mitochondrial enzymes. Typical findings are also seen in Wilson disease, when the mitochondria appear markedly swollen and show prominent crystalline inclusions. An individual hepatocyte contains 300 to 600 peroxisomes, which appear as small, ovoid, membrane-bound granules measuring 0.2 to 1 μm in diameter. Peroxisomes contain oxidases and catalases, which oxidize a number of substrates and produce energy that is dissipated as heat. Alcohol is metabolized in the liver by peroxisomal catalase. 20

Absence of peroxisomes or deficiency of peroxisomal enzymes results in diseases such as Zellweger syndrome. Primary lysosomes are single-membrane-bound vesicles (see Fig. 1.24C) that contain enzymes, serving to store and sequester them from the cytoplasm. Secondary lysosomes are formed by fusion of primary lysosomes with other membrane-bound vesicles containing endogenous or exogenous material destined for degradation (autophagic vesicles). Secondary lysosomes are highly pleomorphic, vary in size and number, and contain a variety of materials, including lipofuscin, ferritin in iron overload states, and copper in Wilson disease. Hepatocytes also contain coated endocytic vesicles or endosomes, which result from internalization and endocytosis of receptor-ligand complexes.

Sinusoidal Lining Cells Unlike endothelial cells elsewhere in the body, those lining the sinusoids do not have a basement membrane and do not form intercellular junctions but simply overlap each other. They contain fenestrations, which are larger near the portal tracts than near the central veins. Passage of material from the sinusoids into the Disse space is controlled by the size of these fenestrae, which is itself regulated by a variety of endogenous and exogenous mediators. Endothelial cells possess marked endocytotic activity, targeted at the uptake and lysosomal degradation of a variety of compounds. They also possess “scavenger receptors” that mediate uptake of various substances destined for degradation through binding of the Fc portion of immunoglobulins. Kupffer cells lie in gaps between endothelial cells. Members of the macrophage-monocyte system, they represent fixed macrophages of the liver and constitute the largest population of macrophages anywhere in the body. Kupffer cells are more numerous in periportal areas but can migrate along the sinusoids, both in and against the direction of blood flow. They are large cells with a highly ruffled membrane (see Fig. 1.11), microvilli on the sinusoidal surface, and processes extending into the perisinusoidal space. Kupffer cells contain numerous lysosomes, phagosomes, and peroxisomes; these cells bear receptors for the complement and Fc portion of immunoglobulins, which facilitate phagocytosis of an extensive array of substances. They bear major histocompatibility complex class II antigens but are not as efficient at antigen presentation as macrophages. Kupffer cells play a leading role in clearing endotoxin from blood.

Disse Space The perisinusoidal Disse space is best seen on electron micrographs, where it appears as a narrow space between sinusoidal lining cells and hepatocytes (see Fig. 1.11). It extends between the lateral walls of adjacent hepatocytes closely approaching the bile canaliculi where it is separated by a narrow gap (zone of minimal distance). This gap along with the junctional complexes of the bile canaliculi forms the barrier between plasma and bile, and it is a possible site of regurgitation of bile into plasma in disease states. Neither hepatocytes nor sinusoidal endothelial cells possess basement membranes; therefore the Disse space is not a membrane-bound space. Transfer of substances from blood passing through the sinusoids into the Disse space is thus regulated by the size of fenestrations in endothelial cells. Once in the Disse space, molecules have access to the hepatocyte membrane, which controls passage to and from the cell. Lymph is formed in the Disse space and flows toward portal tracts to drain into portal lymphatics. Stellate cells reside in the Disse space (see Figs. 1.11 and 1.23) and can be recognized by the presence of prominent lipid droplets. They number 5 to 20 per 100 hepatocytes. The Disse space also contains the so-called pit cells, which represent the natural killer cells of the liver (ie, they are not major histocompatibility complex restricted and do not require activation for killing). They derive from circulating large

Microscopic Anatomy, Basic Terms, and Elemental Lesions

RER

G

1

SER H H

M

GC

GC MV P

B

A SER

SER

G G

GC

C

D Figure 1.24  A, The hepatocyte is a large cell with numerous organelles, including abundant smooth endoplasmic reticulum (SER), rough endoplasmic reticulum (RER), as well as numerous mitochondria (M) and peroxisomes (P). The small dark granules represent the equally abundant cytoplasmic glycogen (G). The sinusoidal domain of hepatocytes contains microvilli (MV). B, The canalicular domains of adjacent hepatocytes (H) form the bile canaliculus (arrows), which contains microvilli. The bile canaliculus is separated from adjacent tissue spaces by tight junctions (arrowheads). The Golgi complex (GC) appears as flattened stacked cisternae adjacent to the bile canaliculus. C, Mitochondria (arrow) are distinguished from peroxisomes (arrowhead) by the presence of cristae and crystalline inclusions, which are absent in peroxisomes. In addition, the matrix of peroxisomes appears slightly flocculent. Hepatocytes contain abundant dark granules of glycogen (G), which is seen intermingled with SER. D, Stacked, flattened cisternae of the GC and single membrane-bound vesicles representing Golgi vesicles (arrowheads); those sequestering enzymes are termed primary lysosomes. Numerous granules of glycogen (G) are also seen. (Courtesy Michael Goheen, MS, Department of Pathology, Indiana University School of Medicine.)

21

Practical Hepatic Pathology: A Diagnostic Approach granular cells and like the latter, possess small azurophilic granules, rod-cored vesicles, and natural killer activity.

Utility of Electron Microscopy in Routine Diagnostic Practice The utility of electron microscopy in routine diagnostic pathology is limited because of the availability of reliable serologic and biochemical tests for diagnosis of most common diseases as well as by the availability of sensitive and specific antibodies for immunohistochemical staining of frozen and paraffin embedded tissue (Box 1.3). Currently, electron microscopic examination is most often used in the hope of “finding something” in suspected storage diseases or viral infections that may have eluded detection by more standard modalities. Prominent exceptions to this statement include the diagnosis of Byler disease, which is often clinched by the characteristic electron microscopic appearance of inspissated intracanalicular bile (see Fig. 29B.8); the diagnosis of phospholipidosis, which is based on the presence of characteristic myelin figures on electron microscopy; and the diagnosis of Reyes syndrome, in which electron microscopy reveals distinctive mitochondrial changes and fat globules not always visible on H&E stain. Only a tiny amount of tissue can be examined at any given time by electron microscopy. Therefore, the field to be studied should be carefully chosen on methylene blue–stained thin sections.

Basic Terms and Elemental Lesions Structural

• Liver segments: organization of the liver into anatomically independent segments, each with its own independent vascular supply as well as biliary and venous drainage. This anatomic arrangement facilitates limited segmental resections of the liver (Fig. 1.25). • Centrilobular, perivenular: around the central veins. • Periportal: around the portal tracts. • Zones: refers to the zones of the vascular acinus as described by Rappaport (see Fig. 1.2). Lesions occurring around the central vein are said to involve zone 3 and those around portal tracts involve zone 1. Zone 2 lies between zones 1 and 3. • Limiting plate: row of hepatocytes that borders the portal tract. • Disse space: tissue space between hepatocytes on one side and sinusoidal endothelial cells on the other. Liver-specific natural killer cells (pit cells) and stellate cells reside in the Disse space (see Fig. 1.11).

• Canals of Hering: biliary channels that connect bile canaliculi to bile ductules; present in the outer third of the lobule and lined by cholangiocytes on one side and hepatocytes on the other. They cannot be visualized on H&E stain but are highlighted by biliary keratins K7 and K19 (see Fig. 1.19D and E). • Bile ductule: biliary channel with a circumferential lining of cholangiocytes that connects canals of Hering to interlobular bile ducts and lies at the edge of portal tracts (see Fig. 1.19D and E). It is prominent in conditions, causing obstruction of bile flow. It is also referred to as a cholangiole. • Pit cells: natural killer cells of the liver that are derived from circulating large granular cells. These cells are responsible for innate immunity, which does not require activation and is not major histocompatibility complex restricted. • Stellate cells: reside in the Disse space and normally store lipids. When activated, they acquire myofibroblastic properties, expressing smooth muscle antigen and producing collagen (see Figs. 1.11 and 1.23). They are also called Ito cells and lipocytes. • Kupffer cells: cells of the macrophage-monocyte system, representing fixed macrophages of the liver. Intensely phagocytic, weak antigen presenters orchestrate response to endotoxin (see Fig. 1.11).

Inflammation, Cell Damage, and Necrosis • Ballooning degeneration/change: swelling and rounding up of hepatocytes (Fig. 1.26) as seen in steatohepatitis and viral hepatitis. It is presumed to be caused by membrane damage, which allows influx of fluid into the cell or by damage to cytoskeleton, leading to loss of cell shape. • Feathery degeneration: swollen, pale-staining hepatocytes containing wispy cytoplasmic threads (Fig. 1.27), which resemble ballooned cells. The term is used in the context of chronic cholestasis to indicate cellular injury due to retention of bile salts (cholate stasis). • Spotty necrosis: foci of inflammatory cell necrosis consisting of lymphocytes and macrophages surrounding a single or tiny cluster of damaged or necrotic hepatocytes (Fig. 1.28). Most commonly used in the context of viral hepatitis, spotty necrosis may be seen in a variety of inflammatory processes and even as rare foci in otherwise normal biopsy results. It is also referred to as lytic necrosis, especially when the damaged cells are no longer visible (ie, have already been lysed).

Box 1.3  Special Studies in Routine Diagnostic Practice Immunohistochemistry Detection and characterization of viral infections (hepatitis B surface and core antigens, adenovirus, cytomegalovirus, Epstein-Barr virus, herpes viruses) Detection of intracytoplasmic protein accumulation (alpha-1 antitrypsin, fibrinogen) Characterization of tumors Electron Microscopy Diagnosis of storage disorders Diagnosis of viral infections Diagnosis of Byler disease Diagnosis of phospholipidosis Diagnosis of mitochondriopathies In Situ Hybridization Diagnosis of Epstein-Barr virus infection Molecular Diagnostics Mutational analysis of metastatic tumors for precision therapies Mutational analysis of hereditary cholestatic disorders (progressive familial intrahepatic cholestasis, Alagille disease)

22

Figure 1.25  The liver is composed of eight independent segments, each with their own independent vascular supply as well as biliary and venous drainage. This anatomic organization facilitates limited, segmental resections. (Copyright Rashmil Saxena, BFA, Indiana University School of Medicine.)

Microscopic Anatomy, Basic Terms, and Elemental Lesions

Figure 1.26  Ballooning change is characterized by enlargement and swelling of hepatocytes, which show clear or pale-staining cytoplasm.

Figure 1.27  Feathery degeneration (arrow) of hepatocytes is characterized by clear cytoplasm that contains wispy cytoplasmic threads. There is evidence of cholestasis in the form of bile within canaliculi, hepatocytes, and clusters of macrophages (arrowheads).

• Confluent necrosis: large areas of necrosis (Fig. 1.29), usually seen in viral hepatitis, autoimmune hepatitis, and drug-induced hepatitis. Confluent necrosis may bridge adjacent structures (bridging necrosis), involve entire lobules or acini (panlobular or panacinar necrosis), or extend over multiple lobules or acini (multilobular or multiacinar necrosis). Confluent necrosis may be zonal (Fig. 1.30), involving a certain zone of the acini/lobule, or nonzonal and random. • Bridging necrosis: confluent necrosis that bridges adjacent structures; initially used to indicate bridging of portal tracts to central veins. A possible cause of presinusoidal and postsinusoidal shunting, the term is also used for bridging of adjacent portal tracts or adjacent central veins. Bridging necrosis is usually associated with severe acute viral hepatitis, autoimmune hepatitis, or drug-induced hepatitis. • Zonal necrosis: necrosis involving specific portions of the acini/ lobule but not others (see Fig. 1.30); for instance, acetaminophen toxicity causes necrosis of parenchyma around central veins, which is also referred to as perivenular necrosis, centrilobular necrosis, or zone 3 necrosis (eSlide 1.13). Yellow fever involves hepatocytes that are away from both portal tracts and central veins, and it is therefore said to cause midzonal or zone 2 necrosis (see eSlide 13.3). • Punched-out necrosis: sharply demarcated areas of necrosis (as though they were caused by a paper punch) distributed randomly within the parenchyma. Such necrosis is usually seen with herpes simplex and adenovirus infections (see eSlide 13.5). • Piecemeal necrosis, interface hepatitis, periportal activity: damage and progressive loss of hepatocytes at the interface with portal tracts (Fig. 1.31), denoting progressive disease, which usually results in fibrosis. This condition is seen with viral and autoimmune hepatitis. The term spillover is used for the presence of an inflammatory infiltrate at the interface that does not damage the limiting plate. • Apoptosis: self-regulated cell death, which appears morphologically as single cells with condensed and fragmented cytoplasm and nuclei unaccompanied by inflammation (Fig. 1.32). Apoptotic cells are often referred to as apoptotic or acidophilic bodies, and in the context of yellow fever, as Councilman bodies. • Activity: inflammation and necrosis (eg, severe interface activity, severe lobular activity). • Collapse: condensation of the reticulin framework due to necrosis and loss of hepatocytes (see Fig. 1.5B and eSlide 1.14).  • Surgical hepatitis: presence of a neutrophilic infiltrate in the liver parenchyma following a surgical procedure. The inflammation is not accompanied by necrosis (Fig. 1.33).

1

Intracellular Pathology

Figure 1.28  Spotty necrosis (arrow). A focus of inflammatory cells consisting of lymphocytes and macrophages surrounding a necrotic hepatocyte.

• Microvesicular steatosis: multiple small vacuoles that indent but do not displace the nucleus (see Fig. 1.34A). • Macrovesicular steatosis: large intracytoplasmic lipid vacuole enlarging a hepatocyte and pushing the nucleus against the cell membrane (Fig. 1.34B). Vacuoles that are smaller and do not enlarge the cell (see Fig. 1.34C) are sometimes referred to as medium-droplet fat or small-droplet fat; the latter term may cause confusion with microvesicular steatosis. • Lipogranulomas: lipid droplets surrounded by inflammatory cells, usually macrophages. Usually associated with fibrosis, lipogranulomas present most commonly around central veins (see Fig. 1.34D). • Ground-glass cells/inclusions: hepatocytes with a homogenous glassy appearance to the cytoplasm (Fig. 1.35). Although the term is typically used for the appearance of cells containing hepatitis B surface antigen, this cytoplasmic appearance has been observed in many other conditions (see Table 14.1). 23

Practical Hepatic Pathology: A Diagnostic Approach

* A

B

*

C Figure 1.29  A, Confluent necrosis. Large areas of collapse (between arrows) are seen in this biopsy. B, On a trichrome stain, these areas may be mistaken for bridging fibrosis. C, The true nature of the lesion can be appreciated on higher magnification. (The area marked with an asterisk in B corresponds to the area marked with an asterisk in C; also see eSlide 1.14.)

Figure 1.30  Large areas of confluent necrosis (arrows) due to acetaminophen toxicity in a zonal, perivenular distribution (zonal necrosis). Although the central veins or portal tracts cannot be seen at this low magnification, the occurrence of necrosis alternating with viable areas at regular intervals suggests a zonal distribution of the pathologic process (also see eSlide 1.13). 24

Figure 1.31 Interface hepatitis showing lymphocytes infiltrating and encircling hepatocytes at the limiting plate, which appears irregular and eroded.

Microscopic Anatomy, Basic Terms, and Elemental Lesions

1

Figure 1.32  Apoptotic cells (arrows) showing condensation of cytoplasm and nuclear fragmentation.

A

Figure 1.33  Surgical hepatitis. Small collections of neutrophils (arrows) in a biopsy, which was obtained at the time of a segmental colonic resection.

B

*

C

D Figure 1.34  A, Microvesicular steatosis consists of multiple small vacuoles that indent a central nucleus but do not displace it to the cell periphery (arrows). B, Macrovesicular steatosis shows large lipid droplets that push the nucleus against the cell membrane (arrows), including the two nuclei of a binucleated hepatocyte (arrowheads). C, Sometimes the lipid droplets do not enlarge the hepatocyte or push the nucleus against the cell membrane; this is referred to as medium- or small-droplet fat. D, Lipogranulomas consist of lipid droplets surrounded by lymphocytes and macrophages and are often present adjacent to a central vein (asterisk). 25

Practical Hepatic Pathology: A Diagnostic Approach

Figure 1.35  Ground-glass cells (arrows) in a patient with chronic hepatitis B demonstrate a homogenous cytoplasm surrounded partially by a clear zone (“halo”) (see eSlides 14.2 and 14.3).

Figure 1.37  Ductular reaction is the presence in various combinations of increased ductules, edema, inflammation, and fibrosis (see eSlide 5.1).

Figure 1.36 Mallory hyaline (arrows) consists of densely eosinophilic inclusions (sometimes described as “ropy” or resembling “bubble gum”) formed by condensation of cytoskeletal filaments (also see eSlide 5.4).

Figure 1.38  Ductular (cholangiolar) cholestasis. Dilated bile ductules at the edge of a portal tract containing inspissated bile (arrows). A bile duct is present within the portal tract (arrowhead) (also see eSlide 3.3).

• Mallory hyaline: a densely eosinophilic ropy structure formed by condensation of cytoskeletal filaments. It is typically seen in alcoholic hepatitis and chronic cholestatic diseases (Fig. 1.36; see eSlides 24.1 and 24.2).

• Bile infarct: area of necrosis because of leakage of bile. These are of variable size and contain variable amounts of bile and foamy macrophages (Fig. 1.39). • Biliary halo: lightly staining area in the periportal region or around cirrhotic nodules in chronic biliary diseases caused by the presence of ductular reaction and ballooned hepatocytes with cholate-stasis (Fig. 1.40; also see eSlide 5.4). • Biliary rosette: glandlike structure (pseudogland) caused by hepatocytes arranged around a central space containing bile (Fig. 1.41). Biliary rosettes are seen in severe cholestasis. This is also referred to as acinar or pseudoacinar change. • Florid duct lesion/granulomatous cholangiodestruction: histologic lesion comprising a granuloma surrounding a damaged bile duct (Fig. 1.42) that is seen typically with primary biliary cholangitis; the pathologic process of damage and loss of bile ducts is granulomatous cholangiodestruction. Bile duct loss associated with portal granulomata also occurs in sarcoidosis. • Onion skinning (concentric periductal fibrosis): concentric fibrosis usually accompanied by edema and inflammatory infiltrate

Biliary Lesions • Ductular reaction: presence in various combinations of increased ductules, edema, inflammation (usually neutrophilic), and fibrosis, usually at the edges of portal tracts. It may be seen with extrahepatic biliary obstruction or chronic biliary disease, or as a nonspecific reaction in any chronic liver disease (Fig. 1.37). • Bland cholestasis: cholestasis manifested as bile plugs in canaliculi, usually in the perivenular regions (canalicular cholestasis), unaccompanied by inflammation, necrosis, or ductular reaction (see Figs. 1.18C and 1.19B). • Ductular (cholangiolar) cholestasis: presence of inspissated bile/ bile plugs in dilated ductules at the edges of the portal tracts (Fig. 1.38). It is typically seen with sepsis, when it is often referred to as cholangitis lenta. 26

Microscopic Anatomy, Basic Terms, and Elemental Lesions

1

Figure 1.39  A bile infarct consisting of an area of necrosis caused by chronic cholestasis, which contains bile pigment and foamy macrophages.

A

Figure 1.41  Biliary rosettes showing a glandular arrangement of hepatocytes around a central lumen containing bile (arrows).

Figure 1.42  Florid duct lesion comprising a granuloma surrounding a damaged bile duct in a patient with primary biliary cholangitis.

around a damaged bile duct. This lesion is seen in cases of sclerosing cholangitis, both primary and secondary (see Fig. 1.14C and D and eSlides 27.1 and 27.2). • Bile duct scar: dense fibrous tissue obliterating and replacing a bile duct. Bile duct scars are seen in cases of sclerosing cholangitis, both primary and secondary (Fig. 1.43; also see eSlide 27.1). • Ductopenia: absence of bile ducts, in at least 50% of portal tracts, in a biopsy that contains at least 10 portal tracts (detailed discussion in Chapter 28). • Ductal plate malformation: lesion consisting of excess ductal structures in a configuration reminiscent of the developing ductal plate. The lesion appears as complete or partial ring of open ducts arranged circumferentially at the periphery of a portal tract (Fig. 1.44; also see eSlides 25.3, 25.4, and 25.5).

B Figure 1.40  Biliary halo (A) refers to a lightly stained area around cirrhotic nodules that is caused by the presence of ductular reaction and periseptal-ballooned hepatocytes with cholate-stasis (B) (see eSlide 5.4).

Sinusoidal Lesions • Sinusoidal lymphocytosis: presence of lymphocytes in sinusoids in linear arrays (Figs. 1.45 and 38.46), usually unaccompanied by necrosis. Sinusoidal lymphocytosis is most often associated with hepatitis C and infectious mononucleosis (eSlide 1.15). 27

Practical Hepatic Pathology: A Diagnostic Approach

Figure 1.43  A bile duct scar (arrows) consisting of dense fibrous tissue replacing a bile duct. Note the accompanying hepatic artery (arrowhead) (also see eSlide 27.1).

Figure 1.46  Perisinusoidal fibrosis showing fibrous tissue along sinusoids in a patient with nonalcoholic steatohepatitis.

• Perisinusoidal, pericellular, and perivenular fibrosis: Perisinusoidal fibrosis is a distinct pattern of fibrosis in which fibrous tissue is laid down along sinusoids (Fig. 1.46). Pericellular and perivenular fibrosis imply fibrosis surrounding individual hepatocytes and central veins, respectively. Perisinusoidal and pericellular fibrosis are seen in several metabolic diseases and more commonly in steatohepatitis, both alcoholic and nonalcoholic. In the latter, pericellular, perisinusoidal, and perivenular fibrosis begin around the central veins and may occur simultaneously. Suggested Readings

Figure 1.44  Ductal plate malformation showing ductal structures in a configuration reminiscent of the developing ductal plate. In contrast to the ductules seen in ductular reaction, these structures lie within the portal tracts and show open lumina (also see eSlides 25.3, 25.4, and 25.5).

Figure 1.45  Sinusoidal lymphocytosis in a patient with chronic hepatitis C consisting of linear arrays of lymphocytes in sinusoids (also see eSlide 1.15). 28

Bismuth H. Surgical anatomy and anatomical surgery of the liver. World J Surg. 1982;6:3–9. Crawford AR, Lin XZ, Crawford JM. The normal adult human liver biopsy: a quantitative reference standard. Hepatology. 1998;28:323–331. Matsumoto T, Kawakami M. The unit-concept of hepatic parenchyma—a re-examination based on angioarchitectural studies. Acta Pathol Jpn. 1982;32(suppl 2):285–314. Saxena R, Theise N. Canals of Hering: recent insights and current knowledge. Semin Liver Dis. 2004;24:43–48. Saxena R, Theise ND, Crawford JM. Microanatomy of the human liver—exploring the hidden interfaces. Hepatology. 1999;30:1339–1346.

References 1. Kiernan F. The anatomy and physiology of the liver. Philos Trans R Soc Lond. 1833;123:711–770. 2. Arey LB. On the presence of so-called portal lobules in the seal’s liver. Anat Rec. 1932;51:315–322. 3. Mall FP. A study of the structural unit of the liver. Am J Anat. 1906;5:227–308. 4. Rappaport AM. Subdivision of hexagonal liver lobules into a structural and functional unit. Anat Rec. 1954;119:11–27. 5. Rappaport AM. The structural and functional unit in the human liver (liver acinus). Anat Rec. 1958;130:673–689. 6. Rappaport AM, Hiraki GY. The anatomical pattern of lesions in the liver. Acta Anat (Basel). 1958;32:126–140. 7. Lamers WH, Hilberts A, Furt E, et al. Hepatic enzymic zonation: a reevaluation of the concept of the liver acinus. Hepatology. 1989;10:72–76. 8. Matsumoto T, Komori R, Magara T, et al. A study on the normal structure of the human liver, with special reference to its angioarchitecture. Jikeikai Med J. 1979;26:1–40. 9. Matsumoto T, Kawakami M. The unit-concept of hepatic parenchyma—a re-examination based on angioarchitectural studies. Acta Pathol Jpn. 1982;32(suppl 2):285–314. 10. Teutsch HF. Regionality of glucose-6-phosphate hydrolysis in the liver lobule of the rat: metabolic heterogeneity of “portal” and “septal” sinusoids. Hepatology. 1988;8:311–317. 11. Teutsch HF, Chilko DM. Use of 3-D-computer graphics for imaging of distribution of hepatic metabolites. Histochemistry. 1986;84:396–400. 12. Ekataksin W, Zou ZZ, Chunhabundit P, et al. The hepatic microcirculatory subunits: an over-three-century-long search for the missing link between an exocrine unit and an endocrine unit in mammalian liver lobules. In: Motta PM, ed. Recent Advances in Microscopy of Cells, Tissues and Organs. Rome: University of Rome La Sapienza; 1997: 375–380.

Microscopic Anatomy, Basic Terms, and Elemental Lesions 13. Ekataksin W, Zou ZZ, Wake K, et al. HMS, hepatic microcirculatory subunits in mammalian species: intralobular grouping of liver tissue with definition enhanced by the drop-out sinusoids. In: Wisse E, Knook DL, Wake K, eds. Cells of the Hepatic Sinusoid. Leiden, The Netherlands: Kupffer Cell Foundation; 1995:247–251. 14. Teutsch HF. The modular microarchitecture of human liver. Hepatology. 2005;42:317–325. 15. Nakanishi Y, Mneimneh WS, Sey M, Al-Haddad M, DeWitt JM, Saxena R. One hundred thirteen consecutive transgastric liver biopsies for hepatic parenchymal diseases: a single-institution study. Am J Surg Pathol. 2015;39:968–976. 16. Petrelli M, Scheuer PJ. Variation in subcapsular liver structure and its significance in the interpretation of wedge biopsies. J Clin Pathol. 1967;20:743–748. 17. Crawford AR, Lin XZ, Crawford JM. The normal adult human liver biopsy: a quantitative reference standard. Hepatology. 1998;28:323–331. 18. Ludwig J, Ritman EL, LaRusso NF, et al. Anatomy of the human biliary system studied by quantitative computer-aided three-dimensional imaging techniques. Hepatology. 1998;27:893–899. 19. Fiel MI, Deniz K, Elmali F, Schiano TD. Increasing hepatic arteriole wall thickness and decreased luminal diameter occur with increasing age in normal livers. J Hepatol. 2011;55:582–586. 20. Balakrishnan M, Garcia-Tsao G, Deng Y, Ciarleglio M, Jain D. Hepatic arteriolosclerosis: a smallvessel complication of diabetes and hypertension. Am J Surg Pathol. 2015;39:1000–1009.

21. Morgan JD, Hartroft WS. Juvenile liver: age at which one-cell-thick plates predominate in the human liver. Arch Pathol. 1961;71:86–88. 22. Gupta S. Hepatic polyploidy and liver growth control. Semin Cancer Biol. 2000;10:161–171. 23. Feldmann G. Liver ploidy. J Hepatol. 1992;16:7–10. 24. Levene AP, Goldin RD. Physiological hepatic nuclear vacuolation—how long does it persist? Histopathology. 2010;56:426–429. 25. Butler SL, Dong H, Cardona D, et al. The antigen for Hep Par 1 antibody is the urea cycle enzyme carbamoyl phosphate synthetase 1. Lab Invest. 2009;88:78–88. 26. Saxena R, Theise ND, Crawford JM. Microanatomy of the human liver—exploring the hidden interfaces. Hepatology. 1999;30:1339–1346. 27 Theise ND, Saxena R, Portmann BC, et al. The canals of Hering and hepatic stem cells in humans. Hepatology. 1999;30:1425–1433. 28. Saxena R, Hytiroglou P, Thung SN, et al. Destruction of canals of Hering in primary biliary cirrhosis. Hum Pathol. 2002;33:983–988. 29. Hytiroglou P, Tobias H, Saxena R, et al. The canals of Hering might represent a target of methotrexate hepatic toxicity. Am J Clin Pathol. 2004;121:324–329.

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29

2 Clinical Features of Liver Disease Paul Y. Kwo, MD

Definitions and Synonyms  33

Definitions and Synonyms

Acute Liver Disease  34 Etiology 34 Clinical Manifestations  34 Treatment and Prognosis  35

Acute liver disease refers to a variety of liver diseases with different etiologies and pathogenic mechanisms that occur in an individual with a previously healthy liver, in whom the history of illness and/or elevation of liver enzymes does not exceed 6 months. Acute (fulminant) liver failure (ALF) is the most severe form of acute liver disease; it is characterized by decompensation of liver function that manifests clinically as acute onset of hepatic encephalopathy and coagulopathy in an individual without previously known liver disease. By definition, ALF is characterized by liver disease of short duration, coagulopathy with an international normalized ratio (INR) greater than 1.5, and encephalopathy of any degree. Encephalopathy may be difficult to evaluate in children; therefore it is not required for the diagnosis. ALF results either from actual loss of hepatocytes seen histologically as submassive or massive necrosis (eg, acetaminophen toxicity) or from functional impairment of hepatocytes without actual loss of cells (eg, Reye syndrome). Sudden-onset liver failure is a synonym. Subacute liver failure is defined by development of encephalopathy 29 days to 12 weeks after onset of jaundice. This condition is characterized by a higher mortality and lower chance of spontaneous recovery than ALF, despite low incidence of cerebral edema. Subacute liver disease also differs from ALF by late development of renal failure, modest coagulation disorder, and presence of ascites. Subacute hepatic failure may be easily confused with chronic liver disease. Synonyms include late-onset hepatic failure, subfulminant liver failure, protracted viral hepatitis with impaired regeneration, subchronic atrophy of the liver, subacute hepatitis, and subacute hepatic necrosis. Chronic liver disease is defined by liver disease and abnormal liver tests that last for more than 6 months. Chronic liver disease may be associated with progressive fibrosis that ultimately leads to liver cirrhosis. Cirrhosis is the end stage of chronic liver disease characterized by development of fibrous septa and formation of regenerative nodules. These pathologic changes lead to alterations in the microvascular architecture of the liver, which is critical to its functional integrity. Liver function can be compensated in the early stages, and cirrhosis may remain clinically silent for a variable number of years. Eventual decompensation of hepatic synthetic, metabolic, and hemodynamic functions by any one of a multitude of factors brings the patient to clinical attention. Synonyms include endstage liver disease, end-stage liver failure, and chronic liver failure.

Acute Liver Failure  35 Subacute Liver Failure  35 Chronic Liver Disease  36 Etiology 36 Assessing the Severity of Cirrhosis  36 Clinical Signs (Stigmata) of Chronic Liver Disease  36 Complications of Liver Cirrhosis  38

Abbreviations ALF acute liver failure ALFSG Acute Liver Failure Study Group APACHE Acute Physiology and Chronic Health Evaluation HAV hepatitis A virus HBeAg hepatitis B e antigen HBV hepatitis B virus HCV hepatitis C virus HE hepatic encephalopathy HELLP hemolysis, elevated liver levels, and low platelet count HEV hepatitis E virus HPS hepatopulmonary syndrome HRS hepatorenal syndrome INR international normalized ratio MELD model for end-stage liver disease NAC N-acetylcysteine POPH portopulmonary hypertension SAAG serum-ascites albumin gradient SBP spontaneous bacterial peritonitis TIPS transjugular intrahepatic portosystemic shunt

33

Practical Hepatic Pathology: A Diagnostic Approach

Acute Liver Disease Etiology

Acute liver disease may result from a variety of etiologic agents, the most common of which are viral hepatitis, acetaminophen overdose, idiosyncratic reaction to medicines, excessive alcohol intake, autoimmune diseases, metabolic disorders, and circulatory disorders. Viral hepatitis accounts for 72% of cases of acute hepatitis,1 and infections with hepatitis A and B viruses account for most of these cases. Acute infection with hepatitis C virus (HCV) is usually subclinical, and clinical manifestations occur in only about 15% of patients. Infection with hepatitis D virus usually occurs in intravenous drug users, either as a superinfection in those already infected with hepatitis B virus (HBV) or as a coinfection acquired simultaneously with HBV. Acute hepatitis due to hepatitis E virus (HEV) occurs in endemic areas that include Central and Southeast Asia, North and West Africa, and Mexico. Sporadic cases occur in the rest of the world. All five viruses have been implicated in ALF; however, ALF due to HCV is rarely seen in the Western Hemisphere, with most cases being reported from Japan and Taiwan. These reports indicate that there is a greater likelihood of a fulminant course of HCV in individuals who already have chronic HBV infection.1,2 Fulminant HBV infection follows de novo infection in the West but is usually the result of activation of latent infection in the East; the reason for these differences is not known. An increasing cause of ALF due to HBV is reactivation of latent infection in patients undergoing chemotherapy for various malignancies or receiving immune modulating agents of immune diseases.1,3 The enteric viruses, hepatitis A virus (HAV) and HEV, cause self-limited disease in most individuals, with only a minority proceeding to ALF. A fulminant course caused by HAV occurs in elderly patients and intravenous drug users. A fulminant course is also more likely to occur when HAV occurs as a superinfection in patients with chronic liver disease.4 Fulminant HEV infection occurs most commonly in pregnant women, in whom it may be accompanied by hemolysis, elevated liver levels, and low platelet count (HELLP syndrome [hemolysis, elevated liver enzymes, and low platelet count]).1 Mortality is 20% in the third trimester. Acute alcoholic hepatitis after heavy or binge drinking may present as acute liver disease and is associated with a high risk of increased short-term mortality. An increasing incidence, especially in women and at a younger age, is reported at least in some parts of the world.5 Overdose from acetaminophen, the most widely available analgesic, is the most common cause of fulminant acute failure in the United States and the United Kingdom. Overdose may be intentional or unintentional from self-medication for pain or fever, leading to daily doses exceeding 4 g/day. Susceptible patients have concomitant depression, chronic pain, alcohol or narcotic use, and they may take several preparations simultaneously.6 Idiosyncratic reactions from common over-the-counter therapeutic drugs, herbal remedies, and dietary supplements cause a significant number of cases of acute hepatitis, some of which may follow a fulminant course. The United States Acute Liver Failure Study Group (ALFSG) found these cases to be the second most common cause of ALF. A comprehensive list of causes of ALF is shown in Table 2.1.

Clinical Manifestations Clinical symptoms of ALF reflect pathophysiologic mechanisms associated with rapid arrest of normal hepatic function, and the presentation is marked by the acute onset of hepatic encephalopathy and coagulopathy in a patient without previous history of liver disease. In addition, the acute loss of hepatic function in ALF leads to profound and deleterious effects on all body systems, resulting in acute renal failure, gastrointestinal bleeding, infections, sepsis, respiratory failure, and cardiovascular collapse. Ascites is not common except in cases of ALF caused by acute Budd-Chiari disease. 34

Encephalopathy and cerebral edema result from the dysregulation of neurotransmission and cerebral blood flow caused by the accumulation of toxic substances such as ammonia and benzodiazepine receptor agonists, which would normally be cleared by a healthy liver. In contrast to cirrhosis, intracranial hypertension and cerebral edema are predominant features of ALF because the brain does not have adequate time to compensate for the abnormal homeostasis. Bleeding diathesis in patients with ALF is multifactorial and results from decreased production by the liver of coagulation factors II, V, VII, IX, and X; thrombocytopenia; and qualitative platelet functional defects. Concurrent complications such as disseminated intravascular coagulation and sepsis, combined with abnormalities in antithrombin III, protein C, and protein S, further exaggerate the bleeding diathesis. The levels of factor VIII, which is produced by hepatic endothelium, are increased because of endothelial activation. Tests of coagulation including prothrombin time, INR, and levels of factors V and VII are useful parameters for monitoring progression of fulminant hepatic failure; of these, factors V and VII are the most sensitive to changes in hepatic function because they have the shortest serum half-lives of all coagulation factors. Transfusion of fresh-frozen plasma or platelets is generally encouraged only if invasive procedures are indicated, or if platelets are less than 20,000/mm3, to avoid false interference with measures of coagulation. Infectious complications, especially of the respiratory and urinary tracts, occur in about 80% of patients with ALF, and bacteremia is seen in 20% to 26% of patients.7 The risk of infection derives from reticuloendothelial dysfunction and decreased opsonization of microorganisms. Fungal infections, especially with Candida albicans, occur in a third of patients with ALF and can exclude them from the option of transplantation, thus representing a poor prognostic factor. Acute renal failure occurs in 40% to 80% of patients with ALF. It is multifactorial, occurring secondary to prerenal azotemia, acute tubular necrosis, hepatorenal syndrome, drug-induced interstitial nephritis caused by contrast material or antibiotics, and sepsis. Patients present with oliguria and increased creatinine levels. Creatinine is preferred over blood urea nitrogen for monitoring kidney function in ALF because the latter is affected by impaired hepatic urea production. Patients with ALF have profound electrolyte and fluid abnormalities; water retention and hyponatremia are common. Hypokalemia and hypophosphatemia Table 2.1  Etiology of Fulminant Hepatic Failure Etiologic Category

Common Agents and Causes

Viral

Hepatitis A, B, ±D, and E viruses, herpes simplex virus, cytomegalovirus, Epstein-Barr virus, herpes varicella-zoster virus, adenovirus, hemorrhagic fever viruses

Drugs and toxins: dose-dependent

Acetaminophen, carbon tetrachloride (CCl4), yellow phosphorus, Amanita phalloides, Bacillus cereus toxin, sulfonamides, tetracycline, Ecstasy (3, 4-methylenedioxymethamphetamine [MDMA]), herbal remedies (ginseng, pennyroyal oil, Teucrium polium, chaparral or germander tea, kava kava)

Drugs and toxins: idiosyncratic drug reactions

Halothane, rifampicin, valproic acid, nonsteroidal antiinflammatory drugs, disulfiram, antibiotics (ampicillin-clavulanate, ciprofloxacin, doxycycline, erythromycin, isoniazid, nitrofurantoin, tetracycline)

Vascular

Right-sided heart failure, Budd-Chiari syndrome, veno-occlusive disease/sinusoidal obstruction syndrome, shock liver (ischemic hepatitis), heat stroke

Metabolic

Acute fatty liver of pregnancy, Wilson disease, Reye syndrome, galactosemia, hereditary fructose intolerance, tyrosinemia

Miscellaneous

Malignant infiltration (liver metastases, lymphoma), autoimmune hepatitis, sepsis

Clinical Features of Liver Disease accompany hyponatremia, but in patients with oliguric renal failure, hyperkalemia and hyperphosphatemia may occur. Hypoglycemia is common and occurs because of deficient glycogenolysis and gluconeogenesis by a diseased liver. Cardiorespiratory abnormalities in ALF include systemic vasodilatation, low vascular resistance, increased cardiac output, and abnormal oxygen transport and utilization, leading to hypotension, hypoxia, and lactic acidosis. The laboratory findings in acute liver disease are described in Chapter 3.

Treatment and Prognosis Acute liver disease may resolve spontaneously with supportive therapy or progress to ALF or develop into chronic liver disease. Acute autoimmune hepatitis can potentially respond to corticosteroid administration. Short-term mortality associated with severe acute alcoholic hepatitis may be reduced by a short course of corticosteroids. Acute hepatitis B or an acute flare of hepatitis B in a known carrier may respond to antiviral therapy. Drug-induced injury seems to resolve completely following the drug’s withdrawal in less severe cases. Acetaminophen overdose responds well to N-acetylcysteine (NAC) administration, especially if given within 16 hours of acetaminophen exposure. However, despite cessation of the offending agent, chronic liver injury, including cirrhosis, may develop in a small number of cases.8

Acute Liver Failure Although some patients with ALF may recover spontaneously after supportive therapy, the vast majority require urgent transplantation without which mortality approaches 40%, most commonly because of cerebral edema. Specific therapy aimed at restitution of liver function and averting transplantation may be attempted in some cases. As previously stated, administration of NAC according to the standard treatment nomogram aims to replenish depleted hepatic stores of glutathione in cases of acetaminophen-induced liver failure, and it is most effective in the first 16 hours after ingestion. Its benefit at 24 hours is questionable, and NAC is not effective when given after 48 hours. There is questionable benefit of NAC in ALF resulting from mushroom (Amanita phalloides) poisoning; the administration of Silybum marianum has been shown to ameliorate liver injury in affected patients. Corticosteroids may be given in cases of ALF caused by autoimmune hepatitis, and nucleoside or nucleotide antiHBV agents may be given to patients with ALF caused by acute HBV infection. Supportive therapy of ALF has included lactulose to decrease blood ammonia levels; the benefit is questionable. Antibiotics are administered for complications such as spontaneous bacterial peritonitis (SBP) or bacteremia. Gastrointestinal bleeding is treated with blood products and proton pump inhibitors. Continuous venovenous hemofiltration is used for the treatment of hepatorenal syndrome, which is preferred over hemodialysis because the latter can precipitate hypotension with a fall in central venous pressure and an exacerbation of cerebral edema. INR is an important parameter for monitoring progression of ALF. Mortality is high, and most patients require immediate transplantation; therefore the most important management tool is the ability to distinguish patients who will benefit from liver transplantation from those who will recover spontaneously. Prognosis of ALF is strongly correlated with the degree of encephalopathy; the incidence of spontaneous recovery is 65% to 70% with encephalopathy grades 1 to 2, 40% to 50% with grade 3, and less than 20% with grade 4. Over the decades, several prognostic models and biomarkers have been studied. Although no single marker or model has proven to be significantly sensitive or specific for this purpose, the King’s College Criteria, formulated after a review of 588 patients by O’Grady and colleagues, are the most widely tested and most commonly used (Table 2.2).9 The Acute Physiology and Chronic Health Evaluation (APACHE) II score is used for predicting outcome in acetaminophen-induced ALF; a score

of more than 15 is highly predictive of the need for transplantation. In idiosyncratic drug-induced liver failure, female sex, hepatocellular damage, high total bilirubin, and high aspartate aminotransferase levels were found to be negative predictors of short-term outcome.10,11 The modified discriminant function adapted from the Maddrey scoring system predicts the response of acute alcoholic hepatitis to corticosteroids. A score of greater than 32 showed survival of 84% at 28 days with corticosteroids compared with 65% for those who did not receive corticosteroids.12 The modified discriminant function is calculated as follows:

2

(4.6 × [PT − control PT]) + (serum bilirubin [mg/dL])

Other prognostic factors studied are serum bilirubin, prothrombin time, factor V levels, arterial lactate concentration, serum phosphate level (low levels suggest hepatic recovery), arterial ammonia levels (>200 g/dL is associated with cerebral herniation), presence of a systemic inflammatory response syndrome, α-fetoprotein levels (increased levels suggest liver regeneration), Gc-globulin levels, troponin I, and CD163. Each has its own utility in specific circumstances, but none has universal application.

Subacute Liver Failure Subacute liver disease is a controversial entity as the clinical symptoms can be easily confused with chronic liver disease. Furthermore, many chronic diseases may mimic subacute liver disease; these include acute viral hepatitis A and E superimposed on chronic liver disease (HBV or HCV cirrhosis), Wilson disease, autoimmune hepatitis, seroconversion of hepatitis B e antigen (HBeAg) to anti-HBeAg, and reactivation of chronic HBV infection (Box 2.1). Thus subacute liver disease is a diagnosis of exclusion; patients who present with subacute hepatic failurelike features need to be assessed for chronic liver disease, namely hepatosplenomegaly on imaging, low albumin, high gamma globulin, ascites on ultrasound, and varices on esophagogastroduodenoscopy.13 Most cases represent acute liver disease superimposed on cirrhosis of any etiology. Table 2.2  King’s College Criteria for Liver Transplantation in Acute Liver Failure Acetaminophen-Induced

Non–Acetaminophen-Induced Disease

Arterial pH 100 seconds (irrespective of the grade of encephalopathy)

or Grade III or IV encephalopathy and prothrombin time >100 seconds and serum creatinine >3.4 mg/dL (301 μmol/L)

or Any three of the following variables (irrespective of the grade of encephalopathy): 1. Age 40 years 2. Etiology: non-A, non-B hepatitis; halothane hepatitis; idiosyncratic drug reactions 3. Duration of jaundice before onset of encephalopathy >7 days 4. Prothrombin time >50 seconds 5. Serum bilirubin >18 mg/dL (308 μmol/L)

Box 2.1  Etiology of Subacute Liver Disease Hepatitis A virus, hepatitis B virus, hepatitis C virus Herpes simplex virus Toxins/drugs Reye syndrome Hemorrhagic necrosis Wilson disease Autoimmune hepatitis Right hepatectomy in chronic liver disease Nonalcoholic fatty liver disease with aggressive steatohepatitis Infiltrative diseases, including amyloidosis, sarcoidosis, and malignancy

35

Practical Hepatic Pathology: A Diagnostic Approach

Chronic Liver Disease Etiology

The common causes of chronic liver disease and cirrhosis include nonalcoholic fatty liver disease, HCV, HBV, hereditary hemochromatosis, alpha-1 antitrypsin deficiency, Wilson disease, primary biliary cirrhosis, primary sclerosing cholangitis, autoimmune hepatitis, and alcoholic liver disease. Affected individuals represent an outpatient clinic population that is often referred for chronic elevations of liver tests or for signs of chronic liver disease.

Assessing the Severity of Cirrhosis Multiple scoring systems have been formulated in an attempt to assess the severity of cirrhosis and predict prognosis. The Child-Pugh score, initially derived to predict survival after portacaval shunt surgery, is the most widely used. The score divides patients into classes A, B, and C on the basis of three laboratory tests (prothrombin time, bilirubin, and albumin) and two clinical features (ascites and encephalopathy) (Table 2.3). Two-year survival for patients in class A is 85%, compared with 60% and 35% for patients in classes B and C, respectively Table 2.4. The Child-Pugh score has been replaced by another system, the model for end-stage liver disease (MELD) score as a predictor of 3-month mortality for prioritizing patients awaiting transplantation (Table 2.5). Formulated in 2001 to predict survival after transjugular intrahepatic portosystemic shunt (TIPS) placement, the MELD score is calculated with a formula that incorporates three laboratory values (bilirubin, creatinine, and INR) as follows: 0.957 × Loge (creatinine mg/dL) + 0.378 × Loge (bilirubin mg/dL) + 1.120 × Loge (INR)

Unlike the Child-Pugh score, which partly uses clinically subjective parameters, the MELD score is based entirely on objective data. In addition, the MELD score has a greater range of values than the ChildPugh score: 6 to 40 for the former compared with 5 to 15 for the latter.

Clinical Signs (Stigmata) of Chronic Liver Disease The main clinical signs of cirrhosis represent the effects of portal hypertension and failure of the synthetic and detoxifying functions of the liver. Jaundice is the most common sign of liver injury, which occurs in both hepatocellular injury and cholestatic diseases. Jaundice represents yellow discoloration of the skin and mucous membranes secondary to an increased level of bilirubin, usually greater than 3 mg/dL (Fig. 2.1). It is sometimes associated with so-called “cola-colored” (dark) urine. It should be distinguished from yellow skin secondary to carotenemia; the latter is rare and lacks scleral discoloration. Hepatomegaly represents enlargement of the liver (Fig. 2.2). A cirrhotic liver may have a variable size ranging from small to normal to enlarged. Therefore the absence of a palpable liver does not exclude liver disease. When palpable, the cirrhotic liver usually has a nodular, firm consistency. Splenomegaly is common in cirrhosis of all etiologies and appears to be caused by congestion of the splenic red pulp as a consequence of portal hypertension. However, spleen size does not usually correlate with the degree of portal pressures, suggesting that other mechanisms may be involved. Ascites is the accumulation of fluid in the peritoneal cavity that occurs as a consequence of portal hypertension (Fig. 2.3). It occurs when portal pressure (free hepatic vein pressure minus wedged hepatic vein pressure measurement) exceeds 12 mm Hg and is caused by complex pathophysiologic mechanisms. Ascites is discussed in detail later in this chapter.

Table 2.3  Child-Pugh Score 1 Point

2 Points

3 Points

Bilirubin (mg/dL)

3.0

Prothrombin time (seconds prolonged)

6

Albumin (g/L)

>3.5

2.8–3.5

70%), confusion, abdominal tenderness, and hypotension. Signs and symptoms may be absent in 30% of patients. On initial paracentesis, the fluid is typically sterile in 80% of cases and infected in only 20%; however, empiric therapy with third-generation cephalosporins is initiated in all cases without waiting for the results of fluid analysis. Antibiotic treatment is carried out for 5 days. Clinical and laboratory reevaluation is indicated if the neutrophil count in ascitic fluid has not decreased by at least 25% after 2 days of antibiotic treatment. The risk of recurrent SBP is greater in patients with ascitic total protein level less than 1 g/dL and serum bilirubin greater than or equal to 2.5 mg/dL. Preventive measures include eliminating or reducing ascites and antibiotic prophylaxis with a quinolone, or trimethoprimsulfamethoxazole in case of quinolone intolerance.18 Hepatorenal Syndrome Hepatorenal syndrome (HRS) occurs in patients with advanced liver failure and severe sinusoidal portal hypertension; kidney function returns to normal with the return of liver function (eg, following transplantation). This condition is a “functional” renal failure because no histologic changes are seen on tissue examination. HRS is caused by marked arterial vasodilatation in the extrarenal circulation leading to compensatory renal vasoconstriction, which causes a decrease in glomerular filtration rate. The syndrome is categorized into two types. Type 1 is characterized by rapidly progressive renal failure with doubling of creatinine greater than 2.5 mg/dL or halving of creatinine clearance to less than 20 mL/min over 2 weeks or less. Type 2 progresses more slowly, is characterized by creatinine greater than 1.5 mg/dL or creatinine clearance less than 40 mL/min, and is associated with refractory ascites.17 Conditions other than HRS can lead to renal failure in cirrhotic patients, including nonsteroidal antiinflammatory drugs, diuretics, large-volume paracentesis without albumin replacement, diarrhea, or variceal hemorrhage. Thus, diagnosis of HRS requires not only the presence of advanced liver disease but the exclusion of other causes of renal failure. The major diagnostic criteria therefore include advanced hepatic failure; creatinine greater than 1.5 mg/dL or creatinine clearance less than 40 mL/min; absence of shock, bacterial infection, or nephrotoxic drugs; absence of gastrointestinal or renal fluid loss; no improvement of renal function after plasma volume expansion with 1.5 L of isotonic saline; urinary protein less than 500 mg/dL; and normal renal ultrasound.17 Besides renal failure, patients with HRS almost universally have ascites and hyponatremia; the absence of these two features suggests that renal failure is attributed to causes other than HRS. The current treatment of HRS includes albumin, octreotide, and midodrine titrated for an increase in mean arterial blood pressure of 15 mm Hg or greater. A vasopressin analog, terlipressin, is available in

Clinical Features of Liver Disease Table 2.7  Grades of Hepatic Encephalopathy Grade

Signs and Symptoms

1

Euphoria; fluctuant mild confusion; slowness of mentation and affect; disorder in sleep rhythm

2

Accentuation of grade 1; drowsiness; inappropriate behavior; abnormal electroencephalogram; generalized slowing; asterixis (the inability to hold a flexed posture)

3

Sleeps most of the time but is arousable; incoherent speech; marked confusion; electroencephalogram always abnormal

4

Not arousable

the European Union and other parts of the world outside of the United States. Failure of medical treatment is an indication for transplantation; dialysis can be used as a bridge but does not extend survival in the absence of transplantation.19 Hepatic Encephalopathy There are three types of hepatic encephalopathy (HE). Type A is associated with acute liver failure, type B is associated with portosystemic bypass without hepatocellular disease, and type C is associated with cirrhosis and portosystemic shunting.20 Type B differs from type C by the absence of intrinsic hepatocellular disease in type B. Type A is caused by cerebral edema, is characterized by rapid onset, and is often fatal; the only effective treatment is liver transplantation. Both types B and C are caused by shunting of ammonia away from the liver into the brain, and they are characterized by gradual onset with an identifiable precipitant, such as infection, bleeding, prerenal azotemia, constipation, or sedatives. HE is a clinical diagnosis made by history and findings of altered mental status; the presence of asterixis is the hallmark of the disorder. Ammonia levels are unreliable and do not correlate with diagnosis and are therefore rarely measured. An electroencephalogram typically demonstrates a slow dominant rhythm. The stages of HE are described in Table 2.7. Treatment is typically effective for type C hepatic encephalopathy and consists of lactulose with or without rifaxamin, although some patients have brittle encephalopathy leading to multiple hospitalizations. Lactulose is a nonabsorbable sugar that ferments in the colon and sequesters ammonia, preventing its absorption across the mucosal surface into the mesenteric circulation. Lactulose is also an osmotic laxative. Antibiotics such as metronidazole, neomycin, and rifaximin are used to decrease gut flora. Benefits of probiotics, zinc supplementation (a cofactor for ornithine transcarbamylase pathway), and decreasing dietary protein are questionable.21,22 Hepatopulmonary Syndrome Hepatopulmonary syndrome (HPS) is a gas exchange disorder characterized by severe arterial hypoxemia in patients with cirrhosis or portal hypertension. Pathophysiologically, HPS is caused by intrapulmonary vascular dilatation attributed to diffusion-perfusion defect (type 1) or anatomic shunt (type 2) (Fig. 2.14), which causes impaired oxygenation of venous blood as it passes through the lungs. Diagnostic criteria include portal hypertension, arterial hypoxemia (partial arterial oxygen tension [PaO2] < 80 mm Hg) or alveolar-arterial oxygen gradient greater than 15 mm Hg, pulmonary vascular dilatation seen as a “positive” delayed contrast echo in the absence of significant cardiopulmonary disease, and the 99mtechnetium-labeled macroaggregated albumin uptake scan lung perfusion with brain uptake greater than 6%. The main clinical features of HPS are finger clubbing (see Fig. 2.8), cyanosis, spider angiomas, and exertional dyspnea, which, in the setting of chronic liver disease, can evolve to extreme debilitation. However, HPS is not the only cause for hypoxemia in cirrhosis because 20% to 30% of

2

Figure 2.14  High-resolution computed tomography reveals the peripheral vascular branches to be abnormally dilated extending to the pleural surface, giving a spidery appearance.

patients have concurrent chronic obstructive pulmonary disease, bronchiectasis, pleural effusion, or pulmonary fibrosis.23 Spontaneous resolution of HPS rarely occurs, and medical therapy is largely ineffective. Vascular embolotherapy may be helpful in type 2 disease. Placement of TIPS offers variable results and is generally not recommended. The only effective therapy is liver transplantation, although arterial hypoxemia may take up to 1 year to resolve. HPS reduces survival in cirrhosis: the median survival in cirrhotic patients without HPS is approximately 41 months in contrast to 11 months in those with HPS.24 Patients with HPS are also prone to unique complications after liver transplantation and have greater postoperative mortality. The posttransplantation outcome worsens as HPS progresses. Portopulmonary Hypertension Portopulmonary hypertension (POPH) is pulmonary arterial hypertension occurring in a patient with portal hypertension. The prevailing concept regarding its pathogenesis postulates that the endothelium of the pulmonary vascular bed, being “downstream” to a dysfunctional liver, is chronically exposed to substances normally metabolized by the liver. This results in endothelial proliferation, vascular smooth muscle dysfunction, vasoconstriction, obliteration of vessels, and in situ thrombosis.25 The histology mimics that of primary pulmonary hypertension, with smooth muscle hyperplasia, concentric intimal fibrosis, and plexogenic arteriopathy. The symptoms of POPH include exertional dyspnea, chest pain, and syncope. The clinical signs of POPH include right ventricular heave, accentuated second heart sound, clear lungs, and Raynaud phenomenon. POPH can lead to right-sided heart failure. Diagnosis of POPH is established by right heart catheterization and is based on mean pulmonary artery pressure greater than or equal to 25 mm Hg and pulmonary capillary wedge pressure less than or equal to 15 mm Hg. Medical therapy consists of vasodilators. In the past, POPH represented a relative or absolute contraindication for transplantation; however, currently, transplantation is being safely performed in patients with a mean pulmonary artery pressure less than 35 mm Hg. Suggested Readings Cardenas A, Gines P. Management of complications of cirrhosis in patients awaiting liver transplantation. J Hepato. 2005;42:S124–S133. Sass DA, Shakil AO. Fulminant hepatic failure. Liver Transpl. 2005;11:594–605. Sharma P, Rakela J. Management of pre-liver transplantation patients—Part 1. Liver Transpl. 2005;11:124–133. Sharma P, Rakela J. Management of pre-liver transplantation patients—Part 2. Liver Transpl. 2005;11:249–260.

41

Practical Hepatic Pathology: A Diagnostic Approach References 1. Lee WM. Acute liver failure. N Engl J Med. 1993;329:1862–1872. 2. Chu CM, Yeh CT, Liaw YF. Fulminant hepatic failure in acute hepatitis C: increased risk in chronic carriers of hepatitis B virus. Gut. 1999;45:613–617. 3. Polson J. Assessment of prognosis in acute liver failure. Semin Liver Dis. 2008;28:218–225. 4. Vento S. Fulminant hepatitis associated with hepatitis A virus superinfection in patients with chronic hepatitis C. J Viral Hepatitis. 2000;7(suppl 1):7–8. 5. Williams R. The pervading influence of alcoholic liver disease in hepatology. Alcohol. 2008;43:393–397. 6. Larson AM, Polson J, Fontana RJ, et al. Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study. Hepatology. 2005;42:1364–1372. 7. Sass DA, Shakil AO. Fulminant hepatic failure. Liver Transpl. 2005;11:594–605. 8. Andrade RJ, Lucena MI, Kaplowitz N, et al. Outcome of acute idiosyncratic drug-induced liver injury: long-term follow-up in a hepatotoxicity registry. Hepatology. 2006;44:1581–1588. 9. O’Grady JG, Alexander GJ, Hayllar KM, et al. Early indicators of prognosis in fulminant hepatic failure. Gastroenterology. 1989;97:439–445. 10. Andrade RJ, Lucena MI, Fernandez MC, et al. Drug-induced liver injury: an analysis of 461 incidences submitted to the Spanish registry over a 10-year period. Gastroenterology. 2005;129:512–521. 11. Bjornsson E, Olsson R. Outcome and prognostic markers in severe drug-induced liver disease. Hepatology. 2005;42:481–489. 12. Mathurin P, Mendenhall CL, Carithers Jr RL, et al. Corticosteroids improve short-term survival in patients with severe alcoholic hepatitis (AH): individual data analysis of the last three randomized placebo controlled double blind trials of corticosteroids in severe AH. J Hepatol. 2002;36:480–487.

42

13. Dhawan PS, Desai HG. Subacute hepatic failure: diagnosis of exclusion? J Clin Gastroenterol. 1998;26:98–100. 14. Muehrcke RC. The finger-nails in chronic hypoalbuminaemia: a new physical sign. BMJ. 1956; 1:1327–1328. 15. Naylor CD. The rational clinical examination. Physical examination of the liver. JAMA. 1994; 271:1859–1865. 16. Sharara AI, Rockey DC. Gastroesophageal variceal hemorrhage. N Engl J Med. 2001;345: 669–681. 17. Arroyo V, Gines P, Gerbes AL, et al. Definition and diagnostic criteria of refractory ascites and hepatorenal syndrome in cirrhosis. International Ascites Club. Hepatology. 1996;23:164–176. 18. Gines P, Cardenas A, Arroyo V, et al. Management of cirrhosis and ascites. N Engl J Med. 2004;350:1646–1654. 19. Gines P, Guevara M, Arroyo V, et al. Hepatorenal syndrome. Lancet. 2003;362:1819–1827. 20. Ferenci P, Lockwood A, Mullen K, et al. Hepatic encephalopathy—definition, nomenclature, diagnosis, and quantification: final report of the working party at the 11th World Congresses of Gastroenterology, Vienna, 1998. Hepatology. 2002;35:716–721. 21. Riordan SM, Williams R. Treatment of hepatic encephalopathy. N Engl J Med. 1997;337: 473–479. 22. Cordoba J, Lopez-Hellin J, Planas M, et al. Normal protein diet for episodic hepatic encephalopathy: results of a randomized study. J Hepatol. 2004;41:38–43. 23. Palma DT, Fallon MB. The hepatopulmonary syndrome. J Hepatol. 2006;45:617–625. 24. Schenk P, Schoniger-Hekele M, Fuhrmann V, et al. Prognostic significance of the hepatopulmonary syndrome in patients with cirrhosis. Gastroenterology. 2003;125:1042–1052. 25. Mandell MS. Critical care issues: portopulmonary hypertension. Liver Transpl. 2000;6:S36–S43.

3 Laboratory Tests in Liver Disease Raj Vuppalanchi, MD, and Naga Chalasani, MD

Liver Tests  44 Transaminases 44 “Biliary” Enzymes  44 Measures of Coagulation  45 Other Tests  45 Approach to Evaluation of Abnormal Liver Tests  45 Laboratory Investigation of Acute Liver Injury  46 Laboratory Investigation of Chronic Liver Disease  47 Laboratory Investigation of Liver Disease in Pregnancy  48 Laboratory Investigation of Liver Abnormalities in Systemic Diseases and Disease of Other Organs  49

Abbreviations AAT alpha-1 antitrypsin AIH autoimmune hepatitis ALP alkaline phosphatase ALT alanine aminotransferase AMA antimitochondrial antibodies ANA antinuclear antibodies anti-ASGPR antibodies to asialoglycoprotein receptor anti-HBc antibody to hepatitis B core antigen anti-LCA1 antibody to liver-specific cytosol antigen type 1 anti-LKM1 antibodies to liver/kidney microsome type 1 anti-SLA/LPA antibody to soluble liver antigen/liver pancreas antigen APRI AST-to-platelet ratio index ASMA anti–smooth muscle antibody AST aspartate aminotransferase BD Behçet disease CMV cytomegalovirus DILI drug-induced liver injury EBV Epstein-Barr virus ELISA enzyme-linked immunosorbent assay ERCP endoscopic retrograde cholangiopancreatography EUS endoscopic ultrasound FDA Food and Drug Administration GGT gamma-glutamyl transpeptidase

HAV hepatitis A virus HBsAg hepatitis B surface antigen HBV hepatitis B virus HCV hepatitis C virus HDV hepatitis delta virus HELLP hemolysis, elevated liver tests, low platelets HEV hepatitis E virus HH hereditary hemochromatosis HIC hepatic iron content HII hepatic iron index HOMA-IR homeostasis model assessment of insulin resistance HPLC high performance liquid chromatography IBD inflammatory bowel disease IgG immunoglobulin G IgM immunoglobulin M INR international normalized ratio ISI international sensitivity index LDH Lactate dehydrogenase MCD-NASH  methionine-choline deficient diet–nonalcoholic steatohepatitis MEGX monoethylglycinexylidide MRCP magnetic resonance cholangiopancreatography mRNA messenger RNA NAFLD nonalcoholic fatty liver disease NRH nodular regenerative hyperplasia pANCA perinuclear antineutrophil cytoplasmic antibodies Pi protease inhibitor PBC primary biliary cholangitis PNALD parenteral nutrition-associated liver disease PSC primary sclerosing cholangitis PT prothrombin time RA rheumatoid arthritis RCC renal cell carcinoma RIBA recombinant immunoblot assay SD standard deviation SGOT serum glutamic-oxaloacetic transaminase SGPT serum glutamic-pyruvic transaminase SPEP serum protein electrophoresis SS Sjögren system

43

Practical Hepatic Pathology: A Diagnostic Approach TIBC TPN UDCA UDP ULN US VCA

total iron-binding capacity total parenteral nutrition ursodeoxycholic acid uridine diphosphate upper limit of normal ultrasonography viral capsid antigen

Abnormalities in liver tests result from injury to hepatocytes (hepatocellular injury), the biliary tree (cholestatic injury), or both (cholestatic hepatitis or mixed injury).1-4 Patients may be either asymptomatic or symptomatic with upper abdominal pain, jaundice, acholic stools, darkening of urine, and other constitutional symptoms.2 Clinical evaluation of patients with suspected liver disease typically requires performing a panel of blood tests such as total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), prothrombin time (PT), international normalized ratio (INR), and serum albumin. Because measures of coagulation (PT and INR) and albumin levels are often used clinically to gauge the synthetic function of the liver, these tests are often referred to as liver function tests. However, because they do not measure actual hepatic function and because their values are also affected by nonhepatic causes such as nephrotic syndrome, burns, protein-losing enteropathy, catabolic states, and malnutrition, these tests are more appropriately termed liver biochemistry tests or simply, liver tests, instead of liver function tests. Tests that quantitatively measure liver function, although superior in monitoring the degree of liver dysfunction, are both complex to perform and more expensive than conventional biochemical tests. Their use is therefore currently limited to research applications or preoperative assessment of hepatic reserve before resection.5 These quantitative tests of liver function include those that measure the liver’s synthetic capacity such as indocyanine green, sorbitol, galactose clearance tests, 13C-methacetin breath test, or dual cholate test as well as those that measure liver clearance such as the antipyrine clearance test, aminopyrine breath test, and monoethylglycinexylidide (MEGX) formation after intravenous lidocaine.6-10

Liver Tests

44

approximately 0.8 of ALT levels; they vary slightly with age and gender, with men having higher levels than women.18 AST is also present in cardiac muscle, skeletal muscle, kidneys, brain, pancreas, lungs, leucocytes, and erythrocytes. Its half-life is 17 ± 5 hours, and serum levels show day-to-day variation of 5% to 10%.19 When stored, the activity of AST is stable at room temperature for 3 days, in the refrigerator for 3 weeks (80%) fraction to elevated total bilirubin, hyperbilirubinemia is termed conjugated and unconjugated, respectively. Hemolysis (elevated lactate dehydrogenase and low haptoglobin) and Gilbert syndrome commonly cause unconjugated hyperbilirubinemia and are not associated with any liver injury. Conjugated bilirubinemia is usually seen in liver diseases, both obstructive and hepatocellular.

Measures of Coagulation PT and INR are clinically used to assess hepatic synthetic function because blood clotting factors II, V, VII, IX, and X are produced in the liver. PT is the time taken by a plasma sample to clot after adding tissue factor, a biologically obtained product. Clot formation is usually measured optically but may sometimes have to be measured mechanically to eliminate interferences in lipemic and icteric samples. Because of differences between batches and manufacturers of tissue factor, the INR was devised to standardize results. INR is the ratio of a patient’s PT to a normal (control) sample, raised to the power of the international sensitivity index (ISI) value for the control sample used.15 Because the tissue factors were previously calibrated in plasma from patients TABLE 3.1  Significance of Bilirubin Species and Bilirubin Fractions as Measured in Human Serum Bilirubin Peaks on High-Performance Liquid Chromatography Alpha

Beta

Gamma

Delta

Bilirubin species

Unconjugated

Singly conjugated

Doubly conjugated

Conjugated to albumin

Commonly performed laboratory test

Indirect (calculated)

On request

Unconjugated

Total Bilirubin

Direct bilirubin

Conjugated

Delta (calculated)

on vitamin K antagonists to assign the ISI value for conversion of PT to INR, investigators have proposed using the term INR (liver) where calibration is made by using plasma from patients with cirrhosis to calculate ISI (liver).29 Hemostasis is a fine balance between procoagulants and anticoagulants and despite a lowering of actual levels, the thrombin generation potential may remain intact in cirrhotic patients. Studies using whole blood clotting assays such as thromboelastography that reflect overall hemostatic balance may be superior for clinical use.30 PT and INR are prolonged in chronic liver disease but not until more than 80% of the liver’s synthetic function is compromised, making them relatively insensitive markers in the evaluation of chronic liver disease. However, because factor VII has a short half-life of only about 6 hours, it is a sensitive and significant indicator of acute liver injury. Therefore it is used in the evaluation of fulminant liver injury as an indicator of rapid changes in liver synthetic function.31 Factors II, VII, IX, and X are vitamin K–dependent clotting factors; therefore it is important to remember that PT and INR may be prolonged not only by conditions that compromise liver synthetic function but also by those that compromise vitamin K absorption.

3

Other Tests Albumin, blood ammonia, and platelet count are frequently used in the evaluation of liver disease. Although serum albumin is used as an index of liver synthetic function, it is affected by several nonhepatic factors, making interpretation a bit difficult. Moreover, albumin has a plasma half-life of 3 weeks, resulting in a slow change in serum concentration in response to acute alterations in hepatic function. Isolated hypoalbuminemia with no other liver test abnormality should raise suspicion of a nonhepatic cause. Measurement of blood ammonia is often performed in patients with cirrhosis and known or suspected hepatic encephalopathy presenting with altered mental status. However, blood ammonia levels, either arterial or venous, do not accurately correlate with mental status of patients with liver disease, and increased levels are not required to make the diagnosis of hepatic encephalopathy. Thus there is the variable use of clinical utility of blood ammonia level for monitoring therapy of cirrhosis patients with hepatic encephalopathy.32 The accuracy of the blood ammonia value is affected by factors such as fist clenching, tourniquet use, and placement of the sample on ice.33 Platelet count is lower in patients with cirrhosis and portal hypertension because of splenomegaly and depressed bone marrow production. Several noninvasive tests such as the AST-to-platelet ratio index (APRI), Forns test, FibroIndex, and FibroMeter use platelet count in their scoring algorithm to predict the degree of hepatic fibrosis.18

Approach to Evaluation of Abnormal Liver Tests When encountering abnormal liver tests, the first clinical step is to confirm the presence of liver injury. If the patient is asymptomatic, and there is no suspicion of underlying liver disease, it is reasonable to repeat liver tests to confirm the abnormalities. Serum transaminase levels vary greatly, which means that suspicion of liver injury is higher with concurrent bilirubin rise because it adds specificity to ALT testing without loss of sensitivity. Abnormal liver tests are often the first marker of chronic liver disease. These tests not only point to the presence of underlying liver disease but may also suggest its etiology, severity, and degree of fibrosis. Furthermore, these tests help assess responses to therapy. Pattern recognition of liver enzyme abnormalities is the most frequent cognitive mechanism used by physicians in the evaluation of liver disease. An R ratio defined as (ALT/upper limit of normal [ULN]) ÷ (ALP/ULN) is often used to determine the pattern of injury; this is labeled cholestatic when R is 2 or less, mixed when R is between 2 and 5, and hepatocellular when R is equal to 5 or higher (Table 3.2).34 These biochemical patterns suggest but do not establish the cause of 45

Practical Hepatic Pathology: A Diagnostic Approach TABLE 3.2  Pattern Recognition of Liver Test Abnormalities by R Ratio Hepatocellular (R ≥ 5)

Mixed (2 < R > 5)

Nonalcoholic fatty liver disease

Drug-induced liver injury Primary biliary cholangitis

Cholestatic (R ≤ 2)

Viral hepatitis

Overlap syndrome

Primary sclerosing cholangitis

Alcoholic liver disease

Alcoholic hepatitis

Autoimmune hepatitis

Drug-induced liver injury

Low-flow circulatory failure

Storage disorders

Hereditary hemochromatosis

Chronic biliary obstruction

Wilson disease

Sarcoidosis

Celiac disease

Hepatic mass lesions

Alpha-1 antitrypsin deficiency

Paraneoplastic syndrome

Drug-induced liver injury

liver disease; additional specific tests are required to determine the etiology (Table 3.3).

Laboratory Investigation of Acute Liver Injury Acute hepatic injury/acute liver injury is defined as the presence of abnormal liver tests for less than 6 months in a patient without preexisting liver disease. When the acute hepatic injury is associated with coagulopathy (INR ≥ 1.5) and encephalopathy, the terms acute hepatic failure and fulminant hepatic failure are used to indicate the severity of liver disease. The acute hepatic injury may be associated with jaundice or other constitutional symptoms of acute illness, and elevated liver tests accompany it. Liver test patterns are usually hepatocellular (R > 5) or mixed (2 < R < 5). The more common liver diseases that present as acute hepatic injury are viral hepatitis, autoimmune hepatitis (AIH), Wilson disease, alcoholic hepatitis, ischemic hepatitis, and drug-induced or herbal and dietary supplement–induced hepatitis. The pattern of liver injury in viral hepatitis is mostly hepatocellular and characterized by an increase in AST/ALT greater than 5 × ULN, with ALP elevation less than 3 × ULN. Rarely, patients with hepatitis A virus (HAV) infection can develop a cholestatic pattern of liver injury characterized by an increase in bilirubin and ALP greater than 3 to 5 × ULN with only a mild increase in transaminases.35 The presence of anti-HAV IgM antibody confirms the diagnosis; this immunoglobulin usually disappears after 4 to 6 months and is replaced by anti-HAV IgG antibodies, which persists for life. Acute hepatitis B virus (HBV) infection is recognized by the presence of anti-core IgM antibodies and hepatitis B surface antigen (HBsAg). Anti-core IgG persists for years and helps differentiate immunity acquired through a previous infection (anti-HBs positive, anti-HBc IgG positive) from immunity acquired through vaccination (anti-HBs positive, anti-HBc IgG negative). Testing for antibodies against hepatitis delta virus (HDV) is indicated in patients with prior chronic hepatitis B who have acute hepatitis because of high-risk behavior. Acute hepatitis C virus (HCV) infection is recognized by detecting HCV RNA in serum because anti-HCV antibodies do not typically develop for 6 to 8 weeks after exposure and may take as long as 6 months (range, 2 to 6 months) to appear in serum. Serum aminotransferases become elevated approximately 6 to 12 weeks after exposure (range, 1 to 26 weeks); however, serum ALT levels are variable. Other types of viral hepatitis include those caused by hepatitis E virus (HEV) detected by anti-HEV antibody, cytomegalovirus (CMV) detected by CMV antigenemia or histologic presence of typical nuclear inclusions, and Epstein-Barr virus 46

TABLE 3.3  Summary of Biochemical Tests Performed in the Evaluation of Acute and Chronic Liver Diseases Hepatic Panel Liver-Specific Additional Etiology-Specific Additional Tests (routinely ordered) Tests (often ordered) (ordered only for further evaluation) Aminotransferase AST ALT

Synthetic function Albumin PT/INR

Indirect hyperbilirubinemia Hemolysis: LDH, haptoglobin Gilbert syndrome: genetic testing

Bilirubin Total Direct

Autoimmune activity SPEP Immune electrophoresis

Viral hepatitis HAV: anti-HAV IgM HBV: anti-HBc IgM, HBsAg, anti-HBsAb, HBV DNA levels HCV: anti-HCV Ab, HCV RNA levels, RIBA Other viral hepatitis: anti-EBV VCA IgM, EBV viral load, CMV viral load

Cholestasis GGT 5 NT

Autoimmune AIH: ANA, ASMA, anti-LKM1, anti-SLA, serum IgG PBC: AMA, serum IgM PSC: pANCA, ERCP, MRCP Metabolic liver disease Wilson disease: ceruloplasmin, serum copper, 24-hour urine copper AAT deficiency: AAT phenotype Hemochromatosis: serum ferritin, transferrin saturation, and HFE gene mutation tests NAFLD: HOMA-IR Other Celiac disease: anti-tTG and antigliadin antibodies, small intestinal biopsy, acetaminophen level

ALP

Severity of liver disease Platelet count Blood ammonia

AAT, alpha-1 antitrypsin; AIH, autoimmune hepatitis; ALP, alkaline phosphatase; ALT, alanine aminotransferase; AMA, antimitochondrial antibodies; ANA, antinuclear antibodies; ASMA, anti–smooth muscle antibody; AST, aspartate aminotransferase; CMV, cytomegalovirus; EBV, Epstein-Barr virus; ERCP, endoscopic retrograde cholangiopancreatography; HAV, hepatitis A virus; HBc, hepatitis B core antigen; HBsAb, hepatitis B surface antibody; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus; HCV, hepatitis C virus; HOMA-IR, homeostasis model assessment of insulin resistance; IgM, immunoglobulin M; INR, international normalized ratio; LDH, lactate dehydrogenase; LKM1, liver/kidney microsome type 1; MRCP, magnetic resonance cholangiopancreatography; NAFLD, nonalcoholic fatty liver disease; pANCA, perinuclear antineutrophil cytoplasmic antibodies; PBC, primary biliary cholangitis; PSC, primary sclerosing cholangitis; PT, prothrombin time; SLA, soluble liver antigen; tTG, transglutaminase; VCA, viral capsid antigen.

(EBV) detected by the Monospot test or IgM antibodies against EBV viral capsid antigen or EBV viral levels. Drug-induced liver injury (DILI) typically has variable patterns of injury; however, certain drugs create signature patterns that help identify them as the causative agent. Acetaminophen overdose, either intentional or unintentional, results in very high transaminases (100 × ULN) and is associated with renal failure in approximately 10% to 15% of patients. The Hy law, or Hy rule, is often used by the United States Food and Drug Administration (FDA) as a way of assessing a drug’s risk of causing serious hepatotoxicity; an increase in bilirubin (to at least 2 × ULN) and a concomitant transaminase elevation (to at least 3 × ULN), with no competing etiology, is associated with a high rate of bad outcomes, including 10% to 50% mortality or transplantation.36 Alcoholic hepatitis typically shows marked elevation in bilirubin with only slight elevation in transaminases (100 × ULN). Dramatically improving aminotransferases in the recovery period are equally typical

Laboratory Tests in Liver Disease

3

AST ± ALT > 10  ULN Yes

No

AST > 100  ULN

AST/ALT > 2

Yes

Yes

Hemodynamic instability

Ischemic hepatitis

No

No

No Yes

R ratio > 2 No

Yes

Normal biliary anatomy on imaging studies

No

Positive serology for viral or autoimmune Yes

Consider drug-induced liver injury

Extrahepatic cholestasis

Yes

Consider drug-induced liver injury or follow up

No

Ethanol use

Yes

Acute alcoholic hepatitis No

Acute viral or autoimmune hepatitis

FIGURE 3.1  Algorithm for evaluation of acute liver injury. ALT, Alanine aminotransferase; AST, aspartate aminotransferase; ULN, upper limit of normal.

of ischemic hepatitis and help substantiate the diagnosis. On occasion, the recovery period after the hemodynamic insult may be associated with a cholestatic pattern, which is often (and inaccurately) termed “cholestasis of sepsis.” In situations of severe congestive heart failure, surreptitious acetaminophen intake, and arrhythmias, liver tests fluctuating at high levels (10 to 100 × ULN) may be observed. AIH may present acutely and is characterized by a hepatocellular pattern of liver injury with associated increase in the serum globulin fraction (total protein-albumin >3.5), increase in total IgG, and presence of autoantibodies. Rarely, Wilson disease may present as acute hepatitis associated with acute renal failure and Coombs-negative hemolytic anemia; the ALP-to-total bilirubin ratio is characteristically low (3.5 gms/dL) and serum IgG elevation. The traditional markers of AIH include antinuclear antibodies (ANA), anti–smooth muscle antibodies (ASMA), and antibodies to liver/kidney microsome type 1 (antiLKM1). The presence of antibodies to asialoglycoprotein receptor (anti-ASGPR), liver-specific cytosol antigen type 1 (anti-LCA1), soluble liver antigen/liver pancreas antigen (anti-SLA/LPA), F-actin (antiactin), and/or perinuclear antineutrophil cytoplasmic antibodies (pANCA) support a probable diagnosis of AIH if the other conventional markers are absent. Type 1 AIH (ANA ± ASMA positive) is mainly seen in adults, whereas type 2 AIH (anti-LKM1 positive) is predominantly a pediatric disease. An elevated AST/ALT ratio strongly suggests chronic alcohol-related liver disease and results from depletion of pyridoxine in chronic alcoholics, which leads to inhibition of synthesis of ALT. Moreover, alcohol also causes direct mitochondrial toxicity, releasing the mitochondrial isoenzyme of AST. Hereditary hemochromatosis (HH) is a genetic disorder associated with hemosiderin deposition in hepatocytes that if left untreated, leads to progressive fibrosis and cirrhosis; patients have a high risk of developing hepatocellular carcinoma. The aim of clinical management is to prevent iron accumulation and therefore fibrosis. Although laboratory estimation of hepatic iron content (HIC) and calculation of the hepatic iron index (HII) have historically been used to establish the diagnosis, currently diagnosis of HH is made by genotyping for the two most common mutations, C282Y, and H63D, in the HFE gene. In spite of the high prevalence of these genotypes (1:200 people of North European descent are homozygous for C282Y), phenotypic expression of these genes in terms of iron accumulation is extremely variable, with fewer than 1% of patients showing signs and symptoms of iron overload.23 The role of laboratory tests has therefore shifted from establishing a diagnosis of HH to identifying patients with iron overload and estimating its severity. Tests most commonly used for this purpose are levels of serum iron, serum ferritin, and transferrin saturation. Both transferrin (normal values, 190 to 440 mg/dL in women and 220 to 500 mg/dL in men) and ferritin (normal values, 9 to 140 μg/L in women and 18 to 360 μg/L in men) sequester the highly reactive iron molecules and prevent formation of free radicals. Serum ferritin levels of 1000 ng/mL or more are usually associated with the presence of liver disease. Ferritin, however, is also an acute phase reactive protein and may be elevated in inflammatory conditions.24 Total iron-binding capacity (TIBC) is a test that measures the extent to which iron-binding sites in the serum can be saturated. It reflects the ability of transferrin to carry iron in the blood. Transferrin saturation is calculated from the ratio of serum iron concentration to TIBC and expressed as a percentage (serum iron ÷ TIBC × 100), with normal values ranging from 16% to 45%. HIC can be measured on samples obtained by a liver biopsy and are reported as micromoles of iron per gram dry weight of liver. Values exceeding 71 μmol/g (normal 600 nmol) may indicate Wilson disease and warrants further investigation.44 A cholestatic pattern (R ≤2) is seen commonly with PBC, PSC, and obstruction of the biliary tree. The diagnosis of PBC is usually made when two of the following three criteria are met: elevated ALP, AMA positivity, and liver biopsy suggestive of PBC. The diagnosis of PSC is made by typical radiographic findings of a “beaded” appearance of the extrahepatic biliary tree. Although patients with PSC may demonstrate a number of antibodies, including atypical pANCA, these are not specific and do not correlate with the activity of the disease. The presence of a cholestatic pattern of injury mandates the exclusion of obstruction in the biliary tree; therefore imaging studies (liver ultrasound or computed tomography) are performed to exclude intrahepatic or extrahepatic biliary dilation and tumor masses in these patients. Further evaluation may require the performance of endoscopic retrograde cholangiopancreatography (ERCP), MRCP, or endoscopic ultrasound to evaluate for pancreatic masses, ampullary tumors, cholangiocarcinoma, and choledocholithiasis. Chronic hepatitis with a mixed pattern of elevated liver tests (2 < R < 5) may be seen with chronic DILI and overlap syndromes: the latter are syndromes in which PBC or PSC coexists with AIH. The diagnosis of an overlap syndrome requires the independent demonstration of both biliary disease and AIH.45,46 An algorithmic approach to the diagnosis of chronic liver disease is shown in Fig. 3.2. It is not always possible to distinguish acute hepatitis from chronic liver disease. Therefore, when the chronic liver disease is associated with a pattern of acute liver injury, it is imperative to perform additional testing to rule out concomitant acute hepatitis.

Laboratory Investigation of Liver Disease in Pregnancy Physiologic changes of pregnancy are associated with minor variations in liver tests, except ALP and albumin.47,48 Although the modest increase in ALP during the third trimester results from leakage of

Laboratory Tests in Liver Disease

3

What is the R ratio?

Yes

R5 (Hepatocellular)

Biliary ductal dilation on US or CT

Consider Overlap syndromes Chronic DILI

Positive viral or autoimmune serology

No

Positive No Imaging antimitochondrial studies antibody (ERCP/MRCP Yes /EUS) Liver biopsy to confirm or Primary biliary to assess Normal cholangitis fibrosis

Choledocholithiasis Cholangiocarcinoma Ampullary tumors Pancreatic carcinoma Primary sclerosing cholangitis Hepatic mass lesions

Small duct primary sclerosing cholangitis Antimitochondrial antibody negative primary biliary cholangitis Sarcoidosis Hepatic lymphoma Other infiltrative liver disease

Yes

No

No Excessive alcohol use

Evaluation for metabolic liver disease

Yes

Consider alcoholic liver disease

Nonalcoholic fatty liver disease Hereditary hemachromatosis Wilson disease Celiac disease Alpha-1 antitrypsin deficiency Seronegative hepatitis

FIGURE 3.2  Algorithm for evaluation of chronic liver disease. CT, Computed tomography; DILI, drug-induced liver injury; EUS, endoscopic ultrasound; ERCP, endoscopic retrograde cholangiopancreatography; MRCP, magnetic resonance cholangiopancreatography; US, ultrasonography.

placental ALP into maternal circulation and increased maternal bone turnover, the fall in albumin levels results from hemodilution due to volume expansion.49 Any increase in aminotransferases, bilirubin, GGT, or serum bile acids, on the other hand, indicates hepatobiliary pathology and warrants prompt workup. Pregnant women, like other individuals, may develop acute viral hepatitis,50 AIH, or DILI, but there are certain liver diseases that occur specifically in pregnant women and other diseases that are predisposed to by the physiologic changes of pregnancy. The latter include gallstone disease caused by increased lithogenicity of bile and impaired motility of the gallbladder in pregnancy,51 and fulminant hepatic failure from acute HEV and herpes simplex virus caused by a relative immunocompromised state.52,53 The procoagulant state of pregnancy predisposes patients with inherited coagulation disorders to Budd-Chiari syndrome.54 Differential diagnosis of pregnancy-specific liver disorders is often guided by gestational age.55 Hyperemesis gravidarum characterized by nausea and vomiting usually occurs in the first trimester and resolves by 20 weeks. Approximately half of all patients with severe symptoms show elevated aminotransferases, usually in the 200 to 300 U/L range.56 Although bilirubin may be slightly elevated, it is not associated with clinical jaundice because it is mainly unconjugated. A liver biopsy is not clinically indicated to make the diagnosis, and if performed, it shows minor nonspecific changes. Treatment is mainly supportive. Cholestasis of pregnancy occurs in the second trimester and is characteristically associated with itching and rise in serum bile acid levels. Liver tests demonstrate a hepatocellular pattern of injury with aminotransferase elevations (≤100 U/L) and a normal GGT.56 A liver biopsy, if performed, shows only bland cholestasis and is clinically not warranted. In addition

to supportive care, ursodeoxycholic acid (UDCA) has been used effectively. Preeclampsia/eclampsia; hemolysis, elevated liver tests, low platelets (HELLP) syndrome; and acute fatty liver of pregnancy should be considered in the differential diagnosis of abnormal liver tests in the third trimester. Although preeclampsia is associated with hypertension, proteinuria, and peripheral edema, the onset of seizures and coma signifies eclampsia. There is an elevation in aminotransferases and ALP beyond the normal increase seen in pregnancy. Patients with HELLP syndrome develop thrombocytopenia in addition to signs of preeclampsia and typically present with right upper quadrant pain, fever, nausea, and vomiting. This syndrome develops in as many as 30% of cases after delivery of the infant.56 There is marked elevation of aminotransferases (up to 6000 U/L) in these cases. Patients with acute fatty liver of pregnancy have decompensated liver disease and may or may not have features of preeclampsia and HELLP syndrome.57 The presentation varies from asymptomatic elevations in aminotransferases to fulminant hepatic failure; the condition may also present postpartum. Laboratory studies show prolonged PT and low fibrinogen levels.

Laboratory Investigation of Liver Abnormalities in Systemic Diseases and Disease of Other Organs Liver tests may be abnormal in diseases primarily involving organs other than the liver such as the heart (congestive cardiac disease) or intestines (celiac disease, ulcerative colitis), in systemic diseases (systemic lupus erythematosus), endocrine disorders (hyperthyroidism) as well as with neoplastic processes that do not directly involve the liver (Stauffer syndrome). Therefore, when screening serology and diagnostic imaging are negative for primary liver disorders as a cause for abnormal liver tests, 49

Practical Hepatic Pathology: A Diagnostic Approach Box 3.1  Systemic Diseases That Show Liver Involvement Cardiovascular Disease Ischemic hepatitis Congestive hepatopathy Endocrine Disorders Hyperthyroidism Glycogen hepatopathy Adrenal insufficiency Glycogen storage disorder Autoimmune/Connective Tissue Disordersa Rheumatoid arthritis/Felty syndrome Juvenile rheumatoid arthritis Scleroderma/CREST Polyarteritis nodosa Behçet disease Idiopathic inflammatory bowel disease Infections Infectious mononucleosis Mycobacterial infection Fungemia Cholestasis of sepsis

Hematologic Disorders Malignant Hodgkin lymphoma Non-Hodgkin lymphoma Leukemia Myelofibrosis Benign Sickle cell hepatopathy Thalassemia Paraneoplastic Syndrome Stauffer syndrome Vanishing bile duct syndrome Other Total parenteral nutrition Heatstroke Amyloidosis Sarcoidosis Celiac disease Gilbert syndrome Graft-versus-host disease

Oncologic Disorders Metastatic liver disease Extrinsic biliary obstruction aThese

conditions have been associated with nodular regenerative hyperplasia.

consideration should be given to evaluate for a systemic disease with liver involvement (Box 3.1). Because, in most cases, the primary or underlying condition is already known, abnormal liver tests do not automatically call for a liver biopsy. The latter is only performed when there is a known association with liver disease that needs to be excluded or that needs an assessment of severity. Knowledge of liver involvement is therefore very important for an accurate diagnosis and histologic interpretation when a liver biopsy is performed. In some instances, as with ischemic hepatitis or congestive hepatopathy, definitive and distinctive histologic changes may be seen in addition to abnormal liver tests (eSlides 30.4 and 30.12). Other diseases, however, give rise to elevated liver tests either without any accompanying histologic changes or with minimal nonspecific changes, often referred to as nonspecific reactive hepatitis (eSlide 3.1). The latter refers to a variable constellation of histologic findings that include minimal to mild portal lymphocytic inflammation with no interface hepatitis, foci of lobular inflammation, spotty necrosis, and prominence of Kupffer cells; there is no fibrosis. These changes are mild and almost always focal in distribution. Liver test abnormalities are usually mildly elevated in a hepatocellular or mixed pattern. Connective Tissue Diseases Connective tissue diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjögren syndrome (SS), and scleroderma are immunologically mediated disorders that typically present with multisystem involvement.58 Although clinically significant liver involvement is rare, liver enzyme abnormalities are reported in up to half of these patients. These abnormalities are typically mild and transient, and histologic abnormalities are usually nonprogressive; they are typically ascribed to the primary rheumatologic condition and require no specific management. Common histopathologic findings in SLE include hepatic steatosis, portal inflammation, and vascular changes like hemangioma, congestion, nodular regenerative hyperplasia, arteritis, and abnormal vessels in portal tracts. The role of a liver biopsy is to rule out the presence of a concomitant pathology, which is not unusual. 50

Patients with RA have been frequently reported to have abnormal LT sometimes with hepatomegaly. Histologic findings are nonspecific and include nonspecific reactive hepatitis, steatosis, chronic hepatitis, and minimal portal fibrosis. Rarely, RA is associated with splenomegaly and neutropenia and is termed Felty syndrome.59-62 In Sjögren syndrome, hepatomegaly and abnormal liver tests are reported in about 25% of the cases; liver biopsy findings are nonspecific. Liver involvement by polyarteritis nodosa presents diagnostic challenges because of the variability of clinical manifestations and occult liver involvement.63 It may present with fever, ALP elevation, and no obvious jaundice. Histologic examination of the liver may reveal necrotizing arteritis of small hepatic arteries that may be associated with intrahepatic bile duct damage, which resembles sclerosing cholangitis.64 Connective tissue disorders such as RA and other autoimmune disorders affect the liver through portal obliterative venopathy resulting in nodular regenerative hyperplasia (NRH) and noncirrhotic portal hypertension (NCPH).65,66 NRH was first described by Ranstrom in 1953 in a patient with Felty syndrome.67 In 1959, Steiner coined the term “nodular regenerative hyperplasia,” emphasizing that hepatocyte hyperplasia or regeneration occurred in the absence of fibrous tissue proliferation resulting in a nodular liver simulating cirrhosis.65 It is speculated that obliterative portal venopathy and subsequent alterations in perfusion cause local hepatocyte ischemia with compensatory hypertrophy of unaffected adjacent hepatocytes resulting in NRH. The recent demonstration of downregulation of Notch1, delta-like 4, and ephrinB2, genes involved in vascular differentiation, suggest that NRH is indeed caused by sinusoidal injury.68,69 NRH can develop in all age groups, but more commonly affects older individuals.70 Inflammatory bowel disease has also been associated with NRH and was incidentally found in 6% of thiopurine naive inflammatory bowel disease (IBD) patients undergoing bowel resection.71 The majority of patients with milder forms of NRH likely remain unidentified, and their disease course is rarely characterized because of asymptomatic course of the disease with mild elevations in transaminases (300 U/L are unusual and prompt workup for concomitant liver diseases. These enzyme values fluctuate and may rarely be associated with an increase in alkaline phosphatase.78 Type 1 (insulin-dependent) diabetes is associated with hepatomegaly, LT abnormalities, and a bright liver on imaging studies.79 In contrast to type 2 diabetes, however, the bright liver is caused by glycogen, rather than fat, deposition within hepatocytes (glycogen hepatopathy), which resolves after successful pancreatic transplantation.79 Liver test abnormalities usually show a hepatocellular or mixed pattern of injury and may be elevated up to 10 × ULN. Histologically, there is diffuse enlargement of hepatocytes that contain pale cytoplasm that has a finely granular and vaguely ground-glass appearance. Giant mitochondria and glycogenated nuclei may be prominent. In contrast to nonalcoholic fatty liver disease associated with metabolic syndrome, inflammation, Mallory-Denk bodies and fibrosis are not present (eSlide 3.2). The histologic features have been variously referred to as glycogen hepatopathy, hepatic glycogenosis, and diabetic hepatopathy. The biochemical and histologic findings are associated with poor glycemic control and improve rapidly when glycemic control is achieved.79-81 Infectious Diseases Infection and sepsis-associated cholestasis often occurs in patients hospitalized in the intensive care unit for gram-negative bacteremia complicated by hemodynamic alterations requiring vasopressor usage.82 The diagnosis is based on marked elevations in serum bilirubin with modest elevations in lactate dehydrogenase (LDH) and liver enzymes. Recovery is usually protracted and improves with antibiotic therapy; persistent LT abnormalities are associated with worse outcomes.83 Histologically, the prominent feature is intrahepatic cholestasis with Kupffer cell hyperplasia, portal mononuclear cell infiltrates, and focal hepatocyte dropout.82 Cholangitis lenta is an unusual manifestation that is characterized by the presence of periductal cholangiocytes and inspissated bile within dilated and proliferated portal and periportal ductules84-88 (see Fig. 1.38) (eSlide 3.3). Interestingly, a recent study revealed that by withholding parenteral nutrition for more than a week, increased plasma bilirubin but reduced the occurrence of biliary sludge and lowered serum alkaline phosphatase and transminases.89 It is suggested that hyperbilirubinemia during critical illness may not completely be related to cholestasis and may also be an adaptive response caused by suppression by parenteral nutrition.89 Behçet disease (BD) is characterized by a triple-symptom complex of recurrent oral aphthous ulcers, genital ulcers, and uveitis.90 It is

characterized by chronic recurring lymphocytic vasculitis targeting the vasa vasorum and other small blood vessels, which affects veins more than arteries.90-92 Clinical manifestations are a consequence of vascular damage that causes arterial pseudoaneurysms and venous thrombophlebitis of the veins.90-92 The most common complication involving the liver is Budd-Chiari syndrome occurring from hepatic vein vasculitis.91

3

Neoplastic Diseases The liver is a common site for metastasis from a wide variety of neoplasms and is often involved as part of multiorgan hematologic malignancies (see Chapter 36). Abnormal liver tests in cholestatic or mixed patterns may result from compression of the bile duct or invasion of portal or hepatic veins from tumors that do not directly invade the liver. Imaging studies are usually diagnostic and a liver biopsy is not required for diagnosis. Much less frequent is paraneoplastic involvement of the liver, particularly with renal cell carcinoma and malignant lymphoproliferative diseases such as lymphomas, that can induce a reversible form of cholestasis through mechanisms that are not completely understood.93-95 Stauffer syndrome is a rare paraneoplastic manifestation of renal cell carcinoma (RCC) that is characterized by elevated serum alkaline phosphatase, total bilirubin, and γ-glutamyl transferase, thrombocytosis, prolongation of prothrombin time, and hepatosplenomegaly, in the absence of hepatic metastases.95-97 Liver involvement in Hodgkin lymphoma is common and could be due to hepatic infiltration, biliary obstruction by lymphoma, hepatitis, sepsis, or DILI from chemotherapeutic agents. The vanishing bile duct syndrome is reported as a rare paraneoplastic manifestation of Hodgkin lymphoma in which cholestasis and loss of bile ducts are seen in the absence of a malignant infiltrate.98 The mechanism is poorly understood. Cardiac Diseases Hepatic manifestations of cardiac diseases include ischemic hepatitis and congestive hepatopathy. The pathophysiology of ischemic hepatitis, also known as “shock liver,” is poorly understood but is thought to result from a combination of reduced hepatic blood flow and passive congestion of liver from the underlying cardiac disease. Patients usually show sudden and dramatic transient increases in serum aminotransferase (>100 × ULN), lactate dehydrogenase (LDH) levels, and bilirubin following periods of hemodynamic instability or hypoxia. There may be damage to other organs such as the kidney. Patients improve rapidly, usually within 7 to 10 days, once the cardiac disease is stabilized. The diagnosis is usually apparent clinically; if a liver biopsy is performed, it shows perivenular (zone 3) necrosis of hepatocytes (eSlide 30.12). Cardiac disease may also manifest as right-sided failure that leads to congestive hepatopathy results due to increased stasis and backflow pressure along the venous system. Liver test abnormalities show a mixed pattern of injury but predominantly with elevations in alkaline phosphatase. These levels may fluctuate with an associated increase in PT and INR and correlate with severity of heart failure. A liver biopsy is rarely performed, often through a transjugular approach and primarily in patients where the etiology is not apparent or as part of workup for cardiac transplantation (eSlide 30.4). Varying degrees of hepatic venular and centrilobular sinusoidal dilatation and congestion with fibrosis are the main findings (discussed in Chapter 30). Gastrointestinal Diseases The prevalence of LT abnormalities is relatively high in certain gastrointestinal disorders such as IBD and celiac disease but the development of severe liver injury is exceptional (eSlide 3.4). Moreover, most alterations of liver tests are mild and related to activity of the primary disease with spontaneous return to normal values.99 Mild liver test abnormalities, mainly presenting as elevated transaminases (5 minutes) images. The distinction of a vascular thrombus in the portal vein from a tumor thrombus has profound therapeutic implications; features suggesting tumor thrombus include distended vein, irregular enhancement of thrombus, and higher signal than liver on T2-weighted MR images. Practice guidelines of the American Association for the Study of Liver Diseases11 (AASLD) use the typical enhancing pattern of HCC on dynamic imaging as definite diagnostic criteria for HCC. Thus, a hypervascular mass in a cirrhotic liver with washout on either CT or MRI is likely to be HCC if it is more than 2 cm in size, and a diagnostic biopsy is not necessary. If the lesion is 1 to 2 cm in size and shows typical findings on two different imaging modalities, a confirmatory biopsy is again not necessary. A biopsy is recommended only if the CT and MRI findings are discordant or if the lesion shows atypical findings. HCC in a cirrhotic liver needs to be differentiated from regenerative and dysplastic nodules; these benign lesions may be isointense or hyperintense to the surrounding liver on noncontrasted T1-weighted MRI (Fig. 4.8). Unlike most cases of HCC, these benign nodules are isointense to the liver on T2-weighted MRI and do not show arterial enhancement. HCC is not the only hypervascular lesion in a cirrhotic liver. Small peripheral triangular hypervascular lesions may be seen and almost always represent regions of vascular shunting. These lesions usually do not persist on serial CT/MRI studies. Rarely, a dysplastic nodule may be hypervascular. If it increases in

Investigative Imaging of the Liver size, such a nodule would be followed with serial imaging and treated as HCC. Table 4.3 gives the differential diagnosis of liver lesions seen in a patient with cirrhosis.

4

Metastases

A

B

Metastases develop neovascularity primarily from hepatic arterial branches. For imaging purposes, they are classified as hypervascular (higher CT density or MRI signal than surrounding liver in arterial phase) or hypovascular. Most metastases (eg, from lung, breast, and the gastrointestinal tract) are hypovascular and show decreased enhancement relative to normal liver and are most conspicuous on portal venous phase images. Therefore routine cancer staging is often performed in the venous phase only. In contradistinction, hypervascular metastases enhance earlier, are best seen on arterial phase images, and show washout on delayed images. Hypervascular metastases typically arise from neuroendocrine tumors (Fig. 4.9), renal cell carcinoma, thyroid carcinoma, melanoma, gastrointestinal stromal tumor, and sarcomas. Table 4.4 gives the differential diagnosis of liver lesions seen in patients without chronic liver disease. The sensitivity of CT and MRI in detecting liver metastases is thought to be 80% to 90%; lower reported sensitivities come from earlier studies that used less sophisticated technology of the 1990s. MRI not only has the advantage of differentiating small cysts and hemangiomas from metastases because of hyperintensity on T2-weighted sequences but also benefits from the added advantage of newer contrast agents that further increase sensitivity, compared with traditional gadolinium contrast agents. Superparamagnetic iron oxide particles are taken up by Kupffer cells and cause a normal liver to appear very dark on T2-weighted images, allowing the detection of small metastases that stand out as bright lesions. Continuing improvements of CT and MRI technology allow the routine detection of hepatic lesions less than 10 mm in size; these lesions rarely represent metastases from an unknown primary cancer. Most such lesions are cysts, hemangiomas, focal eosinophilic necrosis, and biliary hamartomas. Even in patients with known breast cancer, the likelihood of such a small lesion being metastatic is 4% to 7%.12 Similarly, a study of patients with known gastric and colorectal cancer demonstrated that the probability of a hepatic lesion less than 15 mm being metastatic, in the absence of larger lesions, was 3%.13 MRI is helpful in confirming the benign nature of these lesions, especially when they represent cysts, hamartomas, or hemangiomas. Metastases should be considered when there are multiple lesions of varying sizes, especially if they are ill-defined and larger than 2 cm.

Cholangiocarcinoma

C Figure 4.4 Liver metastasis. A 64-year-old male with known colorectal cancer. A, Computed tomography (CT) component of positron emission tomography (PET)–CT shows a barely visible low density lesion (arrowhead) in the right lobe and a larger well-defined lesion in the left lobe (thin arrow). The xiphisternum (thick arrow) is unremarkable. B, PET component shows increased activity in the right lobe lesion (arrowhead) and the sternum (thick arrow). The left lobe lesion (thin arrow) is hypometabolic. C, Composite image, made by fusion of CT and PET, shows not only the activity of the three lesions but also their exact site. The left lobe lesion (thin arrow) was confirmed as a simple cyst on subsequent studies (not shown). PET images are more sensitive than CT images for small liver metastases but lack accurate anatomic localization, which is provided by the fusion of the CT and PET images.

Mass-forming cholangiocarcinoma show heterogeneous enhancement because of the presence of central fibrosis. The periphery of the tumor enhances early and there is delayed central enhancement (Fig. 4.3).14 Necrosis or hemorrhage is rare. These tumors usually occur in the hepatic hilum and cause bilateral biliary dilation and occasionally venous encasement without venous thrombosis. The centripetal delayed enhancement of a central mass, with associated biliary dilation, is unique for cholangiocarcinoma. Cholangiocarcinoma that do not form a mass are difficult to visualize on CT or MRI; often the only clue to their presence is an abrupt biliary stricture with mild duct wall dilation.

Imaging of Diffuse Liver Disease Hepatic Steatosis

Sonographic findings of hepatic steatosis include increased echogenicity of liver, blurring of vascular margins, and increased acoustic 59

Practical Hepatic Pathology: A Diagnostic Approach

A

B

C

D Figure 4.5  Hemangioma. A 34-year-old female with right upper quadrant pain and a hepatic lesion demonstrated on sonography (not shown). Magnetic resonance imaging performed in arterial (A), venous (B), and 5-minute delayed (C) phases show a right lobe lesion (arrowhead) with initial nodular, peripheral enhancement (B, arrow) and gradual centripetal filling in C (arrow). In large lesions, the center may not completely fill in. Note that the enhancement is of same intensity on all phases as that of the aorta. D, On T2-weighted image, the mass (arrowhead) is uniformly hyperintense and is of similar intensity as cerebrospinal fluid (arrow). These findings are diagnostic of hemangioma, and biopsy is not necessary.

attenuation. The sensitivity and specificity of detecting severe fatty liver (more than 30% fat by weight) by sonography are 67% to 84% and 77% to 100%, respectively.15,16 However, sonography is insensitive for smaller amounts of fat in the liver. In addition, the degree of fatty liver change can only be subjectively classified as mild or severe on sonography. Fatty change is seen on CT as decreased attenuation of liver density. The reported sensitivity and specificity values are around 50% to 75%.17 CT is not sensitive in detecting mild or moderate elevations of hepatic lipid content (5% to 30%).16 Because of the effect of surrounding electrons, the magnetic field experienced by a nucleus is slightly different than the field produced by the MRI magnet. Thus hydrogen nuclei (protons) in water and fat molecules have slightly different processional (or vibrational) frequencies; this physical phenomenon allows MRI to quantitatively assess fatty infiltration. The most commonly used sequence is called chemical shift imaging, which obtains two series of images in which the signal from fat and water protons are added (in-phase image) or subtracted (out-of-phase). Reduction of signal on out-of-phase T1-weighted images has been shown to be an accurate predictor of hepatic fat content (Fig. 4.10), with correlation values (r) of 0.86 to 60

0.91 compared with histologic assessment of liver fat.18-20 Increasingly sophisticated methods of chemical shift imaging, such as three-point Dixon techniques, which take into account the confounding effect of hepatic iron content on the signals of in-phase and out-of-phase series, are now available. Magnetic resonance spectroscopy (MRS) is a technique that quantitatively assesses the concentrations of various chemical species in a tissue, using the frequency shift of nuclei in their molecules. Hydrogen (1H) MRS has been found to have good correlation with hepatic lipid content (Fig. 4.11), as determined by liver biopsy, with correlation (r) values of 0.91 to 0.98.21-23 This technique is considered sensitive to small variation (as little as 0.5% change) in hepatic lipid content and may thus be potentially useful in the assessment of the effectiveness of therapy for steatosis.24

Hepatic Fibrosis and Cirrhosis Liver biopsy is the current gold standard for diagnosing and staging fibrosis. However, there are well-known disadvantages of liver biopsy, including sampling error due to heterogeneity of disease; interobserver and intraobserver variation of histologic interpretation; and a small, but definite, risk of complications.

Investigative Imaging of the Liver

4

A A

B B

C Figure 4.6  Focal nodular hyperplasia (FNH). A 19-year-old female with an abnormal computed tomography scan (not shown). A, Arterial phase magnetic resonance imaging scan shows a lobulated hepatic lesion (arrowhead) that enhances brightly and uniformly, except for a central curvilinear scar (arrow). B, On the 5-minute delayed phase, the lesion (arrowhead) is isointense to liver, rapidly washing out the contrast. However, the fibrous scar (arrow) shows delayed enhancement. C, The patient had been given gadobenate as gadolinium agent. On the hepatocellular phase (performed at 2 hours after contrast injection), the lesion (arrow) is hyperintense to the liver. This is due to the presence of functioning hepatocytes and biliary radicals in FNH that enable biliary excretion of the contrast agent. The only other lesions that show hyperintensity on the hepatocellular phase are regenerating nodules and some well-differentiated hepatocellular carcinoma (HCC). The lesion may be distinguished from fibrolamellar HCC by the enhancement pattern for the scar (see text).

C Figure 4.7  Hepatic adenoma. A 25-year-old female taking oral contraceptives presenting with abdominal pain. A, On the arterial phase of magnetic resonance imaging, there is a 4-cm hypervascular lesion (arrowhead). No scar is seen. B, On the venous phase, the lesion (arrowhead) has reduced in enhancement but is still mildly hyperintense to the surrounding liver. C, On the hepatocellular phase of gadobenate, the lesion (arrowhead) is predominantly hypointense to liver. Results of the biopsy indicated the lesion to be a hepatic adenoma.

61

Practical Hepatic Pathology: A Diagnostic Approach Table 4.3  Differential Diagnosis of Dominant Liver Nodules in Cirrhotic Liver Hypervasculara

A

Hypovascularb

Hepatocellular carcinoma

Arterial enhancement, washout on venous phase, delayed capsular enhancement

Hemangioma

Enhancement follows that of aorta with peripheral nodular (not ringlike) enhancement followed by centripetal filling on delayed phases; “flash-filling” if small; density and signal intensity same as aorta; very hyperintense on T2-weighted MRI

Vascular shunt

Peripheral, triangular rather than rounded, no mass effect; not persistent on followup scan

Regenerating nodule

No arterial enhancement or washout; usually less than 2 cm in size

Hepatocellular carcinoma

Poorly differentiated cancer may be hypovascular; usually infiltrative and causes venous thrombosis

Cyst

Small, well-defined edge, no wall or internal enhancement, bright on T2-weighted MRI

aHypervascular: Brighter than surrounding liver on arterial phase with reduced brightness on subsequent phases. bHypovascular: Less bright than surrounding liver on the arterial, and particularly, on the venous phase.

B

C Figure 4.8  Regenerating nodules. A and B, A 41-year-old male with hepatitis C– induced cirrhosis. Note that the liver has a nodular outline. A, Precontrast image shows two lesions (arrows) which are mildly hyperintense. Hyperintensity on T1-weighted images could be because of the presence of intralesional fat or paramagnetic elements, such as copper. B, On postcontrast image, the lesion in the right lobe (arrow) is barely visible as a hypointense focus. The lesion in the left lobe is not visible. C, Postcontrast magnetic resonance imaging in a 48-year-old female with nonalcoholic steatohepatitis–related cirrhosis shows several subcentimeter hypointense lesions (arrowheads) throughout the liver consistent with regenerating nodules.

CT, MRI, and sonography can detect advanced cirrhosis and the presence of portal hypertension. Sonographic findings of nodular liver contour, altered architecture such as hypertrophy of left lobe, and altered appearance of parenchyma such as coarse echotexture are features of cirrhosis. Findings of portal hypertension, including splenomegaly, ascites, and the presence of varices, are easily determined on 62

CT or MRI. However, these tests are not sensitive enough to detect the presence of lower grades of fibrosis. Several new techniques have been investigated for the diagnosis of hepatic fibrosis, including contrastenhanced sonography, diffusion-weighted MRI, perfusion CT and MRI, and MRS. Liver T1 mapping and intravoxel incoherent motion (IVIM) imaging are the latest promising diagnostic tool for assessing cirrhosis diagnosis and severity.24,25 Contrast-Enhanced Sonography This technique is performed with intravenous injection of 2- to 6-μm gas-filled microbubbles with a biocompatible shell of proteins or biopolymers.26 The contrast agent produces intense echogenicity as it passes through vessels of the organ being sonographically evaluated. The time from injection to the appearance of the microbubbles in the hepatic veins, called the hepatic vein transit time (HVTT), has been suggested as an indicator of liver fibrosis. Studies have shown that HVTT is lower in patients with cirrhosis than in those without cirrhosis,27,28 most likely because of arteriovenous shunting and arterialization of the sinusoidal capillary bed seen in chronic liver disease. A recent prospective multicenter study of 99 patients showed that an HVTT of less than 13 seconds had sensitivity and specificity of 79% in differentiating high-grade fibrosis (METAVIR F3 and F4) from lower grades of fibrosis.29 These sonographic contrast agents are not widely available in the United States. Transient Elastography Liver elastography has been proposed for liver stiffness monitoring, prognostication of hepatic complications, assessment of cirrhosis, and detection of inflammation and portal hypertension. Sonographic waves cause distortion (also called shear) of the tissues they pass through; the degree of distortion is related to the stiffness of tissue. This is analogous to clinical palpation to determine the stiffness and flexibility of an organ. With appropriate technology, it is possible to measure the degree of distortion and convert this into a map of tissue elasticity, or elastogram.

Investigative Imaging of the Liver Studies have shown good specificity (85% to 91%) for the detection of fibrosis in hepatitis C and alcohol-related liver disease.30-33 A recent metaanalysis found pooled estimates for sensitivity and specificity of 87% and 91%, respectively.34,35 Although the test may not easily distinguish each grade of fibrosis in a stepwise fashion, it is useful for differentiating patients with chronic hepatitis C with advanced fibrosis (F3 or F4) from those with less severe stages of fibrosis.36 The limitations of this imaging technique are operator errors, patient’s inability to hold still, increased depth because of increased subcutaneous fat or ascites around the liver.

Figure 4.9  Hypervascular metastases. Coronal reformation of computed tomography in a 38-year-old female presenting with uncontrolled diarrhea. There is a 2-cm enhancing mass in the ileum (arrow). Hypervascular liver lesions (arrowheads) were seen in the liver. Surgery revealed metastatic carcinoid tumor. Untreated metastases from neuroendocrine tumors are typically hypervascular.

Table 4.4  Differential Diagnosis of Focal Liver Lesions in Noncirrhotic Liver Hypervascular

Hypovascular

Fibrolamellar hepatocellular carcinoma

Arterial enhancement, washout on venous phase, scar that usually does not enhance.

Focal nodular hyperplasia

Bright arterial enhancement followed by almost complete washout on the venous phase. Scar enhances on delayed phase, is bright on T2-weighted MRI. Lesion is hyperintense or isointense on hepatocellular phase.

Hepatic adenoma

May be similar to FNH in early enhancement but washout is usually incomplete (ie, variable hyperintensity on venous phase). No scar. Hypointense on hepatocellular phase.

Hypervascular metastases

Metastases from neuroendocrine, renal, thyroid cancer; melanoma; gastrointestinal stromal tumors. Multiple rounded lesions of variable enhancement and sizes. Vascularity may change dramatically after treatment.

Hemangioma

See Table 4.3.

Cyst

Small, well-defined edge, no wall or internal enhancement, very hyperintense on T2-weighted MRI.

Hypovascular metastases

Most metastases, including colon, breast, lung, gastric. Multiple, rounded lesions of different sizes.

Cholangiocarcinoma

Masslike lesions show delayed central enhancement. Bile duct obstruction is seen more often than venous invasion, unlike HCC.

Abscess

Thick-walled mass with low density center, may mimic necrotic metastases. Usually clinically obvious/ suspicious.

FNH, Focal nodular hyperplasia; HCC, hepatocellular carcinoma: MRI, magnetic resonance imaging.

4

Magnetic Resonance Elastography Ultrasound elastography techniques are relatively inexpensive, portable, increasingly available, and generally provide good diagnostic accuracy for advanced fibrosis. Nevertheless, they sample relatively small portions of the liver, and they may be unreliable in obese patients and in those with narrow intercostal spaces. Magnetic resonance elastography (MRE) samples larger portions of the liver and offers excellent diagnostic accuracy that probably slightly exceeds that of ultrasound-based techniques. The MRE technique uses mechanical waves at a known frequency (40 to 200 Hz) produced by an active generator and conducted into the body by a device (passive driver) that is placed directly over the liver while the patient is in an MR scanner. The wave images are then processed with a special inversion algorithm to generate a stiffness map or elastogram from which the stiffness of liver can be quantified (Fig. 4.12). Standardized mechanical wave generator and pulse sequences are being established. The potential advantages compared with sonographic elastography include the ability to scan obese patients and larger volumes of liver (thus reducing error caused by geographic variability of fibrosis), as well as to detect complications, such as HCC, in the same study with other MRI sequences. MRE may have the potential to differentiate intermediate stages of fibrosis.35 Histologically determined fibrosis stage is a semiquantitative assessment of cumulative liver injury based on the location and amount of excess collagen, as well as associated remodeling of liver architecture.37 Because the location of collagen and the presence of remodeling contribute to the fibrosis stage, the fibrosis stage is not dictated solely by the total amount of collagen, and the relationship of fibrosis stage to total collagen content is not linear.38 The accuracy of elastography techniques for assessment of fibrosis may be influenced by technical and instrument-related factors and biological and patient-related factors. Some confounding factors may be technique or instrument specific, but it is reasonable to assume that the physiologic underpinning of several biological and patient-related confounding factors should be equally applicable to ultrasound elastography and MRE.

Summary In summary, improvements in CT and MRI technology and the availability of newer contrast agents have improved the detection and characterization of liver lesions. It is estimated that preoperative or prebiopsy characterization is possible in over 80% of liver tumors. MRI techniques are very accurate in quantifying hepatic fat content; however, current imaging tests are not satisfactory in determining the presence or severity of hepatitis. The main clinical application for elastography techniques in the abdomen is noninvasive detection and staging of liver fibrosis. Both ultrasound elastography and MRE techniques report very good to excellent diagnostic performance for diagnosis of advanced fibrosis. It is difficult to foresee that imaging tests will completely replace liver biopsy. However, they may reduce the necessity for a biopsy in many instances, and direct the site for biopsy in others. 63

Practical Hepatic Pathology: A Diagnostic Approach

B

A

Figure 4.10  Chemical shift magnetic resonance imaging (MRI) showing a 59-year-old male with diabetes. Liver appears diffusely hypointense on out-of-phase chemical shift MRI scan (A), compared with in-phase image (B) indicating presence of fat. The degree of signal loss may be used to quantify the fat content, estimated as 45% in this case.

b f

f

g

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c e

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B Figure 4.11  Proton magnetic resonance spectroscopy showing a 39-year-old female with hepatic steatosis (A) and a 29-year-old male symptom-free volunteer (B). In the healthy volunteer, only resonances of water (f) and methylene (b), found in hepatic triglycerides and fatty acids, are discernible. Normal liver contains less than 5% fat by weight. In patient with hepatic steatosis, amplitude of methylene resonance (b) is much higher. Several other lipid resonances are now visible. This technique allows very accurate quantification of hepatic fat but has not found clinical use because of the long acquisition time and the lack of specialist spectroscopy physicists in most radiology departments. (With kind permission of American Journal of Roentgenology (AJR). From Lall CG, Aisen AM, Bansal N, Sandrasegaran K. Nonalcoholic fatty liver disease. AJR Am J Roentgenol. 2008;190:993–1002.) (1H)

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Investigative Imaging of the Liver

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A

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Figure 4.12  Magnetic resonance elastography (MRE). MRE in a 43-year-old male with known steatohepatitis and biopsy proven mild hepatic fibrosis (A-C) and in a 58-year-old patient with history of alcohol use and elevated liver enzymes (D-F) with histologically proven cirrhosis of liver. Axial T1-weighted images (A, D) at the level of MRE section, wave images (B, E), and stiffness maps (C, F) are shown. The color scale represents the shear stiffness from 0 to 8 kilopascals (kPa). The outline of liver is shown. The propagating shear waves in the case of severely fibrotic liver (E) are longer as compared with the mild fibrosis (B). The cirrhotic liver in this example has elevated shear stiffness (7.4kPa), nearly three times that of normal liver (2.45 kPa).

References 1. Kim T, Federle MP, Baron RL, Peterson MS, Kawamori Y. Discrimination of small hepatic hemangiomas from hypervascular malignant tumors smaller than 3 cm with three-phase helical CT. Radiology. 2001;219:699–706. 2. Hussain SM, Terkivatan T, Zondervan PE, et al. Focal nodular hyperplasia: findings at state-ofthe-art MR imaging, US, CT, and pathologic analysis. Radiographics. 2004;24:3–17. 3. Ungermann L, Elias P, Zizka J, Ryska P, Klzo L. Focal nodular hyperplasia: spoke-wheel arterial pattern and other signs on dynamic contrast-enhanced ultrasonography. Eur J Radiol. 2007;63:290–294. 4. Mortele KJ, Praet M, Van Vlierberghe H, Kunnen M, Ros PR. CT and MR imaging findings in focal nodular hyperplasia of the liver: radiologic-pathologic correlation. AJR Am J Roentgenol. 2000;175:687–692. 5. Carlson SK, Johnson CD, Bender CE, Welch TJ. CT of focal nodular hyperplasia of the liver. AJR Am J Roentgenol. 2000;174:705–712. 6. Choi CS, Freeny PC. Triphasic helical CT of hepatic focal nodular hyperplasia: incidence of atypical findings. AJR Am J Roentgenol. 1998;170:391–395. 7. McLarney JK, Rucker PT, Bender GN, Goodman ZD, Kashitani N, Ros PR. Fibrolamellar carcinoma of the liver: radiologic-pathologic correlation. Radiographics. 1999;19:453–471. 8. Grazioli L, Morana G, Kirchin MA, Schneider G. Accurate differentiation of focal nodular hyperplasia from hepatic adenoma at gadobenate dimeglumine-enhanced MR imaging: prospective study. Radiology. 2005;236:166–177. 9. Kelekis NL, Semelka RC, Worawattanakul S, et al. Hepatocellular carcinoma in North America: a multiinstitutional study of appearance on T1-weighted, T2-weighted, and serial gadoliniumenhanced gradient-echo images. AJR Am J Roentgenol. 1998;170:1005–1013. 10. Earls JP, Theise ND, Weinreb JC, et al. Dysplastic nodules and hepatocellular carcinoma: thin-section MR imaging of explanted cirrhotic livers with pathologic correlation. Radiology. 1996;201:207–214. 11. Bruix J, Sherman M. Practice Guidelines Committee AAftSoLD. Management of hepatocellular carcinoma. Hepatology. 2005;42:1208–1236. 12. Khalil HI, Patterson SA, Panicek DM. Hepatic lesions deemed too small to characterize at CT: prevalence and importance in women with breast cancer. Radiology. 2005;235:872–878. 13. Jang HJ, Lim HK, Lee WJ, Lee SJ, Yun JY, Choi D. Small hypoattenuating lesions in the liver on single-phase helical CT in preoperative patients with gastric and colorectal cancer: prevalence, significance, and differentiating features. J Comput Assist Tomo. 2002;26:718–724.

14. Horton KM, Bluemke DA, Hruban RH, Soyer P, Fishman EK. CT and MR imaging of benign hepatic and biliary tumors. Radiographics. 1999;19:431–451. 15. Graif M, Yanuka M, Baraz M, et al. Quantitative estimation of attenuation in ultrasound video images: correlation with histology in diffuse liver disease. Invest Radiol. 2000;35:319–324. 16. Saadeh S, Younossi ZM, Remer EM, et al. The utility of radiological imaging in nonalcoholic fatty liver disease. Gastroenterology. 2002;123:745–750. 17. Johnston RJ, Stamm ER, Lewin JM, Hendrick RE, Archer PG. Diagnosis of fatty infiltration of the liver on contrast enhanced CT: limitations of liver-minus-spleen attenuation difference measurements. Abdom Imaging. 1998;23:409–415. 18. Levenson H, Greensite F, Hoefs J, et al. Fatty infiltration of the liver: quantification with phasecontrast MR imaging at 1.5 T vs biopsy. AJR Am J Roentgenol. 1991;156:307–312. 19. Mitchell DG, Kim I, Chang TS, et al. Fatty liver. Chemical shift phase-difference and suppression magnetic resonance imaging techniques in animals, phantoms, and humans. Invest Radiol. 1991;26:1041–1052. 20. Fishbein MH, Gardner KG, Potter CJ, Schmalbrock P, Smith MA. Introduction of fast MR imaging in the assessment of hepatic steatosis. Magn Reson Imaging. 1997;15:287–293. 21. Machann J, Thamer C, Schnoedt B, et al. Hepatic lipid accumulation in healthy subjects: a comparative study using spectral fat-selective MRI and volume-localized 1H-MR spectroscopy. Magnet Reson Med. 2006;55:913–917. 22. Longo R, Pollesello P, Ricci C, et al. Proton MR spectroscopy in quantitative in vivo determination of fat content in human liver steatosis. JMRI. 1995;5:281–285. 23. Thomsen C, Becker U, Winkler K, Christoffersen P, Jensen M, Henriksen O. Quantification of liver fat using magnetic resonance spectroscopy. Magnet Reson Imaging. 1994;12:487–495. 24. Cassinotto C, Feldis M, Vergniol J, et al. MR relaxometry in chronic liver diseases: Comparison of T1 mapping, T2 mapping, and diffusion-weighted imaging for assessing cirrhosis diagnosis and severity. Eur J Radiol. 2015;84:1459–1465. 25. Ichikawa S, Motosugi U, Morisaka H, et al. MRI-based staging of hepatic fibrosis: Comparison of intravoxel incoherent motion diffusion-weighted imaging with magnetic resonance elastography. JMRI. 2015;42:204–210. 26. Quaia E. Microbubble ultrasound contrast agents: an update. Eur Radiol. 2007;17:1995–2008. 27. Giuseppetti GM, Argalia G, Abbattista T. Liver cirrhosis: evaluation of haemodynamic changes using an ultrasound contrast agent. Eur J Radiol. 2004;51:27–33. 28. Lim AK, Taylor-Robinson SD, Patel N, et al. Hepatic vein transit times using a microbubble agent can predict disease severity non-invasively in patients with hepatitis C. Gut. 2005;54:128–133.

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Practical Hepatic Pathology: A Diagnostic Approach 29. Staub F, Tournoux-Facon C, Roumy J, et al. Liver fibrosis staging with contrast-enhanced ultrasonography: prospective multicenter study compared with METAVIR scoring. Eur Radiol. 2009;19:1991–1997. 30. Kawamoto M, Mizuguchi T, Katsuramaki T, et al. Assessment of liver fibrosis by a noninvasive method of transient elastography and biochemical markers. World J Gastr. 2006;12: 4325–4330. 31. Takeda T, Yasuda T, Nakayama Y, et al. Usefulness of noninvasive transient elastography for assessment of liver fibrosis stage in chronic hepatitis C. World J Gastr. 2006;12: 7768–7773. 32. Nguyen-Khac E, Capron D. Noninvasive diagnosis of liver fibrosis by ultrasonic transient elastography (Fibroscan). Eur J Gastroenterol Hepatol. 2006;18:1321–1325. 33. Friedrich-Rust M, Ong MF, Herrmann E, et al. Real-time elastography for noninvasive assessment of liver fibrosis in chronic viral hepatitis. AJR Am J Roentgenol. 2007;188:758–764.

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34. Talwalkar JA, Kurtz DM, Schoenleber SJ, West CP, Montori VM. Ultrasound-based transient elastography for the detection of hepatic fibrosis: systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2007;5:1214–1220. 35. Huwart L, Sempoux C, Salameh N, et al. Liver fibrosis: noninvasive assessment with MR elastography versus aspartate aminotransferase-to-platelet ratio index. Radiology. 2007;245:458–466. 36. Vizzutti F, Arena U, Marra F, Pinzani M. Elastography for the non-invasive assessment of liver disease: limitations and future developments. Gut. 2009;58:157–160. 37. Tang A, Cloutier G, Szeverenyi NM, Sirlin CB. Ultrasound elastography and MR elastography for assessing liver fibrosis: part 2, diagnostic performance, confounders, and future directions. AJR Am J Roentgenol. 2015;205:33–40. 38. Xu S, Wang Y, Tai DC, et al. qFibrosis: a fully-quantitative innovative method incorporating histologic features to facilitate accurate fibrosis scoring in animal model and chronic hepatitis B patients. J Hepatol. 2014;61:260–269.

5 Liver Diseases of Childhood Rebecca A. Marks, MD, and Romil Saxena, MD, FRCPath

Neonatal Cholestasis  69 Incidence and Demographics  70 Role of Liver Biopsy in Neonatal Cholestasis  70 Biliary Atresia  71 Incidence and Demographics  71 Clinical Manifestations  71 Radiologic Features  71 Pathology 72 Differential Diagnosis  74 Treatment and Prognosis  74 Neonatal (Giant Cell) Hepatitis  76 Clinical Manifestations  76 Pathology 77 Differential Diagnosis  77 Treatment and Prognosis  77 Alagille Syndrome  77 Incidence and Demographics  78 Molecular Genetics  79 Clinical Manifestations  79 Gross Pathology  80 Microscopic Pathology  80 Differential Diagnosis  80 Treatment and Prognosis  81 Primary Sclerosing Cholangitis  81 Incidence and Demographics  81 Clinical Manifestations  81 Radiologic Findings  82 Microscopic Pathology  82 Diagnosis 82 Treatment and Prognosis  82 Sclerosing Cholangitis Due to Langerhans Cell Histiocytosis 83 Microscopic Pathology  84 Molecular Pathology  84 Treatment and Prognosis  85 Neonatal Sclerosing Cholangitis  85

Abbreviations AIH autoimmune hepatitis ALGS Alagille syndrome CMV cytomegalovirus ERK extracellular signal-regulated kinases GGT gamma glutamyltransferase HIDA hepatobiliary iminodiacetic acid JAG1 jagged-1 LCH Langerhans cell histiocytosis MAPK mitogen-activated protein kinases MAP2K1 mitogen-activated protein kinase kinase 1 NISCH neonatal sclerosing cholangitis NOTCH2 notch homolog 2 PILBD paucity of interlobular bile ducts PSC primary sclerosing cholangitis TORCH toxoplasmosis, other agents, rubella, cytomegalovirus, herpes simplex UDCA ursodeoxycholic acid This chapter focuses on liver disease that is distinctive to children and has no counterpart in adults; neonatal hepatitis and biliary atresia constitute the majority of such cases, both of which present in the first weeks of life with cholestasis. Neonatal hepatitis is not a distinct entity but a histologic pattern of injury manifested in the infant liver caused by a wide variety of injurious agents; this histologic pattern is seen only rarely, if at all, in adults. Primary sclerosing cholangitis (PSC) demonstrates features that are distinctive enough in the pediatric age-group to merit separate discussion in this chapter.1-3 Metabolic and inherited diseases of childhood are discussed in their own separate chapters, namely Chapters 6 and 7.

Neonatal Cholestasis The first week of life is characterized by physiologic jaundice, which results from an inability of the immature liver to adequately clear bilirubin; it usually resolves within 5 days. Breastfed neonates are also prone to having jaundice, which may last longer than physiologic jaundice. Thus, jaundice is a relatively common finding at 2 weeks of age, occurring in 2.5% to 15% of newborns.4 Both physiologic and breast milk jaundice are characterized by unconjugated hyperbilirubinemia. The presence of

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Practical Hepatic Pathology: A Diagnostic Approach conjugated hyperbilirubinemia in a neonate is pathologic and is referred to as cholestatic jaundice. It may be caused by a vast array of infectious, metabolic, chromosomal, structural/obstructive, and endocrine diseases (Table 5.1), many of which benefit from prompt initiation of specific therapies that improve long-term prognosis and survival. The Cholestasis Guideline Committee of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition recommends that total and direct serum bilirubin be measured if jaundice is present at 2 weeks of age in nonbreastfed infants. Bilirubin estimations may be delayed until 3 weeks of age in breastfed infants with jaundice who are otherwise healthy and do not show signs of liver disease such as dark urine or light stools. Direct bilirubin values greater than 1.0 mg/dL if the total bilirubin is less than 5 mg/dL or more than 20% of the total when total bilirubin is more than 5 mg/dL are pathologic.5

Incidence and Demographics Cholestatic jaundice occurs in 1 in 2500 to 1 in 5000 newborns.6 Obstructive causes dominated by biliary atresia account for one-quarter to one-third of cases, whereas nonobstructive conditions account for approximately 60% to 70% of cases. An increasing number of specific disorders, especially those of bile acid synthesis and bilirubin metabolism, have been identified as causes of nonobstructive neonatal cholestasis (“neonatal hepatitis” on biopsy) in the past two decades; therefore although 65% of cases of neonatal hepatitis remained idiopathic in 1970, only about 15% remain undesignated at present.7,8 Various forms of inherited cholestasis account for 20% of all cases of neonatal hepatitis, alpha-1 antitrypsin deficiency for 10%, and other inborn errors of metabolism for 20%. Congenital infections, including those caused by the TORCH (toxoplasmosis, other agents, rubella, cytomegalovirus, herpes simplex) agents, parvovirus, and various bacteria, account for about 5% of cases.7,9 However, as might be expected, there is considerable geographic variation in the incidence and prevalence of these conditions; thus although alpha-1 antitrypsin deficiency accounts for 25% of all cases of neonatal hepatitis in England, it is present in only 6% of children in Malaysia.10,11 Citrin deficiency is an important cause of neonatal cholestasis in Southeast Asia, whereas sepsis and hypoxia-ischemia account for most cases of neonatal cholestasis in Turkey.12,13 One-quarter of 101 infants with nonobstructive cholestasis in Brazil had infections, 25% had metabolic disease, and about 50% had idiopathic disease.14 Biliary atresia accounted for 25% of 101 infants with neonatal cholestasis in India, followed in frequency by sepsis/urinary tract infections and galactosemia.15

Role of Liver Biopsy in Neonatal Cholestasis Management of cholestatic jaundice consists first and foremost of excluding obstructive causes amenable to surgical correction. The most common cause of obstruction in infants is biliary atresia, which requires urgent portoenterostomy to allow bile flow and prevent rapidly progressive fibrosis and cirrhosis. Other conditions that require surgical intervention include choledochal cyst, choledocholithiasis, biliary strictures, and spontaneous idiopathic perforation of bile ducts. Although some of these can be diagnosed on imaging studies, the diagnosis of biliary atresia often requires a liver biopsy.5,16 Liver biopsy is also required to identify, whenever possible, the cause of nonobstructive cholestatic jaundice, often referred to as intrahepatic cholestasis to distinguish it from obstructive causes in the extrahepatic biliary tree. Thus evaluation of a liver biopsy specimen from a patient with neonatal cholestasis entails, first and foremost, the exclusion of biliary atresia, and, second, the identification of etiologic factors of nonobstructive jaundice that can be visualized on microscopic examination of a liver biopsy. Unfortunately, most injurious agents may simply produce a nonspecific histologic pattern referred to as neonatal hepatitis, 70

Table 5.1  Differential Diagnosis of Neonatal Cholestasis Diagnostic Consideration

Relevant Investigations

Infections • Viral: cytomegalovirus, rubella, reovirus-3, coxsackievirus, human herpesvirus-6, herpes simplex, parvovirus, hepatitis B virus, hepatitis C virus, human immunodeficiency virus • Bacterial: sepsis, urinary tract infection, syphilis, listeriosis, tuberculosis • Parasitic: toxoplasmosis, malaria

Specific serum immunoglobulin M antibodies Tissue/blood/body fluid culture Polymerase chain reaction for microbial nucleic acids Liver biopsy (inclusion bodies; immunohistochemistry/immunofluorescence with specific antibodies)

Structural/obstructive disorders • Biliary atresia • Choledochal cyst • Caroli syndrome • Choledocholithiasis • Neonatal sclerosing cholangitis • Idiopathic perforation of bile ducts • Alagille syndrome

Ultrasound Cholangiography Hepatobiliary iminodiacetic acid scan Liver biopsy Endoscopic retrograde cholangiopancreatography Extrahepatic anomalies, high cholesterol, mutational analysis (Alagille syndrome)

Metabolic disorders • Alpha-1 antitrypsin deficiency • Galactosemia • Cystic fibrosis • Tyrosinemia • Hereditary fructosemia • Bile acid synthetic disorders • Progressive familial intrahepatic cholestasis • Niemann-Pick disease, type C • Gaucher disease • Total parenteral nutrition • Arginase deficiency • Zellweger syndrome

Serum/cellular/tissue enzyme levels/assays Alpha-1 antitrypsin isoenzyme analysis Sweat chloride analysis (cystic fibrosis) Urine and serum amino and organic acid levels Mutational analysis Abnormal metabolites in serum/urine Bile acid levels in serum and urine Gamma glutamyltransferase levels (low in ­progressive familial intrahepatic cholestasis-1, -2, and other rare syndromes; see Chapter 29B) Liver biopsy (globules of alpha-1 antitrypsin, storage cells of Niemann-Pick and Gaucher diseases)

Endocrinopathies • Hypothyroidism • Hypopituitarism

Serum levels of thyroid-stimulating hormone, T4, T3, cortisol

Chromosomal disorders • Turner syndrome • Trisomy 18 • Trisomy 21 • Trisomy 13 • Cat’s eye syndrome

Karyotype analysis Ultrasound, hepatobiliary iminodiacetic acid scan, liver biopsy*

Toxicities • Fetal alcohol syndrome • Drugs (through breast milk)

Maternal and patient history Blood tests (eg, carbohydrate deficient transferrin level)

Immune disorders • Neonatal lupus • Inspissated bile syndrome (ABO blood group incompatibility) • Autoimmune hemolytic anemia • Neonatal hemochromatosis (congenital alloimmune hepatitis)

Maternal history Maternal anti-Ro antibodies (neonatal lupus) Coombs test Liver biopsy (iron and immunohistochemistry for terminal complement cascade [C5b-9] in neonatal hemochromatosis, anti-Ro antibodies in neonatal lupus) Lip biopsy (salivary gland iron in neonatal hemochromatosis)

Neoplasia

Site- and type-specific investigations

*Biliary atresia is associated with many of the listed chromosomal disorders. T3, triiodothyronine; T4, thyroxine.

a misleading term because a significant number of cases of “neonatal hepatitis” represent metabolic, chromosomal, and endocrine diseases, which are primarily neither infectious nor inflammatory in nature. However, although less than appropriate, the term benefits from familiarity of use in routine clinical practice and effectively describes a

Liver Diseases of Childhood constellation of histologic findings that commonly occur in neonatal cholestatic diseases of various causes.

5

Biliary Atresia The first observations of biliary atresia were made by Burns, who in 1817 described jaundice and acholic stools in infants with an “incurable state of the biliary apparatus.”17 In 1891, Thomson reviewed 50 of his own cases as well as others published at that time for his thesis on “so-called congenital obliteration of the bile ducts.”17 The disease was uniformly fatal in the first 2 years of life until the middle of the last century, when in Sendai, Japan, Morio Kasai introduced a surgical procedure for the noncorrectable types of biliary atresia, thus taming to a great extent this “darkest chapter in pediatric surgery.”18 The surgical procedure named for this pioneer surgeon consists of removal of the fibrotic extrahepatic biliary tract followed by dissection of the porta hepatis to identify patent ducts, which are then anastomosed to a loop of small intestine that serves as a conduit for bile flow. Today, the Kasai portoenterostomy remains the first line of treatment for infants with biliary atresia. Although early surgical intervention is undisputedly one of the most important factors in ensuring long-term hepatic function, an effective screening method that would allow accurate and timely diagnosis of biliary atresia is still lacking. Similarly, despite two centuries of familiarity with this disease, the exact etiopathogenesis of biliary atresia is uncertain. Two forms of biliary atresia are recognized, the perinatal form, which accounts for 80% of cases, and the embryonal form, which accounts for the remaining 20%. The embryonal form is associated with malformations such as abnormalities of the abdominal veins, laterality and situs anomalies of abdominal organs, and polysplenia or asplenia. Although aberrant development can be invoked in the embryonal form, it appears that the vast majority of cases of biliary atresia represent inflammatory destruction of already formed bile ducts. Viruses such as rotavirus, reovirus, echovirus, and cytomegalovirus (CMV) have been implicated either as direct agents of injury or as agents that establish a self-perpetuating inflammatory response. Although the process begins as an inflammatory destruction of the extrahepatic bile ducts, the intrahepatic bile ducts are progressively destroyed; thus, the encompassing term biliary atresia is more appropriate than either extrahepatic biliary atresia or intrahepatic biliary atresia. The latter term, initially used to describe paucity of intrahepatic bile ducts in Alagille syndrome, has been largely abandoned following the molecular characterization of that syndrome.

Incidence and Demographics Biliary atresia occurs in 1 in 8000 to 1 in 18,000 newborns; it is the most common cause of cirrhosis, as well as the most common indication for liver transplantation in children. The incidence is greater in girls and in Asians and Africans.19,20 There is lack of concordance among twins, and familial predisposition has not been noted.21

Clinical Manifestations Children with biliary atresia are asymptomatic and almost always appear healthy and well nourished. In one study, low birth weight and prematurity were risk factors, but not in another study that reported normal birth weight and no association with prematurity.11,19 Patients are anicteric at birth and have jaundice in the first few weeks of life or may be continually jaundiced from birth, especially in the embryonal form. Jaundice is accompanied by dark urine and pale stools. The pathologic lesion evolves over time; thus the stools may be pigmented early in the course of the disease and become progressively paler as the obstruction worsens, ultimately acquiring the typical “clay-colored” appearance. Although pale stools may occur randomly in children,

Figure 5.1  Ultrasonography in a 2-month-old with biliary atresia showing a triangular echogenic area (arrowheads) anterior to the right portal vein (arrow). (Courtesy of Dr. K. Sandrasegaran, Department of Radiology, Indiana University School of Medicine.)

persistent pale-colored stools indicate biliary atresia or severe nonobstructive liver disease. Stool color cards are distributed to parents of newborns in Japan and Europe to facilitate identification of pale stools and therefore early diagnosis of biliary atresia. In 2014, an app that works across mobile platforms was made available in the United States with a similar goal.22 Congenital anomalies such as abnormalities of the abdominal veins, midline symmetrical liver, intestinal malrotation, situs anomalies, and polysplenia/asplenia may be present in children with the embryonal form of biliary atresia.23 Patients with biliary atresia usually have an enlarged, hard liver at presentation. Laboratory tests show elevation of bilirubin, alkaline phosphatase, and gamma glutamyltransferase (GGT).

Radiologic Features An abdominal ultrasound is often performed for diagnosis, and specialized institutions have reported an accuracy rate of 98% for the diagnosis of biliary atresia on ultrasound findings.24 However, diagnostic accuracy is highly dependent on operator skill and experience. Ultrasonography helps to exclude other causes of obstruction such as choledochal cyst and stones and detect abnormalities of the gallbladder and bile ducts as well as other developmental anomalies associated with biliary atresia. The gallbladder is absent, atretic, or otherwise abnormal in biliary atresia; “gallbladder ghost triad,” composed of gallbladder length less than 19 mm, irregular wall, and indistinct mucosal lining, is considered to be characteristic.25 The triangular cord sign (Fig. 5.1) is the presence of a triangular or tubular echogenic density above the bifurcation of the portal vein on ultrasonography, which corresponds to a cone of fibrous tissue at the porta hepatis. Reported sensitivity and specificity of the triangular cord sign for the diagnosis of biliary atresia are 70% to 85% and 90% to 100%, respectively.26-28 The positive predictive value of the triangular cord for biliary atresia is reported to be 100% when the gallbladder is abnormal and 88% when it is normal; an abnormal gallbladder without a triangular cord has a 25% positive predictive value.29 The hepatobiliary iminodiacetic acid (HIDA) scan is based on excretion of an injected Tc-99m–labeled iminodiacetic isotope into the gut; nonexcretion into the gut in 24 hours indicates obstruction of the biliary tree (Fig. 5.2). The accuracy is improved by administration of 71

Practical Hepatic Pathology: A Diagnostic Approach

TC-99m choletec

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Figure 5.3  Cut surface of a liver removed at transplantation for biliary atresia and nonfunctioning Kasai portoenterostomy (arrow). The liver is micronodular and dark green in color.

B Figure 5.2  A, Serial images of Tc-99m–hepatobiliary iminodiacetic acid (HIDA) isotope scan in a patient with no bile duct obstruction shows excretion of radioactive tracer through the liver and bile ducts and into multiple loops of the duodenum and jejunum within 30 minutes. This is the dynamic appearance of a normal HIDA scan. B, Three-month-old neonate with biliary atresia. Serial images of Tc-99m–HIDA isotope scan show uptake of radioactive tracer within liver but no excretion into bile ducts for at least 60 minutes. (Courtesy of Dr. K. Sandrasegaran, Department of Radiology, Indiana University School of Medicine.)

ursodeoxycholic acid (UDCA) or phenobarbital to facilitate bile flow. Although excretion into the gut definitively rules out biliary atresia, absence of excretion does not necessarily indicate obstruction because this may also occur in Alagille syndrome and other causes of severe nonobstructive cholestasis. A false-negative result may occur early in the course of biliary atresia when obstruction may be incomplete. Endoscopic retrograde cholangiopancreatography is useful in the diagnosis of biliary atresia and may obviate the need for open laparotomy in doubtful cases. However, it is technically challenging and requires general anesthesia in young children, thus limiting its use to tertiary institutions with specialized pediatric gastroenterologists and skilled support staff.

Pathology

Macroscopic Pathology The liver removed at transplantation in patients who have not had a prior Kasai procedure has a hard, dark green appearance and shows micronodular cirrhosis (Fig. 5.3). When removed many years after a successful Kasai procedure, the cut surface, although also hard and dark green, shows large nodules in the perihilar region surrounded by 72

Figure 5.4  Liver removed at transplantation many years after a successful Kasai portoenterostomy. The cut surface shows dilated intrahepatic ducts containing bile sludge radiating from the perihilar region.

cirrhotic micronodular liver at the periphery. It is postulated that the Kasai procedure achieves drainage in segments 4, 5, and 8, allowing regeneration of the perihilar parenchyma, which corresponds morphologically to the large perihilar nodules.30,31 Dilated intrahepatic bile ducts with inspissated bile may be found in both instances (Fig. 5.4). Microscopic Pathology The microscopic features of biliary atresia in a liver biopsy reflect obstruction of the biliary tree. The portal tracts are expanded by edema, marked bile ductular reaction with numerous bile ductules, and minimal to mild inflammatory infiltrate (Fig. 5.5). Sometimes, there may be a configuration resembling ductal plate remnants. Bile plugs are present in bile ducts and ductules. The interlobular bile ducts are present early in the course of the disease but may be absent late in the disease. The hepatic arterioles appear prominent and thick-walled, and they may be more numerous (Fig. 5.6 and eSlide 5.1A). There is almost always an increase in portal fibrous tissue, and depending on the age of the child and evolution of the lesion, varying degrees of fibrosis ranging from periportal to bridging fibrosis to frank cirrhosis are seen (see Fig. 5.5) (eSlide 5.1B). The lobular parenchyma shows cholestasis of varying, but usually marked, degree. Cholestasis is both cellular and canalicular and begins in the centrilobular regions. Enlarged, multinucleated hepatocytes (giant cells), extramedullary hemopoiesis, hepatocellular ballooning and damage, and apoptotic bodies (Fig. 5.7) may

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* A Figure 5.7  Liver biopsy sample from a patient with biliary atresia. The portal tract shows mild ductular reaction and prominent arterioles. Numerous giant cells and mild inflammation are present in the perivenular region around the hepatic venule (asterisk), features that overlap with those of neonatal hepatitis (also see eSlide 5.1).

B Figure 5.5  A, Liver biopsy from a 7-week-old girl with biliary atresia. The portal tract is expanded by fibrosis, an increased number of ductules, and a neutrophilic infiltrate. Bile plugs are noted in the ductules (arrows). B, Masson trichrome stain shows portal fibrosis (also see eSlide 5.1).

Figure 5.6  Liver biopsy sample from a 7-week-old boy with biliary atresia. The portal tract is fibrotic and shows numerous ductules at its edges. Numerous prominent arterioles are present in the center of the portal tract unaccompanied by bile ducts (also see eSlide 5.1).

be seen, rendering distinction from neonatal hepatitis difficult (further discussed in section on neonatal hepatitis). Periportal hepatocytes may stain for the biliary keratins, K7 and K19.*33 Distinctive portal changes of biliary atresia may not be present in the early stages of the disease, and a nondiagnostic biopsy performed in the first 6 weeks of life should be repeated if clinical suspicion for biliary atresia is strong.5,34-36 Furthermore, liver biopsy interpretation is dependent not only on the dynamics of the disease at the time of biopsy, but also on the experience of the pathologist. However, both overdiagnosis and underdiagnosis of biliary atresia may occur in a small number of cases, even in the most experienced hands. The porta hepatis excised during a Kasai procedure shows varying degrees of destruction and obliteration of the major hepatic ducts. Surgeons often request rapid intraoperative evaluation of excised portions of the porta hepatic by frozen section to look for the presence and size of bile duct remnants; the presence of ducts larger than 150 or 200 μm has been associated with better bile flow after Kasai portoenterostomy.37-39 These size criteria are not universally used in current practice; for example, in our institution, although a larger-caliber duct is desirable, bile flow at the porta hepatis trumps duct diameter in evaluating the adequacy of surgical resection. Duct remnants in the excised atretic biliary tree have been classified into three types. Type I is characterized by a completely atretic duct. Type II is characterized by a partially destroyed duct, which appears as a cleftlike lumen lined focally by cuboidal or low columnar cells. Smaller ductal structures with lumina measuring less than 50 μm in diameter and varying degrees of inflammation are usually present in the connective tissue surrounding the duct. Type III is characterized by a duct lined partially by columnar epithelium and smaller ductal structures with lumina less than 50 μm in diameter. An alternate classification that is based on the size of the duct lumen has also been published: type 1 consists of ducts with lumina 150 μm or greater in size; type 2 consists of ducts with lumina less than 150 μm in size; and type 3 does not demonstrate epithelial-lined structures.38 However, duct remnants of different types and variable luminal sizes may be present *Although the prefix CK is widely used in surgical pathology to designate human cytokeratins, consensus nomenclature recommends the replacement of “cytokeratin” with “keratin” and the prefix “CK” with “K.”32 73

Practical Hepatic Pathology: A Diagnostic Approach simultaneously at different levels of the biliary tract, reflecting varying stages of inflammatory destruction (Fig. 5.8 and eSlide 5.2). Therefore it is not surprising that these classifications do not appear to have major clinical impact.25 The gallbladder appears atretic and underdeveloped with a small lumen lined by denuded mucosa (Fig. 5.9 and eSlide 5.3). The liver removed many years after a successful Kasai procedure shows large regenerative nodules in the perihilar region and small micronodules in the periphery. A ductular reaction is present at the edges of the nodules and is usually more prominent around the larger perihilar nodules (Fig. 5.10A). Intrahepatic bile ducts may be present in the perihilar regions but are usually absent in the peripheral liver where numerous arterioles unaccompanied by bile ducts are seen (Fig. 5.10B and eSlide 5.4). The perihilar bile ducts may be dilated and contain biliary sludge or bile stones.

Differential Diagnosis There are three considerations in the differential diagnosis of biliary atresia (Table 5.2). The first is the distinction of biliary atresia from neonatal hepatitis. Although both neonatal hepatitis and biliary atresia show cholestasis, inflammation, giant cells, and ductular reaction, lobular changes predominate in neonatal hepatitis whereas portal tract changes are more prominent in biliary atresia. Ductular reaction, bile plugs, and portal fibrosis serve as the most important discriminatory features favoring biliary atresia.34-36,40 The second consideration is the distinction of biliary atresia from nonobstructive conditions that may also show ductular reaction; these include alpha-1 antitrypsin deficiency (Fig. 5.11), total parenteral nutrition (Fig. 5.12), cystic fibrosis, progressive familial intrahepatic cholestasis-3, perinatal hypoxia, and Alagille syndrome (Fig. 5.13). Differentiation among these conditions is based on a combination of clinical and laboratory findings (see Table 5.1). In this context, it is useful to remember that periodic acid–Schiff-positive globules may not be seen histologically in the very young infant with alpha-1 antitrypsin deficiency; in these patients the diagnosis should be established by serum enzyme levels and isoenzyme typing. Finally, biliary atresia has to be distinguished from other obstructive conditions amenable to surgical resection such as choledochal cyst, bile duct strictures, choledocholithiasis, inspissated bile syndrome, neonatal sclerosing cholangitis, and idiopathic perforation of bile ducts. The differential diagnosis of these conditions cannot be resolved by histologic examination alone and requires correlation with clinical and imaging findings.

A

B

Treatment and Prognosis Kasai portoenterostomy is the first line of treatment for biliary atresia. Best outcomes are associated with surgery performed by 60 days of age at a center experienced in this technique. Bile drainage is achieved in 60% of patients when surgery is performed at 60 to 70 days of life, in 40% when performed at 70 to 90 days of life, and in 25% when performed at 90 to 120 days of life.41 Age at surgery also influences the chances of long-term survival without transplantation.42 Better outcomes have been consistently linked to experience of the center performing the surgery.43,44 The presence of ducts 150 to 200 μm or greater in size and regeneration of perihilar liver parenchyma are associated with better outcomes.30,37-39 The prognostic significance of ductular reaction is not certain.45,46 Better results are reported in Japanese studies, especially over the long term, with one series reporting 44% survival with native liver 20 years after the Kasai procedure.47 Postoperative care in Japan routinely consists of long-term corticosteroids to prevent inflammatory destruction of intrahepatic bile ducts; intravenous antibiotics to prevent ascending cholangitis, a common complication that hastens bile duct damage and liver failure; long-term UDCA to facilitate bile 74

C Figure 5.8  Varying stages of bile duct destruction are present simultaneously in different parts of the biliary tree. A, At this level, the bile duct shows luminal narrowing and denuded epithelium (arrows) surrounded by small ductular structures corresponding to peribiliary glands (arrowheads). B, This part of the bile duct is completely destroyed (arrows) and surrounded by peribiliary glands (arrowheads). C, A scar (arrows) has replaced the atretic bile duct at this level (also see eSlide 5.2).

Liver Diseases of Childhood Table 5.2  Differential Diagnosis of Biliary Atresia Diagnostic Consideration

Differential Diagnosis

Distinguishing Features

Neonatal hepatitis

Various metabolic disorders, infectious diseases, and chromosomal aberrations

Ductular reaction and portal fibrosis more prominent in biliary atresia* Specific findings (eg, viral inclusions, iron deposition, storage cells; see Table 5.1)

Nonobstructive disorders showing ductular reaction on liver biopsy

Alpha-1 antitrypsin deficiency Total parenteral nutrition (also see eSlides 3.6 and 3.7) Cystic fibrosis (also see eSlide 10.1) Progressive familial ­intrahepatic cholestasis-3 (also see eSlide 29B.4) Perinatal hypoxia Alagille syndrome Neonatal sclerosing cholangitis

Ductular reaction and portal fibrosis more prominent in biliary atresia* Specific findings (eg, sweat chloride test, abnormal isoenzyme; see Table 5.1)

Other causes of extrahepatic obstruction

Choledochal cyst Bile duct strictures Choledocholithiasis Inspissated bile syndrome Idiopathic perforation of bile ducts

Cannot be distinguished histologically Imaging studies and clinical history

Figure 5.9  Atretic gallbladder showing attenuated lumen, denuded epithelium, and atrophic wall (same patient as in Figure 5.8) (also see eSlide 5.3).

5

*Biopsies before 6 weeks of age may not show characteristic features of biliary atresia.

A

A

B Figure 5.10  Liver removed at transplantation many years after a successful Kasai portoenterostomy. A, The perihilar parenchyma shows extensive and prominent ductular reaction. B, The peripheral parenchyma is micronodular and ductular reaction is less marked. There are no intrahepatic bile ducts, and numerous arterioles (arrows) are present without accompanying bile ducts (see eSlide 5.4).

B Figure 5.11  A, Liver biopsy from a patient with neonatal cholestasis showing ductular reaction. B, The periodic acid–Schiff stain shows small diastase-resistant granules in periportal hepatocytes (arrows). Subsequent evaluation revealed alpha-1 antitrypsin deficiency (PiZZ). 75

Practical Hepatic Pathology: A Diagnostic Approach the 1-, 5-, and 10-year survival rates were 90%, 87.2%, and 85.8%, respectively.54

Neonatal (Giant Cell) Hepatitis

Figure 5.12  Liver biopsy from a patient receiving total parenteral nutrition that shows portal tract expanded by ductular reaction and fibrosis (also see eSlides 3.6 and 3.7).

Neonatal hepatitis is a term used for a constellation of histopathologic findings, the most distinctive of which is the presence of multinucleated hepatocytes, the so-called giant cells. Multinucleated hepatocytes are accompanied by varying degrees of cholestasis, inflammation, hemopoiesis, and ductular reaction. This histologic picture, seen in a wide variety of neonatal diseases that cause cholestasis, is thought to reflect a unique response of the young liver to injury. It has been postulated that giant cells result from mitotic inhibition of the young, growing liver by an injurious agent, or alternatively from dissolution of cell membranes of adjacent hepatocytes. However, giant cells are not seen in all cases of neonatal hepatitis and are most persistently found in bile acid synthetic disorders, suggesting that they represent hepatocyte injury that is due to accumulation of bile acids in the immature liver challenged by various injurious agents.8 Giant cells are rare after 1 year of age and have been reported occasionally in adults, when the term post–infantile giant cell hepatitis has been used.55

Clinical Manifestations

Figure 5.13  Liver biopsy from a patient with Alagille syndrome who had neonatal cholestasis. The portal tract contains mild inflammatory infiltrate and lacks a bile duct. Features that overlap with neonatal hepatitis, such as multinucleated giant cells (arrow) and foci of extramedullary hematopoieses (arrowheads), are seen.

flow; and herbal therapy to enhance liver function.48 A randomized clinical trial failed to demonstrate a statistically significant difference in bile flow at 6 months with use of post-Kasai high dose steroids; there was, however, an earlier onset of serious adverse events.49 The efficacy of the other measures routinely used post-Kasai in Japan has not been tested in randomized trials.48 The Kasai procedure fails to restore bile flow in approximately one-third of infants, one-third require transplantation before 10 years of age, and the remaining third survive for more than 10 years with the portoenterostomy.50,51 Although most children eventually require transplantation, the Kasai procedure is an effective first line of management because it allows the child to grow and develop before transplantation. Despite clinical or biochemical evidence of liver disease, more than half of all children report a good quality of life after transplantation.52 A previous Kasai procedure does not render subsequent transplantation medically or technically difficult.53 Biliary atresia accounts for almost 50% of all liver transplants in children. In a study of 1976 patients who underwent liver transplantation for biliary atresia, 76

Neonatal hepatitis of various causes presents as neonatal cholestasis, a common response of the young liver to a variety of injurious agents that easily decompensate the immature bile synthetic and secretory pathways. Jaundice may be present continually from birth or develop after a variable jaundice-free period after clearance of physiologic jaundice. Parents may notice dark urine caused by increased excretion of bile pigment. Stools may be light colored but usually contain some pigment; however, severe cases of nonobstructive jaundice may lack biliary pigment in stools and be mistaken for those of biliary atresia. Patients may have symptoms of deficiency of fat-soluble vitamins that are not absorbed in the absence of bile secretion; vitamin K deficiency may cause bleeding. Infants who have cholestasis due to sepsis and systemic infections may be acutely ill, with clinical signs and symptoms pointing to a generalized process. Children with congenital CMV infection may show microcephaly, hydrocephalus, thrombocytopenia, and chorioretinitis. Children who acquire herpes infection either during the birth process or in the early postnatal period may rapidly have multiorgan failure and shock without the presence of cutaneous vesicular lesions. Patients with metabolic diseases such as hypopituitarism, galactosemia, tyrosinemia, fructosemia, and neonatal hemochromatosis may also be very ill and demonstrate poor feeding, inadequate weight gain, hypoglycemia, and hypotonia. A series of 101 patients from Brazil found low birth weight to be frequent in patients with infections, whereas a low international normalized ratio was frequent in those with a genetic/ endocrine/metabolic disease, possibly reflecting severe disease in the latter group.14 Neonatal cholestasis caused by Alagille syndrome or chromosomal abnormalities may be associated with dysmorphic facial features and congenital anomalies in other organ systems. Physical examination of the infant with cholestasis may reveal hepatomegaly or hepatosplenomegaly. Depending on the underlying cause of disease, liver tests show variable elevations of alkaline phosphatase, GGT, and transaminases. Low levels of GGT are characteristic of certain inherited disorders of bile formation (see Chapter 29B), whereas in idiopathic cases, low or normal levels of GGT may be an indicator of more severe liver disease.56 Bile acid synthetic defects are characterized by absent serum bile acids and abnormal bile acid derivatives in urine. However, physical examination and liver biochemistry cannot reliably distinguish the various causes of neonatal hepatitis, and definite diagnosis requires a combination of serologic tests to rule out infection,

Liver Diseases of Childhood

Figure 5.14  Multinucleated enlarged hepatocytes (giant cells) in a patient with neonatal hepatitis. The giant cells may contain variable amounts of bile and hemosiderin (arrows) (also see eSlide 5.5).

Giant cell transformation of hepatocytes is accompanied by varying degrees of mononuclear portal and lobular inflammatory infiltrate, fibrosis, and extramedullary hemopoiesis. Cholestasis is invariably present with biliary rosettes; variable but usually mild ductular reaction is seen (Fig. 5.16 and eSlide 5.5). Although the previously mentioned features are seen nonspecifically across a broad swath of conditions, specific etiologic agents may be identified or suggested by a liver biopsy. Eosinophilic intranuclear inclusions of CMV may be seen and are especially frequent in bile duct epithelium. Punched-out areas of necrosis with intranuclear basophilic inclusions and no inflammation are seen in perinatal herpes infections, whereas viral inclusions in erythroid precursors suggest parvovirus infection. Microabscesses are seen in Listeria infections and congenital syphilis; widening of the sinusoidal spaces by fibrosis is also evident in the latter condition. In some cases, paramyxoviruses and human herpesvirus-6 have been detected in liver tissue by ultrastructural examination and polymerase chain reaction, respectively.60,61 Marked hemosiderin deposition suggests neonatal hemochromatosis, also called congenital alloimmune hepatitis, which results from placental transfer of specific reactive immunoglobulin G. Positivity for the terminal complement cascade (C5b-9, membrane attack complex62) can be demonstrated on hepatocytes and giant cells by immunohistochemistry (Fig. 5.17 and eSlide 5.6).62 Macrovesicular steatosis favors a metabolic disorder such as tyrosinemia. Alpha-1 antitrypsin deficiency causes neonatal hepatitis, but the distinctive intracytoplasmic globules may not be present in very young children.

5

Differential Diagnosis

Figure 5.15  Focal areas of necrosis may be seen in patients with neonatal hepatitis. These are usually associated with a neutrophilic infiltrate (arrows).

imaging studies to identify structural abnormalities, biochemical tests to identify inherited enzyme deficiencies, and genetic analysis to rule out chromosomal abnormalities (see Table 5.1).57

Pathology Grossly, the liver may be enlarged or shrunken depending on the degree of inflammation, necrosis, and fibrosis. The consistency varies with the degree of fibrosis, and some conditions may cause a nodular appearance because of cirrhosis. Focal areas of necrosis may be seen on cut surface in congenital infections caused by CMV, herpes virus, or Toxoplasma. Microscopically, multinucleated hepatocytes are present in variable numbers. They may be present throughout the hepatic lobule but are more frequent in the perivenular region. They may be ballooned and contain bile and/or hemosiderin. The cytoplasm is usually clear and contains wispy cytoplasmic threads (Fig. 5.14). Foci of necrosis may be seen and are associated with a neutrophilic inflammatory response (Fig. 5.15); this feature is especially prominent in patients who have autoimmune hemolytic anemia.58,59 Confluent necrosis and bridging necrosis may be seen.

Biliary atresia is the main differential diagnostic consideration in neonatal hepatitis, and liver biopsy is currently the most accurate method of distinguishing between the two conditions.63 Foci of extramedullary hemopoiesis, giant cell change, and inflammation are more extensive in neonatal hepatitis, but none of these features is consistently present; on the other hand, marked ductular reaction and portal fibrosis are consistently present in biliary atresia.34,36 Ductular reaction, bile plugs, and portal fibrosis serve as the most important discriminatory features favoring biliary atresia.34-36,40 The utility of immunohistochemical staining for CD56 in the differential diagnosis of biliary atresia from other causes of neonatal cholestasis remains to be validated.64-66 A 7-parameter, 15-point histologic scoring system provides diagnostic accuracy for biliary atresia of 92% to 95%, whereas a scoring system that combines clinical, radiologic, laboratory, and histologic findings is reported to offer a diagnostic accuracy of almost 99%.67

Treatment and Prognosis The treatment and prognosis of nonobstructive cholestasis causing neonatal hepatitis depends on the etiology of the underlying condition. Metabolic diseases such as bile salt synthetic defects, tyrosinemia, galactosemia, and fructosemia are managed by special diets that seek to eliminate offending dietary constituents or substitute missing ones. As an example, bile acid replacement therapy arrests liver injury in bile acid synthetic defects, and regression of liver damage has been shown in patients who were diagnosed early in life.8 Neonatal hepatitis due to alpha-1 antitrypsin resolves in most cases, although a small percentage may progress to cirrhosis and rare patients to loss of intrahepatic bile ducts (see Chapter 9). The presence of autoimmune hemolytic anemia is associated with necrosis, liver failure, and recurrence in the allograft.59,68

Alagille Syndrome Through the late 1960s to the late 1980s, Daniel Alagille published several reports in French and English medical literature of a chronic cholestatic disease in children with “hepatic ductular hypoplasia” and 77

Practical Hepatic Pathology: A Diagnostic Approach

*

* *

A

B

C

D Figure 5.16  Neonatal hepatitis shows a constellation of histologic findings that occur in various combinations in different patients and in different conditions (also see eSlide 5.5). A, Multinucleated enlarged hepatocytes (giant cells) (arrows) and lobular inflammation, small areas of necrosis (arrowhead), and biliary rosettes (asterisk) in a patient with idiopathic neonatal hepatitis. B, Canalicular cholestasis with a biliary rosette (arrowhead), apoptotic bodies (arrows), and foci of extramedullary hematopoieses (asterisks) are seen in a patient with urinary tract infection, sepsis, and positive polymerase chain reaction for CMV in blood. C, Marked canalicular cholestasis (arrows), bile-laden macrophages, ballooned and damaged hepatocytes, and foci of extramedullary hematopoieses (arrowhead) in a patient with idiopathic neonatal hepatitis. D, Ballooned hepatocytes, including a multinucleated giant hepatocyte (arrow) in a premature infant with congenital CMV infection.

normal extrahepatic bile ducts. In 1973, he reported on “a homogeneous, readily recognizable group” among children with ductular hypoplasia who “in addition to chronic cholestasis, (they) have characteristic facies, a mesosystolic murmur, vertebral arch defects, growth retardation, mental retardation, and hypogonadism.”69 These seminal findings were further reiterated in a series of 111 cases published in 1987; 80 of these patients had “syndromic paucity of interlobular bile ducts (PILBD)” that was associated with peculiar facies, chronic cholestasis, posterior embryotoxon, butterfly-like vertebral arch defects, and peripheral pulmonary artery hypoplasia or stenosis, with or without other complex cardiovascular abnormalities. The remaining 31 patients had “nonsyndromic” PILBD with no extrahepatic abnormalities.70 The authors concluded that “an autosomal dominant mode of transmission, with variable penetrance, seems likely,” a succinct observation that was proven with the subsequent discovery of genetic mutations in JAG1 and NOTCH2 that underlie Alagille syndrome.71-73 The 78

title of this pivotal paper, “Syndromic Paucity of Interlobular Bile Ducts (Alagille Syndrome or Arteriohepatic Dysplasia): Review of 80 Cases,” acknowledges the earlier report of Watson and Miller, who described a familial disease with pulmonary stenosis and neonatal cholestasis that they termed “arteriohepatic dysplasia.”74 Alagille syndrome, syndromic and nonsyndromic PILBD, Watson-Miller syndrome, Alagille-Watson syndrome and arteriohepatic dysplasia have all been used to describe this syndrome at various periods. Because patients with PILBD and no extrahepatic manifestations also carry mutations in JAG1 and NOTCH2, “nonsyndromic” PIBLD is in fact part of the spectrum of Alagille syndrome, albeit one in which phenotypic expression is limited to a single organ, namely the liver.

Incidence and Demographics ALGS is an autosomal dominant disease with an incidence of 1 in 70,000 to 100,000 live births with no gender predilection. There are no data

Liver Diseases of Childhood linking Alagille disease to a particular race or ethnic group. Chronic cholestasis is said to occur in approximately 95% of cases.75,76 A small proportion of patients have no manifestations of liver disease.75,77

5

Molecular Genetics

A

Mutations in JAG1 and NOTCH2 located on chromosomes 20p12 and 1p12 account for 94% and 1.4% of clinically diagnosed cases of ALGS, which are referred to as ALGS1 and ALGS2.78 Knockout mouse models for JAG1 and NOTCH1 are lethal in utero, whereas mice heterozygous for JAG1 mutation show limited ocular defects. However, double heterozygosity for a JAG1 null allele and a NOTCH2 hypomorphic allele leads to a phenotype similar to human ALGS.79 Genetic abnormalities detected in JAG1 and NOTCH2 include deletions, frameshift mutations, nonsense mutations, and splice site alterations.80 All mutations are present in heterozygous form. Penetrance is highly variable, even in concordant twins, suggesting an important role of as yet unrecognized modifier factors.81 Mosaicism for JAG1 mutations has been demonstrated in parents of affected patients and rarely in affected patients themselves, suggesting somatic deletion of JAG1. The presence of mosaicism may result in failure to detect mutations.

Clinical Manifestations

B

C Figure 5.17  Liver biopsy from a patient with neonatal hemochromatosis (congenital alloimmune hepatitis). A, Extensive canalicular cholestasis and many multinucleated giant hepatocytes are seen. B, Extensive hemosiderin deposition within hepatocytes and bile ducts (arrow). Perls Prussian blue stain (also see eSlide. 5.6). C, Immunohistochemical positivity for terminal complement complex, C5b-9, within giant multinucleated cells. Horseradish peroxidase with diaminobenzidine (DAB). (C, Courtesy Dr. Peter Whitington, Departments of Pediatrics and Transplantation, Children’s Memorial Medical Center, Northwestern University School of Medicine.)

ALGS is characterized by variable combinations of hepatic, ocular, skeletal, cardiac, and renal abnormalities. The penetrance of the genetic disorder is low and highly variable. A significant number of individuals who harbor JAG1 or NOTCH2 mutations are asymptomatic, the genetic mutations being discovered incidentally during investigation for other disorders or during family work-up of an index case. Liver disease presents by 5 years of age and most often within the first 6 months of life with jaundice and severe pruritus.76,82 Xanthomas on the extensor surfaces of the fingers, nape of the neck, and palmar and inguinal creases are a prominent feature, even in very young children. Growth retardation, osteoporosis, or neurologic deficits may be present because of malabsorption of essential fatty acids and fat-soluble vitamins due to deficient bile flow. Laboratory investigations show conjugated hyperbilirubinemia, elevated serum bile acids, elevated GGT and alkaline phosphatase, and hyperlipidemia with increased cholesterol and triglycerides.76,82-84 Hepatomegaly with or without splenomegaly may be present. Although symptoms may resolve with age, almost 20% to 30% of patients with ALGS require liver transplantation, most often for refractory pruritus and xanthomas and a few for liver failure, cirrhosis, and hepatocellular carcinoma.76,82,83 ALGS accounts for approximately 2% of all pediatric liver transplants. Cardiac disease of ALGS most often presents within the first 6 months of life. Stenosis of the peripheral pulmonary arteries with hypoplasia of the peripheral pulmonary tree is the most common and characteristic anomaly but other intracardiac defects and tetralogy of Fallot are not infrequent.70,76 Approximately 10% of patients have extracardiac vascular anomalies such as coarctation and aneurysms of the aorta as well as aneurysms and structural abnormalities of the internal carotid and intracerebral arteries.85,86 Segmental stenosis of the gastrointestinal and respiratory tracts or avascular necrosis of bones may result from vascular compromise.82 Spontaneous bleeding, particularly intracranial bleeding and bleeding during surgical or medical procedures such as liver biopsy, occurs in a significant number of patients, in the absence of underlying organ or tissue structure abnormalities, platelet abnormalities, or abnormalities of prothrombin time. The precise defect underlying spontaneous bleeding in ALGS is not known. Hypercholesteremia and/or impaired vascular development or impaired homeostatic function because of defective JAG1-Notch signaling have been implicated.76,82,86,87 79

Practical Hepatic Pathology: A Diagnostic Approach The most common and typical ocular abnormality is posterior embryotoxon, which provides a useful diagnostic clue in children with intrahepatic cholestasis.70,76,82 Anomalies of the optic disc and iris as well as a variety of retinal pigmentary changes are common; these occur without vitamin deficiencies and are not associated with refractive errors or loss of visual acuity.88 Progressive visual loss has been described rarely and is related to idiopathic intracranial hypertension.89 Skeletal abnormalities include “butterfly” vertebrae, a radiographic appearance caused by nonfusion of the anterior vertebral arch; decrease in interpediculate distance in the lumbar spine; and shortening of the distal phalanges of the fingers. The typical facies of ALGS results from the combined effects of hypertelorism, deep-set eyes, frontal bossing, straight nose, and a narrow, pointed chin.69,70,74,76,82 The ALGS facies is a highly penetrant feature and may be present without any other accompanying abnormality.77,81,90 Renal abnormalities are a prominent component of ALGS2 but may also be present in ALGS1. Renal dysplasia, renal artery stenosis, renal cysts, and tubular acidosis have been described in various combinations.76,82 Kidney disease usually manifests in late childhood or adulthood. Hepatocellular carcinoma occurs rarely in children with ALGS and has been reported in an adult with ALGS without cirrhosis.91-93

A

Gross Pathology The liver at transplantation or autopsy may be normal sized or slightly enlarged. Cirrhosis is not typical of ALGS, and the liver is only slightly firm in consistency. The cut surface appears homogenous and dark green without diffuse nodularity. Hepatocellular carcinoma may be present.

Microscopic Pathology Well-established ALGS shows marked cholestasis with paucity of interlobular bile ducts in the absence of significant inflammation or ductular reaction (Fig. 5.18). Cholestasis is more severe in centrilobular regions and may involve the entire lobule. Bile is seen in dilated canaliculi and within hepatocytes and Kupffer cells. Clusters of foamy macrophages may be seen. There may be copper accumulation in periportal hepatocytes. In the absence of bile ducts, inflammation or ductular reaction, the portal tracts appear inconspicuous although some may show mild edema, dilated veins, and lymphatics. Although ALGS is not classically considered fibrosing, explanted livers often show mild fibrosis that may be both centrilobular and periportal, and bridging septa may be seen (eSlide 5.7). Rare cases may show frank cirrhosis. Typical features of ALGS may not be present in biopsy samples of children younger than 6 months; the samples may instead show presence of bile ducts and even mild ductular proliferation leading potentially to misdiagnosis of biliary atresia.94-98 Mild periductal inflammation or fibrosis accompanied by epithelial damage may be present; lymphocytic cholangitis or bile duct scars as seen in sclerosing cholangitis are not seen.94,96,97 These features suggest that destruction of bile ducts is progressive and inflammatory in nature.99

Differential Diagnosis There are two main considerations in the differential diagnosis of ALGS: distinction from biliary atresia and other causes of neonatal cholestasis with paucity of interlobular bile ducts. Biopsy samples from patients with ALGS younger than 6 months not only may contain bile ducts, but also may show ductular reaction. In addition, radiologic studies, including intraoperative cholangiography, may show nonexcretion of contrast medium into the extrahepatic bile ducts, further mimicking biliary atresia. It is not clear whether nonexcretion results from severe hypoplasia of the bile ducts or lack of bile flow itself. There are several reports of patients with ALGS who have undergone unnecessary Kasai 80

B Figure 5.18  Liver biopsy from a patient with Alagille syndrome showing a portal tract with two arteriolar profiles but no bile duct (A) and severe canalicular cholestasis as well as slight ballooning of perivenular hepatocytes (B) (also see eSlide 5.7).

procedures that do not restore bile flow in these patients and instead predispose them to cholangitis, ultimately worsening their hepatic disease.84,97,98,100 The ductular proliferation of early stage ALGS is, however, never as prominent as that seen in biliary atresia. There is also no or minimal fibrosis in very young children with ALGS in contrast to biliary atresia, in which severe fibrosis occurs early and patients have cirrhosis by 8 to 12 weeks of age. Other clinical stigmata of ALGS in the proband or close relatives assist in correct diagnosis of ALGS. However, presence of embryotoxon should be interpreted with caution because it is found in approximately 15% of individuals in the general population.75,101 Other neonatal cholestatic disorders that have been associated with paucity of interlobular bile ducts include alpha-1 antitrypsin deficiency, Zellweger syndrome, congenital rubella, Down syndrome, Turner syndrome, trisomy 17, and trisomy 18. Some skepticism is required in the evaluation of these putative associations. Older reports antedate use of immunostaining for bile duct keratins to identify hypoplastic biliary radicles; because bile flow is trophic for bile duct development, intrahepatic cholestasis of any cause may be associated with inconspicuous but not absent interlobular bile ducts. All these disorders, except alpha-1 antitrypsin deficiency, present with characteristic clinical features that aid diagnosis. Diagnosis of alpha-1 antitrypsin deficiency relies on demonstration of low levels of the enzyme in serum and the presence

Liver Diseases of Childhood of abnormal enzyme isoforms on isoelectric focusing. Biopsy samples from children younger than 6 months do not show the typical intracytoplasmic globules of alpha-1 antitrypsin, and their absence does not exclude the disease.

Treatment and Prognosis Death from ALGS results mainly from cardiac disease, liver disease, and spontaneous bleeding.76,82,83 In a series of 92 patients, liver disease and complications of transplantation accounted for 25% of deaths, cardiac disease for 25%, and bleeding for 15%.76 Total bilirubin 6.5 mg/dL or greater, conjugated bilirubin 4.5 mg/dL or greater, and cholesterol greater than 520 mg/dL in children younger than 5 years are associated with severe liver disease in later life, whereas values below this cutoff point are predictors of a more benign course.102 Along the same lines, a multicenter study found that long-term hepatic outcomes of patients with Alagille syndrome can be predicted on the basis of total serum bilirubin levels between the ages of 12 and 24 months (>3.5 mg/dL), combined with fibrosis on liver biopsy and the presence of xanthomata on physical examination.103 Treatment of liver disease consists of antipruritic drugs and supplementation of fat-soluble vitamins. The pruritus of liver disease is difficult to control and affects the quality of life in a significant number of patients.104 Combinations of UDCA, cholestyramine, and rifampicin are often, but not universally, successful.104 The role of surgical interventions such as biliary diversion, cutaneous cholecystostomy, and hepatoportoenterostomy (Kasai procedure) is limited, if any at all. Approximately 20% to 30% of patients require liver transplantation for intractable pruritus, xanthomas, progressive jaundice, or liver failure, and a few patients even have hepatocellular carcinoma. Survival after transplantation for Alagille syndrome is significantly lower than that for biliary atresia.105 In addition, the effects of long-term immunosuppression on those with renal and vascular disease are uncertain.106 Patients who have neonatal jaundice have a worse prognosis than those who have liver disease later in life. Their jaundice is more severe and unremitting; their pruritus is more difficult to treat; and they are more likely to have xanthomas, hepatomegaly, and splenomegaly. Although overall survival of patients with liver disease is 70% to 75%, those with neonatal onset of disease may have a lower 10-year survival rate.76,82-84 Liver transplantation markedly improves survival; the predicted probability of children presenting in infancy of reaching 19 years of age is 50%, which increases to 87% with transplantation.83

Primary Sclerosing Cholangitis Contrary to established notions, primary sclerosing cholangitis (PSC), a well-recognized entity in adults, is not uncommon in children. However, the incidence is about 20% less than that reported for adults. Although there are many similarities with the adult disease, pediatric PSC is distinct from the latter and does not simply represent an earlier stage of the adult disease.3 In contrast to adults, serum levels of transaminases and GGT are higher, overlap with autoimmune hepatitis is more common, and cholangiocarcinoma is rare in children with PSC.2,3 Diagnosis of PSC in children requires a high degree of suspicion because of atypical and noncholestatic modes of presentation. Sclerosing cholangitis in children, similar to adults, may occur secondary to other underlying diseases, which make up 30% to 50% of all cases; Langerhans cell histiocytosis (LCH), cystic fibrosis, and immune deficiency syndromes constitute the most frequent causes.107

Incidence and Demographics A population-based study of a heterogeneous population in Alberta, Canada, reported an incidence of 0.23 per 100,000 person-years in

children compared with an incidence of 0.9 per 100,000 person-years in adults.108 The incidence of PSC in several other population-based studies in North America and Europe ranges from 0.9 to 1.3 per 100,000 person-years; although these studies do not specifically document the incidence in children, they all include patients younger than 18 years of age.109-111 Male preponderance has been reported in most series of childhood PSC112-114; female preponderance has been observed in series that predominantly include patients with concomitant autoimmune hepatitis (AIH).2,115 PSC is most prevalent in mid-childhood and early adolescence112-114; however, cases have been reported in children younger than 2 years and as young as 6 months.114 As in adults, PSC in children is diagnosed by the cholangiographic appearance of alternating segmental obstruction and dilatation of the biliary tree giving rise to a characteristic beaded appearance.

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Clinical Manifestations The clinical presentation is variable and may not point to a biliary process in many patients. Children may have nonspecific symptoms such as fatigue, anorexia, abdominal pain, and pruritus; most do not have jaundice. Other patients may be completely asymptomatic, presenting late in the disease course with advanced fibrosis, incidental hepatosplenomegaly, isolated splenomegaly, or cryptogenic cirrhosis.112-114,116 Although alkaline phosphatase levels may be normal in a substantial number of patients, GGT is almost always elevated and is considered to be a more sensitive marker of PSC.113,114 A distinct subset of patients has AIH and may not demonstrate evidence of concurrent biliary tract disease unless it is specifically sought by cholangiography.1,2,113-116 These children have increased serum immunoglobulins and serum autoantibodies and fulfill the criteria for “definite” or “probable” AIH. Serum antinuclear and antismooth muscle antibodies are most common, and anti–liver-kidney microsomal and antineutrophil cytoplasmic antibodies may be present.114,115 Alanine aminotransferase and GGT levels are higher in this group than in children without AIH.113 Liver biopsy samples show interface hepatitis, and the children respond to corticosteroids. At this stage, the histologic, clinical, and biochemical findings may not point to a biliary disease, and alkaline phosphatase levels may not be significantly different from those in children who have AIH.117 However, cholangiography shows typical findings of sclerosing cholangitis.115 As the hepatitis improves with immunosuppression, the biliary disease continues to progress. In some patients, AIH may precede the appearance of PSC.113 Designated by some as autoimmune sclerosing cholangitis, the concurrent or synchronous appearance of PSC in patients with AIH is similar to the AIH-PSC overlap syndrome in adults but is much more common in the pediatric age group. In a Canadian population-based analysis of PSC, one-third of children had features of AIH in contrast to 10% of adults.108 Although reported in some series to be more frequent than PSC occurring without AIH, others have found PSC-AIH to constitute one-quarter to one-third of all cases of childhood PSC.112-114 Pathogenesis remains multifactorial; however, recent studies have shown homozygosity for the allele DR3 as a predisposing factor for autoimmune liver disease.118 Approximately one-third of cases represent small-duct disease, which may not show elevated alkaline phosphatase or GGT.113,118 The disease does not progress to large-duct PSC, and the natural course is slower than that of large-duct PSC. Inflammatory bowel disease is present in approximately 50% to 60% of children with PSC. Although ulcerative colitis is more common than Crohn disease, the latter predominates in patients who have small-duct PSC.113,114 Inflammatory bowel disease may be present at the time of diagnosis of PSC or appear before or after the diagnosis. 81

Practical Hepatic Pathology: A Diagnostic Approach

Fig 5.19  Liver biopsy from a child with primary sclerosing cholangitis. The portal tract is expanded by fibrosis and a ductular reaction (also see eSlide 5.8).

Radiologic Findings

Figure 5.20  Liver biopsy from a child with sclerosing cholangitis. Concentric periductal inflammation and fibrosis are present around a bile duct showing epithelial attenuation and damage. Ductular reaction is present at the edge of the portal tract (also see eSlide 5.8).

The radiologic features are similar to those in adults and consist of irregular strictures and dilatations of the large- and medium-sized bile ducts, leading to a typical “beaded” appearance of the biliary tree. The intrahepatic bile ducts shows a “pruned-tree” appearance. A scoring system has been published to assess the severity of involvement in children as mild, moderate, or severe.114 Involvement may be either isolated to the intrahepatic or extrahepatic biliary tree segments but more often involves both portions.113 Calcifications in the wall of the bile ducts and abnormalities of the pancreatic ducts have been described in some patients. Biliary sludge and/or lithiasis have been reported in LCH and immunodeficiency diseases.107,119,120 Distinctive patterns reported include stricture at the confluence of the hepatic ducts in LCH and papillary stenosis in immunodeficiency states.107 Small duct PSC that involves only the small peripheral ducts does not show any abnormal findings on cholangiography.113

Microscopic Pathology The microscopic pathology is similar to that of the adult disease with ductular proliferation, loss of intrahepatic bile ducts, and fibrosis in the small portal tracts (Fig. 5.19) (eSlide 5.8). Concentric periductal inflammation and/or fibrosis (Fig. 5.20) and fibrous scars representing remnants of obliterated bile ducts may be seen. The larger bile ducts show periductal lymphoplasmacytic inflammatory infiltrate. The degree of portal inflammation tends to be more than that seen in adults, even in the absence of concurrent AIH (Fig. 5.21). Epithelial damage and destruction of the bile duct walls may lead to bile leaks and a xanthogranulomatous inflammatory infiltrate. Copper and copper-associated protein can be detected in periportal hepatocytes by special stains. Patients with concomitant AIH show features typical of that condition; in these instances, the portal tracts are widened by a moderate to severe inflammatory infiltrate of lymphocytes, plasma cells, and eosinophils. There is a variable degree of interface hepatitis with damage and destruction of the limiting plate of hepatocytes. This is accompanied by variable degrees of lobular damage with necroinflammatory foci and lobular inflammation. Areas of collapse or confluent necrosis may be seen. Ductular reaction may be seen but is usually mild; features of hepatitis mask biliary changes. As the inflammation subsides in response to corticosteroid therapy, the biliary changes become more apparent with progressive duct damage as well as increasing ductular reaction and fibrosis (Fig. 5.22). 82

Figure 5.21  Liver biopsy from a child with PSC. The ductular reaction is obscured by a lymphocytic inflammatory infiltrate, but there is no interface hepatitis. Prominent portal inflammation may be seen in children with PSC, even when serum autoimmune markers are negative (also see eSlide 5.8).

Diagnosis As in adults, the diagnosis of PSC is made by characteristic cholangiographic findings. However, the noncholestatic and frequently atypical modes of presentation in children, often with normal alkaline phosphatase levels, require a high degree of clinical suspicion to establish the diagnosis. GGT is a reliable marker of PSC and is advocated whenever PSC is suspected and in all children with AIH or inflammatory bowel disease.113,114 Magnetic resonance cholangiopancreatography can also be used to screen patients at risk for PSC.113

Treatment and Prognosis Children respond to UDCA with dramatic decreases in transaminases.113 Patients who have a component of AIH respond well to steroids. Patients who have autoimmune markers without histologic features of hepatitis are not considered to have an overlap syndrome, are not treated with steroids, and respond well to UDCA alone.113,114 A

Liver Diseases of Childhood

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A

B

C

D Figure 5.22  PSC-AIH in a 10-year-old boy. A, The patient had features of severe autoimmune hepatitis including antinuclear antibody titer of 1:2560. Liver biopsy confirmed severe hepatitis with areas of multiacinar collapse. The patient responded to steroids. B, A liver biopsy sample 3 years later shows ductular reaction with only minimal inflammation. C, The liver biopsy also shows marked periportal fibrosis with bridging septa. Masson trichrome stain. D, Coronal T2-weighted image shows beaded appearance of common bile duct (arrowhead). The spleen (arrow) is enlarged as a result of portal hypertension from chronic liver disease. (D, Courtesy Dr. K. Sandrasegaran, Department of Radiology, Indiana University School of Medicine.)

study of 14 children with PSC and inflammatory bowel disease showed improvement in selected laboratory tests on treatment with oral vancomycin, which is itself poorly absorbed in the gut but possibly exerts its benefits either by antibacterial actions against as yet undefined gut microbes or through as yet unrecognized immunomodulatory actions.121 A study comparing outcomes between adults and children with PSC found slower progression and less adverse outcomes such as death or cancer in children in spite of greater interface activity.116 Children with cirrhosis may remain clinically stable for longer periods than adults.114 Disease progression is more likely in those patients who have concomitant AIH.113 Most children need liver transplantation in 7 to 10 years for decompensated cirrhosis or recurrent cholangitis; recurrence in the allograft occurs in up to 25% to 35% of cases.122,123

Sclerosing Cholangitis Due to Langerhans Cell Histiocytosis LCH has a wide clinical spectrum, ranging from systemic disease with multiorgan failure (Letterer-Siwe disease) to isolated osteolytic lesions

(eosinophilic granuloma). The former is rapidly progressive and fatal, whereas the latter may regress spontaneously or with minimal therapy. Almost any organ may be involved in LCH; involvement of bone is by far the most common, followed by the skin, lymph nodes, and lungs. LCH shows a slight male predominance. A higher incidence is seen in Caucasians than in blacks, and a higher incidence is seen in Hispanics compared with non-Hispanics. The incidence is greater in crowded, urban areas.124,125 The liver is involved in 30% to 40% of cases of systemic LCH; the most usual form of hepatic involvement is sclerosing cholangitis that radiologically resembles classic PSC with characteristic “beading” of the biliary tree.126,127 The pathogenesis of biliary disease in LCH is not clear but is thought to result from direct destruction of bile ducts by the infiltrating Langerhans cells. Periductal fibrosis and scarring may occur because of inflammatory destruction or secondary to obstructive changes. Establishing LCH as the cause of sclerosing cholangitis may be challenging because the abnormal cells may not persist in the liver in the terminal, burned-out fibrotic stage of the disease.126 83

Practical Hepatic Pathology: A Diagnostic Approach

A

B

C

D Figure 5.23  Sclerosing cholangitis due to LCH. A, Liver removed at transplantation is cholestatic and shows dilated intrahepatic bile ducts containing bile sludge. B, Section from the perihilar region shows cirrhosis and a dilated intrahepatic duct with bile sludge surrounded by an inflammatory infiltrate (arrows), which C, consists of innumerable eosinophils and scattered larger cells with convoluted nuclei (arrows). These cells are positive for CD1a (inset) and S100. D, Langerhans cells contain Birbeck granules. Although “tennis racket–shaped” configurations (arrow) are classic, these are very rare, whereas straight rods with a trilaminar profile (arrowheads) are both more numerous and more frequent. (D, Courtesy Michael Goheen, MS, Department of Pathology, Indiana University School of Medicine; not the same case as parts A–C.)

Microscopic Pathology Liver involvement by LCH is characterized by a mixed portal inflammatory infiltrate that is particularly rich in eosinophils and histiocytes (Fig. 5.23). Portal tracts are variably involved, in terms of distribution and the density of the infiltrate. At times, the infiltrate may assume a granulomatous appearance and be mistaken for a granulomatous inflammatory process. The pathognomic Langerhans cells are present within this infiltrate in variable numbers and may be very sparse. The Langerhans cell is a large cell containing an abundant amount of eosinophilic or clear cytoplasm and a characteristic convoluted or grooved nucleus with open chromatin. Langerhans cells are immunohistochemically positive for S100, CD1a, and langerin (CD207). Lobular involvement may accompany the portal changes. On ultrastructural examination, Langerhans cells contain characteristic Birbeck granules that are “tennis racket–shaped” intracytoplasmic organelles measuring 200 to 400 nm in length and 84

33 nm in width. The classic tennis racket–shaped configuration is however extremely rare, and straight rods (corresponding to the racquet handle) with a trilaminar profile are more abundant and more frequent (Fig. 5.23). Birbeck granules have been shown to contain cell membrane antigens and are thought to result from receptor-mediated endocytosis.

Molecular Pathology Current molecular studies point to LCH as arising from mutations in a myeloid precursor cell rather than from the dendritic Langerhans cell of the skin. Almost half of all cases of LCH contain the BRAF V600E mutation in which valine (V) is substituted by glutamate (E) at codon 600 of the BRAF gene. Furthermore, half the cases that are negative for BRAF V600E mutation have somatic mutations in MAP2K1 (mitogenactivated protein kinase kinase 1). It thus seems that ERK (extracellular signal-regulated kinases) activation resulting from activation of

Liver Diseases of Childhood upstream signaling proteins is a universal endpoint that underscores the role of RAF/MAPK/ERK pathway in the development of LCH.128-130

Treatment and Prognosis Once established, sclerosing cholangitis due to LCH pursues an inexorable, self-perpetuating course, even after the initiating disease has burned out.126 The value of liver transplantation for sclerosing cholangitis due to LCH is debatable in a malignant condition with possible extrahepatic involvement. However, incomplete response to chemotherapy, progression of the disease despite quiescent LCH, and the accelerated course of sclerosing cholangitis when associated with LCH make transplantation a viable and, in many cases, the only therapeutic option.127,131-134 Some authors have reported no disease recurrence with follow up as long as 7 years, whereas others have reported both hepatic and extrahepatic recurrence following transplantation.127,131-134 An additional benefit of transplantation stems from the observation that the immunomodulant drug cyclosporine, used for graft maintenance, may itself prevent recurrence of LCH.127,134 The Langerhans cell, a dendritic reticulum cell and member of the macrophage-phagocyte system, has limited phagocytic activity but major antigen-presenting functions. On activation, it releases interleukin-1, which stimulates T-helper cells, leading to formation of interleukin-2 and activation of the inflammatory cascade. Cyclosporine is thought to block this cascade by inhibiting lymphokines, particularly interleukin-2 and interferon-γ; receptors for the latter are present on abnormal Langerhans cells. Cyclosporine has been used with beneficial results in children with advanced LCH.127,134,135 The relatively recent discovery of BRAF V600E mutation as well as mutations in MAP2K1 in at least half of all cases of LCH opens the possibility of treatment with BRAF inhibitors such as vemurafenib or dabrafenib as well as inhibitors of MEK such as trametinib. However, no clinical data on their utility or effectiveness are available at the time of going to press.

Neonatal Sclerosing Cholangitis Neonatal sclerosing cholangitis, as the name suggests, is a neonatal disease with cholangiographic findings of sclerosing cholangitis. It presents with conjugated hyperbilirubinemia and demonstrates elevated serum alkaline phosphatase and GGT, and ductular reaction on biopsy, thus mimicking biliary atresia clinically and histologically. However, the biliary tree is not atretic. There is a high incidence of neonatal sclerosing cholangitis in siblings and children of consanguineous marriages. Biallelic mutations in DCDC2 (doublecortin domain containing 2), which encodes a signaling and structural protein found in primary cilia of cholangiocytes, have been detected in these patients.135a,135b Almost half of all patients have extrahepatic manifestation such as subaortic valvular stenosis.1,107 An association of neonatal sclerosing cholangitis with congenital ichthyosis (neonatal ichthyosis sclerosing cholangitis [NISCH] syndrome) has been related to a mutation in the claudin-1 gene.136-138 Thus, neonatal sclerosing cholangitis is a distinct entity that is not related to primary sclerosing cholangitis of childhood. Suggested Readings Balistreri WF, Bezerra JA. Whatever happened to “neonatal hepatitis”? Clin Liver Dis. 2006;10:27–53. El-Guindi MA, Sira MM, Sira AM, et al. Design and validation of a diagnostic score for biliary atresia. J Hepatol. 2014;61:116–123. Girard M, Franchi-Abella S, Lacaille F, et al. Specificities of sclerosing cholangitis in childhood. Clin Res Hepatol Gastroenterol. 2012;36:530–535. Harmon CM, Brown N. Langerhans cell histiocytosis. A clinicopathologic review and molecular pathogenetic update. Arch Pathol Lab Med. 2015;139:1211–1214. Moyer V, Freese DK, Whitington PF, et al. Guideline for the evaluation of cholestatic jaundice in infants: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. J Pediatr Gastroenterol Nutr. 2004;39:115–128.

Russo P, Magee JC, Boitnott J, et al. Design and validation of the biliary atresia research consortium histologic assessment system for cholestasis in infancy. Clin Gastroenterol Hepatol. 2011;9:357– 362 e352. Sokol RJ, Shepherd RW, Superina R, et al. Screening and outcomes in biliary atresia: summary of a National Institutes of Health workshop. Hepatology. 2007;46:566–581.

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References 1. Girard M, Franchi-Abella S, Lacaille F, et al. Specificities of sclerosing cholangitis in childhood. Clin Res Hepatol Gastroenterol. 2012;36:530–535. 2. Mieli-Vergani G, Vergani D. Unique features of primary sclerosing cholangitis in children. Curr Opin Gastroenterol. 2010;26:265–268. 3. Shneider BL. Diagnostic and therapeutic challenges in pediatric primary sclerosing cholangitis. Liver Transpl. 2012;18:277–281. 4. Kelly DA, Stanton A. Jaundice in babies: implications for community screening for biliary atresia. BMJ. 1995;310:1172–1173. 5. Moyer V, Freese DK, Whitington PF, et al. Guideline for the evaluation of cholestatic jaundice in infants: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. J Pediatr Gastroenterol Nutr. 2004;39:115–128. 6. Balistreri WF. Neonatal cholestasis. J Pediatr. 1985;106:171–184. 7. Balistreri WF, Bezerra JA. Whatever happened to “neonatal hepatitis”? Clin Liver Dis. 2006;10:27–53. 8. Bove KE. Liver disease caused by disorders of bile acid synthesis. Clin Liver Dis. 2000;4:831–848. 9. Suchy FJ. Neonatal cholestasis. Pediatr Rev. 2004;25:388–396. 10. Lee WS, Yap SF, Looi LM. alpha1-Antitrypsin deficiency is not an important cause of childhood liver diseases in a multi-ethnic Southeast Asian population. J Paediatr Child Health. 2007;43:636–639. 11. Mowat AP, Psacharopoulos HT, Williams R. Extrahepatic biliary atresia versus neonatal hepatitis. Review of 137 prospectively investigated infants. Arch Dis Child. 1976;51:763–770. 12. Chen HW, Chen HL, Ni YH, et al. Chubby face and the biochemical parameters for the early diagnosis of neonatal intrahepatic cholestasis caused by citrin deficiency. J Pediatr Gastroenterol Nutr. 2008;47:187–192. 13. Tiker F, Tarcan A, Kilicdag H, et al. Early onset conjugated hyperbilirubinemia in newborn infants. Indian J Pediatr. 2006;73:409–412. 14. Bellomo-Brandao MA, Porta G, Hessel G. Clinical and laboratory evaluation of 101 patients with intrahepatic neonatal cholestasis. Arq Gastroenterol. 2008;45:152–155. 15. Poddar U, Thapa BR, Das A, et al. Neonatal cholestasis: differentiation of biliary atresia from neonatal hepatitis in a developing country. Acta Paediatr. 2009;98:1260–1264. 16. Yang JG, Ma DQ, Peng Y, et al. Comparison of different diagnostic methods for differentiating biliary atresia from idiopathic neonatal hepatitis. Clin Imaging. 2009;33:439–446. 17. Mowat AP. Biliary atresia into the 21st century: a historical perspective. Hepatology. 1996;23:1693–1695. 18. Kasai M, Suzuki S. A new operation for “noncorrectable” biliary atresia; hepatic portoenterostomy. Shujutsu (Operation). 1959;13:733–739 (in Japanese); quoted from Kasai M, Watanbe I, Ohi R. Follow-up studies of long-term survivors after hepatic portoenterostomy for “noncorrectable” biliary atresia. J Pediatr Surg 1975;10:173-182. 19. Fischler B, Haglund B, Hjern A. A population-based study on the incidence and possible preand perinatal etiologic risk factors of biliary atresia. J Pediatr. 2002;141:217–222. 20. Lee H, Lewis J, Schoen BT, et al. Kasai portoenterostomy: differences related to race. J Pediatr Surg. 2001;36:1196–1198. 21. Silveira TR, Salzano FM, Howard ER, et al. Extrahepatic biliary atresia and twinning. Braz J Med Biol Res. 1991;24:67–71. 22. Mogul D. Johns Hopkins Children’s Center. The Color of Poop: Stool Guide, Mobile App to Speed up Diagnoses of Life-Threatening Liver Condition in Newborns. 2014. www.hopkinschildrens.org/The-Color-of-Poop-Stool-Guide-Mobile-App/. 23. Carmi R, Magee CA, Neill CA, et al. Extrahepatic biliary atresia and associated anomalies: etiologic heterogeneity suggested by distinctive patterns of associations. Am J Med Genet. 1993;45:683–693. 24. Humphrey TM, Stringer MD. Biliary atresia: US diagnosis. Radiology. 2007;244:845–851. 25. Tan CE, Davenport M, Driver M, et al. Does the morphology of the extrahepatic biliary remnants in biliary atresia influence survival? A review of 205 cases. J Pediatr Surg. 1994;29:1459–1464. 26. Choi SO, Park WH, Lee HJ. Ultrasonographic “triangular cord”: the most definitive finding for noninvasive diagnosis of extrahepatic biliary atresia. Eur J Pediatr Surg. 1998;8: 12–16. 27. Imanieh MH, Dehghani SM, Bagheri MH, et al. Triangular cord sign in detection of biliary atresia: is it a valuable sign? Dig Dis Sci. 2010;55:172–175. 28. Park WH, Choi SO, Lee HJ, et al. A new diagnostic approach to biliary atresia with emphasis on the ultrasonographic triangular cord sign: comparison of ultrasonography, hepatobiliary scintigraphy, and liver needle biopsy in the evaluation of infantile cholestasis. J Pediatr Surg. 1997;32:1555–1559. 29. Park WH, Choi SO, Lee HJ. The ultrasonographic ‘triangular cord’ coupled with gallbladder images in the diagnostic prediction of biliary atresia from infantile intrahepatic cholestasis. J Pediatr Surg. 1999;34:1706–1710. 30. Hussein A, Wyatt J, Guthrie A, et al. Kasai portoenterostomy—new insights from hepatic morphology. J Pediatr Surg. 2005;40:322–326.

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Practical Hepatic Pathology: A Diagnostic Approach 31. Takahashi A, Masuda N, Suzuki M, et al. Evidence for segmental bile drainage by hepatic portoenterostomy for biliary atresia: cholangiographic, hepatic venographic, and histologic evaluation of the liver taken at liver transplantation. J Pediatr Surg. 2004;39:1–5. 32. Schweizer J, Bowden PE, Coulombe PA, et al. New consensus nomenclature for mammalian keratins. J Cell Biol. 2006;174:169–174. 33. Yamaguti DC, Patricio FR. Morphometrical and immunohistochemical study of intrahepatic bile ducts in biliary atresia. Eur J Gastroenterol Hepatol. 2011;23:759–765. 34. Lee WS, Looi LM. Usefulness of a scoring system in the interpretation of histology in neonatal cholestasis. World J Gastroenterol. 2009;15:5326–5333. 35. Rastogi A, Krishnani N, Yachha SK, et al. Histopathological features and accuracy for diagnosing biliary atresia by prelaparotomy liver biopsy in developing countries. J Gastroenterol Hepatol. 2009;24:97–102. 36. Santos JL, Almeida H, Cerski CT, et al. Histopathological diagnosis of intra- and extrahepatic neonatal cholestasis. Braz J Med Biol Res. 1998;31:911–919. 37. Baerg J, Zuppan C, Klooster M. Biliary atresia—a fifteen-year review of clinical and pathologic factors associated with liver transplantation. J Pediatr Surg. 2004;39:800–803. 38. Chandra RS, Altman RP. Ductal remnants in extrahepatic biliary atresia: a histopathologic study with clinical correlation. J Pediatr. 1978;93:196–200. 39. Sanghai SR, Shah I, Bhatnagar S, et al. Incidence and prognostic factors associated with biliary atresia in western India. Ann Hepatol. 2009;8:120–122. 40. Zerbini MC, Gallucci SD, Maezono R, et al. Liver biopsy in neonatal cholestasis: a review on statistical grounds. Mod Pathol. 1997;10:793–799. 41. Sokol RJ, Mack C, Narkewicz MR, et al. Pathogenesis and outcome of biliary atresia: current concepts. J Pediatr Gastroenterol Nutr. 2003;37:4–21. 42. Serinet MO, Wildhaber BE, Broue P, et al. Impact of age at Kasai operation on its results in late childhood and adolescence: a rational basis for biliary atresia screening. Pediatrics. 2009;123:1280–1286. 43. Chardot C, Carton M, Spire-Bendelac N, et al. Prognosis of biliary atresia in the era of liver transplantation: French national study from 1986 to 1996. Hepatology. 1999;30:606–611. 44. McClement JW, Howard ER, Mowat AP. Results of surgical treatment for extrahepatic biliary atresia in United Kingdom 1980-2. Survey conducted on behalf of the British Paediatric Association Gastroenterology Group and the British Association of Paediatric Surgeons. Br Med J (Clin Res Ed). 1985;290:345–347. 45. Mirza Q, Kvist N, Petersen BL. Histologic features of the portal plate in extrahepatic biliary atresia and their impact on prognosis–a Danish study. J Pediatr Surg. 2009;44:1344–1348. 46. Santos JL, Kieling CO, Meurer L, et al. The extent of biliary proliferation in liver biopsies from patients with biliary atresia at portoenterostomy is associated with the postoperative prognosis. J Pediatr Surg. 2009;44:695–701. 47. Shinkai M, Ohhama Y, Take H, et al. Long-term outcome of children with biliary atresia who were not transplanted after the Kasai operation: >20-year experience at a children’s hospital. J Pediatr Gastroenterol Nutr. 2009;48:443–450. 48. Sokol RJ, Mack CL. Optimizing outcomes and bridging biliary atresia into adulthood. Hepatology. 2005;41:231–233. 49. Bezerra JA, Spino C, Magee JC, et al. Use of corticosteroids after hepatoportoenterostomy for bile drainage in infants with biliary atresia: the START randomized clinical trial. JAMA. 2014;311:1750–1759. 50. Altman RP, Lilly JR, Greenfeld J, et al. A multivariable risk factor analysis of the portoenterostomy (Kasai) procedure for biliary atresia: twenty-five years of experience from two centers. Ann Surg. 1997;226:348–353. discussion 353–345. 51. Laurent J, Gauthier F, Bernard O, et al. Long-term outcome after surgery for biliary ­atresia. Study of 40 patients surviving for more than 10 years. Gastroenterology. 1990;99: 1793–1797. 52. Ng VL, Haber BH, Magee JC, et al. Medical status of 219 children with biliary atresia surviving long-term with their native livers: results from a North American multicenter consortium. J Pediatr. 2014;165:539–546 e532. 53. Dolgin SE. Answered and unanswered controversies in the surgical management of extra hepatic biliary atresia. Pediatr Transplant. 2004;8:628–631. 54. Barshes NR, Lee TC, Balkrishnan R, et al. Orthotopic liver transplantation for biliary atresia: the U.S. experience. Liver Transpl. 2005;11:1193–1200. 55. Johnson SJ, Mathew J, MacSween RN, et al. Post-infantile giant cell hepatitis: histological and immunohistochemical study. J Clin Pathol. 1994;47:1022–1027. 56. Wang JS, Tan N, Dhawan A. Significance of low or normal serum gamma glutamyl transferase level in infants with idiopathic neonatal hepatitis. Eur J Pediatr. 2006;165:795–801. 57. Torbenson M, Hart J, Westerhoff M, et al. Neonatal giant cell hepatitis: histological and etiological findings. Am J Surg Pathol. 2010;34:1498–1503. 58. Bernard O, Hadchouel M, Scotto J, et al. Severe giant cell hepatitis with autoimmune hemolytic anemia in early childhood. J Pediatr. 1981;99:704–711. 59. Hadzic N, Portmann B, Lewis I, et al. Coombs positive giant cell hepatitis—a new feature of Evans’ syndrome. Arch Dis Child. 1998;78:397–398. 60. Domiati-Saad R, Dawson DB, Margraf LR, et al. Cytomegalovirus and human herpesvirus 6, but not human papillomavirus, are present in neonatal giant cell hepatitis and extrahepatic biliary atresia. Pediatr Dev Pathol. 2000;3:367–373. 61. Hicks J, Barrish J, Zhu SH. Neonatal syncytial giant cell hepatitis with paramyxoviral-like inclusions. Ultrastruct Pathol. 2001;25:65–71. 62. Pan X, Kelly S, Melin-Aldana H, et al. Novel mechanism of fetal hepatocyte injury in congenital alloimmune hepatitis involves the terminal complement cascade. Hepatology. 2010;51:2061–2068.

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63. Lai MW, Chang MH, Hsu SC, et al. Differential diagnosis of extrahepatic biliary atresia from neonatal hepatitis: a prospective study. J Pediatr Gastroenterol Nutr. 1994;18:121–127. 64. Mahjoub FE, Khairkhah RH, Sani MN, et al. CD 56 staining in liver biopsies does not help in differentiating extrahepatic biliary atresia from other causes of neonatal cholestasis. Diagn Pathol. 2008;3:10. 65. Sira MM, El-Guindi MA, Saber MA, et al. Differential hepatic expression of CD56 can discriminate biliary atresia from other neonatal cholestatic disorders. Eur J Gastroenterol Hepatol. 2012;24:1227–1233. 66. Torbenson M, Wang J, Abraham S, et al. Bile ducts and ductules are positive for CD56 (N-CAM) in most cases of extrahepatic biliary atresia. Am J Surg Pathol. 2003;27:1454–1457. 67. El-Guindi MA, Sira MM, Sira AM, et al. Design and validation of a diagnostic score for biliary atresia. J Hepatol. 2014;61:116–123. 68. Melendez HV, Rela M, Baker AJ, et al. Liver transplant for giant cell hepatitis with autoimmune haemolytic anaemia. Arch Dis Child. 1997;77:249–251. 69. Alagille D, Odievre M, Gautier M, et al. Hepatic ductular hypoplasia associated with characteristic facies, vertebral malformations, retarded physical, mental, and sexual development, and cardiac murmur. J Pediatr. 1975;86:63–71. 70. Alagille D, Estrada A, Hadchouel M, et al. Syndromic paucity of interlobular bile ducts (Alagille syndrome or arteriohepatic dysplasia): review of 80 cases. J Pediatr. 1987;110:195–200. 71. Li L, Krantz ID, Deng Y, et al. Alagille syndrome is caused by mutations in human Jagged1, which encodes a ligand for Notch1. Nat Genet. 1997;16:243–251. 72. McDaniell R, Warthen DM, Sanchez-Lara PA, et al. NOTCH2 mutations cause Alagille syndrome, a heterogeneous disorder of the notch signaling pathway. Am J Hum Genet. 2006;79:169–173. 73. Oda T, Elkahloun AG, Pike BL, et al. Mutations in the human Jagged1 gene are responsible for Alagille syndrome. Nat Genet. 1997;16:235–242. 74. Watson GH, Miller V. Arteriohepatic dysplasia: familial pulmonary arterial stenosis with neonatal liver disease. Arch Dis Child. 1973;48:459–466. 75. Turnpenny PD, Ellard S. Alagille syndrome: pathogenesis, diagnosis and management. Eur J Hum Genet. 2012;20:251–257. 76. Emerick KM, Rand EB, Goldmuntz E, et al. Features of Alagille syndrome in 92 patients: frequency and relation to prognosis. Hepatology. 1999;29:822–829. 77. Kamath BM, Bason L, Piccoli DA, et al. Consequences of JAG1 mutations. J Med Genet. 2003;40:891–895. 78. Penton AL, Leonard LD, Spinner NB. Notch signaling in human development and disease. Semin Cell Dev Biol. 2012;23:450–457. 79. McCright B, Lozier J, Gridley T. A mouse model of Alagille syndrome: Notch2 as a genetic modifier of Jag1 haploinsufficiency. Development. 2002;129:1075–1082. 80. Leonard LD, Chao G, Baker A, et al. Clinical utility gene card for: Alagille Syndrome (ALGS). Eur J Hum Genet. 2014:22. 81. Kamath BM, Krantz ID, Spinner NB, et al. Monozygotic twins with a severe form of Alagille syndrome and phenotypic discordance. Am J Med Genet. 2002;112:194–197. 82. Quiros-Tejeira RE, Ament ME, Heyman MB, et  al. Variable morbidity in Alagille syndrome: a review of 43 cases. J Pediatr Gastroenterol Nutr. 1999;29:431–437. 83. Hoffenberg EJ, Narkewicz MR, Sondheimer JM, et al. Outcome of syndromic paucity of interlobular bile ducts (Alagille syndrome) with onset of cholestasis in infancy. J Pediatr. 1995;127:220–224. 84. Lykavieris P, Hadchouel M, Chardot C, et al. Outcome of liver disease in children with Alagille syndrome: a study of 163 patients. Gut. 2001;49:431–435. 85. Emerick KM, Krantz ID, Kamath BM, et al. Intracranial vascular abnormalities in patients with Alagille syndrome. J Pediatr Gastroenterol Nutr. 2005;41:99–107. 86. Kamath BM, Spinner NB, Emerick KM, et al. Vascular anomalies in Alagille syndrome: a significant cause of morbidity and mortality. Circulation. 2004;109:1354–1358. 87. Lykavieris P, Crosnier C, Trichet C, et al. Bleeding tendency in children with Alagille syndrome. Pediatrics. 2003;111:167–170. 88. Hingorani M, Nischal KK, Davies A, et al. Ocular abnormalities in Alagille syndrome. Ophthalmology. 1999;106:330–337. 89. Narula P, Gifford J, Steggall MA, et al. Visual loss and idiopathic intracranial hypertension in children with Alagille syndrome. J Pediatr Gastroenterol Nutr. 2006;43:348–352. 90. Giannakudis J, Ropke A, Kujat A, et al. Parental mosaicism of JAG1 mutations in families with Alagille syndrome. Eur J Hum Genet. 2001;9:209–216. 91. Adams PC. Hepatocellular carcinoma associated with arteriohepatic dysplasia. Dig Dis Sci. 1986;31:438–442. 92. Bhadri VA, Stormon MO, Arbuckle S, et al. Hepatocellular carcinoma in children with Alagille syndrome. J Pediatr Gastroenterol Nutr. 2005;41:676–678. 93. Kim B, Park SH, Yang HR, et al. Hepatocellular carcinoma occurring in Alagille syndrome. Pathol Res Pract. 2005;201:55–60. 94. Berman MD, Ishak KG, Schaefer EJ, et al. Syndromatic hepatic ductular hypoplasia (arteriohepatic dysplasia): a clinical and hepatic histologic study of three patients. Dig Dis Sci. 1981;26:485–497. 95. Deprettere A, Portmann B, Mowat AP. Syndromic paucity of the intrahepatic bile ducts: diagnostic difficulty; severe morbidity throughout early childhood. J Pediatr Gastroenterol Nutr. 1987;6:865–871. 96. Ghishan FK, LaBrecque DR, Mitros FA, et al. The evolving nature of “infantile obstructive cholangiopathy.” J Pediatr. 1980;97:27–32. 97. Hashida Y, Yunis EJ. Syndromatic paucity of interlobular bile ducts: hepatic histopathology of the early and endstage liver. Pediatr Pathol. 1988;8:1–15.

Liver Diseases of Childhood 98. Markowitz J, Daum F, Kahn EI, et al. Arteriohepatic dysplasia. I. Pitfalls in diagnosis and management. Hepatology. 1983;3:74–76. 99. Deutsch GH, Sokol RJ, Stathos TH, et al. Proliferation to paucity: evolution of bile duct abnormalities in a case of Alagille syndrome. Pediatr Dev Pathol. 2001;4:559–563. 100. Kaye AJ, Rand EB, Munoz PS, et al. Effect of Kasai procedure on hepatic outcome in Alagille syndrome. J Pediatr Gastroenterol Nutr. 2010;51:319–321. 101. McDonald-McGinn DM, Kirschner R, Goldmuntz E, et al. The Philadelphia story: the 22q11.2 deletion: report on 250 patients. Genet Couns. 1999;10:11–24. 102. Kamath BM, Munoz PS, Bab N, et al. A longitudinal study to identify laboratory predictors of liver disease outcome in Alagille syndrome. J Pediatr Gastroenterol Nutr. 2010;50:526–530. 103. Mouzaki M, Bass LM, Sokol RJ, et al. Early life predictive markers of liver disease outcome in an International, Multicentre Cohort of children with Alagille syndrome. Liver Int [Epub ahead of print]. 2015. 104. Kronsten V, Fitzpatrick E, Baker A. Management of cholestatic pruritus in paediatric patients with Alagille syndrome: the King’s College Hospital experience. J Pediatr Gastroenterol Nutr. 2013;57:149–154. 105. Kamath BM, Yin W, Miller H, et al. Outcomes of liver transplantation for patients with Alagille syndrome: the studies of pediatric liver transplantation experience. Liver Transpl. 2012;18:940–948. 106. Kamath BM, Schwarz KB, Hadzic N. Alagille syndrome and liver transplantation. J Pediatr Gastroenterol Nutr. 2010;50:11–15. 107. Debray D, Pariente D, Urvoas E, et al. Sclerosing cholangitis in children. J Pediatr. 1994;124:49–56. 108. Kaplan GG, Laupland KB, Butzner D, et al. The burden of large and small duct primary sclerosing cholangitis in adults and children: a population-based analysis. Am J Gastroenterol. 2007;102:1042–1049. 109. Bambha K, Kim WR, Talwalkar J, et al. Incidence, clinical spectrum, and outcomes of primary sclerosing cholangitis in a United States community. Gastroenterology. 2003;125:1364–1369. 110. Boberg KM, Aadland E, Jahnsen J, et al. Incidence and prevalence of primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune hepatitis in a Norwegian population. Scand J Gastroenterol. 1998;33:99–103. 111. Kingham JG, Kochar N, Gravenor MB. Incidence, clinical patterns, and outcomes of primary sclerosing cholangitis in South Wales, United Kingdom. Gastroenterology. 2004;126:1929–1930. 112. Batres LA, Russo P, Mathews M, et al. Primary sclerosing cholangitis in children: a histologic follow-up study. Pediatr Dev Pathol. 2005;8:568–576. 113. Miloh T, Arnon R, Shneider B, et al. A retrospective single-center review of primary sclerosing cholangitis in children. Clin Gastroenterol Hepatol. 2009;7:239–245. 114. Wilschanski M, Chait P, Wade JA, et al. Primary sclerosing cholangitis in 32 children: clinical, laboratory, and radiographic features, with survival analysis. Hepatology. 1995;22:1415–1422. 115. Gregorio GV, Portmann B, Karani J, et al. Autoimmune hepatitis/sclerosing cholangitis overlap syndrome in childhood: a 16-year prospective study. Hepatology. 2001;33:544–553. 116. Floreani A, Zancan L, Melis A, et al. Primary sclerosing cholangitis (PSC): clinical, laboratory and survival analysis in children and adults. Liver. 1999;19:228–233. 117. Hiejima E, Komatsu H, Sogo T, et al. Utility of simplified criteria for the diagnosis of autoimmune hepatitis in children. J Pediatr Gastroenterol Nutr. 2011;52:470–473. 118. Wang P, Su H, Underhill J, et al. Autoantibody and human leukocyte antigen profiles in children with autoimmune liver disease and their first-degree relatives. J Pediatr Gastroenterol Nutr. 2014;58:457–462. 119. Caruso S, Miraglia R, Maruzzelli L, et al. Biliary wall calcification in Langerhans cell histiocytosis: report of two cases. Pediatr Radiol. 2008;38:791–794.

120. Caruso S, Miraglia R, Spada M, et al. Biliary dilatation secondary to lithiasis in a child affected by Langerhans’ cell histiocytosis. J Clin Ultrasound. 2009;37:366–368. 121. Davies YK, Cox KM, Abdullah BA, et al. Long-term treatment of primary sclerosing cholangitis in children with oral vancomycin: an immunomodulating antibiotic. J Pediatr Gastroenterol Nutr. 2008;47:61–67. 122. Chai PF, Lee WS, Brown RM, et al. Childhood autoimmune liver disease: indications and outcome of liver transplantation. J Pediatr Gastroenterol Nutr. 2010;50:295–302. 123. Feldstein AE, Perrault J, El-Youssif M, et al. Primary sclerosing cholangitis in children: a longterm follow-up study. Hepatology. 2003;38:210–217. 124. Bhatia S, Nesbit Jr ME, Egeler RM, et al. Epidemiologic study of Langerhans cell histiocytosis in children. J Pediatr. 1997;130:774–784. 125. Ribeiro KB, Degar B, Antoneli CB, et al. Ethnicity, race, and socioeconomic status influence incidence of Langerhans cell histiocytosis. Pediatr Blood Cancer. 2015;62:982–987. 126. Kaplan KJ, Goodman ZD, Ishak KG. Liver involvement in Langerhans’ cell histiocytosis: a study of nine cases. Mod Pathol. 1999;12:370–378. 127. Rand EB, Whitington PF. Successful orthotopic liver transplantation in two patients with liver failure due to sclerosing cholangitis with Langerhans cell histiocytosis. J Pediatr Gastroenterol Nutr. 1992;15:202–207. 128. Badalian-Very G, Vergilio JA, Degar BA, et al. Recent advances in the understanding of Langerhans cell histiocytosis. Br J Haematol. 2012;156:163–172. 129. Chakraborty R, Hampton OA, Shen X, et al. Mutually exclusive recurrent somatic mutations in MAP2K1 and BRAF support a central role for ERK activation in LCH pathogenesis. Blood. 2014;124:3007–3015. 130. Rizzo FM, Cives M, Simone V, et al. New insights into the molecular pathogenesis of langerhans cell histiocytosis. Oncologist. 2014;19:151–163. 131. Concepcion W, Esquivel CO, Terry A, et al. Liver transplantation in Langerhans’ cell histiocytosis (histiocytosis X). Semin Oncol. 1991;18:24–28. 132. Hadzic N, Pritchard J, Webb D, et al. Recurrence of Langerhans cell histiocytosis in the graft after pediatric liver transplantation. Transplantation. 2000;70:815–819. 133. Sommerauer JF, Atkison P, Andrews W, et  al. Liver transplantation for Langerhans’ cell histiocytosis and immunomodulation of disease pre- and posttransplant. Transplant Proc. 1994;26:178–179. 134. Zandi P, Panis Y, Debray D, et al. Pediatric liver transplantation for Langerhans’ cell histiocytosis. Hepatology. 1995;21:129–133. 135. Mahmoud HH, Wang WC, Murphy SB. Cyclosporine therapy for advanced Langerhans cell histiocytosis. Blood. 1991;77:721–725. 135a. Grammatikopoulos T, Sambrotta M, Strautnieks S, et al. Mutations in DCDC2 (doublecortin domain containing protein 2) in neonatal sclerosing cholangitis. J Hepatol. 2016;65:1179–1187. 135b. Girard M, Bizet AA, Lachaux A, et al. DCDC2 mutations cause neonatal sclerosing cholangitis. Human Mut. 2016;37:1025–1029. 136. Feldmeyer L, Huber M, Fellmann F, et al. Confirmation of the origin of NISCH syndrome. Hum Mutat. 2006;27:408–410. 137. Hadj-Rabia S, Baala L, Vabres P, et al. Claudin-1 gene mutations in neonatal sclerosing cholangitis associated with ichthyosis: a tight junction disease. Gastroenterology. 2004;127:1386–1390. 138. Paganelli M, Stephenne X, Gilis A, et al. Neonatal ichthyosis and sclerosing cholangitis syndrome: extremely variable liver disease severity from claudin-1 deficiency. J Pediatr Gastroenterol Nutr. 2011;53:350–354.

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6 Medical Genetics and Biochemistry in Diagnosis and Management Bryan E. Hainline, MD, PhD, and Christopher Griffith, MD

Clinical Approach  91 Approach to Biochemical and Genetic Investigation  93 Collection, Storage, and Shipping of Specimens  93 Methodologies Involved in Biochemical and Genetic Testing  94 Tandem Mass Spectrometry  96 Methodologies Used for Specific Biochemical Compounds  97 Treatment and Management  98 Newborn Screening–Related Disorders  98 Other Metabolic Liver Diseases  98 Mitochondrial Disorders  98 Genetic Counseling  98

Abbreviations CDG congenital disorders of glycosylation CE-ESI-MS  capillary electrophoresis–electrospray ionization–mass ­spectrometry GC-MS gas chromatography–mass spectrometry HPLC high-performance liquid chromatography MALDI matrix-assisted laser desorption/ionization MCAD medium chain acyl-CoA dehydrogenase MS/MS tandem mass spectrometry MSUD maple syrup urine disease mtDNA mitochondrial DNA TOF time of flight

The diagnosis of inborn errors of metabolism is a complex process that necessitates a multidisciplinary approach involving the integration of a wide variety of information from a number of sources. In most cases, the medical geneticist is presented with an extraordinarily ill patient who has been evaluated by several other medical specialists. In these cases, the differential diagnostic list is long, and an array of biochemical or molecular genetic panels may be required to identify the offending metabolites and/or absent enzymes producing the symptoms and disease.

Clinical Approach The evaluation of patients with inborn errors of metabolism begins with obtaining a comprehensive history from parents, caregivers, spouses, or other individuals familiar with the patient. Diagnostic clues may be obtained from prenatal and birth history, history of recurrent illnesses in the past, diet history with dietary preferences, and history of exposure and response to pharmaceutical agents. A family history of prior affected individuals, early deaths, or significant medical events in relatives, including unusual symptoms or signs, are invaluable to the diagnosis of metabolic diseases. The developmental history provides insight into neurologic maturation, which may be affected by the presence or lack of liver-based metabolites; recurrent episodes of hyperammonemia from urea cycle disorders (eg, ornithine transcarbamylase deficiency) or hypoglycemia (medium chain acyl-CoA dehydrogenase [MCAD] deficiency) may significantly affect neurologic function. Liver disease in children may manifest with symptoms that are distinct from those in adults and may include refusal to eat, early satiety, avoidance of foods, and onset of vomiting/lethargy with certain foods. Children affected by disorders of protein catabolism (ie, urea cycle defects) may often have a dietary history of avoiding meat, cheese, or milk. Individuals who have hereditary fructose intolerance often avoid sweet beverages or fruits because of nausea or illness induced by liver dysfunction and hypoglycemia.1 Physical examination may provide clues through alterations in growth patterns or deviation from normal in weight, length, head circumference, and other parameters. Examination of the abdomen may be difficult in infants and children, and abdominal distention, pain, or tenderness may be the only available results. Neurologic findings such as acute or chronic hypotonia, hyperreflexia or hyporeflexia, muscle atrophy, and altered mental status may provide support to diagnostic considerations. Integration of patient history with clinical signs and symptoms often helps the examiner decide what tests need to be carried out; the emphasis always remains on using noninvasive methods before turning to major tissue sampling. Some of the common findings for wellknown inborn errors of metabolism are shown in Table 6.1. Unusual inborn errors that are not associated with acute illness may often signal their presence through multiple subtle signs and may have a wide range of clinical manifestations. As an example, congenital disorders 91

Practical Hepatic Pathology: A Diagnostic Approach Table 6.1  Diagnostic Clinical, Biochemical, and Molecular Findings in Metabolic Liver Diseases Disorders

Signs or Symptoms

Tissues for Diagnostic Testing Biochemical/Molecular Testing

Phenylketonuria

Mental retardation, autistic features

Plasma, blood, urine

Blood phenylalanine, PAH sequence

Tyrosinemia I

Jaundice, liver failure, hypoglycemia

Plasma, urine, liver

Blood tyrosine, urine succinylacetone, FAH sequence

Lysinuric protein intolerance

Lethargy, diarrhea, ↑ ammonia, mental retardation

Plasma, blood, urine

↑ Urine lysine, arginine, and ornithine, SLC7A7

Maple syrup urine disease

Ketoacidosis, lethargy, hypoglycemia

Plasma, urine, fibroblasts

↑ Blood leucine, valine, isoleucine, BCKD activity

Type 1A

Plasma, blood, fibroblasts

BCKDHA

Type 1B

Blood

BCKDHB

Type 2

Blood

BCKDH-DBT

Hypotonia, developmental delay, multiple organ involvement, hypoglycemia, protein-losing enteropathy

Blood

Isoelectric focusing, N-glycan profile gene sequencing PMM2, MPI, ALG1-3, -6, -8, -9, -12 plus others

MCAD deficiency

Episodic lethargy, hypoglycemia, increased LFTs, ammonia

Plasma, blood, fibroblasts

Acyl carnitine profile, enzyme assays, common mutation analysis, ACADM sequence

VLCAD deficiency

Episodic lethargy, hypoglycemia, muscle pain; increased CK, Plasma, blood, fibroblasts LFTs, and ammonia

Acyl carnitine profile, enzyme assays, common mutation analysis, ACADVL sequence

LCHAD deficiency

Episodic lethargy, hypoglycemia, muscle pain; increased CK, Plasma, blood, fibroblasts LFTs, and ammonia

Acyl carnitine profile, enzyme assays, common mutation analysis, HADHA, HADHB sequence

Glutaric aciduria type I

Macrocephaly, recurrent acidosis, dystonia

Plasma, blood, fibroblasts

Acyl carnitine profile, enzyme assays, common mutation analysis, GCDH sequence

Glutaric aciduria type II

Episodic lethargy, muscle pain; increased CK and LFTs

Plasma, blood, fibroblasts

Acyl carnitine profile, enzyme assays, ETFA, ETFB, ETFDH sequence

Carnitine translocase and defects

Episodic lethargy, hypoglycemia, muscle pain; increased CK, Plasma, blood, fibroblasts LFTs, and ammonia

Acyl carnitine profile, enzyme assays, gene sequencing

 Other enzyme defects

Muscle pain; increased CK

Plasma, blood, fibroblasts

Acyl carnitine profile, enzyme assays, gene sequencing

Type Ia

Hepatomegaly, ↑ lactate, ↓ glucose, ↑ uric acid

Liver, WBCs*

Glucose-6-phosphatase/G6PC sequence

Type Ib

Hepatomegaly, acidosis, ↓ glucose, ↓ neutrophils

Liver, WBCs*

Glucose-6-phosphate transporter/SLC37A4 sequence

Type II

Cardiomyopathy, myopathy, ↑ CK

Muscle, blood, fibroblasts

Acid alpha-1,4-glucosidase; GAA sequence

Type III

Hepatomegaly, muscle weakness, ↓ glucose

Liver, muscle, blood

Glycogen debranching enzyme, AGL sequence

Type IV

Hepatomegaly, cardiomyopathy, myopathy

Liver, muscle, blood

Glycogen brancher, GBE1 sequence

Type VI

Hepatomegaly, slow growth, ketotic hypoglycemia

Liver, WBCs

Hepatic phosphorylase/PYGL sequence

Type IX

Hepatomegaly, hyperlipidemia

RBCs, liver

Phosphorylase kinase PHKA2 (x-linked), PHKB, PHKG2 (recessive) sequence

Fructose aldolase deficiency

Hepatomegaly, recurrent hypoglycemia, acidosis

Liver, WBCs*

Enzyme assay on liver, ALDOB sequence

Fructose 1,6-diphosphatase deficiency

Hepatomegaly, recurrent hypoglycemia, acidosis

Liver, WBCs*

Enzyme assay on liver, FBP1 sequence

Pyruvate carboxylase deficiency

Severe acidosis, hypoglycemia, coma

Liver, WBCs, fibroblasts

Enzyme assay on fibroblasts, liver, PC sequence

MPS disorders (Hurler, Hunter, Sanfilippo A,B,C, Morquio, Maroteaux-Lamy)

Hepatosplenomegaly, dysmorphic features

WBCs, fibroblasts

Enzyme assay on WBCs, fibroblasts, IUDA, IDS, NAGLU, SGSH, HGSNAT, GLNAS, GLB1, ARSB sequence

Gaucher disease

Hepatosplenomegaly, aseptic necrosis of femoral head

WBCs, fibroblasts

Enzyme assay on WBCs, fibroblasts, GBA sequence

Fabry disease

Renal tubular disease, heart disease

WBCs, fibroblasts

Enzyme assay on WBCs, fibroblasts, GLA sequence

Mitochondrial disease

Multiple system involvement, myopathy, obstructive sleep WBCs, liver, muscle, fibroblasts, apnea, dystonia, hypotonia, autistic behavior, hypoglyceDNA mutation analysis mia, increased liver enzymes

Amino Acids

Congenital disorders of glycosylation Fatty Acid Oxidation

Glycogen Storage

Gluconeogenesis

Lysosomal Storage Disorders

Oxidative phosphorylation assays, mtDNA, sequence and structure analysis, nuclear gene sequence

Continued 92

Medical Genetics and Biochemistry in Diagnosis and Management Table 6.1  Diagnostic Clinical, Biochemical, and Molecular Findings in Metabolic Liver Diseases—cont’d Disorders

Signs or Symptoms

Tissues for Diagnostic Testing Biochemical/Molecular Testing

Methylmalonic aciduria and B12 related syntheses disorders

Acidosis, hyperammonemia, coma

Urine, plasma, WBCs, fibroblasts

Organic acids, acyl carnitine profile, fibroblast complementation analysis, mutation sequence, MUT, cblA–cblG

Propionic aciduria

Acidosis, hyperammonemia, coma

Fibroblasts

Organic acids, acyl carnitine profile, fibroblast complementation analysis, mutation sequence, PCCA, PCCB

Zellweger spectrum

Dysmorphic features, hypotonia, hepatomegaly

Plasma, WBCs, fibroblasts

Very long chain fatty acids, PEX genes sequence

X-linked adrenal leukodystrophy

Developmental regression, leukodystrophy

Plasma, WBCs, fibroblasts

Very long chain fatty acids, ABCD1 sequence

Carbamoyl phosphate synthase deficiency

Hyperammonemia, coma, lethargy

Plasma, liver, WBCs*

Amino acids, enzyme assays, CPS1 sequence

Ornithine transcarbamylase deficiency

Hyperammonemia, coma, lethargy

Plasma, liver, WBCs*

Urine orotic acid, amino acids, OTC sequence, enzyme assays

Citrullinemia, ASS deficiency

Hyperammonemia, coma, lethargy

Plasma, liver, WBCs*

Amino acids, enzyme assays, ASS sequence

Citrullinemia type II (citrin deficiency)

Hyperammonemia, coma, lethargy

Plasma, WBCs*

Amino acids, SLC25A13 sequence

Argininosuccinic acid lyase deficiency

Hyperammonemia, coma, lethargy, developmental delay

Plasma, RBCs, WBCs

Amino acids, RBC enzyme assay, ASL sequence

6

Organic Acidurias

Peroxisomal Disorders

Urea Cycle Disorders

*White blood cells for DNA/mutation analysis only. ASL, Argininosuccinate lyase; ASS, argininosuccinate synthetase; BCKDHA, branched chain ketoacid dehydrogenase A (E1a subunit gene); BCKDHB, branched chain ketoacid dehydrogenase B (E1b subunit gene); BCKDH-DBT, branched chain ketoacid dehydrogenase (E2 subunit gene); CK, creatine kinase; CPS, carbamoyl phosphate synthetase; FAH, fumarylacetoacetate hydrolase; LCHAD, long chain 3-hydroxyacyl–CoA dehydrogenase; LFT, liver function test; MCAD, medium chain acyl-CoA dehydrogenase; MPS, mucopolysaccharide; MUT, methylmalonyl CoA mutase; OTC, ornithine transcarbamylase; PAH, phenylalanine hydroxylase; PCC, propionyl-CoA carboxylase; PC, pyruvate carboxylase; RBCs, red blood cells; SLC7A7, solute carrier family 7 (cationic amino acid transporter); VLCAD, very long chain acyl-CoA dehydrogenase; WBCs, white blood cells.

of glycosylation (CDG) are a group of disorders of abnormal glycosylation of N-linked oligosaccharide-containing proteins caused by a deficiency in 1 of at least 42 different enzymes. Manifestations may appear in infancy and may range from severe developmental delay and hypotonia with multiple organ system involvement to hypoglycemia and protein-losing enteropathy with normal development. The clinical course is also highly variable, ranging from death in infancy to normal life expectancy with minimal functional compromise. Patients affected by mitochondrial or other neuromuscular disorders may manifest histories similar to those with CDG and even show similar results on standard screening tests, in the face of completely different underlying pathophysiologic processes. The means of differentiating CDG from mitochondrial/neuromuscular disease lies within the realm of biochemical and/or molecular genetic testing.1,2

Approach to Biochemical and Genetic Investigation The investigation of acutely ill patients with potential inborn errors is greatly facilitated by determining the most proximal cause of symptoms (eg, acidosis, hyperammonemia, hypoglycemia). A simplified diagnostic algorithm with this approach is shown in Fig. 6.1. Such biochemical clues may not be present in a chronically ill patient with episodic illness, and diagnostic hints have to be obtained by screening tests. Because of the multitude of disorders with similar symptoms, it is often necessary to evaluate for a long list of diseases, proceeding from the more common to the exceedingly rare. The use of screening panels for metabolites, beyond those of standard chemistry testing, is often necessary. Some of the commonly used testing panels are shown in Table 6.2. Although positive results may be obtained in asymptomatic patients, sampling may have to be carried out on multiple occasions, especially when the patient is symptomatic. The timing of the sampling may be critical because some metabolites such as organic acids and amino acids may be influenced by recent diet and oral intake or by infusion of fluids. Analysis of the metabolites may take several days to

weeks, depending on the reference laboratory. At times, treatment for a suspected disorder may need to be initiated before laboratory results become available.1 Once a critical metabolite or group of compounds has been identified, specific investigations can be undertaken to define the underlying biochemical and/or genetic error precisely; these investigations may require obtaining tissue for microscopic evaluation as well as biochemical and/or genetic testing. Tissue sampling may also be required if an abnormal metabolite is not detected by the initial screening panels. It is at this point that the surgical pathologist becomes an important part of the investigating team. Because a large number of disorders involve the liver, liver biopsies are often sought for diagnosis of metabolic diseases.

Collection, Storage, and Shipping of Specimens The diagnosis of metabolic disorders often involves the use of sophisticated methodologies, which may be offered only in specialized referral laboratories; thus, the collection, preparation, storage, and shipping of body fluids and tissue samples is a critical step in the care of patients suspected to have inborn errors of metabolism. Biologic material for biochemical and genetic analysis requires more stringent procedures for procurement, handling, and transportation to the testing facility to prevent degradation of the often labile and sometimes unstable metabolites and enzymes. Table 6.3 lists the optimal methods for collection, storage, and shipping of the most commonly procured biologic specimens. The most common specimens used for biochemical and genetic analysis include whole blood, plasma, red or white blood cells, urine, spinal fluid, and tissue biopsy samples of the skin or other organs such as the kidney, liver, heart or muscle. In the past, tissue biopsies were usually obtained to confirm the diagnosis suspected from initial screening panels. With the advent of lower cost and rapid DNA sequencing technology offering single or multiple gene testing, tissue biopsies can often be avoided unless gene testing results are not 93

Practical Hepatic Pathology: A Diagnostic Approach Clinical History

Laboratory Findings

Frequent Metabolic Diagnoses + Ketosis

Congenital hyperlactic acidemias Organic acidurias

– Ketosis

Ketogenesis disorders Fatty acid oxidation disorders Fructose 1,6-diphosphatase deficiency

Normal blood sugar

Urea cycle disorders Mitochondrial disease

Hypoglycemia

Fatty acid oxidation disorders

Acidosis

Organic aciduria (MSUD) GSD IA, IB, and III Gluconeogenic disorders

No acidosis

Fatty acid oxidation disorders Mitochondrial disease

Normal blood sugar

Congenital hyperlactic acidemias Mitochondrial disease

Hypoglycemia

Gluconeogenic disorders Fatty acid oxidation disorders Glycogen storage disorders

Acidosis

Hyperammonemia Coma, recurrent emesis, or lethargy Hypoglycemia

Hyperlactacidemia

Differential Diagnosis

Diabetes Drug toxicity CNS infection

Reye syndrome CNS infection Drug toxicity Drugs, toxins Fasting Adrenal insufficiency Endocrine causes

Figure 6.1  Algorithm showing the diagnoses often associated with coma, recurrent emesis, and lethargy. CNS, Central nervous system; GSD, glycogen storage disorder; MSUD, maple syrup urine disease.

positive. In the case of potentially affected females with X-linked or mitochondrially inherited disorders, DNA testing results may not be positive, and enzymatic diagnosis may be needed for confirmation. In the setting of mitochondrial or neuromuscular disorders, confirmation of altered protein expression needed to initiate therapy or conclude the process of evaluation may not yield definitive results and genetic testing may be the only diagnostic modality. In other cases, initial indirect testing may have failed to detect or identify an abnormal metabolite, and tissue from a symptomatic organ, such as the liver, may be needed for further testing. Diagnostic information may be derived not only from histologic findings but also from electron microscopy, enzyme assays, nucleic acid analysis, immune blots, metabolite testing, or even transient cell culture. Depending on the needs of the assay, the samples may have to be obtained by interventionally trained physicians such as surgeons, radiologists, or gastroenterologists. Pathologists may participate in tissue procurement at autopsy, which in cases of suspected metabolic disorders, should be conducted expediently to prevent autolysis and preserve metabolites of interest. Tissue samples for diagnostic investigations may often be obtained at the same time as feeding tubes are placed in severely ill patients. Unfortunately, infants and small children with muscle disease or poor growth often have small muscle mass, which makes it difficult to obtain sufficient material for adequate enzyme or nucleic acid analysis. Tissue sampling under these circumstances may have to be directed to other sites, including the liver or skin (to obtain cells for culture), to obtain sufficient material for diagnostic testing. Sample preparation in the operating room may be necessary before storage and/or freezing. Common sample preparation may include washing in defined media such as saline or other solutions to remove blood and other materials followed by blotting to remove moisture. Specimens destined for long-term storage or shipping to a distant facility are frozen in specific agents such as dry ice, liquid nitrogen, or other supercooled organic solvents because simple freezing at −20°C is often insufficient for long-distance travel or prolonged storage. Samples may need to be placed in specific containers that are resistant to fracture and contamination. 94

Skin biopsies are often obtained at the time of procurement of other tissues for alternate types of testing as well as for storage. Skin fibroblasts may be extracted from 2- to 5-mm skin punch biopsies obtained by sterile techniques from various body sites. Cultures of skin fibroblasts are usually available within 2 to 3 weeks of procurement and may be used for enzyme, DNA/RNA, or immune protein analysis. It should be remembered that not all biochemical pathways are sufficiently expressed in skin fibroblasts to give meaningful results in all assays. Although skin fibroblasts may provide clues to disorders resulting from abnormalities in nuclear DNA, they may not be helpful for disorders resulting from abnormalities of mitochondrial DNA (mtDNA). The reason is that differential assortment of mtDNA during early embryonic development precludes even transfer of pathogenic mutations to all tissues of the body. Hence, inherited disorders of mtDNA are not necessarily manifested in all tissues, and detectable abnormalities may be found only in those tissues manifesting the metabolic defect(s).2

Methodologies Involved in Biochemical and Genetic Testing The technology used for investigation of metabolic diseases ranges from time-honored methods such as Southern blotting, polymerase chain reaction, and chromatography to the extremely sophisticated state-of-the art technique of tandem mass spectrometry (MS/MS). The mass spectrometer is a device that ionizes compounds to generate charged ions that are separated and quantified based on their massto-charge ratios. The fragmentation pattern displayed is compared with patterns of known compounds in a “library” that helps identify and quantify abnormal compounds. Although all mass spectrometers follow this basic principle, they may differ from each other in the method used for ionization of the analyte and the method used for separation of the ions. Electrospray ionization and matrix-assisted laser desorption/ionization (MALDI) are commonly used for laboratory analysis of biologic compounds because they are “softer” on macromolecules; the former method causes ionization by dispersing the analyte into a

Medical Genetics and Biochemistry in Diagnosis and Management Table 6.2  Tests, Methods and Required Biologic Samples for Metabolic Liver Disorders Disorder Group

Testing

Method

Source

Amino acid disorders

Amino acid analysis

HPLC, ion exchange

Plasma, CSF, urine

Selected enzyme analysis

Enzyme assays

Fibroblasts, tissues, WBCs, RBCs

Common gene mutations

Mutation analysis

Fibroblasts, tissues, WBCs

Gene sequencing

DNA sequencing

Fibroblasts, tissues, WBCs

Acylcarnitine profile

MS/MS

Plasma, CSF, fibroblasts, WBCs

Selected enzyme analysis

Enzyme assays

Frozen liver or muscles, fibroblasts, WBCs

Common gene mutations

Mutation analysis

WBCs, fibroblasts

Gene sequencing

DNA sequencing

WBCs, fibroblasts

Liver glycogen content and enzyme analysis

Chemical/enzyme assays

Fresh or frozen liver

Muscle glycogen content and enzyme analysis

Chemical/enzyme assays

Fresh or frozen muscle

Common gene mutations

Mutation analysis

WBCs, liver, muscle

Gene sequencing

DNA sequencing

WBCs, liver, muscle

Selected enzyme analysis (guided by phenotype/ metabolites)

Enzyme assays with artificial substrates

Plasma, serum, WBCs, fibroblasts, frozen tissue, filter paper blood spot

Common gene mutations

Mutation analysis

WBCs, liver

Gene sequencing

DNA sequencing

WBCs, liver

Selected enzyme testing

Enzyme assays

Plasma, serum, WBCs, fibroblasts

Nonenzymatic testing for metabolites (Niemann-Pick C, Wolman disease)

Liver extract chromatography, radioactive substrate incorporation

Frozen liver or fibroblasts

Common gene mutations

Mutation analysis

WBCs, liver

Gene sequencing

DNA sequencing

WBCs, liver

OXPHOS complexes I-IV enzymology

Enzyme complex assays, II–IV for fibroblasts only

Fresh/frozen muscle, liver, heart, fibroblasts

mtDNA analysis

Southern blot analysis

WBCs, fibroblasts, liver, muscle

Common mtDNA mutational analysis

Mutation analysis

WBCs, fibroblasts, liver, muscle

mtDNA sequencing for protein, tRNA and ribosomal RNA gene analysis

DNA sequencing

WBCs, fibroblasts, liver, muscle

mtDNA encoded peptides

Western blotting

Fibroblasts, liver, muscle

High-resolution respirometry testing: respiratory control ratio, leak flux control ratio, phosphorylation potential

Oxygraph studies

Fibroblasts

Very long chain fatty acid analysis

GC/MS, LC/MS, MS/MS

Plasma, WBCs

Fatty acid oxidation disorders

Glycogen storage disorders

Lysosomal storage disorders, MPS

Lysosomal storage disorders, non-MPS

Mitochondrial disorders

Peroxisomal disorders

RBC plasmalogen analysis

Glycosylation of protein disorders

6

RBCs, fibroblasts

Complementation analysis

Cell culture, cell fusion

Fibroblasts

Selected enzyme testing

Enzyme assays

WBCs, fibroblasts

Selected gene mutation analysis

Mutation analysis

WBCs, fibroblasts

Gene sequencing

DNA sequencing

WBCs, fibroblasts

Carbohydrate deficient transferrin

Isoelectric focusing/isoform analysis by capillary electrophoresis, GC/MS, CE-ESI-MS, MALDI-MS

Serum, WBCs, tissue

Gene sequencing

Subtype determination by sequence analysis

CE-ESI-MS, Capillary electrophoresis–electrospray ionization–mass spectrometry; CSF, cerebrospinal fluid; GC-MS, gas chromatography–mass spectrometry; HPLC, high-performance liquid chromatography; LC/MS, liquid chromatography/mass spectrometry; MALDI, matrix-assisted laser desorption/ionization; MPS, mucopolysaccharide; MS, mass spectrometry; MS/MS, tandem mass spectrometry; mtDNA, mitochondrial DNA; RBCs, red blood cells; tRNA, transfer RNA; WBCs, white blood cells.

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Practical Hepatic Pathology: A Diagnostic Approach Table 6.3  Methods of Collection, Storage, and Transportation of Biologic Specimens Test

Diseases

Collection and Preparation

Storage and Transportation

Acylcarnitine profile

Fatty acid oxidation disorders, organic acidurias

• C  ollect whole blood in heparinized tube • Keep cold on ice and separate plasma from cells • Blood spot on filter paper

• S tore plasma at −20°C or −70°C • Ship on dry ice • Send filter paper in mail at room temperature

Quantitative amino acids

Amino acid disorders

• C  ollect whole blood in heparinized tube • Keep cold on ice and separate plasma from cells • Blood spot on filter paper

• S tore plasma at −20°C or −70°C • Ship on dry ice • Send filter paper in mail at room temperature

Very long chain fatty acids

Peroxisomal disorders

• C  ollect whole blood in EDTA or heparinized tube • Keep cold on ice and separate plasma from cells

• S tore at −20°C or −70°C • Ship on dry ice

Lysosomal hydrolase testing

Lysosomal storage diseases

• Collect whole blood in heparinized tube

• S hip overnight at room temperature

Gluconeogenic enzymes

Pyruvate carboxylase, pyruvate dehydrogenase deficiency

• C  ollect whole blood in EDTA or heparinized tubes

• S hip overnight at room temperature

Selected fatty acid oxidation disorders

CPT 2 deficiency

• C  ollect whole blood in EDTA or heparinized tubes

• S hip overnight at room temperature

Nuclear and mtDNA testing including mutation analysis, gene sequencing, Southern blotting

Various genes for different disorders in amino or organic acid metabolism, mitochondrial disorders

• Collect whole blood in EDTA tube

• S hip overnight at room temperature

Galactose-related enzymes

Galactose 1-phosphate uridyl transferase deficiency and related disorders

• Collect whole blood in EDTA tube

• S hip overnight at room temperature

Plasmalogens

Peroxisomal disorders

• C  ollect whole blood in EDTA and wash cells

• Freeze and ship on dry ice

Skin fibroblasts

Enzyme testing for selected disorders, acylcarnitine profile, mitochondrial respirometry, mutational analysis, gene analysis

Lysosomal or glycogen storage disorders, gluconeogenic disorders, fatty acid oxidation enzymes and acylcarnitine profile, mitochondrial disease

• Obtain biopsy under sterile conditions*

• S hip 1–2 T-25 flasks at room temperature in medium desired by receiving laboratory

Tissue biopsies from liver, muscle, kidney, heart

Enzyme testing for selected lysosomal or glycogen storage disorders, mitochondrial OXPHOS complex analysis, mutational analysis, gene or sequencing

Lysosomal or glycogen storage disorders, gluconeogenic disorders, fatty acid oxidation enzymes, mitochondrial disorders

• U  se 5–100 mg of fresh tissue, not in preservative • Collect as a fresh sample† and freeze immediately on dry ice or in liquid nitrogen

• F reeze at −70°C • Ship on dry ice

Urine

Amino acids, organic acids, MPS and other spot testing and chromatography

Organic acid disorders, amino acid disorders, MPS disorders

• C  ollect as fresh sample, without preservatives

• F reeze at −20°C • Transport on wet ice and ship on dry ice

Spinal fluid

Amino acids, organic acids, lactate, neurotransmitters

Amino acid disorders, organic acid disorders, lactate-related disorders, mitochondrial disorders, defects in synthesis of neurotransmitters

• C  ollect samples, keep frozen at −20°C until analysis or at 4°C for short time

• F reeze at −20°C for short time, –70°C for prolonged periods • Ship on dry ice

Blood, plasma

White blood cells

Red blood cells

*Some laboratories may require preshipment testing for infectious organisms (eg, Mycoplasma). †Fresh tissue obtained at surgery is best. Autopsy tissue is best collected within 1 to 2 hours of death but may still not be intact for DNA or enzyme testing. Immunoblot or histologic testing may use autopsy material. CPT 2, Carnitine palmitoyltransferase 2; EDTA, ethylenediamine tetra-acetic acid; MPS, mucopolysaccharide; OXPHOS; oxidative phosphorylation.

fine aerosol, whereas the latter uses a laser beam to create ionization. MALDI received its name because a matrix is used to protect the molecule from being destroyed by the laser.3 The two commonly used methods for separation of ions are time of flight (TOF) and quadrupole analyzers. TOF analyzers use an electric field to accelerate ions through the same potential and measure the time taken by the ions to reach the detector. Quadrupole analyzers use oscillating electric fields to alter the paths of ions passing through a radiofrequency quadrupole field. 96

Tandem Mass Spectrometry The modern MS/MS received its name because it consists of two tandem mass spectrometers that can perform two rounds of mass spectrometry; these are usually separated by some form of molecule fragmentation. The two tandem mass spectrometers consist of two quadrupole analyzers separated by a reaction chamber or collision cell, which is often another quadrupole. The mixture to be analyzed is subjected to a soft ionization procedure (eg, fast atom bombardment or electrospray) to create quasimolecular ions that are injected into the

Medical Genetics and Biochemistry in Diagnosis and Management first quadrupole, which separates the parent ions. These ions then pass in order of mass-to-charge ratio into the reaction chamber, where they are fragmented by a second technique, and the mass-to-charge ratios of the fragments are then analyzed in the second quadrupole. The entire process, from ionization and sample injection to computer data acquisition, takes only seconds. The computer data can be analyzed in several ways. One can use a parent ion mode to obtain an array of all parent ions that fragment to produce a particular daughter ion or a neutral loss mode to obtain an array of all parent ions that lose a common neutral fragment. MS/MS was introduced for laboratory analysis in the late 1990s for acylcarnitine analysis. This methodology led to improved diagnostic testing for disorders of fatty acid oxidation, whose characteristic metabolites were hitherto difficult to detect. MCAD deficiency and other fatty acid oxidation defects, as well as glutaric acidemia type I, are relatively common but difficult to detect before the onset of symptoms. MS/MS has made it possible to substantially improve the care of patients with these disorders by facilitating early diagnosis and therefore early treatment. With appropriate internal standards, MS/MS permits very rapid, sensitive, and accurate measurement of many different types of metabolites with minimal sample preparation and without prior chromatographic separation. Because many amino acidemias, organic acidemias, and disorders of fatty acid oxidation can be detected in 1 to 2 minutes, the system has adequate throughput to handle the large number of samples that are processed in newborn screening programs. The advent of the MS/MS has permitted significant expansion of the newborn screening menu to include a number of disorders that were not covered by the initial screening protocols.3

binding. Some analytic techniques use radiochemical or nonradioactive fluorescent imaging. The diagnostic test for carbohydrate-deficient glycoprotein syndromes is serum transferrin isoform analysis; the isoforms are identified by changes in the number of sialylated N-linked oligosaccharide residues linked to serum transferrin. The first identified and most common form is CDG-Ia. Isoform analysis may be carried out by serum transferrin isoelectric focusing, capillary electrophoresis–electrospray ionization–mass spectrometry (CE-ESI-MS), GC-MS, or MALDI mass spectrometry. The underlying gene responsible for the abnormal enzyme activity may be studied by DNA analysis and gene sequencing.4 Enzymes Most inborn errors of metabolism are associated with underlying changes in enzymatic activity. Various assays have been developed over the past 3 decades to reliably determine native (intact) enzyme activity as well as subunit interactions with substrate. Various technologies may specifically require fresh liver tissue (glycogen storage disease type Ib) or be able to use snap frozen liver tissue (glycogen storage disease types Ia, III, IV, and V). Fibroblasts may be used for some assays, but they may not always show reduction in activity of the affected enzyme.

Organic Acids Organic acid analysis is carried out by gas chromatography–mass spectrometry (GC-MS) in which the sample is first subjected to gas chromatography to separate the organic acid derivatives, which then enter the mass spectrometer, often a quadrupole instrument. Each organic acid derivative peak is ionized and fragmented, and the abundance and mass-to-charge ratio of the various fragment ions are determined. The identity of the original organic acid is determined by analyzing the fragmentation pattern of each separated peak, which gives the significant parts of the structure. The fragmentation pattern displayed by each compound may be compared with known patterns held in a “library.” A report can then be generated describing the different physiologic components of the sample and giving a diagnosis, depending on the relative amounts of abnormal acids present. The analysis can be reported either in a semiquantitative analysis, which gives quantities of significant acids, or in absolute or quantitative amounts.

DNA Determination of the specific genetic mutation in a patient allows confirmation of a suspected diagnosis that may permit later prenatal testing as well as testing of relatives. Laboratory methods used to detect DNA mutations include automated capillary gel-based fluorescent sequencing and genotyping, MALDI-TOF mass spectrometry, real-time quantitative polymerase chain reaction, classic polymerase chain reaction, and Southern blotting. If mutations/or gene structural changes are not found in a specific gene by one of the above t­ echniques, new multigene sequencing panels are now available to look for alterations in genes that may produce similar metabolic findings. This new technology, called whole exome sequencing, allows investigations into all functional genes. Next-generation gene sequencing, sometimes denoted as high-throughput sequencing or massively parallel sequencing, allows sequencing of DNA or RNA fragments to help identify rare gene changes in multiple genes simultaneously. Multiple gene panels are now available for groups of genes with similar metabolic functions or symptoms. Disease-related panels for such disorders as Leigh disease and mitochondrial DNA disorders are available. Whole exome sequencing looks at the expressed exons of all genes with highthroughput DNA sequencing technology. Unfortunately, the technique will not detect gene changes in nonexpressed genes, so developmentally related disorders cannot be evaluated.5 Genetic testing for mitochondrial disorders is often performed in laboratories specializing in these types of analyses. These laboratories often first perform molecular DNA analysis of the common point mutations and large deletions in the mitochondrial genome in various tissues, starting with whole blood/white cells or fibroblasts. If this testing is insufficient to identify potentially abnormal genes, then whole mitochondrial genome sequence analysis is performed. In addition, it is now possible to perform DNA sequence analysis of nuclear genes that are involved in mtDNA biosynthesis and respiratory chain enzyme complexes assembly. Some laboratories now offer a mitochondrial oligonucleotide array comparative genomic hybridization analysis for the detection of copy number changes in both nuclear and mitochondrial genomes.6

Proteins Protein analysis may involve electrophoresis linked to native or subunit activity determination, Western blotting, cofactor binding, or metal

Very Long Chain Fatty Acids and Related Molecules Testing for various forms of very long chain fatty acids and related metabolites often makes use of capillary GC-MS.7

Methodologies Used for Specific Biochemical Compounds

Amino Acids Ion exchange chromatography with detection of separated amino acids by ninhydrin or other organic reagents has long been the method of choice for determining plasma, cerebrospinal fluid, or urine concentrations of amino acids. High-performance liquid chromatography (HPLC) has become a more rapid analytic method, but it still requires sample preparation and analytic time. Amino acid quantitation by MS/ MS is relatively new and offers more accurate determinations than in the past, especially for detection of phenylketonuria and maple syrup urine disease (MSUD) in newborn screening programs that use blood spots on filter paper for samples.

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Practical Hepatic Pathology: A Diagnostic Approach

Treatment and Management

Newborn Screening–Related Disorders The purpose of newborn screening is to detect diseases early enough so that effective treatment can be initiated before tissue damage results from accumulation of abnormal metabolites or lack of essential enzymes. Because cost-effectiveness, speed, and ease of diagnosis are essential to the success of newborn screening programs, tissue sampling has largely been eliminated from this process. Newborn screening for inborn errors was introduced in the mid to late 1960s for a handful of disorders. The advent of MS/MS, DNA multiplex testing, and various other rapid testing technologies currently allows the screening of approximately 50 disorders that benefit from early intervention.8 Disorders include amino acidopathies, endocrinologic diseases, hemoglobinopathies, organic acidurias, fatty acid oxidation defects, cystic fibrosis, galactosemia, and biotinidase deficiency.9 Disorders such as Gaucher, Pompe, and Fabry diseases, which can be successfully treated by recombinant enzyme therapies, are also being considered for screening, at least by some states.10,11 Treatment with specific diets and pharmacologic agents has been very successful in preventing sequelae such as mental retardation, organ failure, and neurologic deterioration. In the case of amino acid– related diseases, special medical foods or formulas low in the offending amino acid help reduce or even eliminate tissue damage. In the case of lysosomal disorders, infusion therapy with the specific recombinant enzyme leads to resolution of tissue damage over time and reestablishment of normal growth. For tyrosinemia type 1 (fumarylacetoacetate hydrolase deficiency), the use of nitisinone (Orfadin) has virtually eliminated the need for liver transplantation and reduced the use of liver biopsy for diagnostic monitoring.12 On occasion, metabolic disorders may not be detected by newborn screening programs, and patients may present later in life with symptoms of varying degrees. Under these circumstances, biochemical testing and liver biopsy may be necessary. Late-onset disorders, including urea cycle defects and lysosomal storage disorders, may have little expression in external tissues, whereas significant changes are seen on liver study. The biopsy finding of hepatic steatosis in adults with unusual symptoms, including altered mental status, may provoke investigation for late-onset metabolic disorders. Procedures discussed in the earlier sections would apply to the evaluations of these late-onset disorders.

Other Metabolic Liver Diseases For a number of inborn errors, symptomatic treatment is often the only means to reduce morbidity and, sometimes, mortality in patients. In the case of glycogen storage diseases types I and III, frequent feeding of glucose polymers or starch-containing foodstuffs reduces the hypoglycemic episodes and delays progressive organ damage. Avoidance of galactose- or fructose-containing foods allows liver cells to return to normal homeostatic function. Specific drug therapy for these types of liver disorders is not yet available and/or is limited to activating anticoagulant pathways or supplying cofactors. In many conditions, changes in lifestyles involving special or restricted diets, although unpleasant, provide significant symptomatic relief and prevent organ damage. These include elimination diets such as decreased natural protein intake, galactose-free, fructose-free, low-fat, low-carbohydrate, and low-choline diets; diets that supplement specific components such as complex carbohydrates or fats; and replacement diets such as those that replace long chain fat by oil containing medium chain triglycerides or those that replace simple sugars with starch or glucose polymers (SolCarb). Other lifestyle measures may include mandated exercise sessions to encourage energy use in addition to lowering total caloric intakes. 98

Some patients with enzyme deficiencies who are advised against excessive exercise to prevent build-up of toxic metabolites from catabolism of tissue protein/fat may be at special risk for weight gain.

Mitochondrial Disorders In the past, disorders of oxidative phosphorylation and mitochondrial development were frequently diagnosed on tissue biopsies. Advances in genetic testing, though, allow mtDNA and nuclear DNA sequencing for mitochondrial disorders to be performed on blood or buccal swabs, precluding the need to obtain tissue by invasive procedures. Many of these disorders involve multiple organs and require specific therapies for alleviation of symptoms. Therapeutic strategies include use of medications such as coenzyme Q10, carnitine, riboflavin, anticonvulsants, and various neurologically active medications, as well as special diets. Various orphan drugs such as dichloroacetate may be needed to reduce blood/tissue lactic acid levels. Several new pharmaceutical agents are now in development, and they raise hope for treatment of these disorders. Diets may often have to use an elemental formula to encourage adsorption of essential nutrients for alleviation of symptoms of poor growth, slow development, and neurologic damage from processes such as dysmyelination or demyelination.

Genetic Counseling Genetic counseling is the process of providing information to patients and their families about the nature, inheritance, and implications of genetic disorders that allow them to make informed medical and personal decisions. In addition, counseling involves communicating recurrence risks in future newborns and the risk of family members developing late-onset symptoms. Advances in diagnostic methodologies and therapeutic strategies have made genetic counseling increasingly critical in the management of inborn errors of metabolism; simultaneously, the wide variety and range of Internet-based information has made the process far more complicated. Counselors and caregivers often assume that informed patients and their families understand not only the name and diagnosis of an affliction, but also the pathophysiology, symptoms, and possible treatments. Understanding diagnostic technology is therefore more important than ever before. Because many patients come to geneticists via a complex route of interaction with many other health professionals, it often becomes necessary to discuss the context of inherited disorders and how rare disorders fit in with medical care. Genetic counselors are trained to aid physicians in the diagnostic process, explain testing results to patients, and provide emotional and social support. In the situation with inherited metabolic disorders that affect the liver, symptoms of liver disease may or may not be present at the time of presentation or diagnosis. Parents of patients identified by newborn screening or asymptomatic family members often require education and reassurance about the timing of their diagnosis. Access to results from complex diagnostic procedures often makes the education process easier, but it also requires considerable time and follow-up to ensure that patients and families grasp the information being conveyed. Often, pathologists may be involved in patient care conferences and may have the unique opportunity of integrating clinical features with molecular findings and the underlying pathophysiologic process. Suggested Readings American College of Medical Genetics/American Society of Human Genetics Test and Technology Transfer Committee Working Group Tandem. Mass spectrometry in newborn screening. Genet Med. 2000;2:267–269. Boelens JJ. Trends in haematopoietic cell transplantation for inborn errors of metabolism. Inherit Metab Dis. 2006;29:413–420. GeneTests. Medical Genetics Information Resource (database online). Copyright. Seattle: University of Washington; 1993–2015. www.genetests.org. Saudubray JM, Sedel F, Walter JH. Clinical approach to treatable inborn metabolic diseases: an introduction. J Inherit Metab Dis. 2006;29:261–274.

Medical Genetics and Biochemistry in Diagnosis and Management References 1. Saudubray JM, Sedel F, Walter JH. Clinical approach to treatable inborn metabolic diseases: an introduction. J Inherit Metab Dis. 2006;29:261–274. 2. Di Donato S. Multisystem manifestations of mitochondrial disorders. J Neurol. 2009;256: 693–710. 3. American College of Medical Genetics/American Society of Human Genetics Test and Technology Transfer Committee Working Group. Tandem mass spectrometry in newborn screening. Genet Med. 2000;2:267–269. 4. Sparks SE, Krasnewich DM. Congenital disorders of glycosylation overview. In: GeneReviews at GeneTests: Medical Genetics Information Resource (database online; updated January30, 2014). Seattle: University of Washington; 1997–2015. www.genetests.org. 5. Gilissen C, Hehir-Kwa JY, Thung DT, et al. Genome sequencing identifies major causes of severe intellectual disability. Nature. 2014;511:344–347. 6. Lee WS, Sokol RJ. Liver disease in mitochondrial disorders. Semin Liver Dis. 2007;27:259–273. 7. Shimozawa N. Molecular and clinical aspects of peroxisomal diseases. J Inherit Metab Dis. 2007;30:193–197. 8. Dionisi-Vici C, Deodato F, Roschinger W, et al. “Classical” organic acidurias, propionic aciduria, methylmalonic aciduria and isovaleric aciduria: long-term outcome and effects of expanded newborn screening using tandem mass spectrometry. J Inherit Metab Dis. 2006;29:383–389.

9. Shekhawat PS, Matern D, Strauss AW. Fetal fatty acid oxidation disorders, their effect on maternal health and neonatal outcome: impact of expanded newborn screening on their diagnosis and management. Pediatr Res. 2005;57:78R–86R. 10. Mehta A, Hughes DA. Fabry disease (Anderson-Fabry disease, alpha-galactosidase A deficiency. Includes: classic Fabry disease, atypical variants of Fabry disease). In: GeneReviews at GeneTests: Medical Genetics Information Resource (database online; updated October 17, 2013). Seattle: University of Washington; 1997–2015. www.genetests.org. 11. Pastores GM, Hughes DA. Gaucher disease (Glucocerebrosidase deficiency, glucosylceramidase deficiency. Includes: Gaucher disease type 1; Gaucher disease type 2 (acute); Gaucher disease type 3 (subacute/chronic); Gaucher disease, perinatal-lethal form; Gaucher disease, cardiovascular form). In: GeneReviews at GeneTests: Medical Genetics Information Resource (database online; updated February 26, 2015). Seattle: University of Washington; 1997–2015. www.genetests.org. 12. Boelens JJ. Trends in haematopoietic cell transplantation for inborn errors of metabolism. J Inherit Metab Dis. 2006;29:413–420.

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7 Histologic Patterns of Metabolic Liver Diseases Kevin E. Bove, MD

Handling Liver Biopsy Specimens for Suspected Metabolic Disease 102 Analysis and Reporting of Liver Biopsy Specimens for Suspected Metabolic Disease  102 Histologic Patterns of Metabolic Liver Disease  102 Metabolic Diseases with Normal Liver Histology  102 Metabolic Diseases with an Inflammatory Pattern  102 Metabolic Diseases with Prominent Lobular Cholestasis  103 Bile Ductules Versus Ducts in Metabolic Disease  104 Metabolic Diseases with a Steatotic Pattern  104

CoA FAO mDNA nDNA OTC PAS PFIC PH RS UCD ZSS

coenzyme A fatty acid oxidation mitochondrial DNA nuclear DNA ornithine transcarbamylase periodic acid–Schiff progressive familial intrahepatic cholestasis perinatal hemochromatosis Reye syndrome urea cycle disorder Zellweger syndrome spectrum

Fatty Acid Oxidation Defects  105 Mitochondriopathies 106 Reye Syndrome  108 Urea Cycle Defects  108 Citrin Deficiency  110 Galactosemia 110 Hereditary Fructose Intolerance  111 Lysosomal Storage Disorders  111 Acid Lipase Deficiency  112 Niemann-Pick Disease, Type C  112 Cystinosis 115 Nonlysosomal Glycogenosis and Polyglucosan Storage Disorders 115 Bile Acid Synthetic Defects  116 Peroxisomal Diseases  119 Hereditary Tyrosinemia  120 Genetic Hemolytic Disorders  121 Perinatal Hemochromatosis  122 Genetic Metabolic Diseases of Unknown Etiology  123 Abbreviations ALF acute liver failure BASD bile acid synthetic defect CDG congenital disorders of glycosylation

Metabolic liver diseases result from genetically determined malfunction of enzymes, transporters, structural proteins, or organelles that are critical for normal liver function. Although the term metabolic disease may be extended to include transient functional disturbances that are precipitated by factors such as infections, drugs, pregnancy, and systemic diseases that may stress subclinically compromised physiologic pathways (synergistic heterozygosity), this chapter deals only with the former. Genetic disorders of canalicular bile secretion are considered in detail in Chapter 29B. Metabolic diseases may affect the liver only or may involve other organs as well (Table 7.1). When a metabolic disease in the liver is suspected, a liver biopsy is often performed to establish the diagnosis; interpretation of such a biopsy is an exercise in both morphology and context, being most effectively performed in concert with the clinician caring for the patient. In some diseases, morphologic findings are specific. In others, the histology and electron microscopy are distinctive and diagnostic for a particular group of metabolic diseases, significantly narrowing the differential diagnosis. Often, the microscopic findings may serve as a guide to selection of appropriate biochemical and/or genetic and molecular tests. Modern laboratory methods increasingly provide alternative approaches to a definitive diagnosis of metabolic disorders such as identification of diagnostic metabolites in body fluids or by molecular analysis of DNA from blood leukocytes or cultured fibroblasts. This process can be focused by the findings on a liver biopsy. The aim of this chapter is to provide an approach to pathologists who evaluate liver biopsy specimens in patients who are suspected to have a metabolic disease. For more exhaustive coverage of the subject, the reader is encouraged to consult other sources.1–4 101

Practical Hepatic Pathology: A Diagnostic Approach Table 7.1  Common Patterns of Organ Involvement in Metabolic Liver Diseases Pattern

Diseases

Isolated hepatomegaly

Glycogen storage disease, types I, VI, VIII, and IX; cholesterol ester storage disease

Reticuloendothelial pattern: liver, spleen, bone marrow, lymph nodes

Gaucher type B disease; Niemann-Pick disease, all types; Farber disease

Generalized, including central nervous system

Mucopolysaccharidoses I, II, and III; GM1 gangliosidosis; Niemann-Pick disease, types A and C; glycogen storage disease IIa

Liver fibrosis prominent

Tyrosinemia, type IV glycogen storage disease, alpha-1 antitrypsin deficiency, Gaucher disease, bile acid synthetic defects, perinatal hemochromatosis

No liver involvement/no hepatomegaly

Fabry disease, urea cycle defects

Liver, brain, muscle, heart, gastrointestinal

Mitochondriopathy

Liver, muscle, heart

Fatty acid oxidation defects

Liver, brain, adrenal, malabsorption

Peroxisomal disease

The clinical circumstances that raise suspicion for liver disease are well known and typically neither exclude nor strongly suggest an underlying metabolic disease. However, in patients with one or more of the conditions listed in Box 7.1, the probability of a metabolic liver disease is increased.

Handling Liver Biopsy Specimens for Suspected Metabolic Disease If clinical suspicion for a metabolic liver disease is high, at least two cores of liver tissue should be obtained. A surgical biopsy specimen is almost always sufficient, but cautery must be avoided or enzyme studies may be useless. One core of liver tissue or one slice of a surgical biopsy specimen must be frozen in anticipation of need for biochemical or genetic analysis. The decision about use of frozen liver tissue is best delayed until light microscopy and electron microscopy are completed, unless the clinical information or laboratory values clearly indicate a particular metabolic disease. The value of electron microscopy is severely limited if part of the diagnostic biopsy is not fixed in a suitable fixative such as glutaraldehyde immediately on receipt of the fresh specimen; 2 mm of a typical needle core suffices for this purpose and is sufficient to provide two or three resin blocks that need not be processed further if deemed unnecessary. When clinical suspicion of a metabolic disease/storage disease is supported (or not eliminated) by light microscopy, it is very helpful to then perform electron microscopy to survey the organelles for structural abnormalities and identify any accumulated material and its subcellular location before deciding how to proceed. For example, when light microscopy identifies features of glycogen storage disorder and study of liver ultrastructure confirms that excess nonlysosomal glycogen displaces other organelles to the periphery in most hepatocytes, it is then appropriate to commit the frozen sample to measurement of the glycogen concentration and to screen for glycolytic enzyme defects. In a similar vein, when unusual inclusions or small vesicles accumulate in cytoplasm of hepatocytes or Kupffer cells, and clinical context supports suspicion of a metabolic disease, the ultrastructure of the stored material helps narrow the differential diagnosis and screening for lysosomal storage disorders may result in a specific diagnosis.

Analysis and Reporting of Liver Biopsy Specimens for Suspected Metabolic Disease The following stains on paraffin sections of a diagnostic liver specimen are routine: hematoxylin and eosin, Masson trichrome, reticulin, and periodic acid–Schiff (PAS) with and without prior diastase digestion. Stains that prove useful only in certain contexts, but are nonetheless often routinely used, are Prussian blue for hemosiderin deposition or 102

Box 7.1  Clinical Findings That Suggest the Possibility of Metabolic Liver Disease • P ersistent neonatal cholestasis • Asymptomatic hepatomegaly • Multiorgan enlargement in a pattern that suggests reticuloendothelial system involvement in the absence of signs of portal hypertension • Multiorgan dysfunction in a pattern that suggests a disorder of energy metabolism (involvement of heart, skeletal muscle, brain, gastrointestinal tract) • Protein intolerance or avoidance • Unexplained episodes of hypoglycemia, precipitated by “trivial” intercurrent viral syndromes • Intolerance of caloric deprivation with inability to form ketones during fasting • Unexplained metabolic acidosis with elevated lactate, lactate-to-pyruvate ratio, or both • Organic acidemia, unusual pattern • Prominent itching • Xanthoma formation

Box 7.2  Metabolic Diseases with Normal Liver Histology • • • • aThe

P henylketonuria Cystinosis Urea cycle defectsa (eSlide 7.3) Aminoacidopathiesa histology depends on the stage of the disease at the time of biopsy.

rhodanine for copper complexes in secondary lysosomes. Other stains may be used to detect a stored material as ceroid (Sudan black, ZiehlNeelsen), mucopolysaccharide (Alcian blue, colloidal iron), phospholipid (Sudan black), or specific immunostains may be used to identify particular proteins such as alpha-1 antitrypsin or fibrinogen or proteins specific to organelles such as mitochondria or lysosomes. A useful liver biopsy report requires systematic assessment of the histologic features in liver tissue. The structural components in a liver specimen to be commented on in the report are sample quality; adequacy in terms of the number of portal areas and central veins; status of portal and lobular architecture; the bile ducts and vessels in the portal tracts; the hepatocytes; the sinusoidal lining cells, especially the Kupffer cells; and the sinusoidal/hepatic venous drainage system. Pathologic changes to be specifically mentioned are altered lobular architecture, the pattern and extent of lobular collapse or fibrosis, and the presence or absence of each of the following: cellular infiltrates with specification of location and cell types; changes at the limiting plate (portal-lobular interface); the general condition of hepatocytes and Kupffer cells with note of any unusual appearance or abnormal expansion of cytoplasm or displacement of organelle-containing cytoplasm by an unexpected substance, patterns of degeneration, and/or necrosis; canalicular or cytoplasmic bile stasis; and other pigment deposits.

Histologic Patterns of Metabolic Liver Disease Metabolic Diseases with Normal Liver Histology

A small number of metabolic diseases of the liver are functional disorders with minimal or absent histologic changes and no capacity to cause longterm liver injury. Examples of metabolic diseases that consistently show absence of morphologic abnormalities on a liver biopsy are listed in Box 7.2.

Metabolic Diseases with an Inflammatory Pattern Portal and lobular inflammation (ie, a hepatitic pattern) is inconspicuous or even absent in many metabolic disorders that involve the liver. The explanation for this, even in the face of slowly progressive fibrosis, is incomplete but probably involves the absence of toxic or inflammogenic metabolic by-products or intermediaries. Harmful effects, in some diseases are easily compensated by replacement of injured cells or organelles without permanent injury to the liver. On the other hand, some

Histologic Patterns of Metabolic Liver Diseases Table 7.2  Association of Metabolic Liver Disease with Portal and/or Lobular Inflammation and Progressive Fibrosis Metabolic Disease

Inflammation

Fibrosis

Cystic fibrosis

Focal cholangiopathy

Focal, biliary (eSlides 10.1 and 10.2)

Glycogenosis, types I, II, III, VI, VIII, and IX

Absent or mild

Absent or mild (eSlides 7.9 and 7.10)

Glycogenosis, type IV

Mild

Cirrhosis

Mucopolysaccharidoses

Absent

Absent

Sphingolipidoses

Minimal to absent

Mild, progressive

Niemann-Pick disease, type C

Present

Progressive; cirrhosis

Gaucher disease

Minimal to absent

Mild, progressive (eSlide 7.6)

Cholesterol ester storage disease

Minimal to absent

Mild, slowly progressive storage disease

Urea cycle defects

Minimal or absent

Minimal or absent

Citrin deficiency

Minimal or absent

Progressive

Bile acid synthetic defects

Minimal to mild

Progression varies with defect; acute liver failure in infants

PFIC1: variable phenotype

Usually absent

Slowly progressive (eSlide 29B.1)

PFIC2: variable phenotype

Mild

Rapid or slow progression (eSlides 29B.2 and 29B.3)

PFIC3: highly variable phenotype

Absent to moderate

Absent, mild or biliary cirrhosis (eSlide 29B.4)

Fatty acid oxidation disorder

Absent

Absent

Mitochondriopathy

Mild to moderate

Fibrosis is variable; acute liver failure in infants; cirrhosis

Alpha-1 antitrypsin deficiency (PiZZ)

Variable

Progressive fibrosis is unpredictable; cirrhosis (eSlide 9.1)

Tyrosinemia

May be prominent

Acute liver failure in infants; cirrhosis (eSlide 7.1)

Wilson disease

May be prominent

Progressive fibrosis; acute liver failure; cirrhosis (eSlides 8.1 to 8.4)

Table 7.3  Metabolic Disease Classes with Prominent Lobular Cholestasis Disorders that cause hepatocyte necrosis Tyrosinemia, alpha-1 antitrypsin storage disorder,a or extensive giant cell transformation perinatal iron storage disorder, galactosemia, and of hepatocytes mitochondriopathies Disorders of bile acid synthesis

3-hydroxysteroid dehydrogenase deficiency, 5-beta reductase deficiency

Disorders of bile acid transport

PFIC1, PFIC2 (eSlides 29B.1, 29B.2, 29B.3)

Progressive cholangiopathies

Alagille syndrome (eSlide 5.7),a Zellweger syndrome,a alpha-1 antitrypsin deficiency,a cystic fibrosis (eSlides 10.1 and 10.2), PFIC3 (eSlide 29B.4)

7

aThese diseases may show paucity of interlobular bile ducts (alpha-1 antitrypsin deficiency rarely). PFIC, progressive familiar intrahepatic cholestasis.

A

PFIC, progressive familiar intrahepatic cholestasis.

metabolic diseases of the liver are commonly accompanied by inflammatory changes that may be brisk, mimicking chronic viral hepatitis, druginduced hepatitis, or autoimmune hepatitis. The common denominator in metabolic disorders consistently presenting as “hepatitis” seems to be accumulation of toxic metabolites that cause hepatocyte necrosis or sufficient metabolic stress, making these cells vulnerable to insults that might ordinarily be tolerated without harm. Moreover, it is possible that inflammation incidental to intercurrent events such as viremia, sepsis, systemic inflammatory disease, or drug exposure may be more injurious to the liver of a patient with a primary metabolic disease. Examples of typically nonhepatic and commonly hepatitic metabolic liver diseases and their propensity to evolve to cirrhosis are listed in Table 7.2.

Metabolic Diseases with Prominent Lobular Cholestasis Although many metabolic diseases in the liver are not associated with cholestasis, lobular cholestasis and “cholate-stasis” regularly occur in four classes of metabolic diseases (Table 7.3). The first group is diverse wherein the metabolic disorder causes loss of substantial numbers of hepatocytes as a result of necrosis or extensive giant cell transformation with disruption of

B Figure 7.1  Lobular cholestasis. A, Tyrosinemia. Swollen hepatocytes contain granular cytoplasmic bile pigment in secondary lysosomes (also see eSlide 7.1). B, PFIC2 (bile salt export pump defect). Swollen multinucleate hepatocytes contain granular bile pigment in secondary lysosomes (also see eSlides 29B.2 and 29B.3).

the canalicular network, resulting in liver failure with nonobstructive cholestasis (Fig. 7.1). Examples are tyrosinemia (eSlide 7.1), alpha-1 antitrypsin storage disease, perinatal iron storage disorder (eSlide 5.6), galactosemia, and mitochondriopathies. The second and third groups include disorders in which the transport or synthesis of bile acids is abnormal (eSlides 29B.2 and 29B.3); serum gamma glutamyl transferase is typically normal in these conditions (see Fig. 7.1). The fourth group includes diseases that are characterized by progressive cholangiopathy affecting bile ducts such as Alagille syndrome (eSlide 5.7), Zellweger syndrome, cystic fibrosis (eSlides 10.1 103

Practical Hepatic Pathology: A Diagnostic Approach and 10.2), and progressive familial intrahepatic cholestasis type 3 (PFIC3) (eSlide 29B.4); serum gamma glutamyl transferase is typically elevated. Paucity of interlobular bile ducts occurs regularly in Alagille syndrome and much less commonly in alpha-1 antitrypsin storage disease. Paucity has been reported rarely in a host of other metabolic, genetic, and acquired diseases such as PFIC2, bile acid synthetic defects (BASDs), congenital panhypopituitarism, or conditions such as Zellweger syndrome, Down syndrome, and arthrogryposis-renal-cholestasis syndrome. Paucity may be due to bile duct destruction with or without sclerosis, or developmental delay; the basis for paucity in metabolic diseases is poorly understood.5,6

Bile Ductules Versus Ducts in Metabolic Disease It is always challenging to interpret increases in the number of bile duct or bile ductlike structures in portal areas. This common interpretative problem has important implications for the distinction between metabolic diseases that are primary hepatocellular diseases with progressive liver fibrosis from true metabolic cholangiopathies such as PFIC3 and differentiation of both categories from obstructive cholangiopathies. Central to this problem is the need for the pathologist to appreciate the ductular reaction and the varied contexts in which it may be seen. This reaction, in addition to being a major component of the reaction to mechanical obstruction of large bile ducts, is a common nonspecific response to epithelial injury of the ductules (cholangioles), which are structures located at or near the margins of portal areas. The nonspecific ductular reaction, highlighted by a keratin immunostain, intensifies, in conjunction with progressive periportal fibrosis, in a wide variety of acute and chronic or persistent liver injuries such as drug reactions, or autoimmune, alloimmune, and chronic viral hepatitis, as well as in obstructive cholangiopathies of various types, biliary atresia in particular, even as the interlobular bile ducts disappear in the latter condition. Interlobular bile ducts may be selectively highlighted by K19 and EMA immunostains, but location in the interior of a portal zone and a patent lumen are more helpful features. In the absence of proliferative changes in the interlobular and septal bile ducts, the ductular reaction should not be interpreted as evidence of an obstructive cholangiopathy. Similarly, the frequent association of the ductular reaction with a collar of polymorphonuclear leukocytes is not sufficient by itself to support a diagnosis of ascending cholangitis. Ductular reactions are typically absent or mild early in the course of most types of metabolic liver disease but may be observed in alpha-1 antitrypsin deficiency and in the relatively more hepatotoxic BASDs, and they may be extremely prominent in PFIC3 (Fig. 7.2). The epithelium of bile ducts of large and intermediate caliber and of interlobular bile ducts is not commonly involved in metabolic diseases of the liver. Exceptions include cystic fibrosis; some lysosomal storage diseases (type II glycogenosis, GM1 gangliosidosis, mucolipidosis); and perinatal hemochromatosis (PH) (eSlide 5.6), in which hemosiderin deposits in duct epithelium may be observed as part of the general deposition of hemosiderin in extrahepatic parenchymal cells.

Metabolic Diseases with a Steatotic Pattern Fatty change in the liver of infants and children may either be acquired or be a manifestation of an underlying genetic metabolic disease (Box 7.3). Accumulation of lipid in hepatocytes without inflammation, hepatocyte necrosis or other abnormalities of liver cells, or evidence of fibrosis is called simple steatosis (Fig. 7.3). Transient hepatocyte steatosis readily occurs in infants and children during periods of temporary caloric deprivation and may also occur during a metabolic crisis in a patient with an underlying metabolic disorder such as a urea cycle defect (UCD) or an aminoacidopathy (see Fig. 7.3). There are no known pathologic consequences. Simple steatosis is also common at autopsy of critically ill children and adults who die in hospital intensive care units, as well as in a minority of infants who are diagnosed with sudden infant death syndrome. In both groups, lipid droplets are of small to medium size, often 104

A

B Figure 7.2  Ductular reaction. A, Mild ductular reaction with periductulitis due to toxic monohydroxy bile acids in 5-beta reductase bile acid synthetic defect. B, Florid ductular reaction accompanies severe periportal fibrosis in progressive cholangiopathy due to multidrug resistance-3 deficiency (also see eSlide 29B.4). Box 7.3  Fatty Liver Arising from Accumulation of Triglycerides: Diverse Etiologies • S imple steatosis, transient • Macrovesicular steatosis, persisting Dietary deficiency of protein (eg, poverty, avoidance) Protein malabsorption (eg, cystic fibrosis, enteropathy) Glycogen storage disease, types I and III Galactosemia Fructose aldolase deficiency (hereditary fructosemia) Carnitine-acylcarnitine translocase deficiency Urea cycle defects Citrin deficiency (type II citrullinemia) Secondary to hypertriglyceridemia Chronic hepatitis C: nonalcoholic fatty liver disease/nonalcoholic steatohepatitis Diabetes mellitus Drug toxicity (eg, methotrexate) Phytotoxin (eg, Senecio alkaloids, Amanita phalloides toxin, aflatoxin) Chemical toxins (eg, elemental phosphorus, carbon tetrachloride) • Macrovesicular and microvesicular steatosis Fatty acid oxidation defects Mitochondriopathy (eg, mDNA depletion) Aminoacidopathy (eg, isovaleric acidemia) Drug toxicity (eg, valproic acid–induced liver failure, tetracycline) • Microvesicular steatosis, transient, postviral (epidemic Reye syndrome) mDNA, mitochondrial DNA.

Histologic Patterns of Metabolic Liver Diseases panlobular, and do not displace the hepatocyte nuclei. Because lipid has been extracted during processing, it can be presumptively identified only in paraffin sections based on the sharp interface with surrounding hepatocyte cytoplasm. Storage lysosomes may have a similar sharp interface by light microscopy, but a limiting membrane characterizes the ultrastructure.

Chronic protein deficiency caused by inadequate diet, malabsorption (as in cystic fibrosis), or avoidance (as in UCD) results in fatty change in hepatocytes characterized by large vacuoles of neutral lipid that displace the nucleus to the periphery (Fig. 7.4). This change is commonly limited to periportal hepatocytes (zone 1) but may be panlobular. Because coalescence of lipid into visible medium-size and large-size vacuoles is a dynamic process, hepatocytes containing medium-size and large-size lipid droplets often coexist. It is the predominant form that provides a clue, albeit an imperfect one, to the tempo and the underlying cause of lipid accumulation. Paradoxically, the dietary imbalances now prevalent in western societies have produced an epidemic of obesity and metabolic stress that cause steatosis accompanied by portal and lobular inflammation, hepatocyte degeneration and reactive changes in the ultrastructure of the endoplasmic reticulum and in mitochondria. The prevalence of this acquired fatty liver disease in the pediatric age group adversely affects the reliability of morphologic criteria previously considered useful for recognition of specific liver diseases.

7

Fatty Acid Oxidation Defects A

B

Clinical Manifestations More than a dozen defects in fatty acid oxidation (FAO) have been described in the past two decades.7,8 Mortality is high, particularly during the first year of life and often in early infancy. Hepatic presentations with hepatomegaly and nonketotic hypoglycemia are most common, but true hepatic failure is rare. Cardiomyopathic and myopathic presentations are less common. Medium-chain acyl-coenzyme A (CoA) dehydrogenase deficiency, the most common of the defects in FAO, presents as an acute metabolic crisis, often with nonketotic hypoglycemia, usually precipitated by a febrile illness that causes loss of appetite, exposing the inability to metabolize lipid during brief periods of starvation. FAO disorders may mimic epidemic Reye syndrome (RS) in clinical presentation, but morphologic manifestations differ.9 Long-chain acyl-CoA dehydrogenase deficiency (Fig. 7.5) may be associated with progressive liver fibrosis or with cardiomyopathy, myopathy, or pigmentary retinopathy. Less common are FAO or lipid transport defects that result in a metabolic crisis in the immediate newborn period before feeding is initiated, as in the infantile forms of carnitine palmitoyltransferase 2 deficiency (see Fig. 7.5) and carnitine-acylcarnitine translocase deficiency.10 Most cases of

C Figure 7.3  Steatosis patterns. A, Medium-size lipid vesicles in hepatocytes: nonspecific steatosis of acute illness (autopsy). B, Macrovesicular and microvesicular steatosis: transient metabolic crisis in isovaleric acidemia. C, Macrovesicular steatosis obscures excess glycogen in type Ia glycogenosis (also see eSlide 7.10).

Figure 7.4  Macrovesicular steatosis in an infant with failure to thrive caused by malabsorption syndrome due to cystic fibrosis. 105

Practical Hepatic Pathology: A Diagnostic Approach acute fatty liver of pregnancy result from recessively inherited FAO defects in the fetus. The most common of these is a mitochondrial trifunctional protein defect that impairs oxidation of long-chain fatty acids.11,12 Several FAO defects, including medium-chain acyl-CoA dehydrogenase, long-chain acyl-CoA dehydrogenase, carnitine transporter defect, and carnitine translocase defect, have been implicated in a small number of sudden deaths in infancy and childhood.

A

B

Pathology On the basis of observations in liver biopsies and autopsy material, infants and children with defective FAO accumulate neutral lipid in organs most dependent on FAO such as the liver, heart, proximal renal tubules, and type 1 skeletal muscle fibers. The lipid accumulation occurs predominantly in the form of microvesicular steatosis in which the lipid vacuoles indent but do not displace the nucleus (see Fig. 7.5); large-droplet lipid is usually, but not always, a minor component. In medium-chain acyl-CoA dehydrogenase, the accumulation of lipid in hepatocytes may be transient and may abate or disappear without permanent liver injury when homeostasis is restored. A useful protocol to identify the underlying FAO defect at autopsy is available.13 Analysis of urine for acyl and acylcarnitine compounds and establishment of a fibroblast culture are essential supplements to appropriate tissue samples when clinical suspicion is high and these studies have not been initiated before death. Prominent lipid vacuoles in hepatocytes of a child with undiagnosed liver disease do not necessarily indicate a primary disorder of the lipid utilization pathway. Hepatic steatosis may coexist as a confounding variable in many metabolic disorders, either because of poor nutrition or because the defect directly interferes with lipid processing or utilization. Fortunately, in such cases, the lipid accumulation usually does not dominate histologic changes of the primary disorder in the liver, although in rare instances this may be the case. In some aminoacidopathies such as isovaleric acidemia, hepatocyte lipid accumulation may be prominent at the time of a metabolic crisis. Large vacuolar lipid accumulation in hepatocytes is common in type I and type III glycogenosis and rarely is so extensive as to obscure the diagnostic histologic features of glycogen excess (see Fig. 7.3). Ultrastructural changes in mitochondria in FAO disorders have been described but not thoroughly characterized. Observations to date suggest that ultrastructure of mitochondria in FAO are not distinctive in comparison to mitochondrial alterations in primary disorders of electron transport, mitochondrial DNA (mDNA) depletion, and epidemic RS. Many metabolic liver diseases that commonly present in infancy are routinely included in the lengthy differential diagnosis of neonatal hepatitis, but it is helpful to know that with the following exceptions, prominent steatosis is unusual in most disorders subsumed under this convenient rubric. The more common exceptions include the following metabolic diseases: galactosemia, hereditary fructose intolerance, hepatic mitochondriopathies, UCDs, citrin deficiency, and lysinuric protein intolerance; in these disorders, lipid vacuoles of variable size accumulate in hepatocytes and may be accompanied by mild portal inflammation, progressive portal fibrosis, and liver failure. Diagnosis Diagnosis is usually based on the plasma acylcarnitine profile determined by fast atom bombardment mass spectrometry from Guthrie card bloodspots, urine acylcarnitine and organic acid profiles, and studies performed on cultured fibroblasts.

Mitochondriopathies

C Figure 7.5 Fatty acid oxidation/transport defects. A, Mixed macrovesicular and microvesicular steatosis: acute metabolic crisis in medium-chain acyl-CoA dehydrogenase defect. B, Mixed macrovesicular and microvesicular steatosis: long-chain acyl-CoA dehydrogenase defect (autopsy). C, Mixed macrovesicular and microvesicular steatosis: lethal carnitine palmitoyltransferase 2 defect in infant. 106

Clinical Manifestations The liver, as well as the brain, skeletal muscle, heart, and other organs, may be involved in systemic or organ-limited mitochondriopathies caused either by nuclear DNA (nDNA) or mDNA mutations/deletions, which result in deficiencies of one particular component of the electron transport system or a reduction in multiple electron transport activities. The liver may be clinically involved alone or in combination with the brain, skeletal muscle, or gastrointestinal tract. Mitochondrial hepatopathy in infants typically progresses to liver failure. The most common basis for liver failure attributed to mitochondriopathy is mDNA depletion caused by mutations in nuclear genes that control mDNA processing, resulting in reduced activity of electron transport proteins that are coded by mDNA.14,15 Examples of mutations

Histologic Patterns of Metabolic Liver Diseases in nuclear genes or nuclear-coded proteins that are reported to cause hepatic or hepatocerebral mitochondriopathy are deoxyguanosine kinase,16POLG1, and MPV17.17 The phenotypic spectrum of MPV17 mutations includes Navajo neurohepatopathy.18 It is now apparent that most, if not all, of the valproic acid–associated cases of acute liver failure in infants or children with seizures have an underlying mitochondriopathy that affects both the liver and brain. Patients with underlying mitochondriopathy are exceptionally vulnerable to valproic acid because it interferes with mitochondrial oxidation of fatty acids.19 Similarly, it is now clear that most cases of AlpersHuttenlocher syndrome are mitochondriopathies in which brain involvement dominates the early clinical presentation.20 The frequent but not invariable association of liver and brain mitochondriopathy is the basis for the warning to avoid liver transplants in infants or children with neurologic disease that is not secondary to liver failure.

Mitochondriopathy arising from hepatotoxicity of nucleoside reverse transcriptase inhibitors that inhibit DNA polymerase gamma may cause steatosis and lactic acidemia. These complications of therapy for chronic viral infections have not been reported in children, perhaps because long-term exposure is a requirement.

7

Pathology Light microscopic abnormalities that point to a primary disorder of mitochondria include patchy, sometimes extensive microvesicular and macrovesicular steatosis, intralobular cholestasis, swollen granular red hepatocytes that contain excessive numbers of mitochondria, scattered necrotic hepatocytes, foci of intralobular regeneration and collapse, and mixed portal/lobular inflammation accompanied by progressive portal fibrosis (Fig. 7.6). In our experience, application of oxidative enzyme histochemistry to cryostat sections of liver may be helpful in

A

B

C

D Figure 7.6  Mitochondriopathy. A, Nonuniform microvesicular steatosis and scattered granular red hepatocytes (oncocytes) in mDNA depletion due to MPV17 defect. B, Nonuniform microvesicular steatosis without granular red hepatocytes (oncocytes) in mDNA depletion due to MPV17 defect. C, Mitochondria in mDNA depletion are pleomorphic with variable abnormal density of matrix. MPV17 defect (electron microscopy). D, Massively enlarged mitochondria due to increased matrix with displacement of cristae to periphery in MPV17 defect (electron microscopy). 107

Practical Hepatic Pathology: A Diagnostic Approach recognition of mitochondriopathy. Selective reduction or hyperintensity of reaction within individual hepatocytes,21 or loss of activity of cytochrome oxidase coupled with preservation of succinic dehydrogenase, has been reported. Individual hepatocytes that contain increased numbers of mitochondria typically contain excessive succinic dehydrogenase activity. As the morphologic phenotype is expanded by descriptions of new variants and new entities in which mDNA depletion is a common feature, it is becoming clear that microscopic findings may not always be so distinctive or may be limited to steatosis only. Furthermore, the light microscopic and ultrastructural changes in hepatic mitochondriopathies before onset of acute liver failure are not wellcharacterized and possibly may be absent at earlier stages of the disease. Distinctive mitochondrial abnormalities have been observed by electron microscopy in patients with proven mitochondriopathy (see Fig. 7.6).17,22 Similar morphologic changes have been observed in acute liver failure associated with what formerly were called idiosyncratic drug reactions to valproic acid used to treat seizures in infants or in older children (Fig. 7.7). Many of these patients may have an unrecognized mitochondriopathy. Diagnosis Criteria for clinical and laboratory diagnosis of possible, probable, and definite mitochondriopathy as a cause for neuromuscular disease with or without multiorgan involvement are not perfect but provide a

A

B Figure 7.7  Alpers disease with valproate-associated liver failure. A, Triad of features includes mild fatty change, scattered granular red hepatocytes, and focal chronic inflammation. B, Tetrazolium reductase reaction product indicative of mitochondrial numbers is abnormally heavy in frozen section of liver (succinate dehydrogenase histochemistry). 108

general guide that applies to the liver and other viscera as well.23 These criteria attempt to account for variability in presentation and laboratory test results, for the fact that organ distribution of pathologic mitochondria is often nonuniform and depends on specific organ energy requirements, and for the fact that the percentage of pathologic mitochondria in a given tissue must reach a threshold to impair organ function. Skeletal muscle is commonly affected in mitochondriopathies but does not always exhibit diagnostic changes by light or electron microscopy. Nonetheless, muscle biopsy is convenient and, when properly triaged and processed, has a reasonably high yield as a screening test for biochemical and molecular genetic disorders (nDNA or mDNA). The utility of muscle biopsy when clinical signs indicate primary liver involvement alone or in conjunction with central nervous system disease has not been thoroughly investigated. Therefore, in such patients, clinical state permitting, open liver biopsy is preferable to obtain sufficient tissue for a complete assessment that includes light and electron microscopy, measurement of electron transport activities, and mDNA content. Blood leukocyte DNA is now being used to assay for specific mutations in nDNA that cause mDNA depletion and liver failure in infants or young children.

Reye Syndrome RS is a transient postviral acute encephalopathy associated with fatty degeneration of hepatocytes in which microvesicular steatosis develops abruptly in the wake of a viral illness, along with signs of failure of hepatic synthetic function, hyperammonemia, and mild to moderate elevation of serum aminotransferases. This was a disorder of older, previously healthy children that peaked in incidence during the 1970s. Clear evidence of association of RS with epidemics of chickenpox and influenza B was followed by epidemiologic evidence linking the syndrome to therapy with salicylate. Mortality and long-term morbidity because of brain injury was about 5%. Both light and electron microscopy of liver tissue obtained early in the course of the disease were distinctive and established the basis as a hyperacute emergence (phanerosis) of microvesicular fat as a marker for acute liver failure because of a transient reversible mitochondriopathy.24 The hepatocytes in the early phase are swollen and contain few visible lipid droplets in paraffin sections; however, abundant microvesicular lipid, apparently briefly concealed during rapid evolution of the hepatopathy, is demonstrable in fat stains on frozen section examination (Fig. 7.8). Histochemical studies showed depletion of succinic dehydrogenase (see Fig. 7.8) and cytochrome oxidase. Ultrastructural changes in mitochondria are very distinctive (see Fig. 7.8), and, in retrospect, suggest what in modern parlance is called membrane permeability transition. The biology of the relationship to salicylate remains mysterious, and the validity of the statistical link, although generally accepted, has been questioned. With decline of aspirin use in children, RS has almost disappeared in the United States,25 except in the context of acute decompensation of a primary disease of energy metabolism typically in infancy or, less commonly, in early childhood. In such cases, the distinctive ultrastructural changes of mitochondria in epidemic RS are absent.26 Skepticism about the existence of RS, except in the context of a specific disorder of energy metabolism, is based on the dramatic advances in recognition and diagnosis of disorders of energy metabolism over the past 30 years with techniques that were not available at the height of the epidemic. This assertion reasonably applies to infants and young children only and overlooks the fact that epidemic RS mainly occurred in older children, most of whom recovered and never had a prior or repeat episode.

Urea Cycle Defects UCDs are inherited enzyme defects that impair nitrogen elimination resulting in hyperammonemia and encephalopathy.27,28 The cycle

Histologic Patterns of Metabolic Liver Diseases involves six enzymes: ornithine transcarbamylase (OTC), argininosuccinic acid synthetase (deficiency causes type I citrullinemia), argininosuccinate acid lyase (deficiency causes “argininosuccinic aciduria”), arginase, carbamoyl phosphate synthetase, and N-acetylglutamate synthetase. Two related disorders that cause hyperammonemia are lysinuric protein intolerance and citrin deficiency, the latter being a disorder prevalent in ethnic East Asian adults that causes type II citrullinemia. Deficiency of N-acetylglutamate synthetase, carbamoyl phosphate synthetase, and ornithine transcarbamylase in the mitochondrial matrix directly impairs urea synthesis by reducing mitochondrial citrulline production. The last steps of the urea cycle involving argininosuccinic acid synthetase and argininosuccinate acid lyase, located in the cell cytoplasm, are necessary for the final assembly of urea from protein degradation. Clinical Manifestations Signs and symptoms of UCDs may be present at birth or delayed until later infancy, childhood, and beyond, and are often episodic, varying with the defect, protein content of the diet, and stress of intercurrent illness. Delayed onset is most common in females who are heterozygous carriers for OTC deficiency. Hepatomegaly is common in UCDs.

Pathology The histology and ultrastructure of the liver in UCDs may be normal or abnormal. It is likely that the described changes in liver morphology are dependent more on the status of the patient at the time of biopsy, such as hyperammonemic crisis or nutritional state, than on the particular defect. Light microscopy may be normal when ammonia levels are normal or in explanted livers. More often seen are macrovesicular and/or microvesicular steatosis, cytoplasmic glycogen excess, and variable portal fibrosis (eSlides 7.2 and 7.3). Intralobular cholestasis and hepatocellular necrosis are inconstant features. Excess glycogen accumulation in nonfatty livers from patients with UCDs may resemble a nonlysosomal glycogen storage disease and, in some instances, takes the form of quasi-clonal clusters of glycogen-laden hepatocytes (Fig. 7.9).29,30 Hypothetical causes for glycogen accumulation in UCDs abound, reflecting incomplete understanding of the altered biochemistry. These include gene expression altered by the lobular microenvironment, effect of hyperammonemia on glycolysis, and/ or a low-protein/carbohydrate-rich diet. Fibrosis may progress to cirrhosis despite control of hyperammonemia.31 Electron microscopy reveals that when excess glycogen is present in UCD, it usually is well admixed with subcellular organelles (see Fig. 7.9) without displacement of organelles to the cytoplasmic

A

B

C

D

7

Figure 7.8  Reye syndrome (RS), epidemic form, acute transient liver failure. A, Hepatocytes are rounded rather than polygonal because of hydropic swelling. B, Microvesicular lipid partly concealed in paraffin sections is easily demonstrated in lipid stains on frozen sections or by electron microscopy. C, General loss of mitochondrial oxidative enzyme activity spares zone 1 hepatocytes (frozen section with succinate dehydrogenase histochemistry). D, Swollen ameboid mitochondria with pale matrix and floating cristae, plus glycogen depletion, typical of RS (electron microscopy). 109

Practical Hepatic Pathology: A Diagnostic Approach periphery, as tends to be true for glycogenosis. One may also see admixed normal and polymorphous mitochondria with occasional megamitochondria, shortened cristae, and paracrystalline matrix inclusions.32 Such changes are observed in several other conditions (alcoholism, cavernous transformation of portal vein,

steatohepatitis) and are best thought of as nonspecific indicators of intramitochondrial stress. Notably, mitochondrial ultrastructural changes typical for epidemic RS, a condition in which only the two urea cycle enzymes located in mitochondria are selectively impaired,33 are absent. Diagnosis Liver tissue can be used for diagnosis by measuring enzyme activity, but diagnosis is usually made by laboratory tests performed on body fluids.

Citrin Deficiency

A

Citrin is a hepatic mitochondrial aspartate-glutamate carrier protein. Mutations cause type II citrullinemia in adults or cholestasis in infants. Both forms of the disease are most prevalent in ethnic East Asians. Laboratory studies in affected infants show hyperammonemia, hypoproteinemia and, in some cases, galactosemia. The liver histology in young infants with citrin deficiency may overlap with features of neonatal hepatitis but differs because of the prevalence of steatosis, which is not a common finding in European-American infants with neonatal hepatitis of known or unknown etiology. The histology, reported in small numbers of cases, consists of macrovesicular steatosis, lobular cholestasis, prominent acinar transformation, and progressive pericellular fibrosis (Fig. 7.10).34 These changes may regress with dietary management.

Galactosemia

B

Galactose is a disaccharide that cannot be metabolized by about 1 in 10,000 infants, in whom it is toxic to the liver and the eye.35 The most common and most severe form of galactosemia is an autosomal recessive disorder caused by a deficiency of galactose 1-phosphate uridyltransferase. A suspected diagnosis based on newborn screening is confirmed by enzyme assay in erythrocytes. Liver biopsy findings evoke the usual broad differential diagnosis of a neonatal hepatitis–like pattern without signs of a cholangiopathy. Partially distinguishing features are frequent acinar arrangements of hepatocytes, fibrosis, and fatty change (Fig. 7.11). Restriction of dietary galactose ameliorates signs of systemic disease that typically presents as feeding difficulties, jaundice, hepatosplenomegaly, and growth failure.

C Figure 7.9  Urea cycle defects. A, Panlobular cytoplasmic clarity because of glycogen accumulation. Argininosuccinate acid lyase deficiency explant simulates glycogenosis. B, Local glycogen accumulation in cluster of hepatocytes ornithine transcarbamylase deficiency (also see eSlide 7.2). C, Glycogen accumulation in ornithine transcarbamylase deficiency tends to not displace organelles (electron microscopy). 110

Figure 7.10  Citrin deficiency in infant. Fatty change and acinar change are prominent. (With permission of Grace Kim, MD, University of California at San Francisco.)

Histologic Patterns of Metabolic Liver Diseases Recognition and treatment may prevent cirrhosis, cataracts, and neurologic deterioration.

Hereditary Fructose Intolerance Fructose, a normal nutrient for most persons, is a noxious sugar for about 1 in 20,000 infants. The most common and most severe form arises from fructose B aldolase deficiency.36 Foods containing fructose cause hypoglycemia, signs of liver injury, and growth failure in affected infants. The severity of symptoms correlates with the fructose content of the diet and duration of exposure. Liver damage may be severe, resulting in cirrhosis and liver failure. A neonatal hepatitis–like pattern is uncommon, probably because recognition is usually delayed. Liver biopsy findings are more likely to be limited to fatty change and fibrosis without evidence of cholangiopathy (Fig. 7.12). The changes are typically reversible when fructose is withdrawn (see Fig. 7.12).

Lysosomal Storage Disorders More than 50 lysosomal storage disorders are known.1 Most result from deficient activity of specific acid hydrolases. Several, such as sialidosis and cystinosis, are due to defective transport of products of lysosomal enzyme activity. As the molecular genetic bases are elaborated, many of the original entities are evolving into a multiplicity of genotypes and phenotypes produced either by different mutations in genes encoding particular enzymes or mutations in genes that control transcription and intracellular trafficking of gene products. The resulting phenotypic variability may be reflected in the rate of disease progression or in the severity of clinical and tissue manifestations in a particular organ, such as the liver. Disease-specific clinical patterns of organ involvement are sufficiently common to be helpful guides, along with other clinical signs to clinicians and pathologists during a diagnostic evaluation.37 Liver involvement only suggests the possibility of type I or type VI glycogenosis, or cholesterol ester storage disease. Involvement limited to the liver, spleen, bone marrow, and lymph nodes suggests a reticuloendothelial storage disorder such as Gaucher disease or Niemann-Pick disease, type B. Generalized lysosomal storage disorders that involve multiple organ systems, including the nervous system, are mucopolysaccharidoses I, II, and III (eSlide 7.4); GM1 gangliosidosis (eSlide 7.5); Niemann-Pick disease, types A and C; and the neuropathic form of Gaucher disease. Clinical manifestations in leukodystrophy because of lysosomal enzyme defects may have clinical manifestations limited to the central nervous system. In some lysosomal storage disorders, liver involvement is mild and produces no clinical manifestations, or as in

Fabry disease, the parenchymal cells of the liver are not involved at all. Progressive hepatic fibrosis is unusual in lysosomal storage disorders, except in Gaucher disease and in acid lipase deficiency. Gaucher disease, a relatively common lysosomal storage disorder, provides a good example of the complexity that has resulted from phenotypic and genotypic investigations in recent years. Gaucher disease has three major forms: type 1 is highly variable in severity and rate of progression, may first manifest at any age, and lacks involvement of the central nervous system; type 2 is the acute infantile neuropathic form; and type 3 is the subacute neuropathic form. All are because of a deficiency of glucocerebrosidase activity. Mutational analysis has revealed a high rate of mutation and more than 100 different mutations in the affected gene. Thus far, phenotype-genotype correlation is insufficient to reliably categorize patients on the basis of molecular analysis.38 Approaches to treatment being studied in human models of lysosomal storage disease include inhibition of synthesis, stimulation of residual enzyme activity, and gene therapy with viral vectors. Modification of phenotype in humans, dramatic in some cases, has now been

7

A

B

Figure 7.11  Galactosemia in infant: acinar change, steatosis, lobular cholestasis, and delicate pericellular fibrosis.

Figure 7.12  Fructose intolerance (aldolase deficiency) in infant. A, Prominent acinar change, variable macrovesicular steatosis, and both portal and pericellular fibrosis. B, Before (left) and after (right) treatment. After several months of dietary management, steatosis has disappeared and fibrosis has begun to regress. 111

Practical Hepatic Pathology: A Diagnostic Approach achieved by effective enzyme replacement therapy for eight lysosomal storage disorders: type 1 Gaucher disease,39 type IIa glycogen storage disease,40 Fabry disease, 41,42 mucopolysaccharidoses I, II, III, and IV,43 and lysosomal acid lipase deficiency.44 Pathology One or more cellular components of the liver may be affected. It is important to determine which of the following cell types display features of storage: hepatocytes, Kupffer cells, endothelial cells, portal macrophages, or fibroblasts. Kupffer cells and portal macrophages are selectively involved in most lysosomal disorders involving the reticuloendothelial system, because the lysosomal degradation pathway is extremely active in most macrophages. Gaucher disease, type 1, is an example of a pure reticuloendothelial storage disease. Storage lysosomes that accumulate in the cytoplasm of hepatocytes create a characteristic light microscopic appearance of abnormal lacy clarity, often with numerous clear empty-appearing vesicles that may mimic microvesicular or macrovesicular steatosis. The possibility of lipid vesicles alone or intermixed with storage lysosomes can be investigated by performing a neutral fat stain on a small sample of the biopsy that has been frozen fresh for histochemical and biochemical study. This is the recommended approach whenever liver tissue is used to investigate for a storage disorder. Vesicles may also be identified as lysosomes by demonstration of acid phosphatase activity or with an immunostain for LAMP2, a marker for lysosomes. With either method, storage lysosomes must be distinguished from normal secondary lysosomes, perhaps on the basis of distribution within hepatocyte cytoplasm. More helpful when a lysosomal storage disorder is suspected is to prepare a small portion of the biopsy sample for electron microscopy. The purposes of this are to verify that the vesicles are defined by a unit membrane, to assess distribution within hepatocyte cytoplasm, and to identify and characterize the storage product, thereby narrowing the range of diagnostic possibilities. The membrane-bound vesicles in a lysosomal storage disorder typically contain a monomorphous storage product that is often specific for a group of lysosomal disorders and is occasionally characteristic of a particular lysosomal enzyme defect. In many lysosomal storage disorders, the partially degraded storage material is water-soluble and readily dissolved in aqueous fixatives or lost during processing in paraffin. The lysosomal vesicles appear to be empty by light microscopy and, to some extent, by electron microscopy as well. Thus, it may be said that the histology of these disorders is, to some extent, independent of the underlying enzyme deficiency (Fig. 7.13). Disorders in which the stored material is especially apt to be lost in processing are mucopolysaccharidoses and conditions involving defects in glycoprotein degradation such as mannosidosis and fucosidosis. Diagnosis of a specific lysosomal storage disorder based on either light microscopy and/or the ultrastructural appearance of the storage product is possible in many, but not all, lysosomal storage diseases. Examples where a specific morphologic diagnosis may be made are as follows. Storage lysosomes in type II glycogenosis almost exclusively contain partially degraded glycogen (Fig. 7.14; see Fig. 7.13). In mucopolysaccharidoses, the ultrastructure of the stored material is an amorphous lacy residue that is frustratingly difficult to stain in paraffin sections (see Figs. 7.13 and 7.14). In Gaucher disease, the storage product is insoluble and retained in paraffin sections, where it is weakly positive for PAS and has a distinctive “crinkled paper” appearance; storage material in the liver is confined to the Kupffer cells and portal macrophages (see Fig. 7.13 and eSlide 7.6). The Gaucher storage product has a unique ultrastructure of platelike tubules (see 112

Fig. 7.14) and can be mobilized from the reticuloendothelial cells by enzyme replacement therapy, thus ameliorating the non-neuropathic manifestations of this disease in the liver, spleen, bone marrow, and lung. In Niemann-Pick disease, types A and B caused by sphingomyelinase deficiency, the Kupffer cells and, to a variable extent, hepatocytes have a characteristic foamy appearance because of accumulation of sphingomyelin, a membranous sudanophilic phospholipid (see Fig. 7.13) (eSlide 7.7). This material has distinctive myelin-like ultrastructural qualities (see Fig. 7.14) that resemble, to some extent, the phospholipid profiles that may accumulate in the secondary lysosomes in chronic cholestasis. Morphologically and chemically similar material accumulates in renal epithelium and blood vessels in Fabry disease. In Farber lipogranulomatosis attributed to acid ceramide deficiency, vacuolated cytoplasm of Kupffer cells, and to a lesser extent hepatocytes (see Fig. 7.13), contains lysosomes filled with minute, tubular, curvilinear bodies (see Fig. 7.14). Diagnosis Diagnostic alternatives to liver biopsy are plentiful for the clinician who suspects a lysosomal storage disorder based on family history, clinical presentation, pattern of organ involvement, or radiologic features. These include obtaining cultured skin fibroblasts, amnion epithelium, or leukocytes as a source of either lysosomal enzymes or nDNA, or using skin, conjunctiva, amnion, and skeletal muscle for electron microscopy. The liver is likely to be subjected to biopsy only when hepatomegaly is a dominant feature at the time of initial examination.

Acid Lipase Deficiency This lysosomal disorder is responsible for both Wolman disease in young infants and cholesterol ester storage disease, a milder form that causes asymptomatic hepatomegaly in older infants and children (Fig. 7.15). Because of the nature of the stored lipid, the liver may be orange-yellow rather than pale yellow, as in neutral lipid storage diseases. In both types of acid lipase deficiency, the stored lipid is membrane-bound by electron microscopy (unlike ordinary lipid vesicles) and contains cholesterol ester crystals that are demonstrable in frozen sections with polarized light. In cholesterol ester storage disease, Kupffer cells and portal macrophages contain a complex of insoluble lipids (ceroid) in lysosomes that are weakly basophilic and PAS positive after diastase digestion. This finding completes an unusual light microscopic constellation that strongly suggests cholesterol ester storage disease. LAMP2 immunostain aids identification of storage lysosomes in acid lipase deficiency in paraffin sections.45

Niemann-Pick Disease, Type C This type of Niemann-Pick disease results from mutations in specific transporters of unesterified cholesterol from lysosomes/endosomes into the cytosol. It is biochemically unrelated to sphingomyelin metabolism but clinically and morphologically overlaps with Niemann-Pick disease, type A, and several other unrelated neurovisceral lipidoses. A morphologic hallmark, especially in the spleen and bone marrow, is the gradual accumulation of foamy reticuloendothelial cells. Transient cholestatic liver disease, which is neonatal hepatitis–like, may begin in infancy and slowly progress to cirrhosis.46 The liver lesion may be frankly inflammatory and fibrogenic in early infancy (Fig. 7.16); a smoldering chronic hepatitis may be the basis for cirrhosis. Compensatory intrahepatic hematopoiesis in the liver occurs as the bone marrow is gradually replaced by foamy histiocytes. In most reported cases, liver disease is overshadowed by neurologic deterioration in later life. The rarity of foam cells in the liver of infants and young children with Niemann-Pick disease, type C, makes recognition in a liver biopsy difficult

Histologic Patterns of Metabolic Liver Diseases

7

A

B

C

D

E

F Figure 7.13  Lysosomal storage disease: light microscopy. A, Glycogen storage disease IIa (Pompe disease). Hepatocytes are slightly enlarged with pale lacy cytoplasm because of accumulation of small glycogen-laden lysosomes. Sinusoids are open. B, Mucopolysaccharidosis, type I (Hurler disease). Hepatocyte cytoplasm is lacy because of accumulation of small storage vesicles. Coexistent lipid droplets are a confounding variable. C, GM1 gangliosidosis. Hepatocyte cytoplasm is focally lacy because of presence of storage lysosomes. Larger vesicles may be lysosomes or lipid (see also eSlide 7.5). D, Gaucher disease. Morphologically unique storage material with a “crinkled paper” texture is located here in Kupffer cells and portal macrophages (not shown), but not in hepatocytes (also see eSlide 7.6). E, Niemann-Pick disease, type B. Microvesicular lipid (phospholipid) in cytoplasm of hepatocytes, Kupffer cells, and portal macrophages (surrounding bile duct) obscures differences in cell types, although irregular nuclear configuration helps identify reticuloendothelial cells (also see eSlide 7.7). F, Farber lipogranulomatosis. Kupffer cells contain more storage material than hepatocytes. The periodic acid–Schiff stain, shown here, may be useful for demonstrating a nonglycogen storage disease predominant in or limited to reticuloendothelial cells. 113

Practical Hepatic Pathology: A Diagnostic Approach

A

B

D

C

E

F Figure 7.14  Lysosomal storage disease: electron microscopy. A, Type II glycogenosis. Glycogen accumulates in membrane-bound vesicles within hepatocyte cytoplasm. B, Mucopolysaccharidosis type I (Hurler disease). Membrane-bound storage vesicles contain amorphous wispy granular residue of water-soluble glycosaminoglycan. C, Mucopolysaccharidosis type III (Sanfilippo disease). Membrane-bound storage vesicles contain amorphous wispy granular residue of water-soluble glycosaminoglycan (also see eSlide 7.4). D, Gaucher disease. Characteristic platelike arrays of globoside (arrows) accumulate in Kupffer cells only. Inset shows magnified storage material in Gaucher cell (also see eSlide 7.6). E, Niemann-Pick disease, type B. Phospholipid storage material is composed of complex layered membranous profiles resembling myelin in hepatocytes (left) and Kupffer cells (right) (also see eSlide 7.7). F, Farber lipogranulomatosis. Storage material is composed of tubular curvilinear bodies in hepatocytes (left) and Kupffer cells (right).

114

Histologic Patterns of Metabolic Liver Diseases

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B

C

D Figure 7.15  Cholesterol ester storage disease. A, Hepatocytes all contain microvesicular empty-appearing vesicles, but the amount perceived in a paraffin section may not be prominent. In contrast, Kupffer cells and portal macrophages contain conspicuous amounts of amphophilic granular residual bodies. B, Frozen section of liver core viewed in polarized light shows myriad lipid crystals, a feature not observed in other forms of genetic or acquired steatosis. C, Periportal fibrosis advances slowly with age in many patients with cholesterol ester storage disease. D, In cholesterol ester storage disease, as opposed to other forms of steatosis, hepatocyte lipid accumulates in membrane-bound vesicles (lysosomes) (electron micrograph).

and may delay definitive diagnosis. Disproportionate splenomegaly is an important clue to the need for examination of bone marrow or study of a fibroblast culture for signs of defective cholesterol metabolism. In a general sense, the PAS stain after digestion with diastase is helpful for evaluation of Kupffer cell reactivity that is accompanied by accumulation of residual bodies. This stain may facilitate demonstration of abnormally enlarged vacuolated Kupffer cells in Niemann-Pick disease, type C (see Fig. 7.16), and other lipid storage disorders.

Cystinosis This rare autosomal-recessive trait causes cystine to accumulate in lysosomes, presumably because of the lack of a membrane transport carrier, resulting in progressive renal tubular and glomerular disease in infants and children. Cystine crystal deposits have been identified in many other organs in patients with cystinosis and may be responsible for local tissue injury at many sites, including the liver (eSlide 7.8), where nodular regenerative hyperplasia and noncirrhotic portal hypertension are described as late complications.47 In the liver, the cystine crystals are mainly localized in Kupffer cells and portal area macrophages. Clinically significant liver disease in nephropathic cystinosis is rare.

Nonlysosomal Glycogenosis and Polyglucosan Storage Disorders Pathology Phenotypic, biochemical, and clinical heterogeneity in glycogen storage diseases have increased substantially since these disorders were first identified.48 Nonetheless, so far as is known, the light and electron microscopic appearances of most nonlysosomal glycogenoses are similar.47 The hepatocytes in each of the nonlysosomal glycogenoses have a dramatic expansion of cytoplasmic volume because of glycogen accumulation that results in an increase in cytoplasmic clarity and a mosaic pattern produced by swollen liver cells with lacy cytoplasm; this compresses sinusoids and effaces the usual architecture of hepatic cell plates (Fig. 7.17). Hepatocyte volume expansion by glycogen results in displacement of hepatocyte organelles to the perinuclear region and to the periphery where the cell membrane is accentuated. The ultrastructure is distinctive (see Fig. 7.17). PAS stain often is used to demonstrate liver glycogen, but its utility and limitations in the recognition of glycogen storage disease are notable. This nonquantitative stain helps identify the material responsible for hepatocyte cytoplasmic expansion. However, it has no value for determining when hepatocyte glycogen content exceeds 115

Practical Hepatic Pathology: A Diagnostic Approach and in its varied presentations (neonatal, and later onset with predominant involvement of the liver, muscle, or heart). Hepatic disease commonly progresses to cirrhosis. The stored material is not glycogen but amylopectin, an unbranched polysaccharide that chemically resembles starch. In frozen sections, this material stains blue-brown with Lugol iodine. The stored material in type IV glycogenosis is PAS positive but diastase resistant and gradually accumulates within the hepatocyte cytoplasm in a distinctive localized pattern (Fig. 7.18). The amylopectin is arranged in bulky nonmembrane-bound granulofibrillar inclusions in electron micrographs (see Fig. 7.18). Progressive fibrosis is typical in type IV glycogenosis. Fibrosis is usually mild in type III glycogenosis, although progression to cirrhosis has been observed in long-term survivors, and is usually mild or absent in other subtypes of glycogenosis.

A

B Figure 7.16 Niemann-Pick disease, type C. A, “Neonatal hepatitis” pattern with sinusoidal erythropoiesis at age 2 months. Periportal fibrosis suggests an underlying metabolic disease. B, Follow-up biopsy at age 10 months demonstrated incomplete resolution of features of “neonatal hepatitis.” Scattered enlarged Kupffer cells with lipid vacuoles are the only clues to the eventual biochemical diagnosis. Patient currently has neurologic impairment typical of Niemann-Pick disease, type C.

the upper limit of normal, which is very high; approximately 6% of wet weight. Experience shows that extremely well-glycogenated liver may mimic the histologic appearance of glycogen storage disease in the absence of a defect in glycolysis and within the upper limit of normal glycogen content. Specific disorders where this caveat applies include UCDs and poorly controlled diabetes mellitus (Mauriac syndrome) (see eSlide 3.2). Several minor differences among the subtypes of nonlysosomal glycogenosis are consistent enough to permit suggestion of a particular diagnosis. Two features, large cytoplasmic lipid vacuoles and prominent glycogenation of hepatocyte nuclei in zone 1, are common and often very prominent in types I and III glycogenosis (see Fig. 7.17 and eSlides 7.9 and 7.10). Cytoplasmic lipid and nuclear glycogenation tend to be minimal in types VI, VIII, and IX glycogenosis (deficiencies of liver phosphorylase, phosphorylase kinase activator, and phosphorylase kinase, respectively). Both features are rare in type II glycogenosis, a lysosomal glycogenosis in which excess glycogen mainly occurs in membrane-bound vesicles (see Fig. 7.13) rather than free in the hepatocyte cytoplasm.49 Type IV glycogenosis is a notable exception to other glycogen storage diseases, both in terms of microscopic and ultrastructural features 116

Diagnosis The most efficient approach to making a correct diagnosis requires clinical suspicion and then selection from available screening methods. If a liver biopsy is performed initially and clinical suspicion for a storage disorder is high, at least two cores of liver tissue or an open biopsy specimen should suffice. One core of liver tissue must be frozen in anticipation of need for biochemical analysis. It is helpful to first perform electron microscopy to identify the stored material and its location in lysosomes or free in the cytoplasm. When excess nonlysosomal glycogen displaces other organelles to the periphery in most hepatocytes, the glycogen concentration should be measured and a homogenate screened for glycolytic enzyme defects (Table 7.4). Polyglucosan accumulation in hepatocytes that resembles type IV glycogenosis may be observed in Lafora disease, a genetic-based progressive form of myoclonic epilepsy. The stored polysaccharide results in cytoplasmic inclusions that are reactive with PAS and are sensitive to diastase, as well as weakly reactive with colloidal iron, indicating a weakly acidic polysaccharide. The inclusions accumulate in hepatocyte cytoplasm as demarcated pools of material that is granular to fibrillar by electron microscopy and displaces hepatocyte organelles in a manner that resembles type IV glycogenosis. However, assays of branching enzyme activity are normal. Hepatocytes with a similar ground-glass cytoplasmic texture may also be observed in chronic hepatitis B and as a result of drug-induced proliferation of smooth endoplasmic reticulum. Ground-glass–appearing, apparently sequestered, compartments in hepatocyte cytoplasm that contain mainly particulate glycogen, which may be intermixed with other organelles such as mitochondria and endoplasmic reticulum (Fig. 7.19), have recently been reported following liver and bone marrow transplantation.50 These inclusions have been called a pseudoglycogenosis, seem to have no clinical significance, and may slowly resolve. The pathogenesis is unknown.

Bile Acid Synthetic Defects BASDs are a relatively new category of liver disease with a wide spectrum of outcomes. Nine defects in the synthetic pathway have been identified with combined mass spectroscopy and gas chromatography to identify abnormal bile acids in blood, urine, or bile.51 The defects result in absence or low levels of normal bile acids and direct hyperbilirubinemia, particularly in infants who typically present with a neonatal hepatitis–like syndrome. Serum levels of gamma glutamyl transpeptidase, an enzyme produced in hepatocytes, secreted in bile, and reabsorbed by damaged bile duct epithelium, are normal, as in PFIC1 and PFIC2. Liver injury in BASD arises from two factors: (1) the absence of the normal choleretic influence of the two normal major bile acids, cholic and deoxycholic acids; and (2) the accumulation in hepatocytes of metabolic intermediaries, hydrophobic monohydroxy bile acids proximal in the synthetic pathway to the missing enzyme. Hydrophobic bile acids are relatively toxic to hepatocytes and probably to the ductular cholangiocytes as well. In infants with the two most common defects, 3-beta

Histologic Patterns of Metabolic Liver Diseases

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B

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D

E Figure 7.17  Nonlysosomal glycogenosis. A, Type Ia glycogenosis. Swollen glycogen-laden hepatocytes in a mosaic pattern, macrovesicular steatosis, and prominent periportal nuclear glycogen pseudoinclusions are most often observed in types I and II glycogenosis (also see eSlide 7.10). B, Type Ib glycogenosis histologically resembles type Ia except that nuclear inclusions may be less conspicuous or absent (also see eSlide 7.9). C, Type III glycogenosis with a prominent mosaic pattern. Expanded hepatocytes compress sinusoids. D, Type VI glycogenosis with prominent mosaicism and no nuclear glycogen inclusions. E, Type IX glycogenosis. Severe glycogen accumulation displaces hepatocyte organelles to the periphery and to the perinuclear location. Neither glycogen nor lipid vesicles are membrane-bound as in other nonlysosomal glycogenoses (electron micrograph).

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Practical Hepatic Pathology: A Diagnostic Approach Table 7.4  Glycogenoses Involving the Liver

A

Type

Enzyme Defect

Tissue Affected

Diagnostic Tools

0

Glycogen synthase

Liver (low glycogen), skeleton (short stature)

Biochemistry/mutation analysis

Ia

Glucose-6phosphatase

Liver, kidney

Biochemistry/mutation analysis

Ib

Glucose 6-phosphate Liver, kidney, translocase myeloid cells

Biochemistry/mutation analysis

IIa

Acid-α-glucosidase

Generalized

Electron microscopy: liver, skin, muscle Biochemistry/mutation analysis

IIb, IIc, IId

Acid-α-glucosidase

Muscle, liver, heart

Electron microscopy: muscle, liver, heart Biochemistry

III

Debrancher enzyme

Liver, heart, muscle

Biochemistry/mutation analysis

IV

Brancher enzyme

Liver, heart, muscle

Biochemistry; no common mutations

VI

Liver phosphorylase

Liver

Biochemistry; no common mutations

VIII

Phosphorylase kinase activator

Liver, brain

Biochemistry

IX

Phosphorylase kinase deficiency

Liver, muscle

Biochemistry

X

Cyclic AMP– dependent phosphorylase kinase

Liver, muscle

Biochemistry

AMP, adenosine monophosphate.

B Figure 7.18  Type IV glycogenosis. A, Amylopectin material, not digestible with diastase, accumulates in pools that occupy part or most of hepatocyte cytoplasm. Not all hepatocytes are equally affected. Cirrhosis is more common than in any other glycogenosis. B, A localized pool of amylopectin displaces hepatocyte organelles. Inset: magnified granulofibrillar amylopectin material (electron micrograph).

hydroxysteroid dehydrogenase deficiency (Fig. 7.20) and 5-beta reductase deficiency (Fig. 7.21), the histology overlaps with ordinary neonatal hepatitis with giant cell transformation with the following exceptions. Necrosis of giant cells tends to be more common than in usual neonatal hepatitis. Interlobular bile ducts are normal, but there may be a cytotoxic interface hepatitis accompanied by swollen and necrotic cholangiocytes in the smallest ductules. Rapid evolution to liver failure in infancy has also been observed in the much rarer oxysterol-7-alpha hydroxylase defect. Important exceptions exist to the pattern of presentation of BASD in early infancy as “neonatal hepatitis.” It is now clear that signs and symptoms caused by 3-beta hydroxysteroid dehydrogenase deficiency may present in older children as well as young adults. In these patients, an indolent course is typical. Signs include persistent direct 118

Figure 7.19  Sequestered hepatocyte cytoplasm in liver allograft, an acquired lesion, is glycogen-rich and resembles type IV glycogenosis.

hyperbilirubinemia, elevated serum aminotransferases, fat-soluble vitamin deficiency, itching, and poor growth. Fibrosis tends to be very slowly progressive. Thus, there is significant overlap with PFIC1 and PFIC2. BASD also include defects in bile acid conjugation. These patients produce bile acids that are not normally esterified and, as a result, are ineffective. Cardinal signs are poor growth and fat-soluble vitamin deficiency. In patients who lack conjugated bile acids, neonatal cholestasis may not have been observed and progressive liver disease may not occur.

Histologic Patterns of Metabolic Liver Diseases

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A A

B

B

Figure 7.20  Bile acid synthetic defects. A, “Neonatal hepatitis” with giant cell transformation in infant with 3-beta hydroxysteroid dehydrogenase deficiency. B, Mild periportal fibrosis in late-onset 3-beta hydroxysteroid dehydrogenase deficiency.

Timely institution of normal bile acid replacement therapy appears to be beneficial for preventing chronic liver disease in the two most common defects, 3-beta hydroxysteroid dehydrogenase deficiency and 5-beta reductase deficiency. However, this therapy has not yet been shown effective in the much rarer oxysterol-7-alpha hydroxylase deficiency.

Peroxisomal Diseases Peroxisomes are subcellular organelles with multiple functions. These include beta oxidation of lipids, especially very long chain fatty acids, as well as synthesis of plasmalogens and bile acids. Peroxisomes are more abundant in hepatocytes than any other cell type. Metabolic disorders caused by peroxisome dysfunction are divided into two biologic groups that have overlapping phenotypes. Peroxisomal biogenesis disorders are multisystem recessively inherited conditions characterized by abnormalities of peroxisome assembly, which result in marked deficiency or absence of peroxisomes. Principally affected are the central nervous system, liver, adrenal glands, and skeleton. Mutations in the PEX family of genes that are involved in peroxisome membrane assembly are a major cause of defective peroxisome biosynthesis. Mutations in ABCD1, a peroxisomal membrane transporter for very long chain fatty acids, are related to X-linked adrenal leukodystrophy. Approximately 80% of patients with peroxisomal biogenesis disorder are classified in the Zellweger syndrome spectrum (ZSS).52 Three single peroxisomal enzyme deficiency disorders have also been recognized:

C Figure 7.21  Bile acid synthetic defects. A, Eosinophilic necrosis of giant hepatocytes is prevalent in 5-beta reductase deficiency diagnosed in the perinatal period. B, Small-duct cholangiopathy in 5-beta reductase deficiency. C, Ductular reaction with pericholangitis in 5-beta reductase deficiency.

straight-chain acyl-CoA oxidase deficiency, which results in accumulation of very long chain fatty acids in the serum; D-bifunctional protein deficiency, which causes familial encephalopathy with seizures; and alpha methyl acyl-CoA racemase deficiency, which results in accumulation of abnormal bile acids and pristanic acid in serum as well as malabsorption of fat-soluble vitamins. 119

Practical Hepatic Pathology: A Diagnostic Approach Clinical Manifestations Zellweger syndrome in infants was the first peroxisomal disease to be recognized as such. Although absence of peroxisomes is a defining feature, clinical severity varies greatly. The complete phenotype includes cholestasis, evolving paucity of bile ducts, progressive hepatic fibrosis, neuronal migration abnormalities, small renal cysts, and an unusual craniofacial appearance. Pathology Among peroxisomal biogenesis disorders and single-enzyme peroxisomal defects, progressive liver disease occurs mainly in classic Zellweger syndrome, which represents the severe end of ZSS. Although reticuloendothelial cells may exhibit distinctive cytoplasmic abnormalities, liver disease is typically absent in other peroxisomal disorders such as X-linked adrenoleukodystrophy, infantile Refsum disease, and single peroxisomal enzyme defects. Progressive liver disease in ZSS is related, at least in part, to the toxicity of accumulated abnormal bile salts, as well as to progressive destruction of small bile ducts leading to paucity, cholestasis, and fibrosis (Fig. 7.22). Unlike the situation in single-enzyme defects in bile acid synthesis, administration of normal bile acids to patients with ZSS disease or to mice with an animal knockout model of ZSS does not prevent progressive liver disease. Diagnosis Diagnosis of peroxisomal disorders is based on clinical findings, laboratory data such as elevated serum levels of very long chain fatty acids, identification of unusual metabolites in serum such as phytanic acid and pipecolic acid, complementation assays in fibroblast culture, and, most recently, genetic testing for abnormalities in the PEX family of genes. Liver ultrastructure is helpful if peroxisomes, which are normally present in considerable number, cannot be found on careful search. However, changes in liver ultrastructure associated with other chronic disease may interfere. Moreover, defects in biogenesis of this organelle may result in the absence, marked reduction in numbers, or appearance of a few morphologically abnormal remnant peroxisomes, thus making liver ultrastructure unreliable as a criterion for diagnosis.

composed of normal-appearing hepatocytes that contain immunoreactive fumarylacetoacetase, an apparent reversion to a normal genotype. Cirrhosis and dysplastic nodules develop in late infancy or early childhood (see eSlide 7.1). The dysplastic liver nodules (Fig. 7.24) are difficult to distinguish from hepatocellular carcinoma. Tyrosinemia is an important model for the study of early histologic and genetic changes during hepatic carcinogenesis as well as for the study of genetic events that spontaneously correct the mutations in fumarylacetoacetase in many of the liver nodules. Diagnosis The accumulation of succinylacetone, a by-product of tyrosine degradation, in urine and serum is the basis for a specific diagnostic test.

A

Hereditary Tyrosinemia Clinical Manifestations Type I tyrosinemia is an autosomal-recessive disorder caused by a deficiency of fumarylacetoacetase, the last enzyme in the pathway of tyrosine degradation. Accumulation of toxic intermediate metabolites causes either acute liver failure associated with neonatal hepatitis or slowly progressive liver disease in children and young adults. Hypophosphatemic rickets in infants is because of renal tubular dysfunction. Both phenotypes may result in cirrhosis with a high risk of hepatocellular carcinoma at a young age. Liver transplantation is effective but has been supplanted by long-term administration of an enzyme inhibitor of tyrosine degradation, 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione, coupled with dietary management. This places emphasis on early diagnosis. The enzyme inhibitor reverses the production of toxic intermediary metabolites and ameliorates the liver disease.53 However, persistent elevation of serum alpha fetoprotein, a tendency to develop dysplastic liver nodules, and the risk of hepatocellular carcinoma are not eliminated. Pathology The histology of the liver in infants with hereditary tyrosinemia (Fig. 7.23) shows lobular cholestasis, pseudoacini, giant cell transformation, focal fatty changes, necrosis, early pericellular fibrosis, and excessive inflammation compared with other metabolic disorders that cause nonobstructive cholestasis in infants.54 Hemosiderin deposits in hepatocytes may be prominent (see Fig. 7.23). Fibrosis may be established very early, even before birth. A fascinating phenomenon is the appearance of nodules 120

B

C Figure 7.22  Peroxisomal disease, Zellweger syndrome. A, Bile plug in duct and canaliculus. B, Lobular cholestasis with giant cell transformation, ballooned hepatocytes, and absent bile duct. C, Periportal and delicate pericellular fibrosis (trichrome stain).

Histologic Patterns of Metabolic Liver Diseases

Genetic Hemolytic Disorders A host of uncommon genetically determined hemolytic disorders exist that are capable of causing liver injury, either as a consequence of anemia, heart failure, or overloading of the immature liver with the products of rapid hemoglobin degradation. In the prenatal period, rapid hemolysis because of hemoglobinopathy

A

or to Rh incompatibility may cause hydrops fetalis. Liver lesions include abnormal persistence and often left-shifted sinusoidal erythropoiesis, siderosis involving the reticuloendothelial cells of sinusoids and portal spaces, and lobular cholestasis accompanied by giant cell transformation (Fig. 7.25). If perfusion or the oxygencarrying capacity of the blood is impaired, liver necrosis may be superimposed.

7

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B B

Figure 7.24  Tyrosinemia-explanted liver. A, Multiple nodules in cirrhotic liver. B, Nodule with dysplasia (also see eSlide 7.1).

C Figure 7.23 Tyrosinemia. A, Lobular disarray, acinar change, siderosis, and inflammation in neonatal-onset tyrosinemia. B, Prominent acinar change in tyrosinemia. C, Hepatocyte siderosis in tyrosinemia (Perls iron stain) (also see eSlide 7.1).

Figure 7.25  ”Neonatal hepatitis” pattern with erythroblastosis due to hemolytic anemia. 121

Practical Hepatic Pathology: A Diagnostic Approach Congenital erythropoietic porphyria is a recessive trait that impairs heme biosynthesis and shortens red blood cell survival.55 The broad phenotype includes mild and severe forms, and the genotype shows extreme variation with poor genotype-phenotype correlation. Clinical presentation may occur at any age and includes rare reports of hydrops fetalis and/or liver failure during infancy. The liver lesion in affected infants is neonatal hepatitis–like and presumably is related to excess hemolysis and liver immaturity, as with other hemolytic disorders that occur in this age group (Fig. 7.26).

Perinatal Hemochromatosis Clinical Manifestations PH is a poorly understood disorder characterized by acute liver failure beginning before, at, or shortly after birth caused by severe liver disease accompanied by excessive iron deposition in the parenchymal cells of the liver, pancreas, endocrine organs, glandular epithelia, heart, and other sites.56 Death in early infancy is typical. The broad pattern of tissue siderosis in PH simulates hereditary hemochromatosis in adults but has no genetic relationship to hereditary hemochromatosis. Notable, but not understood, is the fact that reticuloendothelial cells in PH are typically spared hemosiderin accumulation. Unique characteristics of PH are a high recurrence rate in siblings, a predilection for the perinatal period, the established absence of a connection to hereditary hemochromatosis in both affected infants and their mothers, and

Pathology and Diagnosis Microscopic findings in the liver are largely based on autopsy descriptions supplemented by study of explants, a successful rescue procedure in some cases. Liver histology varies with the duration of the liver disease and includes florid giant cell transformation, extensive parenchymal necrosis and collapse, and, in some cases, extensive fibrosis or established cirrhosis with regenerative nodules (Fig. 7.27) (see eSlide 5.6).

A

A

B

B

Figure 7.26  Congenital erythropoietic porphyria. A, Neonatal hepatitis pattern with prominent erythroblastosis. B, Kupffer cell siderosis (Perls iron stain). 122

the diversity of the occasionally associated conditions ranging from infections to specific metabolic diseases. The associated stressors that have been identified in a minority of cases of PH are in utero infections, metabolic disorders (hereditary tyrosinemia, 3-oxosteroid 5-beta reductase deficiency), in utero hemolytic disorders, exogenous iron overload, and severe hypoperfusion because of congenital heart disease or perinatal hypoxic-ischemic liver injury. However, no such associations exist in most cases. Thus, the high recurrence rate in siblings remains unexplained. It is theorized that conditions for PH include developmental immaturity, an immune insult of some sort, and perinatal liver disease severe enough to cause fulminant liver failure. Alloimmunity is posited as a cofactor and has resulted in advocacy for treatment of mothers of an affected child with hyperimmune globulin and exchange transfusion before subsequent pregnancies; the absence of a recurrence of PH in subsequent siblings of mothers so treated supports the hypothesis.57,58

Figure 7.27  Perinatal hemochromatosis. A, Extensive periportal and lobular fibrosis. B, Siderosis in hepatocytes and bile duct epithelium (Perls iron stain) (also see eSlide 5.6).

Histologic Patterns of Metabolic Liver Diseases Inflammation is usually inconspicuous. Occasionally, a pattern of sinusoidal/venoocclusive disease is seen. Excessive iron deposition in hepatocytes is a regular feature but may not be particularly severe. Hemosiderin deposits in bile duct epithelium suggest the possibility of more widespread tissue siderosis, a suspicion that may be explored further in life with a biopsy of oral submucosal glands or after death with a survey for hemosiderin deposits in parenchymal cells of other viscera. The alloimmune hypothesis for etiology of PH requires more study as no antigen has been identified and the C5-9 deposits identified in hepatocytes in paraffin sections of liver in PH are not well-characterized.59 It should be remembered that periportal hepatocytes normally contain hemosiderin early in life only to lose it within several months of birth, indicating that perinatal iron-handling pathways may differ significantly during development from those in adults. Thus, the finding of hemosiderin in periportal hepatocytes of newborn infants is a normal feature and should not be taken as evidence for PH. Protein synthetic failure limits use of liver biopsy for diagnosis of PH.

Genetic Metabolic Diseases of Unknown Etiology Acute liver failure (ALF) in children is rare. The etiology is undetermined in about half of the cases. Because the necessary investigations are complex and often incomplete, the contribution of unrecognized metabolic disease has been underestimated until recently when a survey of one-decade experience suggests that many cases are caused by unrecognized metabolic diseases.60 Newborn screening programs are able to detect some potentially lethal diseases such as galactosemia, aminoacidopathies, and fatty acid oxidation disorders. Many others, such as mitochondriopathies, urea cycle defects, glycogenosis, lysosomal storage disease, or congenital disorders of glycosylation (CDG), are not detected in newborn screens and must be identified on the basis of features such as growth failure, nonspecific neurological or gastrointestinal symptoms, or signs of liver disease.61 Liver biopsy is a powerful diagnostic tool in the work-up of infants who are not thriving, but histologic features may be nonspecific as in CDG. In the future, DNA sequencing, targeted to disorders of energy metabolism, or whole exome sequencing will help to reduce the frequency of both chronic liver disease and ALF of undetermined cause.62-63 Suggested Readings Gilbert-Barness E, Barness LA. Metabolic diseases: foundations of clinical management, genetics, and pathology. Natick, MA: Eaton; 2000. Gilbert-Barness E, Kapur RP, Oligny LL, et al. Potter’s pathology of the fetus, infant and child. Philadelphia: Mosby Elsevier; 2007. Kaplowitz N. Liver and biliary disease. Baltimore: Williams & Wilkins; 1992. Klatskin G, Conn HO. Histopathology of the liver. Vols. I and II. New York: Oxford University Press; 1993. Phillips MJ, Poucell S, Patterson J, Valencia P. The liver: An atlas. New York: Raven Press; 1987.

References 1. Gilbert-Barness E, Barness LA. Metabolic diseases: foundations of clinical management, genetics, and pathology. Natick, MA: Eaton; 2000. 2. Gilbert-Barness E, Kapur RP, Oligny LL, et al. Potter’s pathology of the fetus, infant and child. Philadelphia: Mosby Elsevier; 2007. 3. Clayton PT. Inborn errors presenting with liver dysfunction. Semin Neonatol. 2002;7:49–63. 4. Clayton PT. Diagnosis of inherited disorders of liver metabolism. J Inherit Metab Dis. 2003; 26:135–146. 5. Kahn E, Daum F, Markowitz J, et al. Nonsyndromatic paucity of interlobular bile ducts: light and electron microscopic evaluation of sequential liver biopsies in early childhood. Hepatology. 1986;6:890–901. 6. Sinha J, Magid MS, VanHuse C, et al. Bile duct paucity in infancy. Semin Liver Dis. 2007; 27:319–323. 7. Vockley J, Whiteman DA. Defects of mitochondrial beta-oxidation: a growing group of disorders. Neuromuscul Disord. 2002;12:235–246. 8. Saudubray JM, Martin D, de Lonlay P, et al. Recognition and management of fatty acid oxidation defects: a series of 107 patients. J Inherit Metab Dis. 1999;22:488–502. 9. Treem WR, Witzleben CA, Piccoli DA, et al. Medium-chain and long-chain acyl-CoA dehydrogenase deficiency: clinical, pathologic and ultrastructural differentiation from Reye’s syndrome. Hepatology. 1986;6:1270–1278.

10. Chalmers RA, Stanley CA, English N, et al. Mitochondrial carnitine-acylcarnitine translocase deficiency presenting as sudden neonatal death. J Pediatr. 1997;131:220–225. 11. Ibdah JA, Bennett MJ, Rinaldo P, et al. A fetal fatty-acid oxidation disorder as a cause of liver disease in pregnant women. N Eng J Med. 1999;340:1723–1731. 12. Yang Z, Yamada J, Zhao Y, et al. Prospective screening for pediatric mitochondrial trifunctional protein defects in pregnancies complicated by liver disease. JAMA. 2002;288:2163–2166. 13. Rinaldo P, Yoon HR, Yu C, et al. Sudden and unexpected neonatal death: a protocol for the postmortem diagnosis of fatty acid oxidation disorders. Semin Perinatol. 1999;23:204–210. 14. Labarthe F, Dobbelaere D, Devisme L, et al. Clinical, biochemical and morphological features of hepatocerebral syndrome with mitochondrial DNA depletion due to deoxyguanosine kinase deficiency. J Hepatol. 2005;43:333–341. 15. Sarzi E, Bourdon A, Chretien D, et al. Mitochondrial DNA depletion is a prevalent cause of multiple respiratory chain deficiency in childhood. J Pediatr. 2007;150:531–534. 534.e1–534.e6. 16. Freisinger P, Futterer N, Lankes E, et al. Hepatocerebral mitochondrial DNA depletion syndrome caused by deoxyguanosine kinase (DGUOK) mutations. Arch Neurol. 2006;63:1129–1134. 17. Wong LJ, Brunetti-Pierri N, Zhang Q, et al. Mutations in the MPV17 gene are responsible for rapidly progressive liver failure in infancy. Hepatology. 2007;46:1218–1227. 18. Karadimas CL, Vu TH, Holve SA, et al. Navajo neurohepatopathy is caused by a mutation in the MPV17 gene. Am J Hum Genet. 2006;79:544–548. 19. Silva MF, Aires CC, Luis PB, et al. Valproic acid metabolism and its effects on mitochondrial fatty acid oxidation: a review. J Inherit Metab Dis. 2008;31:205–216. 20. Gordon N. Alpers syndrome: progressive neuronal degeneration of children with liver disease. Dev Med Child Neurol. 2006;48:1001–1003. 21. Holve S, Hu D, Shub M, et al. Liver disease in Navajo neuropathy. J Pediatr. 1999;135:482–493. 22. Mandel H, Hartman C, Berkowitz D, et al. The hepatic mitochondrial DNA depletion syndrome: ultrastructural changes in liver biopsies. Hepatology. 2001;34:776–784. 23. Bernier FP, Boneh A, Dennett X, et al. Diagnostic criteria for respiratory chain disorders in adults and children. Neurology. 2002;59:1406–1411. 24. Bove KE, McAdams AJ, Partin JC, et al. The hepatic lesion in Reye’s syndrome. Gastroenterology. 1975;69:685–697. 25. Belay ED, Bresee JS, Holman RC, et al. Reye’s syndrome in the United States from 1981 through 1997. N Engl J Med. 1999;340:1377–1382. 26. Partin JC, Schubert WK, Partin JS. Mitochondrial ultrastructure in Reye’s syndrome (encephalopathy and fatty degeneration of the viscera). N Engl J Med. 1971;285:1339–1343. 27. Tuchman M, Lee B, Lichter-Konecki U, et al. Cross-sectional multicenter study of patients with urea cycle disorders in the United States. Mol Genet Metab. 2008;94:397–402. 28. Summar ML, Dobbelaere D, Brusilow S, et al. Diagnosis, symptoms, frequency and mortality of 260 patients with urea cycle disorders from a 21-year, multicentre study of acute hyperammonaemic episodes. Acta Paediatr. 2008;97:1420–1425. 29. Badizadegan K, Perez-Atayde AR. Focal glycogenosis of the liver in disorders of ureagenesis: its occurrence and diagnostic significance. Hepatology. 1997;26:365–373. 30. Miles L, Heubi JE, Bove KE. Hepatocyte glycogen accumulation in patients undergoing dietary management of urea cycle defects mimics storage disease. J Pediatr Gastroenterol Nutr. 2005;40:471–476. 31. Mori T, Nagai K, Mori M, et al. Progressive liver fibrosis in late-onset argininosuccinate lyase deficiency. Pediatr Dev Pathol. 2002;5:597–601. 32. Latham PS, LaBrecque DR, McReynolds JW, et al. Liver ultrastructure in mitochondrial urea cycle enzyme deficiencies and comparison with Reye’s syndrome. Hepatology. 1984;4:404–407. 33. Brown T, Hug G, Lansky L, et al. Transiently reduced activity of carbamyl phosphate synthetase and ornithine transcarbamylase in liver of children with Reye’s syndrome. N Engl J Med. 1976;294:861–867. 34. Yeh JN, Jeng YM, Chen HL, et al. Hepatic steatosis and neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) in Taiwanese infants. J Pediatr. 2006;148:642–646. 35. Bosch AM. Classical galactosaemia revisited. J Inherit Metab Dis. 2006;29:516–525. 36. Ali M, Rellos P, Cox TM. Hereditary fructose intolerance. J Med Genet. 1998;35:353–365. 37. Elleder M. Sequelae of storage in Fabry disease—pathology and comparison with other lysosomal storage diseases. Acta Paedlatr Suppl. 2003;92:46–53. discussion 45. 38. Koprivica V, Stone DL, Park JK, et al. Analysis and classification of 304 mutant alleles in patients with type 1 and type 3 Gaucher disease. Am J Hum Genet. 2000;66:1777–1786. 39. Grabowski GA, Andria G, Baldellou A, et al. Pediatric non-neuronopathic Gaucher disease: presentation, diagnosis and assessment. Consensus statements. Eur J Pediatr. 2004;163:58–66. 40. van der Ploeg AT, Reuser AJ. Pompe’s disease. Lancet. 2008;372:1342–1353. 41. Ries M, Gupta S, Moore DF, et al. Pediatric Fabry disease. Pediatrics. 2005;115:e344–e355. 42. Willis A, Vanhuse C, Newton KP, et al. Farber’s disease type IV presenting with cholestasis and neonatal liver failure: report of two cases. Pediatr Dev Pathol. 2008;11:305–308. 43. Baldo BA. Enzymes approved for human therapy: indications, mechanisms and adverse effects. Biodrugs. 2015;29:31–55. 44. Burton BK, Balwani M, Feillet F, et al. A phase 3 trial of sebelipase alpha in lysosomal acid lipase deficiency. N Engl J Med. 2015;373:1010–1020. 45. Hulkova H, Elleder M. Distinctive histopathological features that support a diagnosis of cholesterol ester storage disease in liver biopsy specimens. Histopathology. 2012;60:1365–2559. 46. Kelly DA, Portmann B, Mowat AP, et al. Niemann-Pick disease type C: diagnosis and outcome in children, with particular reference to liver disease. J Pediatr. 1993;123:242–247. 47. DiDomenico P, Berry G, Bass D, et al. Noncirrhotic portal hypertension in association with juvenile nephropathic cystinosis: case presentation and review of the literature. Inherit Metab Dis. 2004;27:693–699.

7

123

Practical Hepatic Pathology: A Diagnostic Approach 48. Shin YS. Glycogen storage disease: clinical, biochemical, and molecular heterogeneity. Semin Pediatr Neurol. 2006;13:115–120. 49. McAdams AJ, Hug G, Bove KE. Glycogen storage disease, types I to X: criteria for morphologic diagnosis. Hum Pathol. 1974;5:463–487. 50. Lefkowitch JH, Lobritto SJ, Brown Jr RS, et al. Ground-glass, polyglucosan-like hepatocellular inclusions: a “new” diagnostic entity. Gastroenterology. 2006;131:713–718. 51. Bove KE, Heubi JE, Balistreri WF, et al. Bile acid synthetic defects and liver disease: a comprehensive review. Pediatr Dev Pathol. 2004;7:315–334. 52. Yik WY, Steinberg SJ, Moser AB, et al. Identification of novel mutations and sequence variation in the Zellweger syndrome spectrum of peroxisome biogenesis disorders. Hum Mutat. 2009;30:E467–E480. 53. Masurel-Paulet A, Poggi-Bach J, Rolland MO, et al. NTBC treatment in tyrosinaemia type I: longterm outcome in French patients. J Inherit Metab Dis. 2008;31:81–87. 54. Dehner LP, Snover DC, Sharp HL, et al. Hereditary tyrosinemia type I (chronic form): pathologic findings in the liver. Hum Pathol. 1989;20:149–158. 55. Desnick RJ, Glass IA, Xu W, et al. Molecular genetics of congenital erythropoietic porphyria. Semin Liver Dis. 1998;18:77–84. 56. Silver MM, Valberg LS, Cutz E, et al. Hepatic morphology and iron quantitation in perinatal hemochromatosis. Comparison with a large perinatal control population, including cases with chronic liver disease. Am J Pathol. 1993;143:1312–1325.

124

57. Whitington PF, Hibbard JU. High-dose immunoglobulin during pregnancy for recurrent neonatal haemochromatosis. Lancet. 2004;364:1690–1698. 58. Baruteau J, Heissat S, Collardeau-Franchon S, et al. New insights into perinatal hemochromatosis. Arch Pediatr. 2012;19:755–761. 59. Melin-Aldana H, Park C, Pan X, et al. Gestational alloimmune disease in newborns with an indeterminate cause of death following complete autopsy. J Neonatal Perinatal Med. 2015;8:25–31. 60. Hegarty R, Hadzic N, Gissen P, et al. Inherited metabolic disorders presenting as acute liver failure in newborns and young children. Eur J Pediatr. 2015;174:1387–1392. 61. Janssen JC, de Kleine RH, van den berg AP, et al. Successful liver transplantation and long term follow-up in a patient with MPI-CDG. Pediatrics. 2014;134:279–283. 62. Choi R, Woo HI, Choe BH, et al. Application of whole exome sequencing to a rare inherited metabolic disease with neurological and gastrointestinal manifestations: a congenital disorder of glycosylation mimicking glycogen storage disease. Clin Chim Acta. 2015;444:50–53. 63. Leslie N, Wang X, Peng Y, et al. Neonatal multi-organ failure due to ACAD9 mutation and complex I deficiency with mitochondrial hyperplasia in liver, cardiac myocytes, skeletal muscle, and renal tubules. Hum Pathol. 2016;49:27–32.

8 Liver in Wilson Disease Kay Washington, MD, PhD

Incidence and Demographics  125 Clinical Manifestations  126 Radiologic Features  126 Pathology 126 Gross Pathology  126 Microscopic Features  127 Grading and Staging  129 Ancillary Diagnostic Studies  129 Differential Diagnosis  129 Other Disorders of Hepatic Copper Accumulation  130 Genetics 130 Treatment and Prognosis  130

Abbreviations ALT alanine aminotransferase AMA antimitochondrial antibody ANA antinuclear antibody AST aspartase aminotransferase FDA Federal Drug Administration HAV hepatitis A virus HBV hepatitis B virus HCV hepatitis C virus ICC Indian childhood cirrhosis PCR polymerase chain reaction SMA smooth muscle antibody

Wilson disease is an autosomal recessive inherited disorder of copper transport that leads to toxic accumulation of copper in the liver, with subsequent release of hepatic copper and deposition in other sites such as the brain. Phenotypically, Wilson disease is highly variable but is clinically characterized primarily by hepatic disease and neurologic symptoms. Although recognized as a distinct entity as early as 1912 because of the association of cirrhosis and degeneration of the basal

ganglia, Wilson disease was diagnosed solely on clinical grounds until 1952 when the distinctive combination of low serum ceruloplasmin and increased urinary copper was noted. The underlying defect is the absence or dysfunction of a copper-transporting ATPase, ATP7B, localized primarily in vesicles of the trans-Golgi network in the canalicular area of the hepatocyte.1 The ATP7B protein is primarily expressed in liver, kidney, and placenta, and is related to a similar protein, ATP7A, that is more widely expressed and is mutated in Menkes disease, an X-linked disorder manifested by copper deficiency. Copper is a cofactor in a number of critical enzymatic pathways necessary for cellular respiration, iron homeostasis, pigment formation, antioxidant defense, and connective tissue biosynthesis. Specific metabolic pathways have evolved to handle copper in biologic systems because of its extreme reactivity, and homeostasis is highly regulated by gastrointestinal absorption and excretion. The healthy adult human maintains total body copper stores of approximately 100 mg. An average daily diet contains 5 mg copper; a large percentage is absorbed in stomach and duodenum; newly absorbed copper is rapidly cleared by the liver, the main organ regulating copper homeostasis, which regulates storage and excretion into bile. There is no enterohepatic circulation, and copper excreted into bile is not reabsorbed. ATP7B transfers copper from the cytosol of the hepatocyte into the lumen of the trans-Golgi network, where it is incorporated into copper-dependent enzymes. As the copper concentration within the hepatocyte increases, ATP7B moves from the trans-Golgi network to the canalicular pole of the cell, where it sequesters copper into cytoplasmic vesicles. Copper is discharged at the cell membrane into the bile canaliculus and subsequent drop in cytosolic copper concentration triggers movement of the ATP7B protein moves back to the transGolgi network.2 The liver also synthesizes and secretes ceruloplasmin, a ferroxidase that plays an essential role in iron homeostasis and also serves as the principal protein involved in copper transport in blood. Approximately 95% of circulating plasma copper is bound to ceruloplasmin, which, however, plays no role in copper excretion into bile.

Incidence and Demographics Wilson disease has a worldwide distribution and occurs in all ethnic groups. The carrier rate is roughly 1 in 90.3 The calculated frequency of two mutant alleles is 1 in 7026,4 much higher than the disease frequency in most populations of around 1 in 30,000. In a few areas such 125

Practical Hepatic Pathology: A Diagnostic Approach as Sardinia where the incidence of clinical disease is as high as 1 in 10,000,5 a founder effect may be detected by the presence of mutation unique to the population.6

Clinical Manifestations Presentation in Wilson disease is classified as hepatic or neurologic (Table 8.1). Wilson disease usually presents in children with liver involvement manifested by asymptomatic elevation of serum transaminases, chronic hepatitis and cirrhosis, or acute liver failure.7 The average age in patients with hepatic presentation is 10 to 13 years, although individuals have presented with liver disease in the sixth decade or later; the neurologic presentation is later by about 10 years. The oldest described patients to date were in their seventies at presentation.8,9 Neuropsychiatric problems are common in adults and include dystonia, tremor, personality changes, and cognitive impairment; the underlying changes in the basal ganglia due to copper deposition include cavitary degeneration, gliosis, and neuronal loss. The reason for preferential deposition of copper in the basal ganglia with relative sparing of the motor and sensory cortex is unknown. Although the disease has been considered to be fatal by age 30 if untreated, the identification of older patients with Wilson disease indicates that the disease spectrum may be wider than previously appreciated. Wilson disease may also present as fulminant hepatic failure accompanied by antibody-negative hemolytic anemia because of sudden release of excess copper from necrotic hepatocytes. This fulminant presentation is more common in women by a ratio of 4 to 1. Ceruloplasmin levels are unreliable in the setting of acute liver failure, but if the alkaline phosphatase/total bilirubin ratio is greater than 4 along Table 8.1  Clinical and Genetic Features of Wilson Disease Finding Liver abnormalities

• Increased AST or ALT levels, especially in those younger than 40 yr, with chronic hepatitis pattern of injury progressing to cirrhosis • Fulminant hepatic failure with hemolytic anemia

Neurologic abnormalities

• N  eurologic abnormalities, behavioral, or psychiatric problems, with or without associated liver disease • Kayser-Fleisher rings are present in almost all patients with neurologic disease

Demographics

• D  iagnosed in all age groups, but most commonly presents in first through fourth decade of life • All ethnic groups

Genetics

• • • • •

Treatment

 utosomal recessive A 1:30,000 disease prevalence Mutation in ATP7B copper transport gene Over 600 mutations have been described Most patients are compound heterozygotes

with AST:ALT ratio less than 2.2, then Wilson disease is considered highly likely.10 ATP7B genotypes resulting in truncated protein may be more likely to produce fulminant hepatic failure.11 Kayser-Fleisher rings due to deposition of copper in Descemet’s membrane are found in 50% to 60% of patients with clinically apparent liver disease in most populations; however, they may be absent in young patients.12 Virtually all patients with neurologic manifestations will have Kayser-Fleisher rings, which are an indication that hepatic necrosis has released free copper into the circulation. Endocrine, renal, cardiac, and skeletal abnormalities may be found in up to 10% of patients with Wilson disease,13 and are manifested by findings such as hypoparathyroidism, infertility, nephrolithiasis, cardiomyopathy, and arthritis. The diagnosis of Wilson disease depends on multiple factors and no single test is diagnostic. In patients with unexplained liver disease, the combination of Kayser-Fleischer rings, serum ceruloplasmin less than 20 mg/dL, and 24-hour urine copper greater than 100 μg is considered diagnostic of Wilson disease14 (Table 8.2). However, urinary copper excretion may be less than 100 μg over 24 hours in 16% to 23% of patients with Wilson disease, and greater than 40 μg over 24 hours may be a better threshold for diagnosis.14 If one of these criteria is not met, liver biopsy is indicated for histology and copper quantification. If the liver contains 250 or less μg copper per gram of dry weight, molecular testing may be needed for establishment of diagnosis. Ceruloplasmin is low because the copper-free form released from hepatocytes in Wilson disease is rapidly degraded. However, the protein is an acute phase reactant and may be normal in 5% of affected patients; the positive predictive value of a low ceruloplasmin is only 6%. Notably, ceruloplasmin is normally low in newborns, making it an unreliable test for newborn screening of Wilson disease. Serum copper in Wilson disease is usually low because of low ceruloplasmin levels, but is unreliable as a diagnostic test. Urinary copper is elevated, often greater than 100 μg over 24 hours, and is very helpful in the diagnosis of Wilson disease. However, high levels can be seen in biliary disease or in autoimmune hepatitis, and clinical correlation is required. Testing urinary copper excretion after penicillamine challenge may be informative15 in adults but may not be useful in young children with mild liver disease.16

Radiologic Features Radiographic findings in Wilson disease are related to disease stage; irregular contours on computed tomography and parenchymal heterogeneity on ultrasound are common findings. Small, hypointense nodules on T2-weighted magnetic resonance imaging have also been described.17

Pathology

Gross Pathology

• d-Penicillamine and other copper chelation therapies • Avoidance of foods with high copper content • Zinc maintenance therapy interferes with copper absorption

ALT, Alanine aminotransferase; AST, aspartase aminotransferase.

The liver in affected cases has no distinguishing features on gross examination to suggest Wilson disease. The accumulation of hepatic copper does not result in discernible changes in coloration, and neither the macronodular cirrhosis seen in late-stage disease (Fig. 8.1) nor the

Table 8.2  Key Laboratory and Clinical Findings in Wilson Disease

126

Test

Value

Reference Values

Comments

24-hour urinary copper level

>100 µg/day (symptomatic patients)

3–50 µg/day

May be increased with penicillamine challenge test; latter not reliable in young children

Hepatic copper content

>250 µg/g dry weight

twice normal size)

2

Lobular inflammation (Overall assessment of all inflammatory foci)

0 1 2

Fibrosis score (F)

0-4

Fibrosis

0 1a

None 2 foci/20x field

None Mild, zone 3 perisinusoidal/ pericellular fibrosis (requires collagen stain to identify) Moderate, zone 3 perisinusoidal/ pericellular fibrosis Portal/periportal fibrosis Perisinusoidal/pericellular and portal/ periportal Bridging fibrosis Cirrhosis

1b 1c 2 3 4

Table 12.6  Diagnostic Algorithm for NASH Based on Steatosis, Activity, and Fibrosis Scores91 Steatosis →

Ballooning →

Lob, inflammation→ Diagnosis

Grade 1, 2, 3

0

0 1 2

Steatosis Steatosis Steatosis

1

0 1 2

Steatosis NASH NASH

NASH, Nonalcoholic steatohepatitis.

Although investigated in more detail for chronic hepatitis C,140,141 DIA could also evolve into a useful tool for the assessment of some features of NAFLD. For example, DIA has been used to objectivate erroneous estimation of the extent of steatosis by conventional histology.81,142 In addition, the use of guideline images of histologic features that have been quantified by DIA could also be a valuable asset to reduce interobserver bias.82 Current scoring systems are solely based on H&E histology to allow for easy translation and application in routine practice. However, the implementation of immunohistochemical markers like those for hepatocellular ballooning (see earlier) could also help to improve the interobserver variation and accuracy of semiquantitative scorings and histopathologic diagnosis, which might be particularly beneficial for clinical trials. In all histopathologic evaluation, adequate biopsy material is a prerequisite to obtain reliable results. In this respect, the size, both length and width of the biopsy core and area of the tissue sampling,

Nonalcoholic Fatty Liver Disease is important. A biopsy length of at least 1.5 cm taken with a 16-gauge or wider needle is considered appropriate.143-145 The biopsy should be taken preferably from the right lobe of the liver because of anatomic differences between the lobes. In the left lobe the potential for fibrosis is greater because of larger portal structures near the Glisson capsule and a higher capsule to parenchyma ratio as compared with the right lobe. However, conflicting findings have also been reported.146,147 Furthermore, as the morphologic hallmarks of NALFLD/NASH are not expressed homogeneously in the liver, sampling variability is another parameter affecting the accuracy of histologic evaluation.144 Also in this respect the availability of a sample of sufficient size is very important.

Table 12.7  Comparison of Histologic Features in Noncirrhotic Nonalcoholic Fatty Liver Disease and Alcoholic Liver Disease.94,152 Histological feature

ALD

NAFLD

Accentuation of liver injury in centrilobular region Steatosis Ballooning Lobular inflammation Pericellular fibrosis Few small Mallory-Denk bodies Many large Mallory-Denk bodies

+ + + + + + May occur

+ + + + + + Not common

Portal inflammation Chronic Acute

+/− May occur

+/− Not reported

Alcoholic Liver Disease

Satellitosis

More common

Not common

ALD and NAFLD are highly prevalent in many populations worldwide. Both conditions, although related to different causes,73,148 show a broadly overlapping spectrum of changes of liver injury that prevents an etiology-related morphologic diagnosis in many patients. Therefore, clinical information including metabolic parameters and anamnestic information on alcohol consumption is required to differentiate between alcoholic and nonalcoholic causes of FLD. As mentioned, there is no universally accepted threshold of the amount of alcohol consumed that would definitively link liver disease to alcohol. However, a patient is not considered eligible for participation in clinical studies if alcohol consumption exceeds 21 or 14 drinks per week over a period of 2 years for men and women, respectively.84 In clinical practice it is not unusual to identify alcohol and insulin resistance as causes of liver injury together in a patient. The effects of both conditions are thought to synergistically aggravate liver injury.149-151 In general, histologic liver disease is milder in NAFLD as compared with ALD. Although the spectrum of morphologic lesions of ALD and NAFLD is overlapping,73 several histologic changes have been described as ALD-related rather than NAFLD-related (see Chapter 24). These include obliterative lesions of the central veins (see eSlide 24.4), canalicular cholestasis, alcoholic foamy degeneration, and marked portal and lobular infiltration by neutrophilic granulocytes as well as marked ductular reaction (see eSlide 24.1) and cholangiolitis.152 Other features, like ballooned hepatocytes surrounded by neutrophilic granulocytes (satellitosis), many large MDBs, or canalicular cholestasis, are rarely seen in NAFLD (Table 12.7). On clinical grounds, patients with ALD/ASH usually have consumed significant amounts of alcohol over several years. They frequently present with advanced fibrosis or cirrhosis and symptoms of alcoholic hepatitis with jaundice, liver failure, fever, and ascites at the time of diagnosis,153,154 whereas patients with NAFLD/NASH are often either asymptomatic or have only mild and unspecific complaints.

Cholestasis (bilirubinostasis)

May occur

Not common

Dense pericellular fibrosis, bridging fibrosis

May occur

Not common

Sclerosing hyaline necrosis

May occur

Not reported

Fibrous obliteration of hepatic veins

May occur

Not reported

Alcoholic microvesicular steatosis (Alcoholic foamy degeneration)

May occur

Not reported

Differential Diagnosis

Nonalcoholic Fatty Liver Disease with Concurrent Liver Disease Given the high prevalence of NAFLD in many populations, it is not unusual to find its hallmarks combined together with features of other liver diseases95,155-157 such as CHC (discussed earlier), chronic hepatitis B (CHB),158-160 human immunodeficiency virus (HIV) infection,161 autoimmune hepatitis,55,162 biliary diseases120,163 or metabolic liver disease.119 The morphologic features, in particular of NASH, centrilobular accentuation of steatosis, hepatocellular ballooning accompanied by MDBs and pericellular fibrosis are distinct from the morphologic changes of most other chronic liver diseases.95 It is important to recognize and also report NAFLD in these settings because concurrent NAFL or NASH probably aggravates liver disease.119,158,159,156,161 The possibility that

12

ALD, Alcoholic liver disease; NAFLD, nonalcoholic fatty liver disease.

a certain liver disease causes de novo steatosis or steatohepatitis unrelated to insulin resistance like in ALD, CHC, or drug-induced liver injury has to be taken into account as well. Appropriate clinical information is required to delineate the cause(s) of liver disease in such cases.164,165

Nonalcoholic Fatty Liver Disease Outside the Context of Metabolic Syndrome Although the term NAFLD has been mostly used for liver disease in the setting of metabolic syndrome and absence of significant consumption of alcohol, fatty liver and steatohepatitis also occur in people with normal weight39,166 and in the absence of the commonly associated risk factors. In such cases, secondary causes of NAFLD should also be considered (see Table 12.1), which include drugs, disorders of lipid metabolism, nutritional causes, hepatitis C virus infection (eSlide 15.1), Wilson disease (see eSlides 8.1 and 8.2), environmental toxicity, and celiac disease.167

Drug-Induced Fatty Liver Disease It is sometimes difficult to differentiate drug-induced steatosis from that associated with alcohol or the metabolic syndrome. In fact, several conditions may be present simultaneously and contribute to steatosis. In addition, altered expression of hepatic transporters and metabolic enzymes in fatty liver may also affect drug metabolism.168 However, this issue has not been addressed by many studies. Drug-induced steatosis169 may manifest as macrovesicular and mediovesicular as well as microvesicular steatosis (see eSlide 23.9). Macrovesicular steatosis is thought to result from altered lipid trafficking in the liver or from drug deposition and excess accumulation of intracellular triglycerides. It is frequently reversible and mostly associated with a benign, nonprogressive course. However, in some patients, macrovesicular steatosis may evolve into steatohepatitis with fibrosis and eventually progress to cirrhosis.170 In contrast, microvesicular steatosis is associated with mitochondrial dysfunction and inhibition of fatty acid beta-oxidation.169,171 Microvesicular steatosis can be a life-threatening condition in severe cases. Mild forms have a good short-term prognosis but can progress to steatohepatitis.170,172 Some drugs can induce both macrovesicular and microvesicular 179

Practical Hepatic Pathology: A Diagnostic Approach Table 12.8  Drugs and Herbals Associated with Steatosis in Human or Experimental Models169,177 Macrovesicular steatosis

Microvesicular steatosis

Mixed macrovesicular and microvesicular steatosis

Estrogen Tamoxifen

5-Fluoruracil Diltiazem Glucocorticoids Hypervitaminosis A Interferon Margosa oil NSAIDs Tetracycline (intravenous) Valproic acid

Amiodarone Didanosine Methotrexate Stavudine Zidovudine

NSAIDs, Nonsteroidal antiinflammatory drugs.

Box 12.3  Drugs That Can Cause Steatohepatitis178 Amiodarone (see eSlide 12.3) Perhexiline Tamoxifen Irinotecan (see eSlide 12.4) Oxaliplatin Methotrexate Valproic acid Tetracycline

forms of fatty change (Table 12.8). Risk factors for NAFLD, obesity, and/or the metabolic syndrome increase the risk to develop hepatic steatosis with tamoxifen, nifedipine, or methotrexate treatment.166,173 Reye syndrome is a very rare but severe and often fatal condition characterized by the combination of liver disease and noninflammatory encephalopathy. In hepatocytes, microvesicular steatosis and abnormal ultrastructure of mitochondria are found.174,175 Disturbance of mitochondrial metabolism presumably triggered by an abnormal response to a viral infection and/or an exogenous toxin or drug such as acetylsalicylic acid is thought to underlie the pathogenesis of metabolic failure in the liver and other organs.174 Therefore it has been suggested that Reye syndrome be considered a nonspecific descriptive term for a heterogeneous group of disorders that may be caused not only by acetylsalicylic acid but also by other substances or conditions.174,176 Although a large number of drugs may cause fatty liver (see Table 12.7),177 only few are known to induce steatohepatitis178 (Box 12.3). One of the most important pathogenetic mechanisms seems to be mediated by toxic effects of the drugs on hepatocellular mitochondria, leading to mitochondrial dysfunction due to inhibition of beta-oxidation, mitochondrial respiration, and/or oxidative phosphorylation. The majority of drugs capable of inducing steatohepatitis have cationic amphiphilic structures. Drug-induced steatohepatitis is estimated to account for approximately 2% of all cases of NASH.179 The observation that chemotherapeutic agents like tamoxifen, raloxifene, irinotecan (eSlide 12.4) and methotrexate can cause steatohepatitis has promoted use of the term chemotherapy associated steatohepatitis (CASH)180-182 (Fig. 12.20). This form of liver injury has the potential to progress to cirrhosis and portal hypertension.183 CASH induced by irinotecan used for the treatment of liver metastases from colorectal cancer has been associated with adverse prognosis,181,184 in particular in patients with preexisting liver damage.184 However, this association has not been found in all studies.185 Moreover, in certain clinical settings such as metastatic liver disease, cytostatic therapy may be continued despite the development of hepatic steatosis. In such cases, patients should be monitored for progression of liver damage.169 The pattern of drug-related fatty liver usually resembles the morphologic pattern seen in metabolic-syndrome associated NAFLD with 180

100 µm FIGURE 12.20  Severe steatohepatitis with groups of ballooned hepatocytes and inflammation after treatment of metastatic colon cancer with irinotecan (also see eSlide 12.4).

predominance of lesions in centrilobular areas. However, variant patterns may be associated with some agents. For instance, phosphorus leads to fatty change predominantly in periportal hepatocytes. Hepatocellular ballooning may also occur in periportal instead of centrilobular portions in amiodarone-related steatohepatitis (see eSlide 12.3). Moreover, other drug-related morphologic changes, such as phospholipidosis or venoocclusive disease, may be additionally seen.186 Phospholipidosis represents a particular form of lipid accumulation in lysosomes of hepatocytes. It is associated with compounds that have basic and hydrophobic chemical properties (amphiphilic cations). Phospholipidosis causes cellular enlargement, foamy or granular change of the cytoplasm of hepatocytes or Kupffer cells resembling features of inborn disorders of lipid metabolism. The accumulated phospholipids appear as stacks of lamellae or crystalloid bodies187 on electron microscopy. Drugs associated with steatohepatitis are often also associated with phospholipidosis.169

Abnormalities of Lipid Metabolism A number of rare disorders of lipid metabolism, including abetalipoproteinemia, hypobetalipoproteinemia, familial combined hyperlipidemia, glycogen storage disease, and Weber-Christian disease are associated with NAFLD. In abetalipoproteinemia and hypobetalipoproteinemia the synthesis of very low-density lipoprotein (VLDL) particles is impaired. This leads to an accumulation of triglycerides in the liver and to macrovesicular steatosis. Both defects are associated with fat malabsorption from the intestine, hypolipoproteinemia, and neurologic abnormalities. Symptoms improve with a fat-restricted diet and supplementation of fat-soluble vitamins.188,189 Familial combined hyperlipidemia is an autosomal dominant lipid disorder related to an overproduction of apoB-100, enhanced VLDL synthesis, and hepatic steatosis in 75% of patients.167,190 Weber-Christian disease is a rare autoimmune disease of subcutaneous adipose tissue of unknown etiology associated with chronic and recurrent organ disease characterized by the formation of painful nonsuppurative dense nodules in subcutaneous fat, which are accompanied by episodic temperature changes, chills, and muscular pain. Sometimes the visceral organs can be involved. In the liver, frequent findings are macrovesicular steatosis, eventually also features of steatohepatitis with MDBs, lobular polymorphonuclear leukocyte infiltration, and perivenular and pericellular fibrosis.191,192

Nonalcoholic Fatty Liver Disease Among the 12 major forms of glycogen storage diseases (GSD) the types 0, I, III, VI, and IX are most frequently associated with features of fatty liver disease. On histology, glycogenosis or steatosis or mixed patterns of these changes are seen. In some types (GSD type I, III, and VI), hepatic adenomas with increased risk of malignant transformation may occur. In types III and IX fibrosis is also a feature that can progress to cirrhosis. Hypoglycemia and hepatomegaly are the cardinal clinical symptoms of GSD affecting the liver.167,193,194 Lipodystrophies are a heterogeneous group of rare disorders with total or partial loss of fat in association with severe lipid and glucose metabolic abnormalities leading to diabetes and cardiovascular as well as hepatic complications. Many of the genetic abnormalities underlying lipodystrophy have been unraveled.195,196 However, the most common forms of lipodystrophies are iatrogenic and related to treatment of immunodeficiency virus-infected patients with antiretroviral drugs. Partial lipodystrophy can also occur in patients who have been exposed to long-term endogenous or exogenous corticoid excess.197 The inability of adipose tissue to properly store triglycerides may result in impaired insulin sensitivity. Decreased insulin sensitivity is related to altered secretion of adipokines, cytokines, and free fatty acids with effects on liver, muscle, heart, and vessels.198 In the liver, steatosis can progress to NASH and cirrhosis.167

Nutritional Causes

Total Parenteral Nutrition In long-term total parenteral nutrition (TPN), intravenous administration of calories and/or glucose causes a depletion of carnitine, which mediates the transfer of free fatty acids in the cytoplasm to the mitochondria for beta-oxidation. In addition, the reduction of cytosolic choline involved in lipoprotein secretion further enhances the accumulation of lipid in the cytoplasm of hepatocytes.167,199 Histologic findings differ with respect to duration of treatment and age. In infants, biliary features including canalicular cholestasis (bilirubinostasis), cholestatic rosettes, and in later stages of the disease, ductular reaction and bile plugs predominate but steatosis is uncommon (see eSlides 3.6 and 3.7). In adults, portal and periportal fibrosis associated with inflammatory infiltrates, macrovesicular steatosis that may be predominantly periportal, and perivenular canalicular cholestasis develop (eSlide 3.5). In some, steatohepatitis and progression to cirrhosis may occur.200,201 However, the manifestation of liver injury may be significantly influenced by the type of lipid infused.202 Starvation and Dietary Effects Severe starvation is associated with a number of changes that can cause hepatocellular lipid accumulation. Protein deficiency causes decreased synthesis of apolipoproteins and VLDL as well as VLDL-mediated export of triglycerides from hepatocytes.203,204 Weight loss and physical activity represent the treatments of choice for metabolic syndrome– associated NAFLD. There is little doubt that controlled weight loss is beneficial. However, not all diets can be recommended. For instance, very low carbohydrate, high fat diets or diets rich in unsaturated fatty acids and refined carbohydrates (eg, like those in soft drinks) may aggravate insulin resistance and NAFLD.205 Celiac Disease Celiac disease (CD) can coexist with a number of liver diseases, mostly of the autoimmune spectrum including autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. The morphologic features of these conditions are not different between CD and non-CD patients. CD has also been associated with NAFL or NASH. NAFLD seems to occur less frequently in CD patients than autoimmune liver diseases and in most CD cases only unspecific morphologic

12

100 µm FIGURE 12.21  Portal based fibrosis and inflammation as well as interphase activity. The hepatic parenchyma shows macrovesicular fatty change in a patient with chronic hepatitis C (see also eSlide 12.5).

findings are observed in the liver.207 The pathomechanisms underlying hepatic injury in CD are not well defined and with respect to NAFLD it has also been hypothesized that these conditions may not be causally related.208 Clinically, patients may present with unexplained hypertransaminasemia.207

Chronic Liver Diseases

Hepatitis C Virus Infection Chronic infection with hepatitis C virus (HCV) is more frequently associated with NAFL than NASH.95 Morphologic features of chronic hepatitis C (CHC) and NAFLD are present: Interphase activity and various degrees of portal-based fibrosis as well as the hallmarks of NAFL or NASH with centrilobular predominance of steatosis, liver injury, inflammation, and pericellular fibrosis can be observed in the same specimen (eSlide 12.5). Steatosis may be found in up to 40% to 86 % of HCV-infected cases209 (Fig. 12.21). In many instances, this is related to the concurrent effects of the metabolic syndrome or its components and HCV infection. Furthermore, recent data suggest that insulin resistance can also be enhanced by viral infection.158 However, other causes for fatty liver such as certain drugs (discussed earlier) and alcohol also have to be considered in CHC patients. A significant proportion of CHC patients without classical risk factors for NAFLD have fatty liver,210,211 which has been attributed to effects related to infection with HCV genotype 3. In this setting, fatty change is usually more severe than in patients with nongenotype 3 infection. Steatosis seems to be caused by a direct cytopathic effect of the virus affecting hepatocellular lipid metabolism212,213 and may be associated with more severe fibrosis than in nongenotype 3 infected patients.214 Because the morphologic features of steatohepatitis, in particular hepatocellular ballooning, in combination with MDBs and centrilobular-based pericellular fibrosis are distinct, the diagnosis of NASH in CHC as well as in most other liver diseases is reliably achieved by histology, provided that an alcoholic cause can be excluded on clinical grounds. NASH is preferentially found in CHC patients with severe steatosis, and in genotype 3 infection.215 Manifestations of NAFL and NASH in CHC215 has been shown to be associated with higher fibrosis stage, impaired treatment response to interferon and ribavirin and increased risk of HCC.216,159 Currently it is not clear whether fatty change and/or NASH also affect the efficacy of newer protease-inhibitor based antiviral therapies.7 In contrast to CHC, presence of NAFLD 181

Practical Hepatic Pathology: A Diagnostic Approach in patients with chronic hepatitis B is not related to increased fibrosis risk and progression of liver disease.158,207 Wilson Disease Wilson disease (WD) is an inherited autosomal recessive disorder of copper metabolism with defective excretion of copper into the bile and accumulation of copper in particular in liver and brain.217-219 The underlying pathologic mechanisms of tissue injury are not entirely known. However oxidative stress due to redox activity and prooxidant effects of copper seems to be a major factor in the pathogenesis. Accumulation of copper is related to inactivating mutations of the ATP7B gene, which encodes a copper transporting ATPase responsible for excretion of copper into the biliary canalicules.221-223 The clinical presentation is typically between ages 5 and 35 with either hepatic or neurologic disease.217 Liver disease in WD may be very variable. Most frequent hepatic manifestations bear resemblance with chronic (autoimmune) hepatitis or NAFLD/NASH.224 Liver injury often leads to fibrosis and progression of liver disease. Cirrhosis is present in many patients by the end of the second decade. In precirrhotic stages, steatosis, which can be macrovesicular and microvesicular; glycogenated nuclei in periportal hepatocytes; focal hepatocellular necrosis; and apoptotic bodies may be seen (see eSlide 8.1).217,224,225 With time features of chronic hepatitis with chronic portal inflammation and interphase hepatitis as well as portal based fibrosis and septa,226-228 or morphologic changes of steatohepatitis prevail. However, in contrast to NASH in adults and type 1 NAFLD in children, hepatocellular ballooning and MDBs are predominantly found in a periportal and periseptal rather than centrilobular distribution in the lobulus in the precirrhotic stage.90,229 In the cirrhotic stage of WD all the histologic changes as described for the precirrhotic change may also be seen (see eSlide 8.2). In addition, accumulated copper in lysosomes can be detected by appropriate histochemical stains, whereas these stains are usually not sensitive enough to indicate increased copper stores diffusely distributed in the cytoplasm in the precirrhotic stages.230,231 Because the copper binding and iron exporter apoceruloplasmin is decreased, iron stores may also be increased in WD.232 WD should be considered in differential diagnosis in particular in young patients with histologic features of NAFLD in whom risk factors for NAFLD have been excluded224 and in all patients with features of autoimmune hepatitis who do not sufficiently respond to treatment with corticosteroids.227,228 However, as in other settings, because of the high prevalence of NAFLD, co-occurrence of WD and NAFLD or AIH cannot be completely excluded. On morphologic grounds, the differential diagnosis of WD with pediatric type 2 NAFLD can be challenging.

Ancillary Diagnostic Tests Histologic evaluation is still considered to be the gold standard for diagnosis of NASH. However, the use of liver biopsy as a diagnostic tool is not ideal because, apart from logistic and economic considerations, it is an invasive procedure associated with a small but definite risk of morbidity and mortality. Over recent years, noninvasive methods for the discrimination of NAFL and NASH have been accumulating in a continuously growing list of novel NASH biomarkers as well as clinical models with variable accuracy for the diagnosis of NASH. Lack of external validation, standardized definitions of cut-offs and availability are currently among the most important limitations for their use as stand-alone tests in clinical practice.233 A number of scores234,235 such as the NAFLD fibrosis score, the FIB-4 index, and radiologic methods, in particular transient elastography (TE) have been developed for the noninvasive assessment of fibrosis stage. These methods are now widely available in clinical practice. They have been evaluated in different cohorts of NAFLD patients and 182

may be used to reliably exclude lower fibrosis stages.68,236 Unfortunately, noninvasive methods for diagnosing progressed NAFLD with fibrosis in children have not been fully evaluated for application in routine practice.237 Noninvasive markers may finally lead to a change in the role of liver biopsy. However, currently it is still the definitive investigation for diagnosis of NAFLD. Liver histology provides comprehensive information in a single evaluation: Reliable classification of NAFLD types (NAFL, NASH, fibrosis/cirrhosis) or exclusion of NAFLD, iron storage, histologic prognostic markers, and diagnosis of concurrent liver diseases. Most expert guidelines recommend liver biopsy for NAFLD patients at high risk for NASH and/or advanced fibrosis 7,56,238 and in patients with suspected NAFLD in whom other causes of steatosis or chronic liver disease cannot be excluded on clinical grounds.50

Genetics NAFLD is considered a complex multifactorial disease trait related to environmental exposure in the setting of a susceptible polygenic background. These factors are thought to promote the development of progressive disease with NASH, fibrosis, cirrhosis, and eventually HCC in some patients.239-241 The influence of genetic background and a heritable component in the expression of NAFLD phenotype is supported by familial aggregation,242-244 results from twin studies,245 and interethnic differences in susceptibility.61,246-249 Recently, the patatin-like phospholipase domain 3 (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) genes besides a number of other genes have emerged as important genetic modifiers from genome-wide association studies using NAFLD patient cohorts that were either characterized by radiologic methods or histology or clinical chemistry.250 The single nucleotide polymorphism (SNP) in the PNPLA3 gene (rs738409 c.444C > G,p.I148M) identified in a genome-wide association (GWA) study in a North American population with different ethnicities (Hispanic, African American, and European ancestry) is a nonsynonymous cytosine to guanine nucleotide transversion mutation resulting in an isoleucine to methionine change at codon 148. Homozygous carriage of the I148M allele is associated with a two-fold increase in hepatic triglyceride content as measured by proton magnetic resonance spectroscopy (H-MRS).251 Furthermore, PNPLA3 I148M seems to be also related to elevated ALT levels.252 The I148M allele is more common in Hispanics compared with people of European descent and it is less frequent in African Americans. In one of the largest GWA studies on NAFLD published to date, other SNPs in the PNPLA3, glucokinase regulator (GCKR), lysophospholipase-like 1 (LYPLAL1), and neurocan (NCAN) genes located at the 19p13.11 chromosomal region were identified and validated for histologic steatosis, lobular inflammation, and fibrosis.253 The SNP in the PNPLA3 gene, rs738408 described in this study is in strong linkage disequilibrium to rs738409 identified earlier.251 In addition, the nonsynonymous genetic variant within the transmembrane 6 superfamily member 2 (TM6SF2), also situated at the 19p13.11 locus was found. Homozygosity for the TM6SF2 rs58542926 minor (T) allele is correlated with elevated H-MRS-measured hepatic triglyceride content.254 The association of the PNPLA3 and the TM6SF genes to a steatosis phenotype was also recently confirmed in other studies.255-258 The PNPLA3 I148M variant (rs738409) is correlated with severity of steatohepatitis, fibrosis stage,259-261 response to dietary or lifestyle interventions,262 and risk of HCC264-266 also in patients with ALD.267-270 The PNPLA3 gene encodes a protein that is structurally related to adipose triglyceride lipase PNPLA2. The physiologic role of PNPLA3 and in particular the I148M polymorphism is only partly understood. From mouse as well as human studies it was concluded that PNPLA3 is involved in the remodeling of triglycerides in lipid

Nonalcoholic Fatty Liver Disease droplets when they accumulate in response to feeding. Modification by the I148 M variant may sensitize the liver to metabolic stress resulting from calorific excess and adiposity.250 Further studies are needed to better understand the role of PNPLA3 and the I148 M variant in the pathogenesis of steatohepatitis, hepatic fibrosis and HCC. The TM6SF2 gene encodes a multipass membrane protein of poorly-defined function.271 The TM6SF2 protein may act as a lipid transporter.272 It is located in endoplasmic reticulum and ER-Golgi intermediate compartments and mediates the export of triglyceriderich lipoproteins like VLDL and APOB.273 The minor (T) allele of TM6SF2 rs58542926 (167K) has been shown to be related to NAFLD, advanced fibrosis, and liver-related complications, whereas the major (G) allele is associated with dyslipidemia and risk of cardiovascular complications rather than liver disease.258,274 On the basis of these correlations it has been hypothesized that TM6SF2 alleles may direct metabolic syndrome–related end organ damage via the protection of the liver at the expense of an increased cardiovascular risk or the other way around.250 In addition to these two major genetic modifiers a number of other genes have been identified as players involved in the pathogenesis and disease progression of NAFLD. Some of these include the mitochondrial superoxide dismutase 2 (SOD2),275,276 phosphatidylethanolamine N-methyltransferase (PEMT),277,278 fatty acid desaturase (FADS1),279 and Kruppel-like factor-6 (KLF6)280 genes.

Treatment and Prognosis The management of patients with NAFLD has to account for liver disease as well as metabolic comorbidities like adiposity, hyperlipidemia, insulin resistance, and type 2 diabetes mellitus or the metabolic syndrome. The comorbidities are also established risk factors for cardiovascular disease, which is the most common cause of death in patients with NAFLD. Notably, liver-related death occurs in less than 5% of patients with NAFLD. It represents the third most common cause of mortality after cardiovascular disease and extrahepatic malignancy.281 However, although NASH is a progressive condition, NAFL is considered nonprogressive.38,282 With respect to liver disease, NAFL has an excellent prognosis. There is broad consensus among experts that the treatment of choice and first-line option for patients with NAFLD is lifestyle change including weight loss, dietary measures, and regular physical exercise.50,283 However, recommendations on how to achieve the lifestyle changes vary among clinical guidelines.50 Weight loss should be at least in the range of 10% to effectively reduce necroinflammation.7 To achieve weight loss, a hypocaloric diet low in carbohydrate, industrial fructose, and saturated fat and high in fibers and antioxidant-rich fruit and vegetables is recommended. Alcohol consumption should be avoided.7,11,13,284 In addition, diet should be accompanied by physical activity of moderate to vigorous intensity13,284 and eventually behavior therapy.11,13,284 Bariatric surgery is considered an option for obese patients with NAFLD/NASH in most guidelines.50 Currently there is no generally approved pharmacologic treatment for NASH. However, most guidelines discuss the option of pharmacologic therapy in particular for patients with NASH.7,50 For example, the current European Association for the Study of the Liver (EASL) guidelines suggest a 1- to 2-year course of glitazones or vitamin E, preferably in combination with high-dose ursodeoxycholic acid (UDCA),13 whereas the American Association for the Study of the Liver (AASLD) guidelines propose pioglitazone and vitamin E in nondiabetic biopsy proven NASH.7 Modifiers of the gut microbiome, novel antifibrotic agents such as pentoxifylline and FXR agonists, and cannabinoid receptor antagonists are being studied and may allow for the development of new drugs and individualized patient management to prevent the progression of NAFLD in the future.285

With respect to cardiovascular disease there is consensus among experts that a thorough assessment of metabolic risk factors and risk stratification is recommended in all NAFLD patients and should be repeated at 6-month to 2-year intervals.11,13,284 Oncologic follow up may be discussed on an individual basis.50

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Suggested Readings Anstee QM, Day CP. The genetics of nonalcoholic fatty liver disease: spotlight on PNPLA3 and TM6SF2. Semin Liver Dis. 2015;35:270–290. Bedossa PFLIP. Pathology Consortium. Utility and appropriateness of the fatty liver inhibition of progression (FLIP) algorithm and steatosis, activity, and fibrosis (SAF) score in the evaluation of biopsies of nonalcoholic fatty liver disease. Hepatology. 2014;60:565–575. Bellentani S, Scaglioni F, Mariano M, et al. Epidemiology of non-alcoholic fatty liver disease. Dig Dis. 2010;28:155–161. Brunt EM. Nonalcoholic steatohepatitis: pathologic features and differential diagnosis. Semin. Diagn. Pathol. 2005;22:330–338. Burt AD, Lackner C, Tiniakos D. Diagnosis and assessment of NAFLD: definitions and histopathological classification. Semin Liver Dis. 2015;35:207–220. Kleiner DE, Brunt EM. Nonalcoholic fatty liver disease: pathologic patterns and biopsy evaluation in clinical research. Semin Liver Dis. 2012;32:3–13. Kleiner DE, Brunt EM, Van Natta M, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology. 2005;41:1313–1321. Matteoni CA, Younossi ZM, Gramlich T, et al. Nonalcoholic fatty liver disease: a spectrum of clinical and pathological severity. Gastroenterology. 1990;116:1413–1419.

References 1. Peters RL, Gay T, Reynolds TB. Post-jejunoileal-bypass hepatic disease. Its similarity to alcoholic hepatic disease. Am J Clin Pathol. 1975;63:318–331. 2. Lewis JH, Ranard RC, Caruso A, et al. Amiodarone hepatotoxicity: prevalence and clinicopathologic correlations among 104 patients. Hepatology. 1989;9:679–685. 3. Ludwig J, Viggiano TR, McGill DB, Oh BJ. Nonalcoholic steatohepatitis: Mayo Clinic experiences with a hitherto unnamed disease. Mayo Clin Proc. 1980;55:434–438. 4. Bellentani S, Scaglioni F, Mariano M, et al. Epidemiology of non-alcoholic fatty liver disease. Dig Dis. 2010;28:155–161. 5. Loomba R, Sanyal AJ. The global NAFLD epidemic. Nat Rev Gastroenterol Hepatol. 2013;10:686–690. 6. Nobili V, Svegliati-Baroni G, Alisi A, et al. A 360-degree overview of paediatric NAFLD: recent insights. J Hepatol. 2013;58:1218–1229. 7. Chalasani N, Younossi Z, Lavine JE, et al. The diagnosis and management of non-alcoholic fatty liver disease: practice guideline by the American Gastroenterological Association, American Association for the Study of Liver Diseases, and American College of Gastroenterology. Gastroenterology. 2012;142:1592–1609. 8. Tannapfel A, Denk H, Dienes HP, et al. Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease. Grade 2 consensus-based guidelines. Pathologe. 2010;31:225–237. 9. Sanyal AJ. AGA technical review on non-alcoholic fatty liver disease. Gastroenterology. 2002;123:1705–1725. 10. Farrell GC, Chitturi S, Lau GK, et al. Guidelines for the assessment and management of nonalcoholic fatty liver disease in the Asia–Pacific region: executive summary. J Gastroenterol Hepatol. 2007;22:775–777. 11. Loria P, Adinolfi LE, Bellentani S, et al. Practice guidelines for the diagnosis and management of nonalcoholic fatty liver disease. A decalogue from the Italian Association for the Study of the Liver (AISF) Expert Committee. Dig Liver Dis. 2010;42:272–282. 12. Farrell GC, Larter CZ. Nonalcoholic fatty liver disease: from steatosis to cirrhosis. Hepatology. 2006;43:99–112. 13. Ratziu V, Bellentani S, Cortez-Pinto H, et al. A position statement on NAFLD/NASH based on the EASL 2009 special conference. J Hepatol. 2010;53:372–384. 14. Brunt EM. Nonalcoholic steatohepatitis. Semin Liver Dis. 2004;24:3–20. 15. Bugianesi E, Leone N, Vanni E, et al. Expanding the natural history of nonalcoholic steatohepatitis: from cryptogenic cirrhosis to hepatocellular carcinoma. Gastroenterology. 2002;123:134–140. 16. Brunt EM. What’s in a name? Hepatology. 2009;50:663–667. 17. Khan AZ, Morris-Stiff G, Makuuchi M. Patterns of chemotherapy-induced hepatic injury and their implications for patients undergoing liver resection for colorectal liver metastases. J Hepatobiliary Pancreat Surg. 2009;16:137–144. 18. Loria P, Lonardo A, Carulli N. Should nonalcoholic fatty liver disease be renamed? Dig Dis. 2005;23:72–82. 19. Cave M, Falkner KC, Ray M, et al. Toxicant-associated steatohepatitis in vinyl chloride workers. Hepatology. 2010;51:474–481. 20. Burt AD, Lackner C, Tiniakos D. Diagnosis and assessment of NAFLD: definitions and histopathological classification. Semin Liver Di. 2015;35:207–220. 21. Brunt EM, Neuschwander-Tetri B, Burt A. Fatty liver disease: alcoholic and non-alcoholic. In: Burt A, Portmann B, Ferrell L, eds. MacSween´s pathology of the liver. 6th ed. Churchill Livingstone: Elsevier; 2012.

183

Practical Hepatic Pathology: A Diagnostic Approach 22. Musso G, Gambino R, Cassader M. Non-alcoholic fatty liver disease from pathogenesis to management: an update. Obes Rev. 2010;6:430–445. 23. Welsh JA, Karpen S, Vos MB. Increasing prevalence of nonalcoholic fatty liver disease among United States adolescents, 1988-1994 to 2007-2010. J Pediatr. 2013;162:496–500. 24. Eguchi Y, Hyogo H, Ono M, et al. Prevalence and associated metabolic factors of nonalcoholic fatty liver disease in the general population from 2009 to 2010 in Japan: a multicenter large retrospective study. J Gastroenterol. 2012;47:586–595. 25. Lazo M, Clark JM. The epidemiology of nonalcoholic fatty liver disease: a global perspective. Semin Liver Dis. 2008;28:339–350. 26. Browning JD, Szczepaniak LS, Dobbins R, et al. Prevalence of hepatic steatosis in an urban population in the United States: impact of ethnicity. Hepatology. 2004;40:1387–1395. 27. Das K, Das K, Mukherjee PS, et al. Nonobese population in a developing country has a high prevalence of nonalcoholic fatty liver and significant liver disease. Hepatology. 2010;51:1593–1602. 28. Bacon BR, Farahvash MJ, Janney CG, et al. Nonalcoholic steatohepatitis: an expanded clinical entity. Gastroenterology. 1994;107:1103–1109. 29. Powell EE, Cooksley WG, Hanson R, et al. The natural history of nonalcoholic steatohepatitis: a follow-up study of forty-two patients for up to 21 years. Hepatology. 1990;11:74–80. 30. Frith J, Day CP, Henderson E, Burt AD, et al. Non-alcoholic fatty liver disease in older people. Gerontology. 2009;55:607–613. 31. Chen ZW, Chen LY, Dai HL, et al. Relationship between alanine aminotransferase levels and metabolic syndrome in nonalcoholic fatty liver disease. Zhejiang Univ Sci B. 2008;9:616–622. 32. Hourigan SK, Torbenson M, Tibesar E, et al. The full spectrum of hepatic steatosis in children. Clin Pediatr (Phila). 2015;54:635–642. 33. Tazawa Y, Noguchi H, Nishinomiya F, et al. Effect of weight changes on serum transaminase activities in obese children. Acta Paediatr Jpn. 1997;39:210–214. 34. Rashid M, Roberts EA. Nonalcoholic steatohepatitis in children. J Pediatr Gastroenterol Nutr. 2000;30:48–53. 35. Molleston JP, Schwimmer JB, Yates KP, et al. Histological abnormalities in children with nonalcoholic fatty liver disease and normal or mildly elevated alanine aminotransferase levels. J Pediatr. 2014;164:707–713. 36. Yki-Järvinen H. Non-alcoholic fatty liver disease as a cause and a consequence of metabolic syndrome. Lancet Diabetes Endocrinol. 2014;2:901–910. 37. Torres DM, Harrison SA. Nonalcoholic fatty liver disease: fibrosis portends a worse prognosis. Hepatology. 2015;61:1462–1464. 38. Vernon G, Baranova A, Younossi ZM. Systematic review: the epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults. Aliment Pharmacol Ther. 2011;34:274–285. 39. Williams CD, Stengel J, Asike MI, et al. Prevalence of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis among a largely middle-aged population utilizing ultrasound and liver biopsy: a prospective study. Gastroenterology. 2011;140:124–131. 40. Angulo P. Nonalcoholic fatty liver disease. N Engl J Med. 2002;346:1221–1231. 41. Caldwell SH, Oelsner DH, Iezzoni JC, et al. Cryptogenic cirrhosis: clinical characterization and risk factors for underlying disease. Hepatology. 1999;29:664–669. 42. Ascha MS, Hanouneh IA, Lopez R, et al. The incidence and risk factors of hepatocellular carcinoma in patients with nonalcoholic steatohepatitis. Hepatology. 2010;51:1972–1978. 43. Ong JP, Pitts A, Younossi ZM. Increased overall mortality and liver-related mortality in nonalcoholic fatty liver disease. J Hepatol. 2008;49:608–612. 44. Bedogni G, Miglioni L, Masutti F, et al. Prevalence of and risk factors for nonalcoholic fatty liver disease: the Dionysos nutrition and liver study. Hepatology. 2005;42:44–52. 45. Ramesh S, Sanyal AJ. Evaluation and management of non-alcoholic steatohepatitis. J Hepatol. 2005;42(Suppl 1):S2–S12. 46. Newton JL, Jones DE, Henderson E, et al. Fatigue in non-alcoholic fatty liver disease (NAFLD) is significant and associates with inactivity and excessive daytime sleepiness but not with liver disease severity or insulin resistance. Gut. 2008;57:807–813. 47. Clark JM, Diehl AM. Defining nonalcoholic fatty liver disease: implications for epidemiologic studies. Gastroenterology. 2013;124:248–250. 48. Dietrich P, Hellerbrand C. Non-alcoholic fatty liver disease, obesity and the metabolic syndrome. Best Pract Res Clin Gastroenterol. 2014;28:637–653. 49. Matteoni CA, Younossi ZM, Gramlich T, et al. Nonalcoholic fatty liver disease: a spectrum of clinical and pathological severity. Gastroenterology. 1990;116:1413–1419. 50. Nascimbeni F, Pais R, Bellentani S, et al. From NAFLD in clinical practice to answers from guidelines. J Hepatol. 2013;59:859–871. 51. Angulo P, Keach JC, Batts KP, et al. Independent predictors of liver fibrosis in patients with nonalcoholic steatohepatitis. Hepatology. 1999;30:1356–1362. 52. Valenti L, Dongiovanni P, Fargion S. Diagnostic and therapeutic implications of the association between ferritin level and severity of nonalcoholic fatty liver disease. World J Gastroenterol. 2012;18:3782–3786. 53. Kowdley KV, Belt P, Wilson LA, et al. Serum ferritin is an independent predictor of histologic severity and advanced fibrosis in patients with nonalcoholic fatty liver disease. Hepatology. 2012;55:77–85. 54. Vuppalanchi R, Gould RJ, Wilson LA, et al. Clinical significance of serum autoantibodies in patients with NAFLD: results from the nonalcoholic steatohepatitis clinical research network. Hepatol Int. 2012;6:379–385. 55. Adams LA, Lindor KD, Angulo P. The prevalence of autoantibodies and autoimmune hepatitis in patients with nonalcoholic fatty liver disease. Am J Gastroenterol. 2004;99: 1316–1320.

184

56. Dyson JK, McPherson S, Anstee QM. Non-alcoholic fatty liver disease: non-invasive investigation and risk stratification. J Clin Pathol. 2013;66:1033–1045. 57. Lee SS, Park SH. Radiologic evaluation of nonalcoholic fatty liver disease. World J Gastroenterol. 2014;20:7392–7402. 58. Kim DY, Park SH, Lee SS, et al. Contrast-enhanced computed tomography for the diagnosis of fatty liver: prospective study with same-day biopsy used as the reference standard. Eur. Radiol. 2010;20:359–366. 59. van Werven JR, Marsman HA, Nederveen AJ, et al. Assessment of hepatic steatosis in patients undergoing liver resection: comparison of US, CT, T1-weighted dual-echo MR imaging, and point-resolved 1H MR spectroscopy. Radiology. 2010;256:159–168. 60. Lee SS, Park SH, Kim HJ, et al. Non-invasive assessment of hepatic steatosis: prospective comparison of the accuracy of imaging examinations. J Hepatol. 2010;52:579–585. 61. Szczepaniak LS, Nurenberg P, Leonard D, et al. Magnetic resonance spectroscopy to measure hepatic triglyceride content: prevalence of hepatic steatosis in the general population. Am J Physiol Endocrinol Metab. 2005;288:E462–E468. 62. Noureddin M, Lam J, Peterson MR, et al. Utility of magnetic resonance imaging versus histology for quantifying changes in liver fat in nonalcoholic fatty liver disease trials. Hepatology. 2013;58:1930–1940. 63. Ochi H, Hirooka M, Koizumi Y, et al. Real-time tissue elastography for evaluation of hepatic fibrosis and portal hypertension in nonalcoholic fatty liver diseases. Hepatology. 2012;56:1271–1278. 64. Nobili V, Vizzutti F, Arena U, et al. Accuracy and reproducibility of transient elastography for the diagnosis of fibrosis in pediatric nonalcoholic steatohepatitis. Hepatology. 2008;48:442–448. 65. Orlacchio A, Bolacchi F, Antonicoli M, et al. Liver elasticity in NASH patients evaluated with real-time elastography (RTE). Ultrasound Med Biol. 2012;38:537–544. 66. Palmeri ML, Wang MH, Rouze NC, et al. Noninvasive evaluation of hepatic fibrosis using acoustic radiation force-based shear stiffness in patients with nonalcoholic fatty liver disease. J Hepatol. 2011;55:666–672. 67. Lee SS, Park SH. Radiologic evaluation of nonalcoholic fatty liver disease. World J Gastroenterol. 2014;20:7392–7402. 68. Chen J, Talwalkar JA, Yin M, Glaser KJ, Sanderson SO, Ehman RL. Early detection of nonalcoholic steatohepatitis in patients with nonalcoholic fatty liver disease by using MR elastography. Radiology. 2011;259:749–756. 69. Burt AD, Mutton A, Day CP. Diagnosis and interpretation of steatosis and steatohepatitis. Semin Diagn Pathol. 1998;15:246–258. 70. Kleiner DE, Brunt EM, Van Natta M, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology. 2005;41:1313–1321. 71. Kleiner DE, Brunt EM. Nonalcoholic fatty liver disease: pathologic patterns and biopsy evaluation in clinical research. Semin Liver Dis. 2012;32:3–13. 72. Tandra S, Yeh MM, Brunt EM, et al. Presence and significance of microvesicular steatosis in nonalcoholic fatty liver disease. J Hepatol. 2011;55:654–659. 73. Yip WW, Burt AD. Alcoholic liver disease. Semin Diagn Pathol. 2006;23:149–160. 74. Smith K. Liver disease: Kupffer cells regulate the progression of ALD and NAFLD. Nat Rev Gastroenterol Hepatol. 2013;10:503. 75. Harmon RC, Tiniakos DG, Argo CK. Inflammation in nonalcoholic steatohepatitis. Expert Rev Gastroenterol Hepatol. 2011;5:189–200. 76. Wan J, Benkdane M, Teixeira-Clerc F, et al. M2 Kupffer cells promote M1 Kupffer cell apoptosis: a protective mechanism against alcoholic and nonalcoholic fatty liver disease. Hepatology. 2014;59:130–142. 77. Singhi AD, Jain D, Kakar S, et al. Reticulin loss in benign fatty liver: an important diagnostic pitfall when considering a diagnosis of hepatocellular carcinoma. Am J Surg Pathol. 2012;36:710–715. 78. Kotronen A, Yki-Järvinen H. Fatty liver: a novel component of the metabolic syndrome. Arterioscler Thromb Vasc Biol. 2008;28:27–38. 79. Chalasani N, Wilson L, Kleiner DE, et al. Relationship of steatosis grade and zonal location to histological features of steatohepatitis in adult patients with non-alcoholic fatty liver disease. J Hepatol. 2008;48:829–834. 80. El-Badry AM, Breitenstein S, Jochum W, et al. Assessment of hepatic steatosis by expert pathologists: the end of a gold standard. Ann Surg. 2009;250:691–697. 81. Hall AR, Dhillon AP, Green AC, et al. Hepatic steatosis estimated microscopically versus digital image analysis. Liver Int. 2013;33:926–935. 82. Hall AR, Green AC, Luong TV, et al. The use of guideline images to improve histological estimation of hepatic steatosis. Liver Int. 2014;34:1414–1427. 83. Neuschwander-Tetri BA1, Caldwell SH. Nonalcoholic steatohepatitis: summary of an AASLD Single Topic Conference. Hepatology. 2003;37:1202–1219. 84. Sanyal AJ, Brunt EM, Kleiner DE, et al. Endpoints and clinical trial design for nonalcoholic steatohepatitis. Hepatology. 2011;54:344–353. 85. Matsuda Y, Takada A, Kanayama R, et al. Changes of hepatic microtubules and secretory proteins in human alcoholic liver disease. Pharmacol Biochem Behav. 1983;18(Suppl 1):479–482. 86. Schaff Z, Lapis K. Fine structure of hepatocytes during the etiology of several common pathologies. J Electron Microsc Tech. 1990;14:179–207. 87. Gores GJ, Herman B, Lemasters JJ. Plasma membrane bleb formation and rupture: a common feature of hepatocellular injury. Hepatology. 1990;11:690–698. 88. Caldwell S, Ikura Y, Dias D, et al. Hepatocellular ballooning in NASH. J Hepatol. 2010;53:719–723. 89. Lackner C, Gogg-Kamerer M, Zatloukal K, et al. Ballooned hepatocytes in steatohepatitis: the value of keratin immunohistochemistry for diagnosis. J Hepatol. 2008;48:821–828.

Nonalcoholic Fatty Liver Disease 90. Zatloukal K, Stumptner C, Fuchsbichler A, et al. The keratin cytoskeleton in liver diseases. J Pathol. 2004;204:367–376. 91. Bedossa P. FLIP Pathology Consortium. Utility and appropriateness of the fatty liver inhibition of progression (FLIP) algorithm and steatosis, activity, and fibrosis (SAF) score in the evaluation of biopsies of nonalcoholic fatty liver disease. Hepatology. 2014;60:565–575. 92. Gill RM, Belt P, Wilson L, et al. Centrizonal arteries and microvessels in nonalcoholic steatohepatitis. Am J Surg Pathol. 2011;35:1400–1404. 93. Brunt EM, Kleiner DE, Wilson LA, et al. Portal chronic inflammation in nonalcoholic fatty liver disease (NAFLD): a histologic marker of advanced NAFLD-Clinicopathologic correlations from the nonalcoholic steatohepatitis clinical research network. Hepatology. 2009;49:809–820. 94. Brunt EM. Nonalcoholic steatohepatitis: pathologic features and differential diagnosis. Semin Diagn Pathol. 2005;22:330–338. 95. Brunt EM, Ramrakhiani S, Cordes BG, et al. Concurrence of histologic features of steatohepatitis with other forms of chronic liver disease. Mod Pathol. 2003;16:49–56. 96. Clouston AD, Powell EE. Interaction of non-alcoholic fatty liver disease with other liver diseases. Best Pract Res Clin Gastroenterol. 2002;16:767–781. 97. Sanyal AJ, Contos MJ, Sterling RK, et al. Nonalcoholic fatty liver disease in patients with hepatitis C is associated with features of the metabolic syndrome. Am J Gastroenterol. 2003;98:2064–2071. 98. Zatloukal K, French SW, Stumptner C, et al. From Mallory to Mallory-Denk bodies: what, how and why? Exp Cell Res. 2007;313:2033–2049. 99. Denk H, Stumptner C, Zatloukal K. Mallory bodies revisited. J Hepatol. 2000;32:689–702. 100. Caldwell SH, de Freitas LA, Park SH, et al. Intramitochondrial crystalline inclusions in nonalcoholic steatohepatitis. Hepatology. 2009;49:1888–1895. 101. Caldwell SH, Chang CY, Nakamoto RK, Krugner-Higby L. Mitochondria in nonalcoholic fatty liver disease. Clin Liver Dis. 2004;8:595–617. 102. Feldstein AE, Canbay A, Angulo P, et al. Hepatocyte apoptosis and fas expression are prominent features of human nonalcoholic steatohepatitis. Gastroenterology. 2013;125:437–443. 103. Nagore N, Scheuer PJ. The pathology of diabetic hepatitis. J Pathol. 1988;156:155–160. 104. Corradini E, Pietrangelo A. Iron and steatohepatitis. J Gastroenterol Hepatol. 2012;27(Suppl 2): 42–46. 105. Turlin B, Mendler MH, Moirand R, et al. Histologic features of the liver in insulin resistanceassociated iron overload. A study of 139 patients. Am J Clin Pathol. 2001;116:263–270. 106. Pietrangelo A. Iron and the liver. Liver Int. 2016;36(Suppl 1):116–123. 107. Myers BM, Prendergast FG, Holman R, et al. Alterations in the structure, physicochemical properties, and pH of hepatocyte lysosomes in experimental iron overload. J Clin Invest. 1991;88:1207–1215. 108. Bacon BR, Britton RS. The pathology of hepatic iron overload: a free radical–mediated process? Hepatology. 1990;11:127–137. 109. She H, Xiong S, Lin M, et al. Iron activates NF-kappaB in Kupffer cells. Am J Physiol Gastrointest Liver Physiol. 2002;283:G719–G726. 110. Xiong S, She H, Tsukamoto H. Signaling role of iron in NF-kappa B activation in hepatic macrophages. Comp Hepatol. 2004;14(3 Suppl 1):S36. 111. Ramm GA, Crawford DH, Powell LW, et al. Hepatic stellate cell activation in genetic haemochromatosis. Lobular distribution, effect of increasing hepatic iron and response to phlebotomy. J Hepatol. 1997;26:584–592. 112. Ahmed U, Latham PS, Oates PS. Interactions between hepatic iron and lipid metabolism with possible relevance to steatohepatitis. World J Gastroenterol. 2012;18:4651–4658. 113. George DK, Goldwurm S, MacDonald GA, et al. Increased hepatic iron concentration in nonalcoholic steatohepatitis is associated with increased fibrosis. Gastroenterology. 1998;114:311–318. 114. Fargion S, Mattioli M, Fracanzani AL, et al. Hyperferritinemia, iron overload, and multiple metabolic alterations identify patients at risk for nonalcoholic steatohepatitis. Am J Gastroenterol. 2001;96:2448–2455. 115. Duseja A, Das R, Nanda M, et al. Nonalcoholic steatohepatitis in Asian Indians is neither associated with iron overload nor with HFE gene mutations. World J Gastroenterol. 2005;11:393–395. 116. Deguti MM, Sipahi AM, Gayotto LC, et al. Lack of evidence for the pathogenic role of iron and HFE gene mutations in Brazilian patients with nonalcoholic steatohepatitis. Braz J Med Biol Res. 2003;36:739–745. 117. Chitturi S, Weltman M, Farrell GC, et al. HFE mutations, hepatic iron, and fibrosis: ethnic-specific association of NASH with C282Y but not with fibrotic severity. Hepatology. 2002;36:142–149. 118. Valenti L, Fracanzani AL, Bugianesi E, et al. HFE genotype, parenchymal iron accumulation, and liver fibrosis in patients with nonalcoholic fatty liver disease. Gastroenterology. 2010;138:905–912. 119. Nelson JE, Wilson L, Brunt EM, et al. Relationship between the pattern of hepatic iron deposition and histological severity in nonalcoholic fatty liver disease. Hepatology. 2011;53:448–457. 120. Sorrentino P, D’Angelo S, Ferbo U, et al. Liver iron excess in patients with hepatocellular carcinoma developed on non-alcoholic steato-hepatitis. J Hepatol. 2009;50:351–357. 121. Pietrangelo A. Iron in NASH, chronic liver diseases and HCC: how much iron is too much? J Hepatol. 2009;50:249–251. 122. Rangwala F, Guy CD, Lu J, Suzuki A, et al. Increased production of sonic hedgehog by ballooned hepatocytes. J Pathol. 2011;224:401–410. 123. Caldwell SH, Lee VD, Kleiner DE, et al. NASH and cryptogenic cirrhosis: a histological analysis. Ann Hepatol. 2009;8:346–352.

124. Schwimmer JB, Behling C, Newbury R, et al. NAFLD in children: a prospective clinical-­ pathological study and effect of lifestyle advice. Histopathology of pediatric nonalcoholic fatty liver disease. Hepatology. 2005;42:641–649. 125. Carter-Kent C, Yerian LM, Brunt EM, et al. Nonalcoholic steatohepatitis in children: a multicenter clinicopathological study. Hepatology. 2009;50:1113–1120. 126. Nobili V, Marcellini M, Devito R, et al. NAFLD in children: a prospective clinical-pathological study and effect of lifestyle advice. Hepatology. 2006;44:458–465. 127. Takahashi Y, Inui A, Fujisawa T, et al. Histopathological characteristics of non-alcoholic fatty liver disease in children: Comparison with adult cases. Hepatol Res. 2011;41:1066–1074. 128. Suzuki A, Abdelmalek MF, Schwimmer JB, et al. Nonalcoholic Steatohepatitis Clinical Research Network. Association between puberty and features of nonalcoholic fatty liver disease. Clin Gastroenterol Hepatol. 2012;10:786–794. 129. Younossi ZM, Gramlich T, Liu YC, et al. Nonalcoholic fatty liver disease: assessment of variability in pathologic interpretations. Mod Pathol. 1998;11:560–565. 130. Lackner C. Hepatocellular ballooning in nonalcoholic steatohepatitis: the pathologist’s perspective. Expert Rev Gastroenterol Hepatol. 2011;5:223–231. 131. Starmann J, Fälth M, Spindelböck W, et al. Gene expression profiling unravels cancer-related hepatic molecular signatures in steatohepatitis but not in steatosis. PLoS One. 2012;7: e46584. 132. Guy CD, Suzuki A, Zdanowicz M, et al. Hedgehog pathway activation parallels histologic severity of injury and fibrosis in human nonalcoholic fatty liver disease. Hepatology. 2012;55:1711–1721. 133. Guy CD, Suzuki A, Abdelmalek MF, Burchette JL, Diehl AM, NASH CRN. Treatment response in the PIVENS trial is associated with decreased Hedgehog pathway activity. Hepatology. 2015;61:98–107. 134. Younossi ZM, Stepanova M, Rafiq N, et al. Pathologic criteria for nonalcoholic steatohepatitis: interprotocol agreement and ability to predict liver-related mortality. Hepatology. 2011;53:1874–1882. 135. Ishak K, Baptista A, Bianchi L, et al. Histological grading and staging of chronic hepatitis. J Hepatol. 1995;22:696–699. 136. Bedossa P, Poynard T. An algorithm for the grading of activity in chronic hepatitis C. The METAVIR Cooperative Study Group. Hepatology. 1996;24:289–293. 137. Brunt EM, Janney CG, Di Bisceglie AM, et al. Nonalcoholic steatohepatitis: a proposal for grading and staging the histological lesions. Am J Gastroenterol. 1999;94:2467–2474. 138. Bedossa P, Poitou C, Veyrie N, et al. Histopathological algorithm and scoring system for evaluation of liver lesions in morbidly obese patients. Hepatology. 2012;56:1751–1759. 139. Hjelkrem M, Stauch C, Shaw J, et al. Validation of the non-alcoholic fatty liver disease activity score. Aliment Pharmacol Ther. 2011;34:214–218. 140. Sandrini J, Boursier J, Chaigneau J, et al. Quantification of portal-bridging fibrosis area more accurately reflects fibrosis stage and liver stiffness than whole fibrosis or perisinusoidal fibrosis areas in chronic hepatitis C. Mod Pathol. 2014;27:1035–1045. 141. Boursier J, de Ledinghen V, Sturm N, et al. Precise evaluation of liver histology by computerized morphometry shows that steatosis influences liver stiffness measured by transient elastography in chronic hepatitis C. J Gastroenterol. 2014;49:527–537. 142. Levene AP, Kudo H, Armstrong MJ, et al. Quantifying hepatic steatosis—more than meets the eye. Histopathology. 2012;60:971–981. 143. Rockey DC, Caldwell SH, Goodman ZD, et al. Liver biopsy. American Association for the Study of Liver Diseases. Hepatology. 2009;49:1017–1044. 144. Ratziu V, Charlotte F, Heurtier A, et al. Sampling variability of liver biopsy in nonalcoholic fatty liver disease. Gastroenterology. 2005;128:1898–1906. 145. Chalasani NP, Sanyal AJ, Kowdley KV, et al. Pioglitazone versus vitamin E versus placebo for the treatment of non-diabetic patients with non-alcoholic steatohepatitis: PIVENS trial design. Contemp Clin Trials. 2009;30:88–96. 146. Merriman RB, Ferrell LD, Patti MG, et al. Correlation of paired liver biopsies in morbidly obese patients with suspected nonalcoholic fatty liver disease. Hepatology. 2006;44:874–880. 147. Larson SP, Bowers SP, Palekar NA, et al. Histopathologic variability between the right and left lobes of the liver in morbidly obese patients undergoing Roux-en-Y bypass. Clin Gastroenterol Hepatol. 2007;5:1329–1332. 148. Marchesini G, Marzocchi R, Agostini F, Bugianesi E. Nonalcoholic fatty liver disease and the metabolic syndrome. Curr Opin Lipidol. 2005;16:421–427. 149. Iturriaga H, Bunout D, Hirsch S, et al. Overweight as a risk factor or a predictive sign of histological liver damage in alcoholics. Am J Clin Nutr. 1988;47:235–238. 150. Naveau S, Giraud V, Borotto E, et al. Excess weight risk factor for alcoholic liver disease. Hepatology. 1997;25:108–111. 151. Raynard B, Balian A, Fallik D, et al. Risk factors of fibrosis in alcohol-induced liver disease. Hepatology. 2002;35:635–638. 152. Yeh MM, Brunt EM. Pathological features of fatty liver disease. Gastroenterology. 2014;147:754–764. 153. EASL clinical practical guidelines. management of alcoholic liver disease. European Association for the Study of Liver. J Hepatol. 2012;57:399–420. 154.  Alcoholic liver disease, O’Shea RS, Dasarathy S, McCullough AJ. Am J Gastroenterol. 2010;105:14–32. 155. Powell EE, Jonsson JR, Clouston AD. Steatosis: co-factor in other liver diseases. Hepatology. 2005;42:5–13. 156. Powell EE, Jonsson JR, Clouston AD. Metabolic factors and non-alcoholic fatty liver disease as co-factors in other liver diseases. Dig Dis. 2010;28:186–191.

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185

Practical Hepatic Pathology: A Diagnostic Approach 157. Nalbantoglu IL, Brunt EM. Role of liver biopsy in nonalcoholic fatty liver disease. World J Gastroenterol. 2014;20:9026–9037. 158. Machado MV, Oliveira AG, Cortez-Pinto H. Hepatic steatosis in hepatitis B virus infected patients: meta-analysis of risk factors and comparison with hepatitis C infected patients. J Gastroenterol Hepatol. 2011;26:1361–1367. 159. Lonardo A, Adinolfi LE, Restivo L, et al. Pathogenesis and significance of hepatitis C virus steatosis: an update on survival strategy of a successful pathogen. World J Gastroenterol. 2014;20:7089–7103. 160. Thomopoulos KC, Arvaniti V, Tsamantas AC, et al. Prevalence of liver steatosis in patients with chronic hepatitis B: a study of associated factors and of relationship with fibrosis. Eur J Gastroenterol Hepatol. 2006;18:233–237. 161. Vallet-Pichard A, Mallet V, Pol S. Nonalcoholic fatty liver disease and HIV infection. Semin Liver Dis. 2012;32:158–166. 162. Yatsuji S, Hashimoto E, Kaneda H, et al. Diagnosing autoimmune hepatitis in nonalcoholic fatty liver disease: is the International Autoimmune Hepatitis Group scoring system useful? J Gastroenterol. 2005;40:1130–1138. 163. Híndi M, Levy C, Couto CA, et al. Primary biliary cirrhosis is more severe in overweight patients. J Clin Gastroenterol. 2013;47:e28–e32. 164. Patel V. Sanyal AJ Drug-induced steatohepatitis. Clin Liver Dis. 2013;17:533–546. 165. Leise MD, Poterucha JJ. Talwalkar JA Drug-induced liver injury. Mayo Clin Proc. 2014;89:95–106. 166. Bellentani S, Saccoccio G, Masutti F, et al. Prevalence of and risk factors for hepatic steatosis in Northern Italy. Ann Intern Med. 2000;132:112–117. 167. Kneeman JM, Misdraji J, Corey KE. Secondary causes of nonalcoholic fatty liver disease. Therap Adv Gastroenterol. 2012;5:199–207. 168. Buechler C, Weiss TS. Does hepatic steatosis affect drug metabolizing enzymes in the liver? Curr Drug Metab. 2011;12:24–34. 169. Amacher DE, Chalasani N. Drug-induced hepatic steatosis. Semin Liver Dis. 2014;34:205–214. 170. Begriche K, Massart J, Robin MA, et al. Drug-induced toxicity on mitochondria and lipid metabolism: mechanistic diversity and deleterious consequences for the liver. J Hepatol. 2011;54:773–794. 171. Day CP, James OF. Steatohepatitis: a tale of two “hits”? Gastroenterology. 1998;114:842–845. 172. Jaeschke H, Gores GJ, Cederbaum AI, et al. Mechanisms of hepatotoxicity. Toxicol Sci. 2002;65:166–176. 173. Ramachandran R, Kakar S. Histological patterns in drug-induced liver disease. J Clin Pathol. 2009;62:481–492. 174. Schrör K. Aspirin and Reye syndrome: a review of the evidence. Paediatr Drugs. 2007;9:195–204. 175. Chang CH, Uchawat F, Massalskis F, et al. Morphologic grading of hepatic mitochondrial alteration in Reye’s syndrome: potential prognostic implication. Pediatr Pathol. 1985;4:265–275. 176. Casteels-Van Daele M, Van Geet C, Wouters C, et al. Reye syndrome revisited: a descriptive term covering a group of heterogeneous disorders. Eur J Pediatr. 2000;159:641–648. 177. Stine JG, Chalasani N. Chronic liver injury induced by drugs: a systematic review. Liver Int. 2015;35:2343–2353. 178. Schumacher JD, Guo GL. Mechanistic review of drug-induced steatohepatitis. Toxicol Appl Pharmacol. 2015;289:40–47. 179. Grieco A, Forgione A, Miele L, et al. Fatty liver and drugs. Eur Rev Med Pharmacol Sci. 2005;9:261–263. 180. Pawlik TM, Olino K, Gleisner AL, et al. Preoperative chemotherapy for colorectal liver metastases: impact on hepatic histology and postoperative outcome. J Gastrointest Surg. 2007;11:860–868. 181. Zorzi D, Laurent A, Pawlik TM, et al. Chemotherapy-associated hepatotoxicity and surgery for colorectal liver metastases. Br J Surg. 2007;94:274–286. 182. Gentilucci UV, Santini D, Vincenzi B, et al. Chemotherapy-induced steatohepatitis in colorectal cancer patients. J Clin Oncol. 2006;24:5467. 183. Raja K, Thung SN, Fiel MI, et al. Drug-induced steatohepatitis leading to cirrhosis: long-term toxicity of amiodarone use. Semin Liver Dis. 2009;29:423–428. 184. Vauthey JN, Pawlik TM, Ribero D, et al. Chemotherapy regimen predicts steatohepatitis and an increase in 90-day mortality after surgery for hepatic colorectal metastases. J Clin Oncol. 2006;24:2065–2072. 185. Wolf PS, Park JO, Bao F, et al. Preoperative chemoterapy and the risk of hepatotoxicity and morbidity after liver resection for metastatic colorectal cancer: a single institution experience. J Am Coll Surg. 2013;216:41–49. 186. Karoui M, Penna C, Amin-Hashem M, et al. Influence of preoperative chemotherapy on the risk of major hepatectomy for colorectal liver metastases. Ann Surg. 2006;243:1–7. 187. Poucell S, Ireton J, Valencia-Mayoral P, et al. Amiodarone-associated phospholipidosis and fibrosis of the liver. Light, immunohistochemical, and electron microscopic studies. Gastroenterology. 1984;86:926–936. 188. Zeissig S, Dougan SK, Barral DC, et al. Primary deficiency of microsomal triglyceride transfer protein in human abetalipoproteinemia is associated with loss of CD1 function. J Clin Invest. 2010;120:2889–2899. 189. Tarugi P, Averna M. Hypobetalipoproteinemia: genetics, biochemistry, and clinical spectrum. Adv Clin Chem. 2011;54:81–107. 190. de Bruin TW, Georgieva AM, Brouwers MC, et al. Radiological evidence of nonalcoholic fatty liver disease in familial combined hyperlipidemia. Am J Med. 2004;116:847–849.

186

191. Kimura H, Kako M, Yo K, et al. Alcoholic hyalins (Mallory bodies) in a case of WeberChristian disease: electron microscopic observations of liver involvement. Gastroenterology. 1980;78:807–812. 192. Wasserman JM, Thung SN, Berman R, et al. Hepatic Weber-Christian disease. Semin Liver Dis. 2001;21:115–118. 193. Burda P, Hochuli M. Hepatic glycogen storage disorders: what have we learned in recent years? Curr Opin Clin Nutr Metab Care. 2015;18:415–421. 194. Torbenson M. Biopsy interpretation of the liver. 1st ed. Wolter´s Kluwer Health; 2015:328–332. 195. Agarwal AK, Garg A. Genetic basis of lipodystrophies and management of metabolic complications. Annu Rev Med. 2006;57:297–311. 196. Garg A. Clinical review: lipodystrophies: genetic and acquired body fat disorders. J Clin Endocrinol Metab. 2011;96:3313–3325. 197. Capeau J, Magré J, Caron-Debarle M, et al. Human lipodystrophies: genetic and acquired diseases of adipose tissue. Endocr Dev. 2010;19:1–20. 198. Vigouroux C, Caron-Debarle M, Le Dour C, et al. Molecular mechanisms of human lipodystrophies: from adipocyte lipid droplet to oxidative stress and lipotoxicity. Int J Biochem Cell Biol. 2011;43:862–876. 199. Allard JP. Other disease associations with non-alcoholic fatty liver disease (NAFLD). Best Pract Res Clin Gastroenterol. 2002;16:783–795. 200. Bowyer BA, Fleming CR, Ludwig J, et al. Does long-term home parenteral nutrition in adult patients cause chronic liver disease? J Parenter Enteral Nutr. 1985;9:11–17. 201. Cai W, Wu J, Hong L, et al. Oxidative injury and hepatocyte apoptosis in total parenteral nutrition-associated liver dysfunction. J Pediatric Surg. 2006;41:1663–1668. 202. Paquot N, Delwaide J. Fatty liver in the intensive care unit. Curr Opin Clin Nutr Metab Care. 2005;8:183–187. 203. Badaloo A, Reid M, Soares D, et al. Relation between liver fat content and the rate of VLDL apolipoprotein B-100 synthesis in children with protein-energy malnutrition. Am J Clin Nutr. 2005;81:1126–1132. 204. Gan SK, Watts GF. Is adipose tissue lipolysis always an adaptive response to starvation? Implications for non-alcoholic fatty liver disease. Clin Sci. 2008;114:543–545. 205. Asrih M, Jornayvaz FR. Diets and nonalcoholic fatty liver disease: the good and the bad. Clin Nutr. 2014;33:186–190. 206. Deleted in review. 207. Marciano F, Savoia M, Vajro P. Celiac disease-related hepatic injury: insights into associated conditions and underlying pathomechanisms. Dig Liver Dis. 2015;15:30241–30243. 208. Mounajjed T, Oxentenko A, Shmidt E, et al. The liver in celiac disease: clinical manifestations, histologic features, and response to gluten-free diet in 30 patients. Am J Clin Pathol. 2011;136:128–137. 209. Asselah T, Rubbia-Brandt L, Marcellin P, et al. Steatosis in chronic hepatitis C: why does it really matter? Gut. 2006;55:123–130. 210. Czaja AJ, Carpenter HA. Sensitivity, specificity and predictability of biopsy interpretations in chronic hepatitis. Gastroenterology. 1993;105:1824–1832. 211. Czaja AJ, Carpenter HA, Santrach PJ, et al. Host- and disease-specific factors affecting steatosis in chronic hepatitis C. J Hepatol. 1998;29:198–206. 212. Rubbia-Brandt L, Quadri R, Abid K, et al. Hepatocyte steatosis is a cytopathic effect of hepatitis C virus genotype 3. J Hepatol. 2000;33(1):106–115. 213. Abenavoli L, Masarone M, Peta V, et al. Insulin resistance and liver steatosis in chronic hepatitis C infection genotype 3. World J Gastroenterol. 2014;20:15233–15240. 214. Rubbia-Brandt L, Fabris P, Paganin S, et al. Steatosis affects chronic hepatitis C progression in a genotype specific way. Gut. 2004;53:406–412. 215. Bedossa P, Moucari R, Chelbi E, et al. Evidence for a role of nonalcoholic steatohepatitis in hepatitis C: a prospective study. Hepatology. 2007;46:380–387. 216. Bugianesi E, Salamone F, Negro F. The interaction of metabolic factors with HCV infection: does it matter? J Hepatol. 2012;56(Suppl 1):S56–S65. 217. European Association for Study of Liver. EASL Clinical Practice Guidelines: Wilson’s disease. J Hepatol. 2012;56:671–685. 218. Sternlieb I. Wilson’s disease: indications for liver transplants. Hepatology. 1984;4(Suppl):15S–17S. 219. Gitlin JD. Wilson disease. Gastroenterology. 2003;125:1868–1877. 220. Deleted in review. 221. Gaetke LM, Chow CK. Copper toxicity, oxidative stress, and antioxidant nutrients. Toxicology. 2013;189:147–163. 222. Valko M, Morris H, Cronin MT. Metals, toxicity and oxidative stress. Curr Med Chem. 2005;12:1161–1208. 223. Britton RS. Metal-induced hepatotoxicity. Semin Liver Dis. 1996;16:3–12. 224. Roberts EA, Schilsky ML. American Association for Study of Liver Diseases (AASLD). Diagnosis and treatment of Wilson disease: an update. Hepatology. 2008;47:2089–2111. 225. Alt ER, Sternlieb I, Goldfischer S. The cytopathology of metal overload. Int Rev Exp Pathol. 1990;31:165–188. 226. Sternlieb I. Evolution of the hepatic lesion in Wilson’s disease (hepatolenticular degeneration). Prog Liver Dis. 1972;4:511–525. 227. Scott J, Gollan JL, Samourian S, et al. Wilson’s disease, presenting as chronic active hepatitis. Gastroenterology. 1978;74:645–651. 228. Milkiewicz P, Saksena S, Hubscher SG, et al. Wilson’s disease with superimposed autoimmune features: report of two cases and review. J Gastroenterol Hepatol. 2000;15:570–574.

Nonalcoholic Fatty Liver Disease 229. Stromeyer FW, Ishak KG. Histology of the liver in Wilson’s disease: a study of 34 cases. Am J Clin Pathol. 1980;73:12–24. 230. Lindquist RR. Studies on the pathogenesis of hepatolenticular degeneration. II. Cytochemical methods for the localization of copper. Arch Pathol. 1969;87:370–379. 231. Irons RD, Schenk EA, Lee JC. Cytochemical methods for copper. Semiquantitative screening procedure for identification of abnormal copper levels in liver. Arch Pathol Lab Med. 1977;101:298–301. 232. Hayashi H, Yano M, Fujita Y, Wakusawa S. Compound overload of copper and iron in patients with Wilson’s disease. Med Mol Morphol. 2006;39:121–126. 233. Kwok R, Tse YK, Wong GL, et al. Systematic review with metaanalysis: non-invasive assessment of non-alcoholic fatty liver disease—the role of transient elastography and plasma cytokeratin-18 fragments. Aliment Pharmacol Ther. 2014;39:254–269. 234. Angulo P, Hui JM, Marchesini G, et al. The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD. Hepatology. 2007;45:846–854. 235. Wong VW, Wong GL, Chim AM, et al. Validation of the NAFLD fibrosis score in a Chinese population with low prevalence of advanced fibrosis. Am J Gastroenterol. 2008;103:1682–1688. 236. McPherson S, Stewart SF, Henderson E, Burt AD, Day CP. Simple non-invasive fibrosis scoring systems can reliably exclude advanced fibrosis in patients with non-alcoholic fatty liver disease. Gut. 2010;59:1265–1269. 237. Mansoor S, Yerian L, Kohli R, et al. The evaluation of hepatic fibrosis scores in children with nonalcoholic fatty liver disease. Dig Dis Sci. 2015;60:1440–1447. 238. Machado MV, Cortez-Pinto H. Non-alcoholic fatty liver disease: what the clinician needs to know. World J Gastroenterol. 2014;20:12956–12980. 239. Anstee QM, Targher G, Day CP. Progression of NAFLD to diabetes mellitus, cardiovascular disease or cirrhosis. Nat Rev Gastroenterol Hepatol. 2013;10:330–344. 240. Singh S, Allen AM, Wang Z, et al. Fibrosis progression in nonalcoholic fatty liver vs nonalcoholic steatohepatitis: a systematic review and meta-analysis of paired-biopsy studies. Clin Gastroenterol Hepatol. 2015;13:643–654. 241. McPherson S, Hardy T, Henderson E, et al. Evidence of NAFLD progression from steatosis to fibrosing-steatohepatitis using paired biopsies: implications for prognosis and clinical management. J Hepatol. 2015;62:1148–1155. 242. Willner IR, Waters B, Patil SR, et al. Ninety patients with nonalcoholic steatohepatitis: insulin resistance, familial tendency, and severity of disease. Am J Gastroenterol. 2001;96: 2957–2961. 243. Struben VM, Hespenheide EE, Caldwell SH. Nonalcoholic steatohepatitis and cryptogenic cirrhosis within kindreds. Heritability of nonalcoholic fatty liver disease. Am J Med. 2000;108:9–13. 244. Schwimmer JB, Celedon MA, Lavine JE, et al. Heritability of nonalcoholic fatty liver disease. Gastroenterology. 2009;136:1585–1592. 245. Makkonen J, Pietiläinen KH, Rissanen A, et al. Genetic factors contribute to variation in serum alanine aminotransferase activity independent of obesity and alcohol: a study in monozygotic and dizygotic twins. J Hepatol. 2009;50:1035–1042. 246. Browning JD, Szczepaniak LS, Dobbins R, et al. Prevalence of hepatic steatosis in an urban population in the United States: impact of ethnicity. Hepatology. 2004;40:1387–1395. 247. Browning JD, Kumar KS, Saboorian MH, et al. Ethnic differences in the prevalence of cryptogenic cirrhosis. Am J Gastroenterol. 2004;99:292–298. 248. Guerrero R, Vega GL, Grundy SM, et al. Ethnic differences in hepatic steatosis: an insulin resistance paradox? Hepatology. 2009;49:791–801. 249. Bambha K, Belt P, Abraham M, et al. Ethnicity and nonalcoholic fatty liver disease. Hepatology. 2012;55:769–780. 250. Anstee QM, Day CP. The genetics of nonalcoholic fatty liver disease: spotlight on PNPLA3 and TM6SF2. Semin Liver Dis. 2015;35:270–290. 251. Romeo S, Kozlitina J, Xing C, et al. Genetic variation in PNPLA3 confers susceptibility to nonalcoholic fatty liver disease. Nat Genet. 2008;40:1461–1465. 252. Yuan X, Waterworth D, Perry JR, et al. Population-based genome-wide association studies reveal six loci influencing plasma levels of liver enzymes. Am J Hum Genet. 2008;83: 520–528. 253. Speliotes EK, Yerges-Armstrong LM, Wu J, et al. Genome-wide association analysis identifies variants associated with nonalcoholic fatty liver disease that have distinct effects on metabolic traits. PLoS Genet. 2011;7: e1001324. 254. Kozlitina J, Smagris E, Stender S, et al. Exome-wide association study identifies a TM6SF2 variant that confers susceptibility to nonalcoholic fatty liver disease. Nat Genet. 2014;46:352–356. 255. Kawaguchi T, Sumida Y, Umemura A, et al. Genetic polymorphisms of the human PNPLA3 gene are strongly associated with severity of non-alcoholic fatty liver disease in Japanese. PLoS One. 2012;7: e38322. 256. Kitamoto T, Kitamoto A, Yoneda M, et al. Genome-wide scan revealed that polymorphisms in the PNPLA3, SAMM50, and PARVB genes are associated with development and progression of nonalcoholic fatty liver disease in Japan. Hum Genet. 2013;32:783–792. 257. DiStefano JK, Kingsley C, Craig Wood G, et al. Genome-wide analysis of hepatic lipid content in extreme obesity. Acta Diabetol. 2015;52:373–382.

258. Dongiovanni P, Petta S, Maglio C, et al. Transmembrane 6 superfamily member 2 gene variant disentangles nonalcoholic steatohepatitis from cardiovascular disease. Hepatology. 2015;61:506–514. 259. Valenti L, Al-Serri A, Daly AK, et al. Homozygosity for the patatinlike phospholipase-3/adiponutrin I148M polymorphism influences liver fibrosis in patients with nonalcoholic fatty liver disease. Hepatology. 2010;51:1209–1217. 260. Sookoian S, Castaño GO, Burgueño AL, et al. A nonsynonymous gene variant in the adiponutrin gene is associated with nonalcoholic fatty liver disease severity. J Lipid Res. 2009;50:2111–2116. 261. Rotman Y, Koh C, Zmuda JM, Kleiner DE, Liang TJ, NASH CRN. The association of genetic variability in patatin-like phospholipase domain-containing protein 3 (PNPLA3) with histological severity of nonalcoholic fatty liver disease. Hepatology. 2010;52:894–903. 262. Sevastianova K, Kotronen A, Gastaldelli A, et al. Genetic variation in PNPLA3 (adiponutrin) confers sensitivity to weight loss-induced decrease in liver fat in humans. Am J Clin Nutr. 2011;94:104–111. 263. Deleted in review. 264. Hassan MM, Kaseb A, Etzel CJ, et al. Genetic variation in the PNPLA3 gene and hepatocellular carcinoma in USA: risk and prognosis prediction. Mol Carcinog. 2013;52(Suppl 1):E139–E147. 265. Burza MA, Pirazzi C, Maglio C, et al. PNPLA3 I148M (rs738409) genetic variant is associated with hepatocellular carcinoma in obese individuals. Dig Liver Dis. 2012;44:1037–1041. 266. Liu YL, Patman GL, Leathart JB, et al. Carriage of the PNPLA3 rs738409 C >G polymorphism confers an increased risk of non-alcoholic fatty liver disease associated hepatocellular carcinoma. J Hepatol. 2014;61:75–81. 267. Guyot E, Sutton A, Rufat P, et al. PNPLA3 rs738409, hepatocellular carcinoma occurrence and risk model prediction in patients with cirrhosis. J Hepatol. 2013;58:312–318. 268. Nischalke HD, Berger C, Luda C, et al. The PNPLA3 rs738409 148M/M genotype is a risk factor for liver cancer in alcoholic cirrhosis but shows no or weak association in hepatitis C cirrhosis. PLoS ONE. 2011;6: e27087. 269. Trepo E, Guyot E, Ganne-Carrie N, et al. PNPLA3 (rs738409 C>G) is a common risk variant associated with hepatocellular carcinoma in alcoholic cirrhosis. Hepatology. 2012;55:1307–1308. 270. Trepo E, Nahon P, Bontempi G, et al. Association between the PNPLA3 (rs738409 C>G) variant and hepatocellular carcinoma: evidence from a meta-analysis of individual participant data. Hepatology. 2014;59:2170–2177. 271. Carim-Todd L, Escarceller M, Estivill X, et al. Cloning of the novel gene TM6SF1 reveals conservation of clusters of paralogous genes between human chromosomes 15q24-->q26 and 19p13.3-->p12. Cytogenet Cell Genet. 2000;90:255–260. 272. Surakka I, Horikoshi M, Mägi R, et al. The impact of low-frequency and rare variants on lipid levels. Nat Genet. 2015;47:589–597. 273. Mahdessian H, Taxiarchis A, Popov S, et al. TM6SF2 is a regulator of liver fat metabolism influencing triglyceride secretion and hepatic lipid droplet content. PNAS. 2014;111:8913–8918. 274. Holmen OL, Zhang H, Fan Y, et al. Systematic evaluation of coding variation identifies a candidate causal variant in TM6SF2 influencing total cholesterol and myocardial infarction risk. Nat Genet. 2014;46:345–351. 275. Namikawa C, Shu-Ping Z, Vyselaar JR. Polymorphisms of microsomal triglyceride transfer protein gene and manganese superoxide dismutase gene in non-alcoholic steatohepatitis. J Hepatol. 2004;40:781–786. 276. Al-Serri A, Anstee QM, Valenti L, et al. The SOD2 C47T polymorphism influences NAFLD fibrosis severity: evidence from case-control and intra-familial allele association studies. J Hepatol. 2012;56:448–454. 277. Dong H, Wang J, Li C, et al. The phosphatidylethanolamine N-methyltransferase gene V175M single nucleotide polymorphism confers the susceptibility to NASH in Japanese population. J Hepatol. 2007;46:915–920. 278. Song J, da Costa KA, Fischer LM. Polymorphism of the PEMT gene and susceptibility to nonalcoholic fatty liver disease (NAFLD). FASEB J. 2005;19:1266–1271. 279. Wang L, Athinarayanan S, Jiang G, et al. Fatty acid desaturase 1 gene polymorphisms control human hepatic lipid composition. Hepatology. 2015;61:119–128. 280. Miele L, Beale G, Patman G, et al. The Kruppel-like factor 6 genotype is associated with fibrosis in nonalcoholic fatty liver disease. Gastroenterology. 2008;135:282–291. 281. Bhala N, Angulo P, van der Poorten D, et al. The natural history of nonalcoholic fatty liver disease with advanced fibrosis or cirrhosis: an international collaborative study. Hepatology. 2011;54:1208–1216. 282. Adams LA, Lymp JF, St Sauver J, et al. The natural history of nonalcoholic fatty liver disease: a population-based cohort study. Gastroenterology. 2005;129:113–121. 283. Pearlman M, Loomba R. State of the art: treatment of nonalcoholic steatohepatitis. Curr Opin Gastroenterol. 2014;30:223–237. 284. Fan JG, Jia JD, Li YM, et al. Guidelines for the diagnosis and management of nonalcoholic fatty liver disease: update 2010. J Dig Dis. 2011;12:38–44. 285. Malhotra N, Beaton MD. Management of non-alcoholic fatty liver disease in 2015. World J Hepatol. 2015;7:2962–2967. 286. Yerian L. Histopathological evaluation of fatty and alcoholic liver diseases. J Dig Dis. 2011;12:17–24.

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13 Acute Viral Hepatitis Venancio Avancini Ferreira Alves, MD, PhD

Histologic Patterns of Injury in Acute Viral Hepatitis  192 Acute “Lobular” Hepatitis (Prototypical Acute Hepatitis)  192 Histologic Clues to the Causative Virus  197 Other Viruses Causing Acute Hepatitis  198 Hepatitis D (Delta) Virus  198 Herpesviruses 198 Adenovirus 202 Parvovirus 203 Icteric Hemorrhagic Fevers  203 Ebola and Marburg Viruses  206 Arenaviruses 207 Hantavirus 207

Abbreviations AIDS acquired immunodeficiency syndrome ALF acute liver failure CDC Centers for Disease Control and Prevention CMV cytomegalovirus DENV Dengue virus DHF/DSS dengue hemorrhagic fever/dengue shock syndrome EBER Epstein-Barr virus encoded RNA EBV Epstein-Barr virus HBV hepatitis B virus HCV hepatitis C virus HDV hepatitis D virus HEV hepatitis E virus HHV human herpesvirus HIV human immunodeficiency virus HSV herpes simplex virus IgM immunoglobulin M IL interleukin PCR polymerase chain reaction scFv single-chain variable fragment Th2 T helper-2 cells TNF tumor necrosis factor VHF viral hemorrhagic fevers

The study of viral infections and related diseases is particularly relevant in the modern world because of new emerging infections in several parts of the world, which are easily transmitted across continents following overall facilitation of global commerce and travel. Moreover, the course of previously stable patterns of viral diseases have been altered by changes in the environment as well as by host responses, especially those modified by comorbidities or by potent immunomodulators and direct antiviral drugs. The term viral hepatitis has been classically used to describe liver disease caused by hepatotropic viruses A to G, which preferentially and primarily infect the liver. However, the liver may also be infected by nonhepatotropic viruses as part of systemic disease, which can be grouped into two categories: (1) hepatitis caused by viruses such as cytomegalovirus (CMV) and adenovirus that mainly cause opportunistic disease in immunocompromised individuals but rarely in immunocompetent individuals (Fig. 13.1); and (2) viral hepatitis as a component of icteric hemorrhagic fevers. Although hepatotropic viruses may lead to some degree of systemic disturbance, their primary effect is an inflammatory process of the liver, and the clinical manifestations result predominantly from liver damage with biochemical elevation of liver tests and variable degrees of hepatic dysfunction.1 In contrast, liver infections caused by nonhepatotropic viruses cause varying degrees of extrahepatic manifestations,2 which in many instances may mask the hepatitis itself. High and prolonged fever, mild increase in transaminases, and signs of multiple organ dysfunction syndrome are the three most important clues suggesting a systemic infection as the cause of hepatic dysfunction.3 Recognizing systemic infections and distinguishing them from hepatitis caused by hepatotropic viruses is essential to improve outcomes. Primary infection by hepatotropic viruses results in an acute hepatitis. The incidence of each type of viral hepatitis differs widely around the world; a series of 206 cases of acute viral hepatitis from India consisted of 95 cases of hepatitis E, 36 cases of hepatitis A, 18 cases of hepatitis B, and 27 cases of mixed infections with these viruses. Hepatitis C virus (HCV) was detected in only one patient. The other 29 cases were ascribed to infections by CMV or Epstein-Barr virus (EBV).4 In contrast, official reports of acute hepatitis from the Centers for Disease Control and Prevention (CDC) USA in 2013, includes 1781 cases of hepatitis A, 3050 cases of hepatitis B (HBV), and 2138 cases of HCV. No data regarding hepatitis E virus (HEV) is depicted because it is stated to be uncommon in the United States; when symptomatic hepatitis E does occur, it is usually the result of travel to a developing country where hepatitis E is endemic.5 191

Practical Hepatic Pathology: A Diagnostic Approach Acute Viral Hepatitis

Nonhepatotropic viruses

Hepatotropic viruses

Hepatitis A Hepatitis B* Hepatitis C* Hepatitis D* Hepatitis E

Viruses causing icteric hemorrhagic fevers (yellow fever, dengue, hantavirus)

Other viruses causing hepatitis in immunosuppressed and rarely in immunocompetent individuals (herpes simplex virus, Epstein-Barr virus, cytomegalovirus, adenovirus, human herpesvirus 6, parvovirus†)

*Progress to chronic hepatitis in a variable number of cases (chronic hepatitis B and C discussed in Chapters 14 and 15, respectively). Parvovirus has not been conclusively found to cause acute hepatitis (see text).

†

Figure 13.1  Major etiologic agents of acute viral hepatitis. Table 13.1  Histologic Patterns of Acute Viral Hepatitis Pattern

Diagnostic Considerations

Acute “lobular” hepatitis (prototypical acute hepatitis) (eSlides 13.1 and 13.2) Hepatotropic viruses A–E

Drug-induced hepatitis

Confluent necrosis (eSlides 13.3 and 13.4)

Drug-induced hepatitis

Hepatotropic viruses, dengue fever, yellow fever

Acute hepatitis with punched-out punctate areas of necrosis (eSlides 13.5 Cytomegalovirus, herpes simplex, adenovirus and 38.23)

Nonviral infections

Acute hepatitis with microabscesses (eSlide 38.23)

Cytomegalovirus

Cholangitis, nonviral infections

Acute hepatitis with microgranulomas

Cytomegalovirus

Drug-induced hepatitis; mycobacterial and fungal infections

Sinusoidal lymphocytosis (eSlide 1.15)

Epstein-Barr virus, cytomegalovirus

Drug-induced hepatitis

Neonatal hepatitis

Cytomegalovirus, herpes simplex

Metabolic diseases, bacterial infections

Hemorrhagic zonal necrosis (eSlides 13.6 and 13.7)

Yellow fever, dengue fever

Mushroom poisoning, toxemia

Most infections by hepatotropic viruses are subclinical. Complete clearance of the virus is the rule in hepatitis A and E infections and occurs in more than 90% of acute hepatitis B infections in adults. In contrast, more than 50% of all patients acutely infected by HCV cannot clear the virus within 6 months, thus leading to chronic infection. Chronic infection also occurs in 80% to 90% of neonates infected with hepatitis B virus (HBV).6-8 Chronic hepatitis B and C infections contribute significantly to the global burden of cirrhosis and hepatocellular carcinoma; these diseases are discussed in detail in Chapters 14 and 15, respectively. A minority of cases of acute viral hepatitis progress to acute liver failure (ALF). The causes of ALF vary from country to country. Acetaminophen accounts for nearly 50% of cases of ALF and hepatitis B for 7%. The etiology remains unclear in approximately 15% of cases despite extensive history taking and laboratory assessment, and these are termed indeterminate.9 Reports from Europe and from Japan account for similar incidences with hepatitis B as the predominant cause and a few cases ascribed to HEV.10 Approximately 1% of acute viral hepatitis A infections and 2% of acute hepatitis B infections progress to acute liver failure.5 Acute liver failure due to hepatitis E infection occurs in 0.1% to 4.0% of patients and has a special predilection for pregnant women, 30% of whom may develop acute liver failure.11,6 In contrast, acute liver failure remains largely unknown in hepatitis C infection. The present chapter deals with viruses as the major morphologic basis of fulminant hepatitis. Several other factors, especially drugs and autoimmune hepatitis, are also important causes of acute hepatic failure in both previously healthy individuals as well as those with underlying chronic liver disease. 192

Differential Diagnosis

Histologic Patterns of Injury in Acute Viral Hepatitis Major histologic patterns of acute viral hepatitis are shown in Table 13.1. Almost any pattern, especially acute “lobular” hepatitis and submassive/massive necrosis, may also be caused by a wide variety of drugs and toxins. The pattern of neonatal hepatitis (discussed in Chapter 5) may be caused by a wide variety of conditions other than viral hepatitis, including numerous metabolic disorders. This chapter first describes the prototypical pattern of acute lobular hepatitis and then describes the other patterns with the viruses most commonly associated with them.

Acute “Lobular” Hepatitis (Prototypical Acute Hepatitis)

Gross Pathology The major macroscopic and histologic lesions are similar in all types of acute viral hepatitis, independent of the etiologic agent. In most cases of acute viral hepatitis, the liver is homogeneously enlarged and congested, stretching the Glisson capsule. The cut surface is usually reddish-brown, except in cholestatic cases; the latter occurs, especially in elderly patients, when a spectrum from brown to green may be seen. In the less frequent cases of massive/submassive hepatic necrosis, a variable degree of liver shrinkage occurs because of parenchymal collapse; the collapsed areas are intermingled with nodules of regenerative parenchyma. Parenchymal collapse in extreme cases of massive necrosis may lead to “acute yellow atrophy” (Fig. 13.2).

Acute Viral Hepatitis

13

B

A

C Figure 13.2  Acute hepatitis, macroscopic findings. A, Acute hepatitis in a patient who died because of a concomitant hemorrhagic bacterial pneumonia. This enlarged liver weighs 3000 g and has a tan-brown, homogeneous, and soft cut surface. B, This explanted liver from a case of fulminant hepatic failure shows extensive hepatic necrosis, with a characteristic heterogeneous cut surface. The depressed brown areas correspond to extensive parenchymal collapse, and the green areas correspond to regenerating nodules with prominent cholestasis. C, Autopsy specimen from a patient who died because of acute hepatic failure. This shrunken atrophic liver weighs 670 g and demonstrates extensively collapsed, cholestatic parenchyma.

Microscopic Pathology Microscopically, acute hepatitis is characterized by a predominance of lobular parenchymal lesions, in contrast to chronic hepatitis in which portal and periportal inflammation, neoangiogenesis, and fibrosis prevail amid variable degrees of parenchymal necroinflammation (eSlides 13.1 and 13.2). Necroinflammation of the liver is diffuse, albeit heterogeneous. Parenchymal lesions in classical acute viral hepatitis encompass the finding of numerous swollen/ballooned hepatocytes, which are groups of large, pale, hydropic cells (Fig. 13.3). Small foci of inflammation, consisting mostly of lymphocytes and macrophages, are seen surrounding damaged hepatocytes or cellular fragments of dead hepatocytes; this lesion is referred to as lytic necrosis or spotty necrosis (Fig. 13.4).12 Another pattern of hepatocytic injury is individual cell death, which is seen as apoptosis of hepatocytes, usually mediated by CD8+ T-cell lymphocytes (Fig. 13.5).13 Apoptotic bodies have also been referred to as acidophilic bodies and Councilman bodies, the latter in the context of yellow fever (eSlide 13.3). As with viral infections in other organs, lymphocytes are the major inflammatory cells even in the acute phase, with variable numbers of accompanying macrophages and plasma cells and small numbers of polymorphonuclear cells (Fig. 13.6). Interestingly, phagocytic cellular components inside Kupffer cells may be seen as iron deposits on Perls stain or as periodic acid–Schiffpositive granules, and this provides evidence of resolving acute hepatitis when the findings on hematoxylin and eosin staining are otherwise unimpressive (Fig. 13.7 and eSlide 1.11). Portal lesions are less exuberant, encompassing edema and variable amounts of mononuclear infiltrate with minor involvement of bile ducts. Although spilling over of lymphocytes may be seen, hepatocytes at the limiting plate are usually not damaged (Fig. 13.8). Similarly, portal fibrosis and neoangiogenesis are not features of acute hepatitis. When patterns of both acute and chronic hepatitis coexist, the pathologist must consider the possibility of an acute viral infection occurring in an already inflamed liver. This event classically occurs with hepatitis D virus (HDV) superinfection of livers chronically infected

by HBV.14 However, one must keep in mind that, although infrequent, all kinds of viral superinfections or coinfections may occur. Minor features of cholestasis may be seen in acute hepatitis, with bile pigment found in the cytoplasm of hepatocytes or in biliary canaliculi. However, more significant biliary changes should raise the possibility of other pathologic processes, such as drug-induced injury or bile duct obstruction, although they can also be seen in viral hepatitis, especially in older patients (Fig. 13.9). Clinicopathologic Course Related to Special Patterns of Hepatic Necrosis and Regeneration In most cases of acute hepatitis, especially those due to hepatitis A and E, lytic necrosis affects multiple minute groups of hepatocytes, which, as in the loss of individual hepatocytes due to apoptosis, do not disturb trabecular architecture (see Fig. 13.4). Thus, when viral infection resolves, which usually occurs a few months after infection, regeneration from neighboring hepatocytes leads to complete restoration of structure and function of the liver. Less commonly, larger groups of hepatocytes die in the acute phase of viral infection, leading to a collapse of reticulin framework, known as confluent necrosis (eSlide 13.4).12 In such cases, which may be potentially (but not always) more severe clinically, a focal unabsorbed but inactive scar may be present (Fig. 13.10). When confluent necrosis is more extensive and links centrilobular venules to the neighboring ones, a vascular bridge ensues (“central-central bridging” or “central-portal bridging”) (Fig. 13.11). As originally purported by Boyer and Klatskin, confluent necrosis linking central veins to portal tracts may enable the pathway for a presinusoidal-postsinusoidal shunt.15 They suggested that acute hepatitis with many “central-portal bridges” harbors a high risk of evolution to cirrhosis. Rarely, hepatocytic necrosis may be even more extensive as typically seen in the clinical condition of “fulminant hepatitis,” in which liver failure ensues only a few weeks after the onset of acute hepatitis. 193

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A A

B Figure 13.3  A, Acute hepatitis B infection showing large, swollen, and pale hepatocytes intermingled with smaller ones containing denser cytoplasm. The portal tract is moderately edematous and contains minimal mononuclear inflammation. There is no periportal activity (interface hepatitis) or fibrosis (also see eSlide 13.2). B, Diffuse ballooning of hepatocytes in a case of severe acute hepatitis due to yellow fever (also see eSlide 13.3).

The terms massive necrosis and submassive necrosis are frequently used in these cases to denote extensive confluent necrosis; however, the amount of necrosis required to distinguish between the two is not defined. Historically, the term submassive necrosis has been used to connote the possibility of spontaneous recovery and survival and massive necrosis to connote a poor possibility of spontaneous recovery and survival. Histologic features predictive of clinical outcome have yet to be identified; thus, the terms are inherently ambiguous and lack precise definitions. Some pathologists use the terms only when the entire liver is available for examination at autopsy or transplantation. These decidedly negative outcomes, irrespective of the variable degree of necrosis (submassive or massive), further confirm the lack of correlation between pathologic findings and prognosis. For these reasons, physicians should not attempt to predict the clinical outcome of severe acute hepatitis exclusively on the basis of histopathologic findings in a needle biopsy.16 Extensive necrosis and consequent collapse of the reticulin framework may be easily confused with fibrosis; the distinction can be aided by silver impregnation stains such as the Gomori silver stain. Confluent necrosis leads to approximation of reticulin fibers (which are collagen III fibers) because of parenchymal collapse, whereas chronic active fibrogenesis leads to deposition of both collagen III and collagen I fibers. Collagen III appears as narrow black fibers (reticulin fibers) 194

B

C Figure 13.4  Lytic necrosis in acute hepatitis. A, A focus of lytic necrosis is seen amid swollen hepatocytes, several with microvesicular steatosis. The focus of lytic necrosis shows damaged hepatocytes surrounded by lymphocytes and macrophages. B, Lytic necrosis in a case of acute hepatitis C. A small group of lymphocytes and macrophages (arrows) replaces a focus of dropped-out hepatocytes in acinar zone 3 close to the efferent “centrilobular” venule in a case of acute hepatitis C infection. C, Silver stain depicts a focus of collapse of reticulin fibers (Gomori reticulin stain).

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Figure 13.5 Apoptosis. A, A hepatocyte with condensed cytoplasm and pyknotic nucleus is seen without accompanying inflammation, thus forming an apoptotic body (arrow). These apoptotic hepatocytes have also been referred to as acidophilic bodies or Councilman bodies, the latter in the context of yellow fever. B, Other than the central apoptotic or Councilman body (arrow), this case of yellow fever depicts several anucleated apoptotic bodies (arrowheads).

Figure 13.6  Lymphocytes are the most common inflammatory cell in acute hepatitis. In this case of acute hepatitis C infection, cords of lymphocytes together with macrophages and rare polymorphonuclear cells are seen along sinusoids. Swollen hepatocytes are intermingled with smaller ones containing dense cytoplasm (also see eSlide 13.1).

Figure 13.8  Moderate portal inflammatory infiltrate in a case of acute hepatitis C infection, consisting predominantly of lymphocytes followed by histiocytes and a minor component of neutrophils. Although some cells are seen at the portal interface, there is no evidence of hepatocyte damage at the limiting plate (also see eSlide 13.1).

Figure 13.7  Hemosiderin pigment is abundant in the cytoplasm of activated histiocytes phagocytosing necrotic hepatocytes in this case of acute hepatitis A infection (Perls iron stain). Cholestasis is also noticeable in this case.

Figure 13.9  Major parenchymal lesions are seen in this case of acute hepatitis B infection in an older patient. Besides several foci of lytic necrosis and ballooning, there is marked canalicular and cellular cholestasis. Kupffer cells contain minimal amounts of phagocytosed hemosiderin (Perls iron stain). 195

Practical Hepatic Pathology: A Diagnostic Approach

Figure 13.10  Acute hepatitis A with confluent necrosis showing a larger area of necrosis of hepatocytes surrounded by lymphocytes and macrophages (also see eSlide 13.4).

A

A

B Figure 13.12  Histologic features of liver regeneration in acute hepatitis. A, Binucleation of hepatocytes (arrows) and widening of liver cell trabeculae (arrowhead) are morphologic evidence of liver cell regeneration. B, Reticulogenesis seen as a thin network of delicate, black thin fibers of reticulin (arrows) denotes regenerative activity (Gomori silver stain).

B Figure 13.11  Bridging necrosis in acute hepatitis A. A, An extensive area of necrosis of hepatocytes has led to an irregular strip of edematous conjunctive tissue (arrows). B, Silver stain shows reticulin collapse forming a bridge linking a portal tract to an adjacent terminal vein (arrows). Several smaller foci of collapse are also seen (Gomori silver reticulin).

on Gomori silver stain, whereas collagen I bands appear golden brown (see figure in Chapter 1). In addition, chronic fibrogenesis is accompanied by production of elastic fibers, which may be visualized by the Shikata orcein, van Gieson, or Weigert stain. On the other hand, areas of acute collapse lack elastic fibers.17 Regeneration is an important process in hepatitis. In common forms with apoptosis and spotty necrosis, regeneration from neighboring 196

mature hepatocytes is usually adequate to restore liver structure and is identified in early biopsies as a widening of liver cell trabeculae, focally depicting a pattern of “double cell plates” of hepatocytes, which may be binucleated and, less commonly, multinucleated (Fig. 13.12). Intense hepatocytic regeneration may lead to the appearance of pseudoacinar groups of liver cells.12,17,18 In very severe cases, when regeneration of adult hepatocytes proves ineffective, activation of a common progenitor epithelial cell of the liver, purported to be located in the canals of Hering in the periportal regions, may lead to a network of small tubular-canalicular structures reminiscent of biliary ductules. These are embedded in variable amounts of collagen and may lead to a fibrous scar as in cases of submassive/massive hepatic necrosis (Fig. 13.13).19 In experimental conditions of extensive hepatic necrosis, when neither regeneration of adult hepatocytes nor activation of hepatic progenitor cells is effective, activation of a bone marrow stem cell has been demonstrated. However, most authors believe this is a rare event in humans.19,20 The fate of liver microarchitecture after acute hepatitis depends on the etiologic agent as well as the patterns of necrosis and regeneration. Hepatic structure and function are usually completely restored in a few months in cases where parenchymal damage consisted only of apoptosis or spotty necrosis. However, variable degrees of fibrous scars may develop in cases with more extensive

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A

B Figure 13.13  A, Postmortem biopsy from a case of fulminant hepatitis D virus infection. Submassive necrosis with loss of trabecular architecture and formation of pseudoacini; the latter may indicate regeneration. B, Submassive hepatic necrosis with pseudoacini and ductular reaction (arrows); the latter is thought to result from activation of a hepatic progenitor cell (Gomori silver stain). (A, Courtesy Leonidas Braga-Dias Jr, MD, Pará, Brazil.)

confluent or submassive/massive necrosis, even after resolution of the infection.

Histologic Clues to the Causative Virus Although most histologic patterns are common to all types of acute hepatitis, some features are more frequently associated with specific viruses. Hepatitis A Lobular features almost always dominate the picture, usually with spotty necrosis and many apoptotic bodies. However, in several instances, the portal infiltrate may be more impressive and may contain a prominent component of plasma cells in addition to lymphocytes. Spillover of these leukocytes into the limiting plate may occur, raising the possibility of chronic interface hepatitis, especially in cases with prolonged or relapsing disease, which may last for more than 6 months. Minor cholestasis may be seen in these cases.21 Hepatitis E HEV is a nonenveloped, single-stranded positive polarity ribonucleic acid (RNA) molecule, classified in the family Herpesviridae with three open reading frames virus with an icosahedral symmetry and is between 32 and 34 nm in diameter.22,23

Hepatitis E infection is endemic in the Indian subcontinent, subSaharan Africa, and Mexico, where infection is waterborne. In many industrialized countries, including the United States, France, and Japan,24,25 infection is acquired either as a food-born zoonotic disease or following travel to endemic areas. Transmission through blood transfusions has been reported in a study from England; viremia from genotype 3 HEV was demonstrated in 79 out 225,000 blood donors and evidence of infection in 18 of 43 recipients (42%). Five of these patients did not clear the infection at follow up of at least 10 weeks and all of them had a clinical condition that led to an immunosuppressed state.26 Acute hepatitis E, most commonly reported as presenting a benign clinicopathologic picture, has a classic pattern of lobular hepatitis with apoptosis and spotty necrosis of hepatocytes. A variable degree of bile pigment accumulation is found in hepatocytes and bile canaliculi. Prominent lipofuscin pigment may be seen in hypertrophic Kupffer cells. A peculiar pattern of mixed inflammation consisting of several polymorphonuclear cells amid lymphocytes has been frequently reported. Peron and colleagues published a series of 11 cases from France, with marked necroinflammatory activity in 9 patients24 and confluent necrosis in 5. Although these authors acknowledged a recruitment bias, 3 patients died. Anisokaryosis and Kupffer cell aggregates with siderosis was found in most of the 11 patients, cholestasis in 8 cases and cholangitis in 9. Characteristic pathologic signs of acute hepatitis E included severe intralobular necrosis, polymorphonuclear inflammation, and acute cholangitis with numerous neutrophils. Similar findings have just been published from Germany: from paraffin-blocks of 221 liver biopsies with acute hepatitis of obscure etiology, Drebber et al.27 extracted RNA and performed reverse transcription polymerase chain reaction (RT-PCR), resulting in positive results in seven patients with genotype 3 detected in four cases. Histopathology of the biopsies revealed a classic acute hepatitis with cholestatic features and in some cases confluent necrosis in zone 3. Beyond relevant histologic findings, this study demonstrates that the diagnosis can be made in paraffin-embedded liver biopsy specimens reliably when no serum is available and also the genotype can be determined. Agrawal et  al. performed postmortem liver biopsies in 11 cases of fulminant hepatitis E from India and compared histologic findings with those from sporadic cases reported in Europe.28 These cases showed prominent hepatocytic necrosis, with no particular zonal distribution of the portal infiltrate or hepatocytic necrosis. Lymphocytic cholangitis and cholangiolitis were found in 50% of biopsy specimens and cholestasis in 90% of the postmortem biopsy specimens. Hepatocyte pseudorosette formation was observed in 70% of biopsy specimens, similar to studies from endemic regions,29 but contrasting with the low frequency of pseudorosettes in sporadic cases from the West.24 Prominence of Kupffer cells has been reported both in studies from Europe as well as those from India and West Africa.28,29 Host and viral factors that determine the severity of illness caused by HEV infection are not fully understood. Viral factors, such as the HEV strain (genotype or subtype), viral load, and other coinfections, might play a role in pathogenesis. It appears that genotype 3 and 4 strains are less pathogenic in humans relative to genotypes 1 and 2.30 Host factors, such as pregnancy, use of contraceptives, age, and preexisting liver disease clearly appear to be important. In addition, host immune response may also play a significant role. Persistence of infection leading to chronic hepatitis has been observed in patients under immunosuppressive conditions, such as transplant recipients or patients with hematologic neoplasms. Some of these patients developed chronic HEV infection progressing to cirrhosis.31 Moreover, distinct from other causes of acute viral hepatitis, hepatitis E has been consistently associated with a high rate of severe disease in pregnant women. Acute HEV infection is especially severe during second and third trimesters of pregnancy, and may lead to fulminant

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Practical Hepatic Pathology: A Diagnostic Approach hepatic failure and death in 30% to 100% of patients.22 There is also an increased number of obstetric complications, especially premature rupture of membranes, postpartum hemorrhage, spontaneous abortions, and intrauterine fetal death. As reviewed by Perez-Gracia,22 such severity is postulated to result from estrogen and progesterone changes, as well as immunologic downregulation of nuclear factor-kappa-B and shift in T helper-1 cells/T helper-2 cells (Th2) balance toward Th2.32 In a promising approach to the etiologic diagnosis of Hepatitis E, Gupta et al.33 produced monoclonal antibodies directed to recombinant hepatitis E virus proteins codified at ORF2 and ORF3. An immunohistochemical assay tested on 30 liver biopsy specimens collected postmortem from patients of ALF caused by HEV infection, yielded positive results in all paraffin-embedded samples from these 30 cases. Fifteen controls used (five noninfected liver tissues, five HBV- and five HCV-infected liver tissues) were all negative. If these results can be validated, this immunohistochemical approach may prove a valuable tool for prospective and retrospective assessment of the worldwide extent of HEV-associated hepatitis. Hepatitis B No particular histologic pattern is consistently reported in acute hepatitis B (eSlide 13.2), not even ground-glass hepatocytes or sanded nuclei, which, in chronic forms, are highly suggestive of HBV infection.10 The absence of demonstrable viral antigens is considered to be a result of immune clearance. The lack of immunohistochemical expression of hepatitis B surface antigen or hepatitis B core antigen in acute hepatitis B has been used to differentiate it from chronic disease in asymptomatic cases with minimal lesions at biopsy.34 Hepatitis C Histologic reports of acute hepatitis C in immunocompetent patients are scarce. These reports usually mention mild nonspecific microscopic findings (eSlide 13.1), with mild to moderate lobular inflammation and relatively mild hepatocytic lesions with less ballooning and fewer apoptotic bodies than other viruses.35,36 Johnson and colleagues reported a series of five symptomatic cases from Johns Hopkins Hospital, suggesting a possible sequence of events in the evolution of the disease.37 In two cases that underwent biopsy in the first 2 weeks, cholestasis and ductular reaction raised the differential diagnosis of early findings of biliary tract disease. Two cases, which underwent biopsy at 8 weeks, showed mild to moderate lobular and portal lymphocytic inflammation without cholestasis. The only patient who had flares in hepatic enzymes after spontaneous HCV clearance, who underwent biopsy at 18 weeks, showed mild portal lymphocytic inflammation, minimal interface hepatitis, and moderate lobular lymphocytic inflammation. Some previous studies reported other features not prominent in their series, such as steatosis, and ductocentric aggregates of lymphocytes. Therefore Johnson and colleagues concluded that histologic manifestations of acute HCV are variable and depend on the time interval between clinical presentation and liver biopsy; most cases show mild-to-moderate lobular lymphocytic hepatitis. Although available immunohistochemical detection of HCV antigen is not sensitive enough to be useful for routine diagnosis, the expression of single-chain variable fragment (scFv) antibodies on the surface of bacteriophage against HCV core protein seems to be a promising immunohistochemical strategy for detection of specific HCV proteins in liver samples.38,39

Other Viruses Causing Acute Hepatitis Hepatitis D (Delta) Virus

HDV is an incomplete, replication-defective RNA virus that requires the molecular machinery of HBV to complete its life cycle. Thus, HDV causes acute and chronic hepatitis by coinfection with or superinfection 198

of HBV.40,41 Replication of HDV depends on the delta antigen, which binds to viral RNA in the nucleus of infected hepatocytes by a double rolling-circle mechanism. Similar to HBV, HDV is most often transmitted by contact with contaminated blood and body fluid. HDV is prevalent in the Mediterranean areas of Europe and Africa, Asia, Eastern Asia, and the Amazon regions of South America. Approximately 5% of the global carriers of HBV are coinfected with HDV, leading to a total of 10 to 15 million carriers of HDV worldwide.41 Coinfection of genotype I of HDV and genotype C of HBV has recently been shown to have a higher risk of adverse outcomes. In Brazil, a high prevalence of genotypes I and III in the Amazon region has been reported.42,43 Important shifts in epidemiology of hepatitis delta have occurred in last 2 decades. Although vaccination against HBV dramatically reduced the circulation of both HBV and HDV in countries with active public health systems, hepatitis D is returning to Western Europe through immigration from HDV endemic areas. Hepatitis D is being rediscovered as a significant medical impact on areas of Africa, Asia, and South America where the partner HBV is not well-controlled44 Clinical Manifestations and Natural History In the Amazon regions of South America and in Africa, superinfection of HBV carriers with the delta virus may lead to epidemic bouts of severe acute viral hepatitis, also known as black vomiting fever. This disease is known by different regional names such as Bangui fever in Africa, Santa Marta hepatitis in Colombia, and Labrea hepatitis in Brazil.45,46 The disease may progress to hepatic failure and death within a few days or weeks, especially in children and young adults.45 Thus, the clinical course of Labrea hepatitis may resemble fulminant yellow fever, with fever, jaundice, bloody vomits (black vomits), and finally hepatic coma and death.47 Chronic hepatitis is also a major complication of hepatitis D infection, occurring in up to 70% to 80% of cases of coinfection or superinfection of HBV.40,44,45 At present, treatment of the disease remains empirical, based on alfa interferon, introduced in clinical practice 30 years ago. As recently reviewed by Rizzetto,44 the results are limited. New therapeutic strategies targeting HDV entry into cells or the assembly of the viriron are being explored. Pathology Histopathologic findings of Labrea hepatitis have been described as acute or subacute hepatic atrophy, hyaline necrosis, fat and ballooning degeneration with the presence of large “spider/morula cells,” preservation of canalicular structure, and scarce lymphoid infiltrate (see Fig. 13.13).14,46 However, in several cases, lack of these typical findings or overlap of morphologic criteria may make distinction from yellow fever difficult. We assessed this differential diagnosis in 42 cases of fulminant hepatic failure from the Amazon basin.14 The most discriminating findings in Labrea hepatitis were extensive, predominantly lytic hepatocytic necrosis, portal and hepatic vein phlebitis, and morula cells (large hepatocytes, with large central nuclei and microvesicular steatosis) in a background of chronic liver disease. When present, reactivity for hepatitis D antigen in the nucleus of hepatocytes is pathognomonic (Fig. 13.14).14,45 Many cases show advanced stages of fibrosis with large fibrous septa and, frequently, with cirrhosis. Distinct from most cases of chronic HBV infection, patients who are superinfected with HDV show marked periportal and periseptal activity, even when cirrhotic (see Fig. 13.14). Parenchymal activity is also frequently severe, with confluent necrosis.14,45,46

Herpesviruses Herpesviridae is a family of large, encapsulated, double-stranded DNA viruses encoding 100 to 200 genes encased within an icosahedral capsid.

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A

B

C

D Figure 13.14  Hepatitis D virus (HDV) infection. A, Panacinar necrosis is seen in this case of fulminant HDV infection. B, The very large ballooned hepatocyte microvesicular steatosis and a large central nucleus with a prominent nucleolus, morula cell (arrow), is considered a possible cytopathic effect of HDV in cases of fulminant hepatitis. Inset: Cytoplasmic and nuclear immunohistochemical positivity for HDV antigen (delta antigen) in a morula cell reinforces the hypothesis that this cell represents the cytopathic effect of HDV. Delta antigen, polymer-amplified peroxidase immunohistochemistry. C, Chronic hepatitis D. Portal tract expansion by fibrosis and an intense mononuclear infiltrate with interface hepatitis. D, HDV antigen (delta antigen) is expressed in several hepatocytes in this case of chronic hepatitis D. HDV antigen, polymer-amplified, peroxidase immunohistochemistry. (A and B, Courtesy Leonidas Braga-Dias Jr, MD, Pará, Brazil. C and D, Courtesy Juliana Freitas, MD, Bahia, Brazil.)

All herpesviruses are nuclear-replicating.48 Infection by herpesviruses is highly prevalent worldwide. Primary infection is acquired in childhood or adolescence, with most cases remaining asymptomatic. Congenital infection may cause severe disease in multiple organs, including hepatitis. Opportunistic infection by herpesviruses is a significant cause of morbidity and mortality in immunocompromised individuals. Epstein-Barr Virus EBV is transmitted mainly by saliva. Rare cases of posttransfusional infections have also been reported. Following initial replication in pharyngeal epithelial cells, EBV infects B lymphocytes and reaches the liver through the systemic circulation. EBV antigens expressed on the membranes of B lymphocytes trigger a vigorous T-cell response, especially of CD8+ T cells, which is considered the major pathogenic mechanism for systemic manifestations of infectious mononucleosis.49

Liver Disease Caused by Epstein-Barr Virus. Primary EBV infection occurring in children is largely asymptomatic or minimally symptomatic. However, approximately 50% of all primary infections in adolescents and adults present as infectious mononucleosis with malaise, fever, throat pain, and a characteristic white membranous exudate on the palatine tonsils. More than 90% of patients have lymphadenopathy, usually generalized, as well as hepatomegaly and splenomegaly. Liver involvement in infectious mononucleosis is selflimited in the majority of cases. In some, it may be prolonged, but evolution to a histopathologic pattern of chronic hepatitis does not occur. Approximately 10% of immunocompetent patients infected by EBV have jaundice and conjugated hyperbilirubinemia. Almost 50% show elevation in aminotransferase levels, which is usually mild with less than 10% of these patients having levels 10 times the upper limit of normal.50 199

Practical Hepatic Pathology: A Diagnostic Approach A review from the series of 1887 adult ALF patients reported to the United States ALF Study Group from 1998 to 2012, four patients (0.21 %) had EBV-related ALF, only one (25%) immunosuppressed. Liver biopsy findings ranged from cholestasis to submassive necrosis with EBV encoded RNA (EBER) plus in situ hybridization in two of the three samples tested. All patients were treated with an antiviral agent, two died of ALF, one underwent liver transplantation, and one survived with supportive care and is well at 5 years. A review of the literature identified four additional liver transplant recipients with favorable long-term outcome.51 In immunocompromised patients, such as those infected by the human immunodeficiency virus (HIV) or those receiving therapeutic immunosuppression for maintenance of an organ graft, the disease manifestations may be severe and include EBV-driven lymphoproliferative disease (discussed in Chapter 38). Pathology. The most remarkable histopathologic feature of EBVrelated hepatitis is the presence of a dense lymphocytic inflammatory infiltrate that is present within sinusoids and portal tracts; the lymphoid cells are enlarged and appear atypical (activated). The density of the infiltrate, the atypical appearance, and the sinusoidal pattern of infiltration may be mistaken for a leukemic infiltrate (Fig. 13.15). The infiltrate does not typically damage hepatocytes in the lobules, and there are no necroinflammatory lesions. Apoptotic hepatocytes may be seen, but the degree of cellular damage is minimal compared with the degree of inflammation. Similarly, although the lymphoid infiltrate may spill over from the portal tracts into the adjacent parenchyma, it does not destroy cells at the portal interface (eSlide 1.15).49,50,52 Diagnosis. Diagnosis of infectious mononucleosis is established by the detection of heterophilic antibodies to EBV by the Monospot or Paul-Bunnell-Davidsohn test or the detection of immunoglobulin M (IgM) antibodies against EBV viral capsid antigen. Lymphocytosis with more than 1000 atypical lymphocytes per cubic millimeter is characteristic and present in more than two thirds of patients. Diagnosis can be established on a liver biopsy specimen by immunohistochemistry for EBV viral capsid antigen or in situ hybridization for EBV nucleic acids (see Fig. 13.15). The latter technique is much more sensitive, especially for detecting EBER sequences, for which it is reported to be as sensitive as PCR.51,53 Cytomegalovirus Seropositivity for CMV is very common in most regions of the world. Transmission is usually oral-oral, involving saliva, but may also involve other secretions such as urine, semen, or uterine cervical fluid. Transmission by blood (transfusional) is rare. Liver Disease Caused by Cytomegalovirus. CMV is the most common cause of congenital infection and is reported in 0.2% to 2.2% of neonates. However, only about 10% of infected neonates present with clinical manifestations. Neonates with severe cases may present with prematurity and various combinations of neurologic dysfunction, jaundice, and hepatosplenomegaly. Laboratory investigation may show hyperbilirubinemia, thrombocytopenia, and elevated aminotransferases. In the postneonatal period, primary CMV infection is most common in teenagers, in whom it presents as an infectious mononucleosis–like syndrome. Hepatic dysfunction is seen in up to 30% of these cases. Cases of fulminant hepatic failure have been described.54,55 Hepatosplenomegaly and lymphadenopathy are present in more than 80% of cases, and variable degrees of jaundice are found in less than 50% of patients. Prolonged fever lasting more than 10 days and a maculopapular cutaneous rash may be useful in differentiating CMV hepatitis from other causes of acute hepatitis. CMV is an important cause of fever of intermediate duration, which is defined as a body temperature of more than 38° C lasting between 1 and 4 weeks. In a study from Granada, 200

A

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C Figure 13.15  Epstein-Barr virus (EBV) infection. A, Dense lymphocytic infiltrate is present in portal tracts and lobular parenchyma. Notice the linear infiltration of lymphocytes along the sinusoids. B, Dense portal infiltration by small and large lymphocytes. The portal interface is blurred, but there is no hepatocyte necrosis, a picture known as spillover (also see eSlide 1.15). C, Chromogenic in situ hybridization shows EBV encoded RNA (EBER) sequences in infected lymphocytes. In situ hybridization for EBER.

16 of 80 patients (20%) with fever of intermediate duration had CMV infection, and 93% of these had elevated aminotransferases.56 Pathology. Congenital CMV infection may lead to neonatal hepatitis, which is discussed in Chapter 5. Histologically, there is portal and lobular inflammation, cholestasis, variable degrees of extramedullary hemopoiesis, and giant cell transformation of hepatocytes. The

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Figure 13.16  Cytomegalovirus hepatitis in an immunocompetent patient showing a microgranuloma with otherwise minimal parenchymal changes.

presence of typical inclusions provides the etiologic diagnosis. These inclusions may be found in variable numbers in bile duct epithelium, hepatocytes, and endothelial cells. The infected cells are greatly enlarged (cytomegaly) and contain an enlarged nucleus with an inclusion that may be either eosinophilic or basophilic, surrounded by a clear halo leading to a characteristic owl’s eye appearance. Variable numbers of basophilic granules are present in the cytoplasm of the infected cells. Ultrastructurally, the nuclear inclusion corresponds to dense aggregates of CMV virions. Histologic findings of CMV hepatitis in immunocompetent patients are usually not pathognomonic. In most cases, a variable degree of lymphocytic portal infiltrate may coexist with sinusoidal lymphocytes, similar to the histologic appearance of EBV hepatitis. Aggregates of macrophages, sometimes forming microgranulomas, may be seen (Fig. 13.16). There may be focal hepatocyte apoptosis. CMV inclusions or microabscesses are usually not found. In immunosuppressed patients, such as recipients of allografts, patients infected with acquired immunodeficiency syndrome (AIDS), or those receiving immunosuppressant drugs for other chronic diseases, CMV hepatitis may present as a rather mild lobular hepatitis or, less frequently, as a more severe form (eSlide 38.22).57 Hepatocyte inclusions, as described previously, are almost pathognomonic, even when not surrounded by inflammation. Microabscesses consisting of collections of neutrophils surrounding an infected hepatocyte containing a CMV inclusion are typical findings. CMV inclusions may also be found in biliary duct epithelium and endothelium (Fig. 13.17).58,59 Immunohistochemical detection of CMV antigen may highlight infected cells, especially those with atypical or less-developed inclusions. Early-expression genes encode for proteins located in the nucleus of infected cells and are more reliable markers for CMV identification, whereas late-expression genes encode for proteins that may be found in the cytoplasm of infected cells (see Fig. 13.17). Lu and colleagues reported that chromogenic in situ hybridization can detect CMV DNA sequences in paraffin sections with moderate sensitivity (67.6%), which is slightly lower than with CMV antigen detection (75.7%). Both methods demonstrated 100% specificity.60 Diagnosis. Diagnosis can be made by histology, viral cultures, or serologic tests that detect antibodies or viral proteins. Serologic detection of antibodies against CMV, especially those of the IgM class, is the usual approach to etiologic diagnosis. A sensitive multiplex PCR DNA array, which allows simultaneous detection and species identification of seven human herpesviruses, may be a useful methodology for identifying the etiologic agent in patients presenting with mononucleosis-like

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C Figure 13.17  Cytomegalovirus (CMV) hepatitis in immunosuppressed patients (also see eSlide 38.22). A, Several eosinophilic CMV inclusions (arrows) in an otherwise uninflamed parenchyma. B, Eosinophilic CMV inclusions within bile duct epithelium (arrows). C, A microabscess consisting of neutrophils around a hepatocyte that appears to have been enlarged. Inset: Nuclear immunohistochemical positivity for CMV. CMV antigen, polymer-peroxidase immunohistochemistry.

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Practical Hepatic Pathology: A Diagnostic Approach syndrome. This array simultaneously detects herpes simplex virus types 1 and 2 (HSV-1, HSV-2), varicella-zoster virus, EBV, CMV, and human herpesvirus 6 (HHV-6A, HHV-6B). Immunohistochemical detection of early expressed antigens of CMV as well as CMV DNA sequences by in situ hybridization are specific, but sensitivity does not seem to match that achieved by PCR.61,62 A peripheral smear shows lymphocytosis with many atypical lymphocytes, as it does in EBV infections. Human Herpesvirus 6 Although many acute infections due to HHV-6 are asymptomatic or poorly symptomatic with a spontaneous favorable outcome, some have been credited with serious clinical manifestations affecting central nervous system, liver, gastrointestinal tract, lungs, and bone marrow. The main favoring factor for such serious diseases is cellular immune deficiency.63 HHV-6 preferentially infects T lymphocytes in children, leading to a transient cutaneous rash (exanthema subitum, roseola infantum) with fever that usually subsides in a few days. It may rarely cause acute hepatitis, more commonly in allograft recipients or HIV-infected individuals than in immunocompetent people. Hemophagocytic syndrome has also been reported. Fulminant hepatitis and cytopenias, as well as neurologic and gastrointestinal disease in immunocompromised hosts, have been described. HHV-6 is sensitive to ganciclovir; thus disease due to HHV-6 may be mistakenly ascribed to CMV. Specific diagnosis can be made by detecting antigenemia by serology and viral nucleic acid sequences by PCR.64,65 Herpes Zoster The etiologic agent of chickenpox, herpes zoster infection almost never affects immunocompetent patients. However, submassive/massive hepatic necrosis may ensue in patients treated with steroids or with chemotherapy. In most of these cases, pathognomonic intranuclear herpetic inclusions are abundant. Immunohistochemistry for detection of early-expressed proteins is sensitive and specific for herpes groups. PCR detection of herpes zoster DNA yields the most sensitive and type-specific diagnosis.66,67 Herpes Simplex Virus Types 1 and 2 Herpes simplex is a viral disease caused either by HSV-1 or HSV-2. Oral herpes, ascribed to HSV-1, is the most common, appearing as blisters evolving to cold sores on the face and in the mouth. Genital herpes, usually related to HSV-2, is often asymptomatic, but it may also appear as vesicles or ulcers, mostly in the vagina or uterine cervix.68 Transmission of herpes simplex occurs through direct contact with a lesion or an infected body fluid, even in periods of asymptomatic shedding. Most cases of severe, fulminant hepatitis that are due to herpes simplex have been reported in infants or in patients who have been immunosuppressed for treatment of cancer or maintenance of organ allografts; it may also occur in patients infected with HIV.69,70 HSV-1 and HSV-2 may rarely cause acute hepatitis and even fulminant hepatic failure in immunocompetent individuals as a primary or recurrent infection. HSV DNA was found in four cases of acute liver failure in a series of 67 patients71; two patients died within the first 2 days, and the other 2 patients underwent liver transplantation. Both developed posttransplant extrahepatic HSV infection despite treatment with acyclovir. Jacques and Qureshi reported the occurrence of three cases of HSV hepatitis in pregnant women, two of whom died.72 Elevated transaminases, which may be very high, together with leukopenia and a relatively low bilirubin level may point to the diagnosis of HSV hepatitis. Disturbances of coagulation as well as a reduced level of consciousness are markers of an ominous prognosis. The diagnosis may be difficult to make because of lack of mucocutaneous involvement in 202

several cases. A review of the most accurate methods for the etiologic diagnosis of herpes simplex virus was recently published by Anderson et al.73 Pathology. The histologic findings are distinctive, with randomly distributed, patchy areas of coagulative necrosis that demonstrate sharp borders with the adjacent viable parenchyma, giving rise to the terms punched-out necrosis and punctate necrosis. Hepatocytes at the periphery of these areas of necrosis demonstrate enlarged nuclei with ground-glass intranuclear viral inclusions; syncytial multinucleated cells are often present (eSlide 13.5). Viral antigen can be demonstrated by immunohistochemistry.74 Diffuse, almost total hepatic necrosis with no viral inclusions and virtually no inflammatory response has been described in a pregnant patient with acute liver failure due to HSV. Immunohistochemical studies in this case were negative, but viral cultures were positive.72 This histologic pattern is also seen in neonates with HSV infection. Two types of viral inclusions, Cowdry A and B bodies, have been described in HSV infection (Fig. 13.18). Cowdry A inclusions are small, round, and eosinophilic and are separated from the nuclear membrane by a halo. Cowdry B inclusions are large, ground-glass, eosinophilic, centrally located structures that push nuclear material to the rim of the nucleus. Type A bodies represent an early stage of nuclear infection, whereas type B bodies represent a later stage. Etiologic confirmation can be achieved by immunohistochemical detection of viral antigens or of DNA sequences by in situ hybridization (see Fig. 13.18).75,76

Adenovirus Adenovirus is a nonenveloped, double-stranded DNA virus that causes respiratory tract infection in infancy and early childhood. Infection is endemic worldwide and occurs throughout the year. Primary infection in children is asymptomatic, and seropositivity provides the only evidence of past infection.77,78 Transmission occurs through aerosols, the fecal-oral route, conjunctival secretions, or exposure to infected blood.79 The virus replicates in human epithelial cells and causes cell lysis on completion of its replication cycle. The virus also exists in a latent form in lymphoid cells, from which it can be reactivated when immunity is compromised as in the posttransplant state or in inherited and acquired immunodeficiency conditions, including AIDS. In a recent review of literature, Ronan et al.80 found reports of 89 cases of hepatitis due to adenovirus; 43 (48%) were liver transplant recipients, 19 (21%) were bone marrow transplant recipients, 11 (12%) had received chemotherapy, 5 (6%) had severe combined immunodeficiency, 4 (4%) were HIV infected, 2 had heart transplantation, and 2 were kidney transplant recipients. Fever was the most common initial symptom. Diagnosis was made by liver biopsy in 43 (48%) and on autopsy in 46 (52%). Only 24 of 89 patients (27%) survived: 16 whose immunosuppression was reduced, 6 with liver retransplantation, and 2 who received cidofovir and intravenous immunoglobulin. Thus, although the virus rarely causes hepatitis in immunocompetent individuals, hepatitis is severe in immunocompromised hosts, progressing rapidly to acute hepatic failure if not managed urgently. Pathology The typical pattern of adenoviral hepatitis consists of punched-out areas of necrosis that are scattered randomly in the parenchyma. Hepatocytes at the periphery of these necrotic areas usually contain nuclear viral inclusions. These are basophilic and slightly angulated and have a ground-glass appearance, making the nucleus look smudgy. Cytoplasmic aggregates of basophilic material represent viral products. Variable amounts of inflammatory cells accompany the infected hepatocytes and consist mostly of macrophages and lymphocytes. The centers of the necrotic areas may contain neutrophils or nuclear debris. Variable

Acute Viral Hepatitis amounts of mononuclear portal inflammatory infiltrate and scattered granulomas may be seen. The diagnosis can be confirmed by immunohistochemistry with specific antibodies that highlight infected cells at the periphery of the necrotic areas (also see eSlide 38.24).81-83

A

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Diagnosis Many adenovirus serotypes can be isolated in cell culture lines commonly used in diagnostic virology laboratories, whereas others fail to grow. Sensitive serologic tests are available, but a single result is of no value because the majority of individuals are seropositive for the virus. Ideally, serum should be obtained as early as possible, followed by a second sampling 2 to 4 weeks later to demonstrate a four-fold rise in titers, which is considered diagnostic of acute infection. The use of PCR and other rapid molecular diagnostic assays in the management of infection in immunosuppressed persons is under investigation, and these tests have not been standardized for routine use.82 A liver biopsy offers rapid diagnosis when viral inclusions are present or when the antigens can be demonstrated by immunohistochemistry.58,80

Parvovirus

B

Human parvovirus B19, a member of the family Parvoviridae, is a nonenveloped virus containing a single copy of a single-stranded linear DNA with approximately 5000 nucleotides. This virus encodes for two major structural or capsid proteins, VP1 and VP2, as well as one nonstructural protein, NS1.84 The spectrum of human disease ascribed to parvovirus B19 is wide, ranging from childhood rash (erythema infectiosum) to transient aplastic crisis, spontaneous abortions, hydrops fetalis, fetal death, hemophagocytic syndrome, myocarditis, neurologic disease, and systemic vasculitis. Although causality has been established in some of these conditions, such as erythema infectiosum and aplastic crisis, coincidence is suspected in others, and additional studies are required to distinguish the incidental presence from pathogenic findings.84 Parvovirus B19 infection has been reported in cases of acute hepatitis, including cases of fulminant hepatitis.85-88 These manifestations are reported in immunocompetent and in immunodeficient patients, sometimes with hemolytic abnormalities, and usually the clinical course is followed by complete remission. In addition, disease exacerbation in patients with cirrhosis has been ascribed to superinfection with parvovirus B19.89 Liver biopsy depicts hepatocellular and canalicular cholestasis, apoptosis, and variable amounts of necrosis depending on immune status of the host and the severity of liver involvement.90

Icteric Hemorrhagic Fevers

C Figure 13.18 Fulminant hepatitis due to herpes simplex virus (HSV) infection. A, Extensive hepatic necrosis with minimal inflammation. Two types of intranuclear inclusions are seen: Cowdry A consisting of amphophilic clumps of viral particles surrounded by clear nuclear halos (arrows) and Cowdry B demonstrating ground-glass inclusions occupying almost the entire nucleus and compressing chromatin against the nuclear membrane (arrowheads) (also see eSlide 13.5). B, Immunohistochemical detection of HSV 1 and 2 antigens in the nuclei of infected hepatocytes. HSV 1 and 2 antigens, polymer-peroxidase immunohistochemistry. C, Positive chromogenic in situ hybridization for herpes simplex II DNA sequences in uninucleated (arrow) as well as syncytial multinucleated hepatocytes (arrowhead). HSV 2 chromogenic in situ hybridization. (C, Courtesy Maria Irma Seixas Duarte, MD, São Paulo, Brazil.)

Viral hemorrhagic fevers (VHF) are systemic infections leading to vascular lesions, with a clinical course that ranges from protean, asymptomatic cases to severe, fatal forms. The etiologic agents, enveloped RNA viruses, from the families Flaviviridae, Arenaviridae, Filoviridae, and Bunyaviridae, depend on animal reservoirs such as arthropods, rodents, ruminants, and primates, and therefore usually infect humans in regions where these animals live, mostly the tropics. Epidemiologic studies have demonstrated that human-to-human transmission or aerosol infections happened in outbreaks of some of these viruses, multiplying the dissemination of these diseases.91,92 Although infections by filovirus such as Ebola and Marburg have so far been associated with the highest fatality rates, it must be acknowledged that most cases of VHF are initially identified by their most severe manifestations, whereas milder or even asymptomatic cases are identified only subsequently by systematic epidemiologic studies. Applying mathematic models, Johansson et al. demonstrated that even yellow fever, one of the most feared hemorrhagic fevers, leads to asymptomatic infection in 55% and a mild clinical disease in 33% of outbreak cases, with severe cases accounting for only 12%.93 203

Practical Hepatic Pathology: A Diagnostic Approach The clinical picture varies among different viruses and in each specific outbreak. However, most typically, symptomatic cases present with fever, headache, myalgia, diarrhea, vomiting, and abdominal pain, with vascular lesions leading to petechial rash, larger hematomas, internal bleeding and, in fatal forms, massive hemorrhage, shock, and disseminated intravascular coagulation because these viruses most usually infect preferentially the endothelial cells. Activation of the mononuclear phagocytic system, as well as high production of cytokines and activation of the coagulation cascade and platelet aggregation are major pathogenetic mechanisms. Liver involvement is variable, most usually with serum aminotransferase elevations of up to 10 times the normal values and reaching more than 100 times the upper limit of normal in yellow fever, where hepatocytes are major targets of the virus and may lead to failure in production of coagulation factors, thus adding to the severity of the hemorrhagic state. At the time of going to press in 2016, numerous cases of other arthropod-borne viruses, specifically Zika virus and chikungunya virus, potentially leading to VHF are being reported from several Latin American countries and from the southern United States; however, it does not seem that the liver is a major target of these agents.94,95 Yellow Fever Virus Yellow fever (YF), the prototype of VHF, occurs predominantly in tropical regions. From 1985 to 2009, the World Health Organization (WHO) was notified of 27,467 cases in Africa and 3988 in South America.96 Official notifications to the WHO are based on passive surveillance; thus the actual incidence may be underestimated. In the last two decades, the yellow fever virus has disseminated from the endemic Amazon region to the central Brazilian states of Goiás and Mato Grosso do Sul, as well as to the neighboring countries of Paraguay and Argentina, where YF had not been recorded for more than three decades. In addition, several outbreaks were reported from Colombia and Peru.96 The etiologic agent is an arbovirus (arthropod-borne virus) of the family Flaviviridae, which includes approximately 50 viruses, including the West Nile virus. These viruses replicate in mosquitoes (Aedes aegypti and Haemagogus) and primates, including humans, and transmission involves hematophagous mosquitoes.97 Yellow fever is found in both urban areas and the wild: A. aegypti mosquitoes transmit the urban form; Haemagogus mosquitoes, whose natural habitat is the jungle, become infected by feeding on sick primates and transmit the wild form. Liver Disease Caused by Yellow Fever Virus. After 4 to 5 days of incubation, the patient presents with fever, headache, diffuse myalgia, photophobia, chills, and jaundice. A high proportion of patients develop severe hepatitis, renal failure, and hemorrhage, and as many as 40% to 50% of these cases progress to rapid terminal events with shock and multiorgan failure.47,94 Pathology. The major histologic finding is hemorrhagic hepatocyte necrosis, which is predominantly midzonal (zone 2) but may be panacinar in severe cases. An important feature in many acini, useful for the morphologic differential diagnosis with other causes of extensive hepatic necrosis, is the frequent presence of nonnecrotic rings of periportal and perivenular hepatocytes in zones 1 and 3, respectively (eSlide 13.3). Numerous apoptotic bodies (Councilman bodies), both nucleated and nonnucleated, are found amid this extensive hemorrhagic necrosis, especially at the borders with less-damaged hepatocytes (see Fig. 13.5B; Fig. 13.19). Widespread fatty change, both macrovesicular and microvesicular, is also present (see Fig. 13.19).97-99 Yellow fever viral antigen is abundantly found on immunohistochemical staining, and high antigenic expression is seen in apoptotic cells as well as in hypertrophic Kupffer cells (see Fig. 13.19). 204

Quaresma et al. assessed the role of the host immune response in pathogenesis of fatal YF cases.100,101 Apoptosis seems to be a major mechanism of cell death, probably because of very high production of transforming growth factor beta (TGF-β), a potent inducer of apoptosis and antiinflammatory cytokine prominent during the course of the disease. TGF-β is also probably a major factor for downregulation of inflammatory infiltrates despite the extensive necrosis. The immune response is prominently Th1 oriented and the proinflammatory cytokine IL-6 is also markedly expressed. CD4+ helper lymphocytes, CD8+ cytotoxic lymphocytes, and CD57+ NK cells are major components of inflammation, whereas neutrophils and plasma cells are rather scarce. Viral antigens, found in affected hepatocytes of zones 2 and 3, usually amidst scarce inflammation, are strong signals of a direct cytopathic (apoptotic) effect of YF virus on hepatic cells, which results in damage to hepatocytes and Kupffer cells.14,98,100 Diagnosis. Besides epidemiologic and clinical symptoms compatible with yellow fever, serologic enzyme immunoassay must detect IgM anti–yellow fever antibody, which appears around the fifth day of disease infection. In previously vaccinated patients, diagnosis is made by a fourfold increase in serum immunoglobulin G antibodies. Immunohistochemical detection, with antibody reported by Hall and colleagues102 or by De Brito and colleagues,103 has been found to be very useful in the differential diagnosis with several other fulminant lesions of the liver, especially in cases where necrosis is extensive, and also when the patient dies within the first days of infection. Recent molecular tests enabled the differential diagnosis of infections caused by wild-type virus versus the 17D vaccine strain. Nunes et  al. developed a protocol to amplify YF viral RNA from paraffin embedded samples. Because histopathology remains the primary means of diagnosing YF, the use of PCR now enables the integration of morphologic basis of the disease with phylogenetic studies on archived specimens.104 Vaccination and Viscerotropic Disease. The presence of only one serotype of the yellow fever virus enabled the successful development in 1936 of a live attenuated (17D) vaccine by serial passage in chicken embryo tissue. The vaccine, used since in more than 400 million people, induces long-lasting neutralizing antibodies in about 99% of vaccinated individuals. Significant progress has also been made over the past decades in the introduction of yellow fever vaccine into routine childhood immunization programs in Africa. In the United States, about 250,000 persons are vaccinated per year to prevent infection during travel or military assignments in tropical regions.47 In 2001, the 17D vaccine, which had been considered extremely safe for decades, was identified as the causative agent of a new syndrome described by Vasconcelos and colleagues105 and Martin and colleagues.106 This viscerotropic disease is an extensive infection of vital organs by the 17D virus, indistinguishable from wild-type yellow fever disease, and carries a 60% case fatality rate. Following the demonstration of the viscerotropic disease, a thorough review of the safety data of 17D yellow fever vaccines demonstrated genetic stability of multiple production lots of the vaccine, the protective immunologic responses of healthy subjects postvaccination, and the long-term immunogenicity of the vaccine.107 Host factors, both genetic (possibly in genes involved in interferon responses) and acquired (advanced age and thymectomy) were subsequently identified as underlying susceptibility to this condition.47,96 The overall incidence is about one in every 200,000 to 400,000 vaccinations, but in persons older than 60 years, the incidence is as high as one in 50,000 vaccinations. In addition, neurotropic adverse events (mainly encephalitis caused by invasion of the brain by the 17D virus) have a similar incidence but a much lower fatality rate (about 6%). The current challenge is appropriate selection of individuals for vaccination, weighing the

Acute Viral Hepatitis

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A

B

C

D Figure 13.19  Histopathologic features of yellow fever (also see eSlide 13.3). A, The characteristic midzonal necrosis, with marked congestion and hemorrhage, spares periportal and perivenular hepatocytes. The nonnecrotic hepatocytes in zone 3 show microvesicular and, predominantly, macrovesicular steatosis. B, The portal tract shows edema, ductular reaction, and a small amount of mononuclear infiltrate. Apoptotic hepatocytes (Councilman bodies) are present at the border of preserved zone 1 and extensively at necrotic zone 2. C, Even in this fatal case with extensive necrosis, a perivenular rim of nonnecrotic, steatotic hepatocytes is seen. D, Yellow fever antigen is preferentially located in the cytoplasm of hepatocytes undergoing apoptosis, stressing the direct relation of the virus with the cellular lesion. Kupffer cells, which have phagocytosed debris from the necrotic hepatocytes, are also positive. Yellow fever antigen, polymer-peroxidase immunohistochemistry.

risks of vaccine-related adverse events against the theoretical benefit of preventing urban yellow fever, especially in nonendemic regions.96 Dengue Virus Dengue virus (DENV), the most prevalent arbovirus in the world, occurs predominantly in tropical and subtropical regions and is transmitted by mosquitos, mainly A. aegypti. The WHO estimates that of the more than two billion people who are at risk of dengue fever, 100 million have already been infected and 250,000 have had the hemorrhagic form of the disease.108,109 Although dengue fever is more prevalent in children, the still developing epidemic in South America has affected both children and adults.109,110 Many infected patients remain asymptomatic. The febrile and selflimiting classical dengue fever is the major presentation in most epidemics with intense headache, fever (frequently reaching 39° C), and intense bone pain. In the severe form of the disease, also known as dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), patients demonstrate

mucosal and cutaneous ecchymotic, petechial and purpuric macules, conjunctival hemorrhage, hepatomegaly, splenomegaly, thrombocytopenia, hemoconcentration, and shock.108 DHF/DSS is fatal in 5% of cases and requires prompt treatment. The risk of DHF/DSS increases with infection by different serotypes of the virus, of which four distinct and antigenically related serotypes (DENV 1, 2, 3, and 4) are known.108 The last decade has witnessed numerous outbreaks of dengue infection in Latin America, leading to an endemic state in several countries as well as outbreaks in Florida. The data coming from Brazil, the largest South American country, are astonishing: during the decade 2000 to 2010, a total number of 8,440,253 cases were reported, with 221,043 (2.6%) severe cases and 3058 fatal cases (1.38% of the severe cases). The serotypes 1, 2, and 3 were differentially prevalent in each Brazilian region, but coprevalence of dengue serotypes was frequent, possibly acting as a major cause for the high number of severe cases.110 During 2009 to 2010, the Florida Department of Health reported 93 autochthonous cases of dengue fever in Key West, Florida, the first autochthonous 205

Practical Hepatic Pathology: A Diagnostic Approach dengue fever cases since 1934.5,6 From November 2010, no cases of dengue have been reported from Key West; however, autochthonous cases have been reported annually since 2010 in other counties of Florida, underscoring the risk of continued local transmission in parts of Florida. Hayden et al. conducted a survey in 2012 with decision makers instrumental to the control of the outbreak. Results indicate the need to focus prevention strategies on educational campaigns designed to increase population awareness of transmission risk.111 Liver Involvement in Severe Dengue Virus Infections. Severe forms of DENV infection demonstrate high level of viremia leading to involvement of several organs. Hepatic manifestations are either a result of direct viral toxicity or dysregulated immunologic injury in response to the virus. As recently reviewed by Samanta and Sharma, liver involvement varies from asymptomatic elevation of aminotransferases to occurrence of severe manifestations, including ALF.109 Both hepatocytes and Kupffer cells are targets for DENV infection. Viral attachment to the receptors present on surface of host cell seems very probable, although the nature of the receptor is yet to be determined. In vitro and in vivo studies have shown that apoptosis is a major mechanism of death of infected hepatocytes, thus leading to numerous Councilman bodies in biopsies or in autopsies. Apoptosis may be the result of combined direct viral cytopathic effect, hypoxic mitochondrial dysfunction, the immune response, and accelerated endoplasmic reticular stress.112 Severe dengue may also derive from antibodydependent enhancement, especially in a second infection.109 Dengue infection induces a cytokine storm, and concentrations of cytokines, such as interleukin (IL)-2, IL-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, reach peak levels in the initial 3 days, whereas IL-4, IL-5, and IL-10 appear later in the course of disease.113 In a recent study from our department, Pagliari et al. assessed the “in situ” host immune response in 14 specimens of liver from patients with dengue hemorrhagic fever (DHF)114: portal tract and hepatic acinus presented high expression of TLR2, TLR3, IL-6, and granzyme B. Hepatic acinus also presented iNOS, IL-18, and TGF-beta. Cells expressing IL-12, IL-13, JAk1, STAT1, and NF-kB were rarely visualized. Treg cells foxp3þ were absent. TLR2 and TLR3 seem to participate in cellular activation and cytokine production. Cytotoxic response seems to play a role. The expression of Treg cells is diminished probably as a result of the high frequency of these cytokines, which, may also contribute to the increased vascular permeability and edema observed in dengue liver specimens, with consequent plasma leakage and severity of the disease. At least in part, the increased number of cells expressing IL-18 could play a role of upregulation of Fas ligand and correlate to the phenomenon of apoptosis, a mechanism of destruction of hepatocytes in DHF.114 Pathology. A wide spectrum of hepatic histologic changes has been noted in dengue. This comprises fatty change (microvesicular), hepatocyte necrosis, hyperplasia and destruction of Kupffer cells, Councilman bodies, and mononuclear cell infiltrates at the portal tract. Hepatocyte injury including necrotic changes commonly involves the midzonal area followed by the centrilobular area. Probable explanation for such a finding could be that the liver cells in this area are more sensitive to the effects of anoxia or immune response or may be a preferential target zone of the DENVs.112,114 Most morphologic data about dengue hepatitis are derived from postmortem studies on cases of DHF/DSS. The major lesions result from infectious vasculopathy that is due to DENV with activation of endothelial cells of the microcirculation. Portal and lobular inflammation is usually scarce, composed mostly of lymphocytes and macrophages. Liver involvement may result in massive midzonal hepatocellular apoptosis/necrosis (eSlide 13.6). However, in contrast to yellow fever, dengue fever may involve periportal or centrilobular areas (zone 3) in addition to zone 2 (Fig. 13.20). A recent autopsy series of dengue patients from 206

A

B Figure 13.20  Dengue hemorrhagic fever (also see eSlide 13.6). A, Extensive hemorrhagic necrosis preferentially involves zones 2 and 3 of the hepatic lobule and, in this example, also affects periportal hepatocytes in zone 1. There is also microvesicular and macrovesicular steatosis, producing a microscopic picture that closely mimics yellow fever. The portal tract contains only a minimal mononuclear infiltrate. B, Immunohistochemical staining for dengue virus antigen shows cytoplasmic positivity in hepatocytes. Dengue antigen, polymer-alkaline phosphatase.

Myanmar115 showed varying degrees of damage in the liver, with the majority of subjects having sinusoidal congestion of moderate to severe degree with predominant midzonal and centrilobular area cell death. Diffuse fatty change was noted within the hepatic lobules. The investigators noted no evidence of any significant fibrosis.115 Diagnosis Diagnosis is established by immunoenzyme serologic tests and, if necessary, reverse transcriptase PCR. When histologic samples are available, immunohistochemical detection of dengue viral antigens is also very useful to establish the diagnosis (see Fig. 13.20).102,108,110,116

Ebola and Marburg Viruses The family Filoviridae consists of Marburg viruses and Ebola viruses, which may lead to hemorrhagic fevers with case fatality rates in the range of 25% to 90%. Severe outbreaks due to person-to-person transmission have occurred over the last decade in several African countries. Bats serve as the major reservoir of infection.91,117 Clinical manifestations included high fever and massive hemorrhages, shock, and disseminated intravascular coagulation. Histopathology of the liver was found to be similar to other VHFs with hepatitis pattern without cholestasis. Main findings

Acute Viral Hepatitis are hepatocellular necrosis, from spotty to confluent and minimal inflammatory infiltrate.117 Characteristic intracytoplasmic viral inclusions are seen within hepatocytes of patients dying with EVD and, less frequently, in those infected with Marburg viruses.118 Ultrastructurally they are composed of aggregates of viral nucleocapsids. The viral inclusions and distribution of antigens can be confirmed by immunohistochemistry.119 Mild to moderate microvesicular steatosis are also reported, as well as Kupffer cell hypertrophy and hyperplasia.117 A small number of EVD cases were diagnosed in Europe and the United States during the present outbreak, and the majority of infections were associated with travel to West Africa.120

Arenaviruses Arenaviruses are segmented negative-sense RNA (nsRNA) viruses divided into the Old World and New World virus complexes.121 Rodents serve as main reservoirs, and humans are infected directly from exposure to rodents’ urine. The range of reservoir rodent species usually restricts the geographic occurrence of arenaviruses. At least seven arenaviruses are known to cause severe hemorrhagic fever in humans: these include Lassa virus (LASV) endemic in West Africa; Junin virus (JUNV) in Argentina; Machupo virus (MACV) in Bolivia; Guanarito virus (GTOV) in Venezuela; Sabia virus (SABV) in Brazil; Lujo virus (LUJV) in Zambia; and Chapare virus (CHAPV) in Bolivia. Pathologic aspects of the liver in severe forms from most types of arenavirus are reported as similar122,123: following systemic hemorrhagic phenomena, grossly, the liver is mottled. The most remarkable histopathologic finding is the contrast of variable degrees of necrosis, with many acidophilic cytoplasm without inflammation (eSlide 13.7). Lipofuscin is frequently seen, but usually there is no cholestasis, nor steatosis.122,123

Hantavirus New World hantaviruses are a group of rodent-borne viruses that are most prevalent in Asia but have also been found in the United States and Europe.124,125 Classically they have led to febrile illness with renal failure, but more recently multiorgan involvement with fever and significant remarkable pulmonary edema and hemorrhage have occurred. Liver lesions are variable and may be similar to those found in bacterial septicemia, albeit less severe.97,126 In our experience with necropsies in Sao Paulo, Brazil,126 a lobular hepatitis with lymphocytes and macrophages surrounding foci of necrotic hepatocytes developed in patients who died because of severe acute edematous/hemorrhagic pulmonary lesions. These patients had a history of contact with rodents, which necessitated the exclusion of bacterial infections such as leptospirosis. We have successfully demonstrated hantaviral antigens in endothelial cells and macrophages in many organs of Brazilian patients126 by immunohistochemistry using an antibody developed by Zaki and colleagues.124 Suggested Readings Aye KS, Charngkaew K, Win N, et al. Pathologic highlights of dengue hemorrhagic fever in 13 autopsy cases from Myanmar. Hum Pathol. 2014;45:1221–1233. Gupta P, Jagya N, Pabhu SB, et al. Immunohistochemistry for the diagnosis of hepatitis E virus infection. J Viral Hepat. 2012;19:e177–e183. Luedde T, Kaplowitz N, Schwabe RF. Cell death and cell death responses in liver disease: mechanisms and clinical relevance. Gastroenterology. 2014;147:765–783. Malcolm P, Dalton H, Hussaini HS, Mathew J. The histology of acute autochthonous hepatitis E virus infection. Histopathology. 2007;51:190–194. Okuna T, Sano A, Deguchi T, et al. Pathology of acute hepatitis A in humans. Comparison with acute hepatitis B. Am J Clin Pathol. 1984;81:162–169. Schiodt FV, Davern TJ, Shakil AO, et al. Viral hepatitis–related acute liver failure. Am Gastroenterol. 2003;98:448–453. Suriawinata AA, Thung SN. Acute and chronic hepatitis. Semin Diagn Pathol. 2006;23:132–148.

References 1. Huang SN, Chen TC, Tsai SL, et al. Histopathology and pathobiology of hepatotropic virusinduced liver injury. J Gastroenterol Hepatol. 1997;12:S195–S217. 2. Shimizu Y. Liver in systemic disease. World J Gastroenterol. 2008;14:4111–4119. 3. Chand N, Sanyal AJ. Sepsis-induced cholestasis. Hepatology. 2007;45:230–241. 4. Gupta E, Ballani N, Kumar M, Sarin SK. Role of non-hepatotropic viruses in acute sporadic viral hepatitis and acute-on-chronic liver failure in adults. Indian J Gastroenterol. 2015;34: 448–452. 5. Centers for Disease Control and Prevention. Viral hepatitis: statistics and Surveillance. www.cdc.gov/hepatitis/statistics 6. Aggarwal R, Naik S. Epidemiology of hepatitis E: current status. J Gastroenterol Hepatol. 2009; 24:1484–1493. 7. Elgouhari HM, Abu-Rajab Tamimi TI, Carey WD. Hepatitis B virus infection: understanding its epidemiology, course, and diagnosis. Cleve Clin J Med. 2008;75:881–889. 8. Seeff LB. The history of the “natural history” of hepatitis C (1968–2009). Liver Int. 2009;29 (suppl 1):89–99. 9. Lee WM. Recent developments in acute liver failure. Best Pract Res Clin Gastroenterol. 2012;26:3–16. 10. Fujiwara K, Yasui S, Nakano M, Yonemitsu Y, Arai M, Kanda T, Fukuda Y, Oda S, Yokosuka O. Severe and fulminant hepatitis of indeterminate etiology in a Japanese center. Hepatol Res. 2015;45:E141–E149. 11. Banait VS, Sandur V, Parikh F, et al. Outcome of acute liver failure due to acute hepatitis E in pregnant women. Indian J Gastroenterol. 2007;26:6–10. 12. Bianchi L. Liver biopsy interpretation in hepatitis. Part I. Presentation of critical morphologic features used in diagnosis (glossary). Pathol Res Pract. 1983;178:2–19. 13. Luedde T, Kaplowitz N, Schwabe RF. Cell death and cell death responses in liver disease: mechanisms and clinical relevance. Gastroenterology. 2014;147:765–783. 14. Dias Jr LB, Alves VA, Kanamura C, et al. Fulminant hepatic failure in northern Brazil: morphological, immunohistochemical and pathogenic aspects of Labrea hepatitis and yellow fever. Trans R Soc Trop Med Hyg. 2007;101:831–839. 15. Boyer JL, Klatskin G. Pattern of necrosis in acute viral hepatitis: prognostic value of bridging (subacute hepatic necrosis). N Engl J Med. 1970;283:1063–1071. 16. Hanau C, Munoz SJ, Rubin R. Histopathological heterogeneity in fulminant hepatic failure. Hepatology. 1995;21:345–351. 17. Scheuer PJ, Maggi G. Hepatic fibrosis and collapse: histological distinction by orcein staining. Histopathology. 1980;4:487–490. 18. Theise N, Bodenheimer Jr HC, Ferrell LD. Acute and chronic viral hepatitis. In: MacSween RNM, Burt AD, Portmann B, eds. MacSween’s pathology of the liver. 5th ed., London: Churchill Livingstone Elsevier; 2007:399–441. 19. Fausto N. Liver regeneration and repair: hepatocytes, progenitor cells, and stem cells. Hepatology. 2004;39:1477–1487. 20. Kuo TK, Hung SP, Chuang CH, et al. Stem cell therapy for liver disease: parameters governing the success of using bone marrow mesenchymal stem cells. Gastroenterology. 2008;134: 2111–2121. 21. Okuno T, Sano A, Deguchi T, et al. Pathology of acute hepatitis A in humans. Comparison with acute hepatitis B. Am J Clin Pathol. 1984;81:162–169. 22. Pérez-Gracia MT, García M, Suay B, Mateos-Lindemann ML. Current knowledge on hepatitis E. J Clin Transl Hepatol. 2015;3:117–126. 23. Mushahwar IK. Hepatitis E virus: molecular virology, clinical features, diagnosis, transmission, epidemiology, and prevention. J Med Virol. 2008;80:646–658. 24. Peron JM, Danjoux M, Kamar N, et al. Liver histology in patients with sporadic acute hepatitis E: a study of 11 patients from south-west France. Virchows Arch. 2007;450:405–410. 25. Teshale EH, Hu DJ, Holmberg SD. The two faces of hepatitis E virus. Clin Infect Dis. 2010;51: 328–334. 26. Hewitt PE, Ijaz S, Brailsford SR, Brett R, et al. Hepatitis E virus in blood components: a prevalence and transmission study in southeast England. Lancet. 2014;384:1766–1773. 27. Drebber U, Odenthal M, Aberle SW, et al. Hepatitis E in liver biopsies from patients with acute hepatitis of clinically unexplained origin. Front Physiol. 2013;13(4):351–355. 28. Agrawal V, Goel A, Rawat A, Naik S, Aggarwal R. Histological and immunohistochemical features in fatal acute fulminant hepatitis E. Indian J Pathol Microbiol. 2012;55:22–27. 29. Malcolm P, Dalton H, Hussaini HS, Mathew J. The histology of acute autochthonous hepatitis E virus infection. Histopathology. 2007;51:190–194. 30. Kamar N, Selves J, Mansuy JM, et al. Hepatitis E virus and chronic hepatitis in organ-transplant recipients. N Engl J Med. 2008;358:811–817. 31. Kamar N, Mansuy JM, Cointault O, et al. Hepatitis E virus-related cirrhosis in kidney- and kidney-pancreas-transplant recipients. Am J Transplant. 2008;8:1744–1748. 32. Mufti AR, Reau N. Liver disease in pregnancy. Clin Liver Dis. 2012;16:247–269. 33. Gupta P, Jagya N, Pabhu SB, et al. Immunohistochemistry for the diagnosis of hepatitis E virus infection. J Viral Hepat. 2012;19:e177–e183. 34. Ray MB, Desmet VJ, Bradburne AF, et al. Differential distribution of hepatitis B surface antigen and hepatitis B core antigen in the liver of hepatitis B patients. Gastroenterology. 1976;71:462–469. 35. Omata M, Iwama S, Sumida M, et al. Clinico-pathological study of acute non-A, non-B post-transfusion hepatitis: histological features of liver biopsies in acute phase. Liver. 1981;1:201–208.

13

207

Practical Hepatic Pathology: A Diagnostic Approach 36. Kobayashi K, Hashimoto E, Ludwig J, et al. Liver biopsy features of acute hepatitis C compared with hepatitis A, B, and non-A, non-B, non-C. Liver. 1993;13:69–72. 37. Johnson K, Kotiesh A, Boitnott JK, et al. Histology of symptomatic acute hepatitis C infection in immunocompetent adults. Am J Surg Pathol. 2007;31:1754–1758. 38. Pessoa MG, Alves VA, Wakamatsu A, et al. Post-transplant recurrent hepatitis C: immunohistochemical detection of hepatitis C virus core antigen and possible pathogenic implications. Liver Int. 2008;28:807–813. 39. Lun YZ, Cheng J, Zhong YW, Yu ZG, Wang Q, Wang F, Feng J. Cloning, expression and identification by immunohistochemistry of humanized single-chain variable fragment antibody against hepatitis C virus core protein. Pol J Microbiol. 2011;60:13–17. 40. Rizzetto M, Canese MG, Arico S, et al. Immunofluorescence detection of new antigen-antibody system (delta/anti-delta) associated to hepatitis B virus in liver and in serum of HBsAg carriers. Gut. 1977;18:997–1003. 41. Farci P, Niro GA. Clinical features of hepatitis D. Semin Liver Dis. 2012;32:228–236. 42. Gomes-Gouvea MS, Pereira Soares M doC, Guedes de Carvalho Mello IM, et al. 2008 Hepatitis D and B virus genotypes in chronically infected patients from the Eastern Amazon Basin. Acta Trop. 2008;106:149–155. 43. Parana R, Kay A, Molinet F, et al. HDV genotypes in the Western Brazilian Amazon region: a preliminary report. Am J Trop Med Hyg. 2006;75:475–479. 44. Rizzetto M. The adventure of delta. Liver Int. 2016;36(suppl 1):135–140. 45. Fonseca JC, Gayotto LC, Ferreira LC, et al. Labrea hepatitis—hepatitis B and delta antigen expression in liver tissue: report of three autopsy cases. Rev Inst Med Trop Sao Paulo. 1985;27:224–227. 46. Bensabath G, Hadler SC, Soares MC, et al. Hepatitis delta virus infection and Labrea hepatitis: prevalence and role in fulminant hepatitis in the Amazon Basin. JAMA. 1987;258:479–483. 47. Monath TP. Yellow fever as an endemic/epidemic disease and priorities for vaccination. Bull Soc Pathol Exot. 2006;99:341–347. 48. Stumpf MP, Laidlaw Z, Jansen VA. Herpes viruses hedge their bets. Proc Natl Acad Sci U S A. 2002;99:15234–15237. 49. Petrova M, Muhtarova M, Nikolova M, et al. Chronic Epstein-Barr virus-related hepatitis in immunocompetent patients. World J Gastroenterol. 2006;12:5711–5716. 50. Markin RS. Manifestations of Epstein-Barr virus-associated disorders in liver. Liver. 1994;14: 1–13. 51. Mellinger JL, Rossaro L, Naugler WE, Nadig SN, Appelman H, Lee WM, Fontana RJ. EpsteinBarr virus (EBV) related acute liver failure: a case series from the US Acute Liver Failure Study Group. Dig Dis Sci. 2014;59:1630–1637. 52. Koch DG, Christiansen L, Lazarchick J, et al. Posttransplantation lymphoproliferative disorder—the great mimic in liver transplantation: appraisal of the clinicopathologic spectrum and the role of Epstein-Barr virus. Liver Transpl. 2007;13:904–912. 53. Suh N, Liapis H, Misdraji J, et al. Epstein-Barr virus hepatitis: diagnostic value of in situ hybridization, polymerase chain reaction, and immunohistochemistry on liver biopsy from immunocompetent patients. Am J Surg Pathol. 2007;31:1403–1409. 54. Ho M. The history of cytomegalovirus and its diseases. Med Microbiol Immunol. 2008; 197:65–73. 55. Samuel D, Dussaix E. Cytomegalovirus infection, fulminant hepatitis, and liver transplantation: the sides of the triangle. Liver Transpl Surg. 1997;3:547–551. 56. Parra Ruiz J, Pena Monje A, Tomas Jimenez C, et al. Clinical spectrum of fever of intermediate duration in the south of Spain. Eur J Clin Microbiol Infect Dis. 2008;27:993–995. 57. Marcelin JR, Beam E, Razonable RR. Cytomegalovirus infection in liver transplant recipients: updates on clinical management. World J Gastroenterol. 2014;20:10658–10667. 58. Hubscher SG. Transplantation pathology. Semin Liver Dis. 2009;29:74–90. 59. Lautenschlager I, Halme L, Hockerstedt K, et al. Cytomegalovirus infection of the liver transplant: virological, histological, immunological, and clinical observations. Transpl Infect Dis. 2006;8:21–30. 60. Lu DY, Qian J, Easley KA, et al. Automated in situ hybridization and immunohistochemistry for cytomegalovirus detection in paraffin-embedded tissue sections. Appl Immunohistochem Mol Morphol. 2009;17:158–164. 61. Zheng ZB, Wu YD, Yu XL, et al. DNA microarray technology for simultaneous detection and species identification of seven human herpes viruses. J Med Virol. 2008;80:1042–1050. 62. Halwachs-Baumann G. Recent developments in human cytomegalovirus diagnosis. Expert Rev Anti Infect Ther. 2007;5:427–439. 63. Agut H. Deciphering the clinical impact of acute human herpesvirus 6 (HHV-6) infections. J Clin Virol. 2011;52:164–171. 64. Zerr DM. Human herpesvirus 6: a clinical update. Herpes. 2006;13:20–24. 65. Li DY, Boitnott JB, Schwarz KB. Human herpes virus-6 (HHV-6): a cause for fulminant hepatic failure or an “innocent bystander”? J Pediatr Gastroenterol Nutr. 2003;37:95. 66. Levitsky J, Kalil A, Meza JL, et al. Herpes zoster infection after liver transplantation: a casecontrol study. Liver Transpl. 2005;11:320–325. 67. Herrero JI, Quiroga J, Sangro B, et al. Herpes zoster after liver transplantation: incidence, risk factors, and complications. Liver Transpl. 2004;10:1140–1143. 68. Azwa A, Barton SE. Aspects of herpes simplex virus: a clinical review. J Fam Plann Reprod Health Care. 2009;35:237–242. 69. McGoogan KE, Haafiz AB, González Peralta RP. Herpes simplex virus hepatitis in infants: clinical outcomes and correlates of disease severity. J Pediatr. 2011;159:608–611.

208

70. Côté-Daigneault J, Carrier FM, Toledano K, Wartelle-Bladu C, Willems B. Herpes simplex hepatitis after liver transplantation: case report and literature review. Transpl Infect Dis. 2014;16:130–134. 71. Levitsky J, Duddempudi AT, Lakeman FD, et al. Detection and diagnosis of herpes simplex virus infection in adults with acute liver failure. Liver Transpl. 2008;14:1498–1504. 72. Jacques SM, Qureshi F. Herpes simplex virus hepatitis in pregnancy: a clinicopathologic study of three cases. Hum Pathol. 1992;23:183–187. 73. Anderson NW, Buchan BW, Ledeboer NA. Light microscopy, culture, molecular, and serologic methods for detection of herpes simplex virus. J Clin Microbiol. 2014;52:2–8. 74. Goodman ZD, Ishak KG, Sesterhenn IA. Herpes simplex hepatitis in apparently immunocompetent adults. Am J Clin Pathol. 1986;85:694–699. 75. Pinna AD, Rakela J, Demetris AJ, et al. Five cases of fulminant hepatitis due to herpes simplex virus in adults. Dig Dis Sci. 2002;47:750–754. 76. Norvell JP, Blei AT, Jovanovic BD, et al. Herpes simplex virus hepatitis: an analysis of the published literature and institutional cases. Liver Transpl. 2007;13:1428–1434. 77. Russell KL, Hawksworth AW, Ryan MA, et al. Vaccine-preventable adenoviral respiratory illness in US military recruits, 1999–2004. Vaccine. 2006;24:2835–2842. 78. Nazir SA, Metcalf JP. Innate immune response to adenovirus. J Investig Med. 2005;53:292–304. 79. Jalal H, Bibby DF, Tang JW, et al. First reported outbreak of diarrhea due to adenovirus infection in a hematology unit for adults. J Clin Microbiol. 2005;43:2575–2580. 80. Ronan BA, Agrwal N, Carey EJ, De Petris G, Kusne S, Seville MT, Blair JE, Vikram HR. Fulminant hepatitis due to human adenovirus. Infection. 2014;42:105–111. 81. Carrigan DR. Adenovirus infections in immunocompromised patients. Am J Med. 1997; 102:71–74. 82. Pehler-Harrington K, Khanna M, Waters CR, et al. Rapid detection and identification of human adenovirus species by adenoplex, a multiplex PCR-enzyme hybridization assay. J Clin Microbiol. 2004;42:4072–4076. 83. Bertheau P, Parquet N, Ferchal F, et al. Fulminant adenovirus hepatitis after allogeneic bone marrow transplantation. Bone Marrow Transplant. 1996;17:295–298. 84. Yoto Y, Kudoh T, Haseyama K, et al. Human parvovirus B19 infection associated with acute hepatitis. Lancet. 1996;347:868–869. 85. Langnas AN, Markin RS, Cattral MS, et al. Parvovirus B19 as a possible causative agent of fulminant liver failure and associated aplastic anemia. Hepatology. 1995;22:1661–1665. 86. Sokal EM, Melchior M, Cornu C, et al. Acute parvovirus B19 infection associated with fulminant hepatitis of favourable prognosis in young children. Lancet. 1998;352:1739–1741. 87. Pinho JR, Alves VA, Vieira AF, et al. Detection of human parvovirus B19 in a patient with hepatitis. Braz J Med Biol Res. 2001;34:1131–1138. 88. Bihari C, Rastogi A, Saxena P, Rangegowda D, Chowdhury A, Gupta N, Sarin SK. Parvovirus b19 associated hepatitis. Hepat Res Treat. 2013;2013:472027. 89. Yamamoto T, Ise K, Nakashima K, et al. Parvovirus B19 as a trigger for spontaneous bacterial peritonitis in a patient with cirrhotic ascites. Am J Gastroenterol. 1996;91:1857–1859. 90. Hatakka A, Klein J, He R, Piper J, Tam E, Walkty A. Acute hepatitis as a manifestation of parvovirus B19 infection. J Clin Microbiol. 2011;49:3422–3424. 91. Paessler S, Walker DH. Pathogenesis of the viral hemorrhagic fevers. Annu Rev Pathol. 2013; 8:411–440. 92. McCarthy M. Zika virus was transmitted by sexual contact in Texas, health officials report. BMJ. 2016;352:i720. 93. Johansson MA, Vasconcelos PF, Staples JE. The whole iceberg: estimating the incidence of yellow fever virus infection from the number of severe cases. Trans R Soc Trop Med Hyg. 2014;108:482–487. 94. Enserink M. An obscure mosquito-borne disease goes global. Science. 2015;350:1012–1013. 95. Weaver SC, Lecuit M. Chikungunya virus and the global spread of a mosquito-borne disease. N Engl J Med. 2015;372:1231–1239. 96. Monath TP, Vasconcelos PF. Yellow fever. J Clin Virol. 2015;64:160–173. 97. Peres LC, Saggioro FP, Dias Jr LB, et al. Infectious diseases in paediatric pathology: experience from a developing country. Pathology. 2008;40:161–175. 98. Quaresma JA, Barros VL, Fernandes ER, et al. Reconsideration of histopathology and ultrastructural aspects of the human liver in yellow fever. Acta Trop. 2005;94:116–127. 99. Vieira WT, Gayotto LC, de Lima CP, et al. Histopathology of the human liver in yellow fever with special emphasis on the diagnostic role of the Councilman body. Histopathology. 1983;7:195–208. 100. Quaresma JAS, Barros VLRS, Pagliari C, et al. Revisiting the liver in human yellow fever: virusinduced apoptosis in hepatocytes associated with TGF_, TNF_ and NK cells activity. Virology. 2006;345:22–30. 101. Quaresma JAS, Pagliari C, Medeiros DBA, et al. Immunity and immune response, pathology and pathologic changes. Progresses and challenges in the immunopathology of yellow fever. Rev Med Virol. 2013;23:305–331. 102. Hall WC, Crowell TP, Watts DM, et al. Demonstration of yellow fever and dengue antigens in formalin-fixed paraffin-embedded human liver by immunohistochemical analysis. Am J Trop Med Hyg. 1991;45:408–417. 103. De Brito T, Siqueira SA, Santos RT, et al. Human fatal yellow fever: immunohistochemical detection of viral antigens in the liver, kidney and heart. Pathol Res Pract. 1992;188: 177–181. 104. Nunes MR, Vianez Jr JL, Nunes KN, et al. Analysis of a reverse transcription loop-mediated isothermal amplification (RT-LAMP) for yellow fever diagnostic. J Virol Methods. 2015;226:40–51.

Acute Viral Hepatitis 105. Vasconcelos PF, Luna EJ, Galler R, et al. Serious adverse events associated with yellow fever 17DD vaccine in Brazil: a report of two cases. Lancet. 2001;358:91–97. 106. Martin M, Tsai TF, Cropp B, et al. Fever and multisystem organ failure associated with 17D– 204 yellow fever vaccination: a report of four cases. Lancet. 2001;358:98–104. 107. Galler R, Pugachev KV, Santos CL, et al. Phenotypic and molecular analyses of yellow fever 17DD vaccine viruses associated with serious adverse events in Brazil. Virology. 2001;290:309–319. 108. Guzman MG, Halstead SB, Artsob H, et al. Dengue: a continuing global threat. Nat Rev Microbiol. 2010;8:S7–S16. 109. Samanta J, Sharma V. Dengue and its effects on liver. World J Clin Cases. 2015;3:125–131. 110. Teixeira MG, Siqueira Jr JB, Ferreira GL, Bricks L, Joint G. Epidemiological trends of dengue disease in Brazil (2000-2010): a systematic literature search and analysis. PLoS Negl Trop Dis. 2013;7:e2520. 111. Hayden MH, Cavanaugh JL, Tittel C, et al. Post outbreak review: dengue preparedness and response in Key West, Florida. Am J Trop Med Hyg. 2015;93:397–400. 112. Seneviratne SL, Malavige GN, de Silva HJ. Pathogenesis of liver involvement during dengue viral infections. Trans R Soc TropMed Hyg. 2006;100:608–614. 113. Chaturvedi UC, Elbishbishi EA, Agarwal R, et al. Sequential production of cytokines by dengue virus-infected human peripheral blood leukocyte cultures. J Med Virol. 1999;59:335–340. 114. Pagliari C, Quaresma JA, Fernandes ER, et al. Immunopathogenesis of dengue hemorrhagic fever: contribution to the study of human liver lesions. J Med Virol. 2014;86:1193–1197. 115. Aye KS, Charngkaew K, Win N, et al. Pathologic highlights of dengue hemorrhagic fever in 13 autopsy cases from Myanmar. Hum Pathol. 2014;45:1221–1233.

116. Jessie K, Fong MY, Devi S, et al. 2004 Localization of dengue virus in naturally infected human tissues, by immunohistochemistry and in situ hybridization. J Infect Dis. 2004;189:1411–1418. 117. Martines RB, Ng DL, Greer PW, Rollin PE, Zaki SR. Tissue and cellular tropism, pathology and pathogenesis of Ebola and Marburg viruses. J Pathol. 2015;235:153–174. 118. Rippey JJ, Schepers NJ, Gear JHS. The pathology of Marburg virus disease. S Afr Med J. 1984;66:50–54. 119. Zaki SR, Shieh WJ, Greer PW, et al. A novel immunohistochemical assay for detection of Ebola virus in skin: implications for diagnosis, spread and surveillance of Ebola haemorrhagic fever. Commission de Lutte contre les Epidémies à Kikwit. J Infect Dis. 1999;179:S36–S47. 120. Heeney JL. Ebola: Hidden reservoirs. Nature. 2015;527:453–455. 121. Yun NE, Walker DH. Pathogenesis of Lassa fever. Viruses. 2012;4:2031–2048. 122. Edington GM, White HA. The pathology of Lassa fever. Trans R Soc Trop Med Hyg. 1972;66: 381–389. 123. Grant A, Seregin A, Huang C, et al. Junín virus pathogenesis and virus replication. Viruses. 2012;4:2317–2339. 124. Zaki SR, Greer PW, Coffield LM, et al. Hantavirus pulmonary syndrome: pathogenesis of an emerging infectious disease. Am J Pathol. 1995;146:552–579. 125. Vapalahti O, Mustonen J, Lundkvist A, et al. Hantavirus infections in Europe. Lancet Infect Dis. 2003;3:653–661. 126. Katz G, Williams RJ, Burt MS, et al. Hantavirus pulmonary syndrome in the state of Sao Paulo, Brazil, 1993–1998. Vector Borne Zoonotic Dis. 2001;1:181–190.

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14 Hepatitis B Prodromos Hytiroglou, MD

Incidence and Demographics  211 Molecular Virology  211 Natural History and Clinical Manifestations  212 Treatment 213 Role of Liver Biopsy in Management of Hepatitis B  213 Microscopic Pathology of Chronic Hepatitis B  213 Portal Changes and Interface Hepatitis  213 Lobular Inflammation, Apoptosis, and Necrosis  213 Ground-Glass Cells and Sanded Nuclei  214 Large Cell and Small Cell Changes  216 Fibrosis and Architectural Distortion  217 Immunohistochemical Stains for Viral Antigens in Chronic Hepatitis B  218 Differential Diagnosis of Chronic Hepatitis B  218 Chronic Hepatitis C  218 Other Chronic Hepatitides  219 Other Chronic Liver Diseases  219 Ground-Glass Cells  219 Practical Approach in Evaluating Liver Biopsy Specimens from Patients with Chronic Hepatitis B  219

Abbreviations cccDNA covalently closed circular deoxyribonucleic acid HBcAg hepatitis B core antigen HBeAg hepatitis B e antigen HBsAg hepatitis B surface antigen HBV hepatitis B virus HCC hepatocellular carcinoma HCV hepatitis C virus HDAg hepatitis delta antigen HDV hepatitis delta virus LCC large cell change mRNA messenger ribonucleic acid SCC small cell change

Incidence and Demographics Hepatitis B is a widespread infection, with more than 350 million carriers worldwide. The hepatitis B virus (HBV) is a DNA virus that is transmitted parenterally, or by intimate, often sexual, contact.1 The prevalence of HBV infection varies significantly in different parts of the world. In regions of high prevalence, such as parts of southeastern Asia, China, and sub-Saharan Africa, transmission of HBV usually occurs in the perinatal period (vertical transmission from mother to child) or during childhood (horizontal transmission in children).2,3 In regions of intermediate prevalence, including parts of Southern and Eastern Europe, much of the former Soviet Union, the Middle East, the Indian subcontinent, and Japan, individuals of all ages are infected, but most infections occur in infancy or childhood. In regions of low prevalence, such as Western Europe, North America, some parts of South America, and Australia, transmission mostly occurs among young adults. In these regions, sexual transmission and injection drug use are the main modes of spread of the virus.4 Blood screening for viral protein has virtually eliminated posttransfusion hepatitis B.5 The past 25 years have witnessed the development of effective screening assays for hepatitis B, distribution of preventive vaccines, and implementation of antiviral drug therapies that significantly improve clinical outcomes. Therefore, the global epidemiology of HBV infection is expected to change in the near future.6 Furthermore, recent establishment of the World Health Organization (WHO) Global Hepatitis Program is considered a cornerstone for all countries to frame their own particular national responses to control hepatitis B.6

Molecular Virology HBV is a member of the Hepadnaviridae family. The genome is composed of four open reading frames in which several genes overlap; as a result, the same DNA sequences are used to encode different viral proteins.3,7,8 The four viral genes are core, surface, X, and polymerase. The core gene encodes the core nucleocapsid protein, which is important in viral packaging and production of hepatitis B e antigen (HBeAg). The surface gene encodes three surface proteins of different sizes (preS1, pre-S2, and S). The X gene encodes a protein with transactivating properties, called the X protein, which appears to be important in hepatocarcinogenesis.9 The polymerase gene encodes a large protein with functions that are critical for viral packaging and DNA replication. 211

Practical Hepatic Pathology: A Diagnostic Approach Comparison of complete HBV genomes has demonstrated 10 genotypes of the virus (A to J), which can be further classified into more than 40 subgenotypes.6,8,10 Different genotypes tend to have distinct geographic and ethnic distributions. There are differences in disease progression and selection of mutations among HBV genotypes, as well as differences in the response to interferon therapy. Viral replication takes place after attachment and entry of the HBV into the hepatocyte. The human receptor for this virus is yet unknown. After entry, the virus is uncoated and the viral genome is transported to the nucleus where the relaxed circular form of the HBV DNA is converted to covalently closed circular DNA (cccDNA). The cccDNA serves as the template for viral transcription, which includes the formation of pregenomic (3.5 kb) and subgenomic (0.7 to 2.4 kb) ribonucleic acid (RNA) molecules, all of which function as messenger ribonucleic acids (mRNAs). In addition, the pregenomic RNA serves as the template for reverse transcription. In the cytoplasm, this molecule is incorporated, together with viral polymerase, into the maturing nucleocapsid, and it is used for minus-strand viral DNA synthesis, which, in turn, is used for plus-strand DNA synthesis. The core particles thus formed are enveloped with surface proteins in the endoplasmic reticulum and are released from the cell. In addition to virions, infected hepatocytes release an abundance of noninfectious particles composed of hepatitis B surface antigen (HBsAg). Some of the nonenveloped nucleocapsids recirculate from the cytoplasm to the nucleus, providing additional templates for transcription. Finally, an important aspect of HBV infection is the ability of viral DNA to become integrated into the host cell genome. Evidence suggests that the viral integration sites are not random11-13; HBV frequently targets cellular genes involved in cell signaling, potentially providing growth advantage to infected cells and in the process, also initiating pathways of hepatocarcinogenesis. This brief overview of the HBV life cycle shows that replication occurs through a reverse transcription mechanism, which is very unusual for DNA viruses and requires an active viral reverse transcriptase/polymerase.3,8 Because the reverse transcriptase lacks proofreading function, the HBV life cycle is characterized by a high rate of mutations; mutations are also induced by host and iatrogenic factors, such as treatment with nucleoside and nucleotide analogs, administration of hepatitis B immunoglobulin, and vaccination. Two types of mutations require specific mention because of their incidence and clinical significance: 1. Mutations in the precore and basal core promoter regions, resulting in loss or diminution of HBeAg production, are very common in Asian and European patients with chronic HBV infection. This leads to HBeAg-negative chronic hepatitis B.3,14 2. Mutations in the viral polymerase region resulting in resistance to therapy with nucleos(t)ide analogs, best exemplified by the tyrosine-methionine-aspartate-aspartate (YMDD) mutants, often emerge after prolonged exposure to lamivudine.15,16 These patients therefore require clinical monitoring for early detection and treatment of resistance.

Natural History and Clinical Manifestations The incubation period of acute HBV infection lasts 1 to 4 months.2 Acute hepatitis B is a largely subclinical disease as suggested by the high rate of serum markers of HBV infection in individuals who have had no history of hepatitis.1 When there are clinical manifestations, patients often present with gastrointestinal and flulike symptoms. The presence of jaundice suggests the diagnosis of hepatitis; however, many cases are anicteric. Fulminant hepatic failure occurs in less than 1% of cases of acute hepatitis B, but this still accounts for 5% to 7% of all cases of acute liver failure.2,3 212

Box 14.1  Serologic and Molecular Markers of Chronic Hepatitis B Virus Infection • H  BsAg: the defining feature of chronic HBV infection, when present for more than 6 months after initial detection • Anti-HBs: undetectable in most patients • Low titers possibly detectable in a minority of patients • Anti-HBc: IgG class: evidence of current or past HBV infection (patients with isolated anti-HBc may be infectious and are excluded from blood donation) • IgM class: detectable during exacerbations (flares) • HBeAg: marker of active viral replication and infectivity • Indicator of active disease and need for antiviral treatment (except in children and young adults with perinatally acquired HBV infection) • Anti-HBe: in regions of low prevalence of precore mutants: suggestive of inactive disease • In regions of high prevalence of precore mutants: consistent with either inactive or active disease • HBV DNA (quantitative): commonly used to assess candidacy for antiviral therapy and to monitor response during treatment Anti-HBc, Antibody to hepatitis B core antigen; anti-HBs, antibody to hepatitis B surface antigen; HBeAg, hepatitis B e antigen; HBV, hepatitis B virus; IgG, immunoglobulin G; IgM, immunoglobulin M.

Although as many as 95% of infected neonates become chronic HBV carriers, only 1% to 5% of adults with acute hepatitis B develop chronic infection, which is defined as persistence of HBsAg in the serum for more than 6 months.4 This difference is attributed to immaturity of the immune system in neonates, resulting in immune tolerance to the virus. Perinatally infected patients often have high levels of serum HBV DNA without biochemical evidence of active hepatitis; however, when followed longitudinally, many of these patients develop abnormal liver function tests, as well as histologic evidence of chronic hepatitis.2 On the other hand, a variety of mechanisms have been suggested to explain why a minority of patients infected in adulthood fail to clear the infection in the acute phase.17,18 Development of chronic HBV infection occurs more often in men than women and in immunosuppressed than immunocompetent individuals. Individuals with chronic HBV infection have been traditionally divided into two groups: healthy carriers (infectious, but without symptoms of liver disease) and patients with chronic hepatitis B. However, accumulating evidence indicates that these two categories are relatively labile and individuals may move from one category to another depending on confounding factors such as immune function, coinfections, and age at any given time.18 Patients with chronic hepatitis B may be asymptomatic or may complain of nonspecific constitutional symptoms, especially fatigue.1,2 Other common symptoms include poor appetite, nausea, and upper abdominal pain. Serum transaminases typically range from normal to several times the upper limit of normal; however, many patients have normal values. The serologic markers of chronic HBV infection are summarized in Box 14.1.2,3,19 Coinfection and superinfection with the hepatitis delta virus (HDV) are discussed in Chapter 13. About 30% of patients with chronic HBV infection develop progressive liver disease culminating in cirrhosis, at a rate of approximately 2% per year.20,21 Active viral replication and long-standing necroinflammatory changes strongly influence the rate of progression to cirrhosis.2 Patients with cirrhosis may have clinical signs of portal hypertension, such as ascites, splenomegaly, esophageal varices, and encephalopathy. The severity of liver disease at presentation is the most important determinant of survival for patients with chronic hepatitis B.22 Fiveyear and 20-year survival rates of 97% and 63%, respectively, have been reported for patients with mild disease; the corresponding numbers for patients with cirrhosis are 55% and 25%, respectively.22–24 Various extrahepatic manifestations may accompany acute or chronic hepatitis B. These may occur in the absence of clinically apparent liver disease and may, therefore, be mistaken for independent

Hepatitis B disease processes.2,3 Such manifestations include membranous and membranoproliferative glomerulonephritis; polyarteritis nodosa; arthropathy, either alone or as part of a serum sickness–like syndrome; and skin disorders. These manifestations are thought to result from aberrant immunologic responses to extrahepatic viral proteins.25 Globally, chronic HBV infection is the most important risk factor for hepatocellular carcinoma (HCC).26 HBsAg carriers have a 98-fold increased relative risk for HCC, as compared with HBsAg-negative individuals.27 In regions of high prevalence, HCC often develops in young individuals between 20 and 40 years of age, who are noncirrhotic. In contrast, in regions of low prevalence of hepatitis B infection, HCC arises in cirrhosis and the tumor is usually detected in individuals older than 60 years. Antiviral treatment appears to reduce the risk of HCC in patients with chronic hepatitis B.27

Treatment Seven drugs are currently approved for the treatment of chronic hepatitis B, including interferon-alpha and its pegylated forms, as well as five nucleos(t)ide analogs (lamivudine, telbivudine, adefovir, tenofovir and entecavir).2,3 Treatment guidelines are regularly published by the American Association for the Study of Liver Disease, the European Association for the Study of the Liver, and the Asian-Pacific Association for the Study of the Liver,28-30 and have been recently reviewed.6,31 Although these drugs are rarely effective in eradicating the virus, they efficiently suppress viral replication, thus decreasing inflammation and preventing progression of liver disease (eSlide 14.1). In addition to clinical and biochemical improvement, histologic improvement in terms of grade and stage of disease has been documented by liver biopsies in series of patients undergoing therapy, including patients with cirrhosis.32-36 Clinical monitoring of patients under treatment is very important; serious adverse effects are common with interferon treatment, whereas viral polymerase gene mutations result in resistance to nucleos(t)ide analog treatment. The introduction of entecavir and tenofovir to the therapeutic armamentarium has minimized the problem of such resistance.31 In addition to chronic hepatitis B, nucleos(t)ide analogs may be useful in the treatment of some cases of acute hepatitis B.3

Role of Liver Biopsy in Management of Hepatitis B Acute hepatitis B is not an indication for liver biopsy; the diagnosis is based on clinical presentation and laboratory findings such as elevated transaminase values, serologic markers of acute HBV infection, and presence of HBV DNA in the serum. However, biopsies may be performed in patients with an unclear cause of acute liver disease, especially if there is suspicion of drug reaction or biliary disease. The histologic features of acute hepatitis B (see eSlide 13.2) are similar to those of acute hepatitis of other causes, as discussed and illustrated in Chapter 13. In chronic hepatitis B, liver biopsy is used to assess the grade (ie, the degree of necroinflammatory activity) and stage (ie, the degree of fibrosis and architectural distortion), as measures of severity and progression, respectively, of the disease. This information has important prognostic and therapeutic implications. The various grading and staging systems are discussed in detail in Chapter 16. Immunohistochemical stains for HBV antigens on paraffin sections can confirm the presence of the virus and provide information regarding its replicative status. Biopsy examination may also resolve whether chronic HBV infection is the major cause of liver damage in patients with more than one potential cause of liver disease, such as other hepatotropic viruses, alcohol consumption, and metabolic disorders. Repeat liver biopsy is useful in assessing disease progression or remission over time and in evaluating the effects of treatment. Finally, guided liver biopsy is essential in making the diagnosis of HCC or dysplastic nodules that may arise in a background of chronic hepatitis B.

Box 14.2  Histologic Features of Chronic Hepatitis B (also see eSlides 14.2, 14.3, and 14.4) A. Changes seen in chronic hepatitis of any cause: 1. Chronic inflammatory cell infiltration of portal tracts 2. Interface hepatitis (ie, necroinflammatory activity at the portal/lobular interface [formerly called piecemeal necrosis]) 3. Intralobular necroinflammatory activity, including: a. Apoptotic hepatocytes (acidophil bodies) b. Foci of spotty necrosis c. Foci of confluent necrosis 4. Bridging necrosis (ie, confluent necrosis linking central veins with portal tracts) 5. Fibrosis of variable degree B. Characteristic changes of chronic HBV infection: 1. Ground-glass hepatocytes 2. Sanded nuclei in hepatocytes C. Immunohistochemical evidence of HBV infection 1. Immunopositivity of hepatocytes for viral antigens (HBsAg, HBcAg)

14

HBcAg, Hepatitis B core antigen; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus.

Microscopic Pathology of Chronic Hepatitis B The histologic features of chronic hepatitis B include changes that are seen in chronic hepatitis of any cause, as well as changes that are characteristic of chronic HBV infection18,37,38 (Box 14.2). These features vary significantly in prominence from one patient to another. In addition, disease activity may vary significantly over time. Sudden flares of disease activity, accompanied by elevated serum transaminases, may occur at the time of HBeAg to anti-HBe seroconversion because of superinfection with other hepatotropic viruses such as HDV, hepatitis A virus, hepatitis C virus (HCV), or hepatitis E virus, as a result of antiviral or immunosuppressive treatment, or spontaneously without obvious cause.3 Use of a semiquantitative scoring system for grading and staging of the histologic features of chronic hepatitis B is not necessary for routine diagnostic purposes but may be helpful in more accurately evaluating any given case.

Portal Changes and Interface Hepatitis The portal inflammatory infiltrates in chronic hepatitis B are predominantly composed of lymphocytes with an admixture of plasma cells (Fig. 14.1A). Lymphoid follicles are occasionally seen, but not as often as in chronic hepatitis C. Interface hepatitis (formerly called piecemeal necrosis) is a common finding and consists of lymphocytes causing hepatocyte damage and loss at the limiting plate (see Fig. 14.1A–D). Swollen hepatocytes and apoptotic (acidophil) bodies are often seen in these areas (see Fig. 14.1B). Interface hepatitis may be mild, moderate, or severe. Furthermore, the severity of this change may vary from one portal tract to the next (eSlides 14.2 and 14.3). Mild ductular reaction may also be present, apparently as a result of proliferation of bipotent progenitor cells from the region of the limiting plate undergoing destruction. Clusters of hepatocytes are sometimes seen within the portal tracts in areas of current or past severe interface hepatitis (see Fig. 14.1D). These appear to consist of periportal hepatocytes separated from the lobules by the inflammatory process; however, in cases of cirrhosis, such clusters have been shown to represent regeneration from bipotent progenitor cells.39 Successful antiviral therapy leads to disappearance of interface hepatitis.

Lobular Inflammation, Apoptosis, and Necrosis Intralobular necroinflammatory activity is characterized by the presence of apoptotic (acidophil) bodies, foci of spotty necrosis, and Kupffer cell activation. Foci of spotty necrosis consist of inflammatory cell aggregates, mostly composed of lymphocytes and macrophages, which 213

Practical Hepatic Pathology: A Diagnostic Approach

A

B

C

D Figure 14.1  Portal and periportal inflammation in chronic hepatitis B. A, Marked expansion of a portal tract with a lymphoplasmacytic infiltrate. There is interface hepatitis, obscuring the limiting plate. A lymphoid follicle is also present (lower center). B, Higher power examination shows swollen hepatocytes and an acidophil body (arrow) in this area of interface hepatitis. Mild ductular reaction is also seen. C, Another area of interface hepatitis. Note that the inflammatory cell infiltration of the limiting plate is accompanied by hepatocyte damage and loss. D, In this area of severe interface hepatitis, clusters of swollen hepatocytes appear to be separated from the lobules.

mark the location of lost, degenerating, or apoptotic hepatocytes (Fig. 14.2A–B). Cytoplasmic swelling of hepatocytes is common and may evolve to ballooning degeneration. Features suggestive of activation of the apoptotic process in hepatocytes include increased cytoplasmic eosinophilia, angulated cell shape, and nuclear hyperchromasia (Fig. 14.3A). Apoptotic (acidophil) bodies are round-shaped or oval-shaped, brightly eosinophilic cell remnants that may contain a shrunken, hyperchromatic, often fragmented nucleus. Apoptotic bodies may be associated with inflammatory cells (see Figs. 14.1B, 14.2B, and 14.3A). In cases with marked necroinflammatory activity, confluent areas of necrosis may be seen, located mostly in centrilobular regions (see Fig. 14.3A–B). Bridging necrosis, defined as confluent necrosis extending from terminal hepatic venules to portal tracts, may also be seen (Fig. 14.4). Bridging necrosis is a histologic feature suggestive of an increased likelihood of progression to cirrhosis, because the ensuing scarring significantly distorts the lobular architecture.40,41 Hepatocyte regeneration follows cell loss; therefore, mitotic figures in hepatocytes and thickened cell plates may be seen in cases with severe necroinflammatory activity. Successful antiviral therapy leads to disappearance of intralobular necroinflammatory activity. 214

Ground-Glass Cells and Sanded Nuclei Two cytologic changes require special mention because they are characteristic of chronic HBV infection, although they are not found in all cases. The first and better known is the presence of ground-glass cells, which are hepatocytes with abundant, finely granular, lightly eosinophilic cytoplasm; their appearance results from the accumulation of HBsAg within dilated cisterns of the endoplasmic reticulum42 (Fig. 14.5A). A clear halo is seen at the peripheral portion of the cytoplasm, separating it from the cell membrane, which appears thickened. The nucleus is often displaced to the cell periphery. Ground-glass cells may be arranged singly, in clusters, or in sheets (eSlides 14.2 and 14.3). These cells stain positive with the orcein43 and Victoria blue stains,18 and are strongly positive for HBsAg by immunohistochemistry (see Fig. 14.5B). Positive immunostaining for HBsAg may however also be seen in hepatocytes that do not display ground-glass cell features. Whereas typical ground-glass cells are characterized not only by the staining quality of the cytoplasm, but also by the clear halo and thick cytoplasmic membrane, some hepatocytes in livers with chronic hepatitis B may just show abundant, finely granular, eosinophilic cytoplasm.

Hepatitis B

14

A

A

B

B

Figure 14.2  Intralobular necroinflammatory activity in chronic hepatitis B. A, There is extensive spotty necrosis, accompanied by Kupffer cell activation. Interface hepatitis is also present around a portal tract (lower left). B, On higher power examination, swollen hepatocytes and an acidophil body (arrow) are seen.

These oncocytic hepatocytes owe their appearance to the presence of abundant mitochondria and are seen in various chronic liver diseases, including other chronic hepatitides44 (Fig. 14.6). Immunohistochemical stains for HBsAg are of obvious utility in distinguishing oncocytic hepatocytes from HBV-infected cells. Other simulators of the groundglass change of HBV-infected hepatocytes are discussed later in the section on differential diagnosis. The second cytologic change that is considered characteristic of chronic HBV infection is the presence of sanded nuclei in hepatocytes, which are pale eosinophilic, very finely granular nuclei45 (Fig. 14.7). Such nuclear appearance is caused by accumulation of large amounts of hepatitis B core antigen (HBcAg) and is therefore seen in cases of active viral replication. Note that an identical appearance of hepatocytic nuclei may occur as a result of the presence of hepatitis delta antigen (HDAg),46 rather than HBcAg. Because there are no histologic features distinguishing HBV infection from HBV/HDV infection, and immunohistochemical stains for HDAg are not easily available, the diagnosis of HDV infection is established by detection of antibodies and HDV RNA in serum. Chronic HBV/HDV infection is usually characterized by significant necroinflammatory activity and accelerated course to cirrhosis.

Figure 14.3  Incipient (A) and evident (B) confluent necrosis. A, Multiple foci of spotty necrosis merging to form an area of confluent necrosis. In addition to two easily identifiable acidophil bodies (arrows), there are occasional hepatocytes with increased cytoplasmic eosinophilia, angulated cell shape, and nuclear hyperchromasia (arrowheads); this is suggestive of activation of the process of apoptosis. B, Confluent necrosis usually involves regions around terminal hepatic venules. Incidental mild steatosis is also seen in this field.

Figure 14.4  Bridging necrosis extending from a terminal hepatic venule (upper right) to a portal tract (lower left). 215

Practical Hepatic Pathology: A Diagnostic Approach

A Figure 14.7  Sanded nuclei in hepatocytes (arrows).

B Figure 14.5  A, Ground-glass hepatocytes. Notice the clear halo in the peripheral portion of the cytoplasm and the thick cytoplasmic membrane. B, Immunohistochemical stain for hepatitis B surface antigen. Ground-glass cells show dense cytoplasmic staining. However, these cells are not the only ones that contain the virus. Staining of variable extent and intensity is also seen in hepatocytes that do not display clear-cut ground-glass features on hematoxylin-eosin (streptavidin-biotin) (also see eSlides 14.2 and 14.3).

Figure 14.8  Large cell change of hepatocytes (case of cirrhosis due to chronic hepatitis B) (also see eSlide 14.4).

Large Cell and Small Cell Changes

Figure 14.6  Oncocytic change of hepatocytes is characterized by large cell size and abundant, finely granular, eosinophilic cytoplasm (case of cirrhosis due to chronic hepatitis B). This change is not directly related to hepatitis B virus infection. 216

Large cell change (LCC) of hepatocytes is often seen in chronic hepatitis B. It is common and widespread in cirrhotic livers, but it may also be found in the absence of cirrhosis. LCC is characterized by increased cell size, nuclear pleomorphism, and hyperchromasia, as well as multinucleation; the nucleocytoplasmic ratio is however preserved47 (Fig. 14.8 and eSlide 14.4). Originally thought to represent a precancerous change,47 LCC was later viewed by most investigators as a marker of chronic hepatic injury occurring in a variety of chronic liver diseases.48-51 However, the presence of LCC indicates an increased risk of HCC development.52,53 It now seems evident that LCC is a heterogeneous entity, with a subset unrelated to tumor development, and another subset associated with cirrhosis due to chronic hepatitis B, related to hepatocarcinogenesis.54 Small cell change (SCC) of hepatocytes,55 a cytologic change of proven precancerous potential may also be seen in livers with chronic hepatitis B, usually when cirrhosis is established. SCC is characterized by small cell size, nuclear hyperchromasia and pleomorphism, increased nucleocytoplasmic ratio, and multinucleation.55 Large and small cell changes are discussed in more detail in Chapter 31 on precancerous hepatic lesions. Identification of either LCC or SCC in liver

Hepatitis B biopsy or resection specimens should be noted in the pathology report to be taken into account for HCC surveillance.56

14

Fibrosis and Architectural Distortion Over time, parenchymal damage in chronic hepatitis B may lead to scarring (eSlide 14.4). Fibrous expansion of portal tracts is a common finding. Fibrous septa extending from the portal tracts into the periportal part of the lobules apparently represent the result of interface hepatitis, whereas fibrous septa linking terminal hepatic venules to portal tracts are the result of scarring along regions of bridging necrosis (Fig. 14.9A). Periportal fibrous septa may link adjacent portal tracts (see Fig. 14.9B). The ongoing hepatocyte loss, regeneration, and fibrosis causes progressive architectural distortion over time (see Fig. 14.9C), leading to cirrhosis. Cirrhosis is of the macronodular or mixed macronodular and micronodular type (Fig. 14.10). Connective tissue stains are valuable in assessing the stage of fibrosis in any given case, as well as in differentiating between bridging necrosis and bridging fibrosis. Although trichrome stains usually suffice for staging, elastic tissue stains may also be helpful, because elastic fibers are only found in established fibrous septa but not in areas of recent parenchymal collapse.57 Until recently, hepatic fibrosis had been considered a progressive process that could be arrested at times but did not regress. Research has now shown that the deposition of connective tissue is a dynamic process that depends on the balance between fibrogenic and antifibrotic mechanisms, and it may progress or regress over time.58-61 Various enzymatic systems, such as the metalloproteinases and their inhibitors, have been shown to play important roles in connective tissue deposition and mobilization, whereas activation of hepatic stellate cells has emerged as a key factor in hepatic fibrosis. Recent clinical studies have also demonstrated that fibrosis in chronic hepatitis B, as well as in other chronic liver diseases, may regress when the causative factor is appropriately treated (see Chapter 40).32-36 Therapeutic suppression of HBV replication leads to loss of necroinflammatory activity, which results in inactivation, apoptosis, or senescence of activated hepatic stellate cells; this in turn provides the opportunity for absorption of excess fibrous tissue and improvement of disease stage.61 Even the fibrosis that is part of cirrhosis may regress after successful antiviral treatment; when this happens, parenchymal nodularity may disappear over time, and the hepatic architecture may improve significantly. This explains the histologic findings of several case reports and recent clinical series documenting regression of cirrhosis in patients with chronic hepatitis B.34,35,62-65 However, there is a range of histologic severity in cirrhosis (also see eSlide 41.5) (see Chapter 41 for staging of cirrhosis), which is correlated with clinical severity.66 The major impediments of architectural improvement include thick fibrous septa containing cross-linked collagen fibers and elastin, as well as vascular lesions such as venous obliterative lesions, arteriovenous shunts, and portovenous shunts. Therefore cases with severe architectural distortion may not improve over time, representing end-stage liver disease. On the other hand, there are cirrhotic livers where significant regression of fibrosis and loss of nodularity after antiviral therapy are not accompanied by significant (or any) improvement of the vascular lesions. These patients will have ongoing portal hypertension. Histologic examination may reveal findings of so-called incomplete septal cirrhosis62 (Fig. 14.11 also see eSlide 41.5), a diagnosis that is notoriously difficult to make in biopsy specimens (discussed in more detail in Chapter 15 on hepatitis C). The recent progress in the treatment of the advanced stages of chronic hepatitis B and other chronic liver diseases has provided evidence that cirrhosis does not always represent an end-stage condition (see Chapter 41). Therefore, an International Liver Pathology study group has challenged the usefulness of the term cirrhosis in modern medicine and suggested to discontinue the use of this term.67

A

B

C Figure 14.9  Fibrosis in chronic hepatitis B. A, Fibrous septa extending from a portal tract into the lobular parenchyma. One of them reaches a terminal hepatic venule (arrow) (reticulin). B, Two adjacent portal tracts are linked by fibrous septa (Masson trichrome). C, Fibrosis with architectural distortion. The rounded edge of the lobules is suggestive of transition to cirrhosis (Masson trichrome) (also see eSlide 14.4B).

217

Practical Hepatic Pathology: A Diagnostic Approach

A Figure 14.10  Established cirrhosis of mixed macronodular and micronodular type, from chronic hepatitis B. Vascular lumens are dilated, apparently because of portal hypertension.

Immunohistochemical Stains for Viral Antigens in Chronic Hepatitis B Immunohistochemical stains for HBcAg and HBsAg are a useful diagnostic adjunct in biopsies of patients with chronic HBV infection. In addition to confirming HBV as the cause of liver disease in any given case, positive staining for HBcAg is also indicative of active viral replication. Such staining is usually confined to hepatocyte nuclei; however, in cases with abundant HBcAg production, the cytoplasm may be stained as well (Fig. 14.12A). Extensive positivity for HBcAg may be seen in perinatally infected patients who have developed tolerance to the virus, as well as in immunosuppressed patients (see Fig. 14.12B). Immunostaining for HBsAg is cytoplasmic (see Fig. 14.5B) but may also be membranous; the latter is seen in cases of active viral replication in parallel with HBcAg positivity.18

B

Differential Diagnosis of Chronic Hepatitis B On histologic grounds, the differential diagnosis of chronic hepatitis B includes other causes of chronic hepatitis, such as hepatitis C, autoimmune hepatitis, and drug-induced hepatitis, as well as other liver diseases characterized by chronic inflammation and fibrosis, such as chronic biliary and metabolic diseases.18,37,68,69 Identification of ground-glass cells and sanded nuclei, as well as positive immunohistochemical stains for HBsAg or HBcAg, are important clues in distinguishing chronic hepatitis B from other conditions. Reliable clinical information is also essential, especially when immunohistochemistry is negative or unavailable. It should also be kept in mind that negative immunohistochemical stains for HBsAg and HBcAg do not exclude chronic HBV infection; such negative results may be due to sampling error, especially in small biopsy samples. On the other hand, positive findings do not necessarily mean that HBV is the only cause of liver disease in any given case.

Chronic Hepatitis C The differential diagnosis between chronic hepatitis B and chronic hepatitis C is based on clinical information, as well as identification of ground-glass cells and sanded nuclei. Chronic hepatitis C does not have pathognomonic histologic findings; however, a triad consisting of steatosis, portal lymphoid aggregates/follicles, and bile duct damage is suggestive of chronic HCV infection. These two common chronic viral 218

C Figure 14.11  Liver biopsy specimen taken from a 60-year-old woman, after 6.5 years of antiviral therapy that was initiated after a biopsy-proven diagnosis of chronic hepatitis B cirrhosis. At the time of the current biopsy, the patient continued to have clinical evidence of portal hypertension. Low-power examination of the biopsy specimen (A) shows lack of nodularity and a small amount of fibrous tissue. Higher power examination reveals remnants of fibrous septa (B), as well as aberrant parenchymal veins (C), representing terminal hepatic venules approximated to portal tracts (A to C: Masson trichrome stain) (also see eSlide 41.5).

Hepatitis B Table 14.1  Cytologic Changes Simulating the Ground-Glass Cells of Chronic Hepatitis B Virus Infection Cytologic Change

Clinical Setting

Oncocytic change Various chronic liver diseases ­(oncocytic hepatocytes)

Cause of Cytologic Change Presence of abundant mitochondria

Enzymatic induction (“induced” hepatocytes)

Marked hypertrophy of endoVarious medications (eg, phenytoin, chlorpromazine, plasmic reticulum barbiturates, and others)

Ground-glass change

Glycogen storage disease type Accumulation of abnormal IV (amylopectinosis, Anderson glycogen (amylopectin-like disease) material)

Ground-glass change

Lafora disease (myoclonus epilepsy)

Accumulation of abnormal glycogen (polyglucosan)

Ground-glass change

“Fibrinogen storage” diseases

Accumulation of abnormal fibrinogen in the endoplasmic reticulum

Ground-glass change

Cyanamide toxicity in alcoholic patients on aversion therapy

Accumulation of glycogen and degenerating organelles

Ground-glass change

Patients on multiple medications, Accumulation of glycogen often immunosuppressed

Ground glass change

Patients on parenteral nutrition (also see eSlide 3.6)

A

14

Accumulation of glycogen

Note: Immunohistochemistry for hepatitis B surface antigen (HBsAg) is negative in all the above conditions.

features simulating chronic viral hepatitis. The differential diagnosis is discussed in detail in Chapter 15 on hepatitis C. Suffice to state here that ground-glass cells, sanded nuclei, and immunopositivity for HBsAg or HBcAg are not features of these diseases. Finally, malignant lymphoma may also need to be distinguished occasionally from chronic hepatitis. This differential diagnosis is also discussed in Chapter 15.

B Figure 14.12  Immunohistochemical stains for hepatitis B surface antigen. A, Positive nuclear and cytoplasmic staining in a patient with active viral replication. B, Extensive nuclear immunopositivity in a perinatally infected 21-year-old patient. Note the absence of necroinflammatory activity. (A and B: Streptavidin-biotin.)

hepatitides share the parenteral route of transmission and therefore may coexist in individuals. In such cases, determining the predominant cause of liver damage may be a difficult exercise requiring careful correlation of clinical, serologic, histologic, and immunohistochemical (HBsAg, HBcAg) data.

Other Chronic Hepatitides Like chronic hepatitis C, autoimmune hepatitis and drug-induced hepatitis do not have pathognomonic histologic features. Autoimmune hepatitis is usually, but not always, characterized by significant necroinflammatory activity and prominent plasma cell infiltrates, whereas drug-induced hepatitis often causes lobular cholestasis. Clinical information, as well as the lack of features of chronic HBV infection such as ground-glass cells, sanded nuclei, and positive immunostaining for HBsAg or HBcAg, are helpful in distinguishing these conditions from chronic hepatitis B.

Other Chronic Liver Diseases Chronic biliary diseases, such as primary biliary cholangitis and primary sclerosing cholangitis, as well as hereditary metabolic diseases, such as alpha-1 antitrypsin deficiency and Wilson disease, may have histologic

Ground-Glass Cells Cytologic changes mimicking the appearance of HBV-infected groundglass cells may be seen in some conditions unrelated to HBV infection (Table 14.1),70-73a and are variously the result of cytoplasmic accumulation of glycogen, fibrinogen, or cellular organelles. Distinction of these changes from chronic HBV infection is based on clinical information as well as lack of immunopositivity for HBsAg. Additional histochemical and immunohistochemical stains may be helpful in deciphering the nature of such cytologic changes in each individual case. For example, the cytoplasmic material in Lafora disease is characteristically positive for colloidal iron, whereas the material of “fibrinogen storage” diseases exhibits positive immunostaining for fibrinogen.

Practical Approach in Evaluating Liver Biopsy Specimens from Patients with Chronic Hepatitis B It is recommended that the pathologist first examines the slides “blindly” (ie, without knowledge of the clinical history) and addresses the issues shown in Box 14.3. This blinded approach is probably the best one in assessing the possible etiology of the histologic changes.74 Once the pathologist has an unbiased impression of the histologic features, he or she should read the clinical information, paying attention to length of infection (if known), laboratory findings such as liver function tests, serum HBV DNA level, and HBeAg status, and treatment. Immunohistochemical stains for HBsAg and HBcAg may provide useful information regarding the replicative status of HBV. If slides of previous liver biopsy samples are available, they should be reviewed and compared with those of the new biopsy. The final diagnosis should include a statement regarding the grade 219

Practical Hepatic Pathology: A Diagnostic Approach Box 14.3  Practical Approach in Evaluating Liver Biopsy Specimens from Patients with Chronic Hepatitis B • Is the biopsy specimen adequate? (See Chapter 16 on grading and staging.) • Is the overall hepatic architecture preserved, or is there distortion suggestive of significant fibrosis or cirrhosis? • Is there chronic inflammation in portal tracts? Is it mild, moderate, or severe? • Is there interface hepatitis? Is it mild, moderate, or severe? • Are there foci of spotty necrosis and acidophil bodies? Are they few, moderate in number, or abundant? • Is there confluent necrosis? Bridging necrosis? What is their extent? • Are there ground-glass cells? How extensive are they? • Are there sanded nuclei in hepatocytes? • Is there fibrosis? How is the biopsy staged, according to one of the available systems? (See Chapter 16 on grading and staging.) • Are there features suggestive of any other liver disease? If so, which one appears to be the predominant disorder? Hepatitis B or other? • Are there cytologic changes suggestive of an increased risk of hepatocellular carcinoma, such as large cell change or small cell change?

of necroinflammatory activity and the stage of fibrosis in descriptive terms, with or without semiquantitative values. In patients with more than one biopsy over time (with or without antiviral treatment), a comment regarding progression or regression of the histologic changes is appropriate. Suggested Readings 1. H  ytiroglou P, Snover DC, Alves V, et al. Beyond “cirrhosis”: A proposal from the International Liver Pathology Study Group. Am J Clin Pathol. 2012;137:5–9. 2. Ishak KG. 2000 Pathologic features of chronic hepatitis. A review and update. Am J Clin Pathol. 2000;113:40–55. 3. Lee YA, Wallace MC, Friedman SL. Pathobiology of liver fibrosis: a translational success story. Gut. 2015;64:830–841. 4. Locarnini S, Hatzakis A, Chen DS, Lok A. Strategies to control hepatitis B: Public policy, epidemiology, vaccine and drugs. J Hepatol. 2015;62:S76–S86. 5. Mani H, Kleiner DE. Liver biopsy findings in chronic hepatitis B. Hepatology. 2009;49:S61–S71.

References 1. Sherlock S, Dooley J. Diseases of the Liver and Biliary System. 10th ed. Oxford: Blackwell Science; 1997. 2. Chan HLY, Wong VWS, Hepatitis B. In: Boyer TD, Manns MP, Sanyal AJ, Zakim D, eds. Zakim and Boyer’s hepatology: A textbook of liver disease. 6th ed. Philadelphia: Saunders/Elsevier; 2012:540–563. 3. Wells JT, Perillo R, Hepatitis B. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease. 10th ed. Philadelphia: Saunders/Elsevier; 2016:1309–1331. 4. Lee WM. Hepatitis B virus infection. N Engl J Med. 1997;337:1733–1745. 5. Lavanchy D. Hepatitis B virus epidemiology, disease burden, treatment, and current and emerging prevention and control measures. J Viral Hepat. 2004;11:97–107. 6. Locarnini S, Hatzakis A, Chen DS, Lok A. Strategies to control hepatitis B: Public policy, epidemiology, vaccine and drugs. J Hepatol. 2015;62:S76–S86. 7. Tiollais P, Pourcel C, Dejean A. The hepatitis B virus. Nature. 1985;317:489–495. 8. Warner N, Locarnini S. Replication of Hepatitis B virus. In: Boyer TD, Manns MP, Sanyal AJ, Zakim D, eds. Zakim and Boyer’s Hepatology. 6th ed. Philadelphia: Saunders/Elsevier; 2012:86–96. 9. Wen YM. Structural and functional analysis of full-length hepatitis B virus genomes in patients: implications in pathogenesis. J Gastroenterol Hepatol. 2004;19:485–489. 10. Kay A, Zoulim F. Hepatitis B virus genetic variability and evolution. Virus Res. 2007;127:164–176. 11. Paterlini-Brechot P, Saigo K, Murakami Y, et al. Hepatitis B virus-related insertional mutagenesis occurs frequently in human liver cancers and recurrently targets human telomerase gene. Oncogene. 2003;22:3911–3916. 12. Murakami Y, Saigo K, Takashima H, et al. Large scaled analysis of hepatitis B virus (HBV) DNA integration in HBV related hepatocellular carcinomas. Gut. 2005;54:1162–1168. 13. Li X, Zhang J, Yang Z, Kang J, Jiang S, Zhang T, et al. The function of targeted host genes determines the oncogenicity of HBV integration in hepatocellular carcinoma. J Hepatol. 2014;60:975–984. 14. Hadziyannis SJ, Vassilopoulos D. Hepatitis B e antigen-negative chronic hepatitis B. Hepatology. 2001;34:617–624. 15. Lai CL, Dienstag J, Schiff E, et al. Prevalence and clinical correlates of YMDD variants during lamivudine therapy for patients with chronic hepatitis B. Clin Infect Dis. 2003;36:687–696.

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16. Zoulim F, Locarnini S. Hepatitis B virus resistance to nucleos(t)ide analogues. Gastroenterology. 2009;137:1593–1608. 17. Jung MC, Pape GR. Immunology of hepatitis B infection. Lancet Infect Dis. 2002;2:43–50. 18. Theise ND, Bodenheimer Jr HC, Ferrell LD. Acute and chronic viral hepatitis. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 6th ed. Philadelphia: Churchill Livingstone; 2012:361–401. 19. Chu CJ, Hussain M, Lok ASF. Quantitative serum HBV DNA levels during different stages of chronic hepatitis B infection. Hepatology. 2002;36:1408–1415. 20. Liaw YF, Tai DI, Chu CM, et al. The development of cirrhosis in patients with chronic type B hepatitis: a prospective study. Hepatology. 1988;8:493–496. 21. McMahon BJ. The natural history of chronic hepatitis B virus infection. Semin Liver Dis. 2004;24(Suppl 1):17–21. 22. Fattovich G. Natural history and prognosis of hepatitis B. Semin Liver Dis. 2003;23:47–58. 23. Weissberg JI, Andres LL, Smith CI, et  al. Survival in chronic hepatitis B. An analysis of 379 patients. Ann Intern Med. 1984;101:613–616. 24. Cardenas CL, Soetikno R, Robinson WS, et al. Long-term follow-up of patients with chronic hepatitis B: a 25 year prospective study. Hepatology. 1999;30. 300Aendash(abstract). 25. Pyrsopoulos NT, Reddy KR. Extrahepatic manifestations of chronic viral hepatitis. Curr Gastroenterol Rep. 2001;3:71–78. 26. Ishak KG, Goodman ZD, Stocker JT. Tumors of the Liver and Intrahepatic Bile Ducts. Atlas of Tumor Pathology Armed Forces Institute of Pathology. Washington, DC. Third series, Fascicle 31; 2001. 27. Abu-Amara M, Feeld JJ. Does antiviral therapy for chronic hepatitis B reduce the risk of hepatocellular carcinoma? Semin Liver Dis. 2013;33:157–166. 28. Lok AS, McMahon BJ. Chronic hepatitis B: update 2009. Hepatology. 2009;50:661–662. 29. EASL clinical practice guidelines. management of chronic hepatitis B virus infection. J Hepatol. 2012;57:167–185. 30. Liaw YF, Kao JH, Piratvisuth T, Chan H, Chien R-N, Liu C-J, et al. Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2012 update. Hepatol Int. 2012;6:531–561. 31. Yapali S, Talaat N, Lok AS. Management of hepatitis B: our practice and how it relates to the guidelines. Clin Gastroenterol Hepatol. 2014;12:16–26. 32. Dienstag JL, Goldin RD, Heathcote EJ, et al. Histological outcome during long-term lamivudine therapy. Gastroenterology. 2003;124:105–117. 33. Hadziyannis SJ, Tassopoulos NC, Heathcote EJ, et al. Long-term therapy with adefovir dipivoxil for HBeAg-negative chronic hepatitis B for up to 5 years. Gastroenterology. 2006;131:1743–1751. 34. Chang TT, Liaw YF, Wu SS, Schiff E, Han KH, Lai CL, et al. Long-term entecavir therapy results in the reversal of fibrosis/cirrhosis and continued histological improvement in patients with chronic hepatitis B. Hepatology. 2010;52:886–893. 35. Marcellin P, Gane E, Buti M, Afdhal N, Sievert W, Jacobson IM, et al. Regression of cirrhosis during treatment with tenofovir disoproxil fumarate for chronic hepatitis B: a 5-year open-label follow-up study. Lancet. 2013;381:468–475. 36. Papachrysos N, Hytiroglou P, Papalavrentios L, Sinakos E, Kouvelis I, Akriviadis E. Antiviral therapy leads to histological improvement of HBeAg-negative chronic hepatitis B patients. Ann Gastroenterol. 2015;28:374–378. 37. Ishak KG. Pathologic features of chronic hepatitis. A review and update. Am J Clin Pathol. 2000;113:40–55. 38. Mani H, Kleiner DE. Liver biopsy findings in chronic hepatitis B. Hepatology. 2009;49:S61–S71. 39. Falkowski O, An HJ, Ianus IA, et al. Regeneration of hepatocyte ‘buds’ in cirrhosis from intrabiliary stem cells. J Hepatol. 2003;39:357–364. 40. Cooksley WG, Bradbear RA, Robinson W, et al. The prognosis of chronic active hepatitis without cirrhosis in relation to bridging necrosis. Hepatology. 1986;6:345–348. 41. Chen TJ, Liaw YF. The prognostic significance of bridging hepatic necrosis in chronic type B hepatitis: a histopathologic study. Liver. 1988;8:10–16. 42. Hadziyannis S, Gerber MA, Vissoulis C, et al. Cytoplasmic hepatitis B antigen in “ground-glass” hepatocytes of carriers. Arch Pathol. 1973;96:327–330. 43. Shikata T, Uzawa T, Yoshiwara N, et al. Staining methods of Australia antigen in paraffin section—detection of cytoplasmic inclusion bodies. Jpn J Exp Med. 1974;44:25–36. 44. Gerber MA, Thung SN. Hepatic oncocytes. Incidence, staining characteristics, and ultrastructural features. Am J Clin Pathol. 1981;75:498–503. 45. Bianchi L, Gudat F. Sanded nuclei in hepatitis B: eosinophilic inclusions in liver cell nuclei due to excess in hepatitis B core antigen formation. Lab Invest. 1976;35:1–5. 46. Moreno A, Ramon y, Cajal S, Maranzuela M, et  al. Sanded nuclei in delta patients. Liver. 1989;9:367–371. 47. Anthony PP, Vogel CL, Barker LE. Liver cell dysplasia: a premalignant condition. J Clin Path. 1973;26:217–223. 48. Natarajan S, Theise ND, Thung SN, et  al. Large-cell change of hepatocytes in cirrhosis may represent a reaction to prolonged cholestasis. Am J Surg Pathol. 1997;21:312–318. 49. Lee RG, Tsamandas AC, Demetris AJ. Large cell change (liver cell dysplasia) and hepatocellular carcinoma in cirrhosis: matched case-control study, pathological analysis, and pathogenetic hypothesis. Hepatology. 1997;26:1415–1422. 50. Hytiroglou P. Morphological changes of early human hepatocarcinogenesis. Semin Liver Dis. 2004;24:65–75. 51. Theise ND, Curado MP, Franceschi S, et al. Hepatocellular carcinoma. In: Bosman FT, Carneiro F, Hruban RH, Theise ND, eds. WHO Classification of Tumours of the Digestive System. 4th ed. Lyon: IARC; 2010:205–216.

Hepatitis B 52. Borzio M, Bruno S, Roncalli M, et al. Liver cell dysplasia is a major risk factor for hepatocellular carcinoma in cirrhosis: a prospective study. Gastroenterology. 1995;108:812–817. 53. Libbrecht L, Craninx M, Nevens F, et al. Predictive value of liver cell dysplasia for development of hepatocellular carcinoma in patients with non-cirrhotic and cirrhotic chronic viral hepatitis. Histopathology. 2001;39:66–73. 54. Kim H, Oh BK, Roncalli M, et al. Large liver cell change in hepatitis B virus-related liver cirrhosis. Hepatology. 2009;50:752–762. 55. Watanabe S, Okita K, Harada T, et al. Morphologic studies of the liver-cell dysplasia. Cancer. 1983;51:2197–2205. 56. Hytiroglou P, Park YN, Krinsky G, et al. Hepatic precancerous lesions and small hepatocellular carcinoma. Gastroenterol Clin North Am. 2007;36:867–887. 57. Scheuer PJ, Maggi G. Hepatic fibrosis and collapse: Histological distinction by orcein staining. Histopathology. 1980;4:487–490. 58. Bonis PA, Friedman SL, Kaplan MM. Is liver fibrosis reversible? N Engl J Med. 2001;344:452–454. 59. Bedossa P, Paradis V. Liver extracellular matrix in health and disease. J Pathol. 2003;200: 504–515. 60. Friedman SL, Bansal MB. Reversal of hepatic fibrosis—fact or fantasy? Hepatology. 2006;43 (Suppl 1):S82–S88. 61. Lee YA, Wallace MC, Friedman SL. Pathobiology of liver fibrosis: a translational success story. Gut. 2015;64:830–841. 62. Wanless IR, Nakashima E, Sherman M. Regression of human cirrhosis. Morphologic features and the genesis of incomplete septal cirrhosis. Arch Pathol Lab Med. 2000;124:1599–1607. 63. Malekzadeh R, Mohamadnejad M, Rakhshani N, et al. Reversibility of cirrhosis in chronic hepatitis B. Clin Gastroenterol Hepatol. 2004;2:344–347. 64. Bortolotti F, Guido M, Cadrobbi P, Crivellaro C, Bartolacci S, Rugge M, et  al. Spontaneous regression of hepatitis B virus-associated cirrhosis developed in childhood. Dig Liver Dis. 2005;37:964–967.

65. Serpaggi J, Carnot F, Nalpas B, Canioni D, Guéchot J, Lebray P, et al. Direct and indirect evidence for the reversibility of cirrhosis. Hum Pathol. 2006;37:1519–1526. 66. Garcia-Tsao G1, Friedman S, Iredale J, Pinzani M. Now there are many (stages) where before there was one: in search of a pathophysiological classification of cirrhosis. Hepatology. 2010;51:1445–1449. 67. Hytiroglou P, Snover DC, Alves V, Balabaud C, Bhathal PS, Bioulac-Sage P, et  al. Beyond “cirrhosis”: a proposal from the International Liver Pathology Study Group. Am J Clin Pathol. 2012;137:5–9. 68. Hytiroglou P, Thung SN, Gerber MA. Histological classification and quantitation of the severity of chronic hepatitis: keep it simple! Semin Liver Dis. 1995;15:414–421. 69. Thung SN, Gerber MA. Differential Diagnosis in Pathology: Liver Disorders. New York: IgakuShoin; 1995. 70. Lefkowitch JH, Lobritto SJ, Brown RS, et  al. Ground-glass, polyglucosan-like hepatocellular inclusions: a “new” diagnostic entity. Gastroenterology. 2006;131:713–718. 71. Wisell J, Boitnott J, Haas M, et al. Glycogen pseudoground glass change in hepatocytes. Am J Surg Pathol. 2006;30:1085–1090. 72. Thompson RJ, Portmann BC, Roberts EA. Genetic and metabolic liver disease. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 6th ed. Philadelphia: Churchill Livingstone; 2012:157–259. 73. Lewis JH, Kleiner DE. Hepatic injury due to drugs, herbal compounds, chemicals and toxins. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 6th ed. Philadelphia: Churchill Livingstone; 2012:645–760. 73a. Brown RM, Gray G, et al. Ground glass hepatocellular inclusions caused by disturbed glycogen metabolism in three children on parenteral nutrition. Pediatr Dev Pathol. 2009;12:79–80. 74. Thung SN, Schaffner F. Liver biopsy. In: MacSween NM, Anthony PP, Scheuer PJ, eds. MacSween’s Pathology of the Liver. 3rd ed. Edinburgh: Churchill Livingstone; 1994:787–796.

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15 Hepatitis C Prodromos Hytiroglou, MD

Incidence and Demographics  223

Incidence and Demographics

Molecular Virology  223

Hepatitis C virus (HCV) is a parenterally transmitted ribonucleic acid (RNA) virus. The global estimate of infected individuals is more than 185 million, with the highest prevalence of infection being in Central and East Asia and in the North Africa/Middle East regions.1 In the United States, there are approximately five million HCV-infected individuals, many of them undiagnosed.2,3 Since 1989, the year of discovery of HCV, the number of new infections has declined by 80% to fewer than 30,000 cases per year, largely because of successful screening of blood and blood products for the virus, as well as needle exchange programs for intravenous drug users.3 However, despite the success of public health measures in reducing the number of new cases, large reservoirs of infection still remain, mostly involving injection drug users. HCV is also transmitted sexually, but the efficiency is low, except in immunosuppressed patients.4-6 Maternal HCV transmission to the infant occurs in fewer than 5% of seropositive mothers but is higher in cases with high levels of viremia or HCV/human immunodeficiency virus (HIV) coinfection.7,8

Natural History and Clinical Manifestations  224 Treatment 224 Role of Liver Biopsy in Management of Hepatitis C  224 Microscopic Pathology of Chronic Hepatitis C  225 Portal Changes and Interface Hepatitis  225 Lobular Inflammation, Apoptosis, and Necrosis  226 Steatosis and Other Cytoplasmic Changes of Hepatocytes  226 Large Cell Change and Small Cell Change  227 Fibrosis and Architectural Distortion  228 Differential Diagnosis of Chronic Hepatitis C  230 Chronic Hepatitides  230 Hereditary Metabolic Disorders  230 Chronic Biliary Diseases  230 Steatohepatitis 230 Malignant Lymphoma  230 Practical Approach in Evaluating Liver Biopsy Specimens from Patients with Chronic Hepatitis C  230

Abbreviations ALD alcoholic liver disease HCC hepatocellular carcinoma HBV hepatitis B virus HCV hepatitis C virus HIV human immunodeficiency virus ISC incomplete septal cirrhosis LCC large cell change NASH  nonalcoholic steatohepatitis SCC small cell change SVR sustained virologic response

Molecular Virology HCV is a single-stranded positive-sense RNA virus of the Flaviviridae family. Hepatocytes are the major site of HCV replication; however, this virus can also replicate in peripheral blood mononuclear cells and dendritic cells.9 The HCV genome is composed of approximately 9600 nucleotides, with a single open reading frame encoding a large viral polypeptide precursor of 3010 to 3033 amino acids; however, the exact length varies slightly in different HCV isolates.10-13 Cleavage of this polypeptide by cellular and viral proteases yields a number of mature proteins, including the core protein; two envelope glycoproteins; the p7 viroporin; and several nonstructural proteins (the NS2-3 and NS3-4A proteases, the NS3 RNA helicase, the NS4B and NS5A proteins, and the NS5B RNA-dependent RNA polymerase). HCV entry in the hepatocytes involves the attachment of the envelope proteins to cell surface molecules. The role of several proteins in this process has been recently reviewed.12,13 HCV has an inherently high mutational rate, leading to considerable genomic heterogeneity; in part, this results from the fact that the RNA-dependent RNA polymerase lacks proofreading

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224

ability.14,15 Therefore, HCV infection is characterized by the emergence of closely related, yet heterogeneous, viral sequences in the same patient, which are called quasispecies. The generation of quasispecies offers HCV considerable advantage in escaping immune responses and antiviral treatment.14,16 In addition, nucleotide sequencing of HCV isolates from different parts of the world has shown that there are six genetically distinct groups, called HCV genotypes, differing in up to 34% of their sequences, which can be further distinguished into more than 70 subtypes.13,14 There are significant differences in HCV genotypes in terms of geographic distribution and response to antiviral therapy.

nodosa, autoimmune thyroiditis, Sjögren syndrome, lichen planus of the buccal mucosa, porphyria cutanea tarda, and diabetes mellitus.2,13,35 The pathogenetic mechanisms underlying these manifestations are not clear, and they may be complex for some conditions such as diabetes mellitus. However, activation of autoimmune mechanisms appears to play a key role in most extrahepatic manifestations of hepatitis C, as suggested by the detection of autoantibodies such as anti–liver-kidney microsome, antismooth muscle, antithyroid, and anti-GOR antibodies.35 This may result from a B-cell response to HCV, which also accounts for the occasional development of B-cell lymphomas in HCV-infected patients.36,37

Natural History and Clinical Manifestations

Treatment

Patients with hepatitis C are usually recognized when they already have chronic disease, because in most cases acute hepatitis C lacks clinical manifestations. However, acute hepatitis C may be diagnosed serologically in patients presenting with signs and symptoms of acute liver disease, such as malaise, anorexia, nausea, upper abdominal discomfort, and jaundice, as well as in individuals undergoing serologic testing after a suspect contact, such as a needlestick accident. Acute hepatitis C is believed to represent approximately 20% of cases of acute hepatitis.13 Fulminant hepatic failure caused by acute HCV infection is considered to be an extremely rare event. The diagnosis of acute hepatitis C is based on laboratory findings, including elevated transaminase values, as well as detection of HCV RNA and anti-HCV antibodies in the serum.11 HCV RNA is detectable within 1 to 2 weeks of exposure to the virus, whereas antibodies to viral proteins appear from 2 weeks to 6 months after exposure.17 Acute HCV infection is self-limiting in 10% to 50% of patients.2 The remaining patients develop chronic hepatitis C, an indolent disease with a natural history extending over many years.18 Chronic hepatitis is defined as hepatic inflammation continuing without improvement for at least 6 months. Once chronic hepatitis C is established, spontaneous HCV clearance rarely occurs. The patients with chronic hepatitis C may be entirely asymptomatic or complain of fatigue and other nonspecific symptoms, such as arthralgia, myalgia, pruritus, and sicca syndrome. The majority of patients have persistently elevated or fluctuating transaminase levels; however, in about one third of cases, transaminase values may be within normal range. Detection of antibodies to HCV in the serum indicates exposure to the virus but does not allow differentiation among acute, chronic, or resolved infection. Therefore, molecular assays detecting HCV RNA are used to confirm ongoing infection, whereas serologic assays are typically used for screening and initial diagnosis.19-21 Approximately 15% to 20% of HCV-infected individuals develop cirrhosis at an average interval of 21 ± 10 years from onset of infection.22 These patients may present with signs of portal hypertension, such as ascites, splenomegaly, gastrointestinal bleeding, and encephalopathy. Jaundice is rarely observed in chronic hepatitis C unless significant hepatic decompensation has occurred.2 Risk factors for disease progression include male gender, older age, alcohol consumption, concomitant steatohepatitis, immunosuppression (commonly due to HIV coinfection), hepatitis B virus (HBV) coinfection, and presence of necroinflammatory activity or fibrosis in the liver biopsy.5,23-31 Hepatocellular carcinoma (HCC) is unusual in chronic hepatitis C without cirrhosis; however, once cirrhosis has developed, the risk of HCC is in the range of 1% to 4% per year.32,33 Eradication of HCV by successful antiviral treatment reduces, but does not abolish, the risk of HCC.34 HCV is also increasingly recognized as a cause of significant extrahepatic disease, such as mixed cryoglobulinemia, membranoproliferative glomerulonephritis, leukocytoclastic vasculitis, polyarteritis

Chronic hepatitis C is a story of success for modern antiviral therapy. Until 2011, the combination of pegylated interferon-alpha with ribavirin constituted the standard of care for treatment-naïve patients,38-40 and achieved an overall sustained virologic response (SVR) in up to 60% of cases. SVR is defined as undetectable HCV RNA in serum 12 weeks (SVR12) or 24 weeks (SVR24) after treatment completion.40 Eradication of HCV is achieved in more than 99% of patients with SVR.41 In recent years, the pace of anti-HCV drug development has accelerated significantly, and a number of direct-acting antiviral (DAA) drugs have been added to the therapeutic armamentarium.40,42 The long list of new drugs (boceprevir, telaprevir, sofosbuvir, simeprevir, daclatasvir, ledipasvir, the combination paritaprevir/ombitasvir/ ritonavir, and dasabuvir) is expected to become even longer in the near future. Interferon-sparing regimens have started to be used with success, and the overall SVR rate is now higher than 90%.42 Treatment guidelines in this rapidly evolving field have been published by the American Association for the Study of Liver Diseases/the Infectious Diseases Society of America, the European Association for the Study of the Liver and the World Health Organization,1,40,42 and are being constantly updated. HCV genotype is a key factor in selecting the most appropriate drug combination in every case. Acute HCV infection can be treated in a similar way to chronic HCV infection; however, the decision to wait for a few months before initiating treatment is often justified.42

Role of Liver Biopsy in Management of Hepatitis C Liver biopsy is not performed in acute hepatitis C, except in patients presenting with severe acute liver disease in whom causes other than viral disease, such as drug reactions or biliary obstruction, are suspected. The histologic features of acute hepatitis C (also see eSlide 13.1) are similar to those of acute hepatitis resulting from other causes, as discussed and illustrated in Chapter 13. In chronic hepatitis C, liver biopsy is performed to determine the severity (grade) of necroinflammatory activity and the stage of fibrosis and architectural distortion, which is a measure of disease progression. This information has important prognostic and therapeutic implications. Detailed information about the various scoring systems for grading and staging is provided in Chapter 16. Despite efforts to replace it with biochemical tests and other noninvasive tests, liver biopsy currently remains the gold standard for grading and staging of chronic hepatitis C. In addition, liver biopsy is useful in ruling out concomitant diseases, such as alcoholic or nonalcoholic steatohepatitis and hemochromatosis, as well as in determining the predominant cause of liver damage in cases with two or more causes of liver disease. Repeat liver biopsy is useful in assessing disease progression or remission over time and in evaluating the effects of treatment. Finally, guided liver biopsy is essential in making the diagnosis of HCC or dysplastic nodules arising in livers with chronic hepatitis C. Such lesions are usually detected after cirrhosis is established.

Hepatitis C Box 15.1  Histologic Features of Chronic Hepatitis C (eSlides 15.1, 15.2, and 15.3) A. Changes seen in chronic hepatitis of any cause: 1. Chronic inflammatory cell infiltration of portal tracts 2. Interface hepatitis (ie, necroinflammatory activity at the portal/lobular interface [formerly called piecemeal necrosis]) 3. Intralobular necroinflammatory activity, including: a. Apoptotic hepatocytes (acidophil bodies) b. Foci of spotty necrosis c. Foci of confluent necrosis 4. Bridging necrosis (ie, confluent necrosis linking central veins with portal tracts; rare in chronic hepatitis C) 5. Fibrosis of variable degree B. Characteristic triad of chronic HCV infection (often, but not invariably, present): 1. Steatosis 2. Dense lymphoid aggregates or lymphoid follicles in portal tracts 3. Bile duct damage C. Immunohistochemistry Not currently standardized for routine diagnostic use

15

A

HCV, Hepatitis C virus.

Microscopic Pathology of Chronic Hepatitis C The histologic features of chronic hepatitis C include changes that are common in all etiologies of chronic hepatitis and changes that are characteristic, although not pathognomonic, of chronic HCV infection35,43–45 (Box 15.1). The use of a semiquantitative scoring system for grading and staging of histologic features is not necessary for daily diagnostic purposes but may be helpful in more accurately evaluating any given case. The scoring systems are discussed in Chapter 16.

Portal Changes and Interface Hepatitis Chronic inflammation of portal tracts, a finding of all types of chronic hepatitis, may be mild, moderate, or severe (eSlides 15.1, 15.2, and 15.3). As a rule, the inflammatory infiltrates in chronic hepatitis C are predominantly composed of lymphocytes and smaller numbers of plasma cells. Dense lymphoid aggregates and lymphoid follicles are often found in the portal tracts and represent a prominent and characteristic feature (Fig. 15.1A–B); however, they may also be seen in other causes of chronic hepatitis, such as hepatitis B and autoimmune hepatitis, as well as in primary biliary cholangitis. Degenerative changes of the epithelium of interlobular bile ducts (“bile duct damage”) are considered to be another characteristic feature, commonly seen in chronic hepatitis C. Such changes include vacuolation, stratification, and crowding of epithelial cells46 (see Figs. 15.1A–C and 15-2B). Bile duct infiltration by lymphocytes may also be seen. Occasionally, mild ductopenia may be found.47 Talc crystals, best visualized under polarized light, may be seen in portal macrophages of individuals with history of intravenous drug use.44 In some cases, the talc may be intermingled with black birefringent granules containing titanium. Interface hepatitis (formerly called piecemeal necrosis) is commonly present in chronic hepatitis C; it is characterized by entry of lymphocytes from the portal tracts into the lobules through the limiting plate, associated with hepatocyte damage and loss (see Figs. 15.1A–C and 15.2A–C). Swollen hepatocytes and acidophil bodies are often found in these areas (see Fig. 15.2A). Mild ductular reaction may also be seen (see Fig. 15.2B). Interface hepatitis is usually of mild or moderate degree in chronic hepatitis C; severe interface hepatitis is unusual but not rare. Sometimes, clusters of hepatocytes are seen in the portal tracts, separated from the lobules (see Fig. 15.2C). Such clusters may be the result of current or past severe interface hepatitis; however, in cases of cirrhosis, they have been shown to represent regeneration from bipotent progenitor cells.48 At the other end of the spectrum, cases with

B

C Figure 15.1  Portal and periportal inflammation in chronic hepatitis C. A, This field is dominated by a dense lymphoid aggregate. Interface hepatitis is seen around half of the perimeter of the portal tract. Bile duct damage is also present (arrows). B, In this portal tract, there is a lymphoid follicle with germinal center. Bile duct damage is seen (arrow). Focal interface hepatitis is also present. C, Bile duct damage (arrow) in a moderately inflamed portal tract. Interface hepatitis is also seen in the right part of the field.

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A Figure 15.3  A lymphoid follicle and an incidental lipogranuloma are seen in this moderately inflamed portal tract. No interface hepatitis is evident.

absent or minimal interface hepatitis are common (Fig. 15.3). It was for such cases that the now obsolete term chronic persistent hepatitis was used in the past. The absence of interface hepatitis in a liver biopsy does not guarantee the absence of such activity in the future; the course of chronic hepatitis C is characterized by exacerbations and remissions, both clinically and histologically. Successful antiviral therapy leads to disappearance of interface hepatitis.

Lobular Inflammation, Apoptosis, and Necrosis

B

C Figure 15.2  Interface hepatitis in chronic hepatitis C (also see eSlides 15.1, 15.2, and 15.3). A, An acidophil body (arrowhead) and several swollen hepatocytes are present in this field. Another hepatocyte (arrow) exhibits increased cytoplasmic eosinophilia and an angulated cell shape, suggestive of activation of the process of apoptosis. B, Bile duct damage and mild ductular reaction accompany interface hepatitis in this field. C, In this portal area, there are clusters of hepatocytes separated from the lobules.

226

Intralobular necroinflammatory activity is characterized by the presence of apoptotic (acidophil) bodies, foci of spotty necrosis, and Kupffer cell activation (Fig. 15.4A–C). Cytoplasmic swelling of hepatocytes is common and may evolve to ballooning degeneration. Foci of spotty necrosis consist of small aggregates of inflammatory cells, mostly lymphocytes and histiocytes, located in spots of degenerating or lost hepatocytes (see Fig. 15.4A–B). Occasionally, acidophil bodies are seen within such aggregates (see Fig. 15.4B); however, acidophil bodies may also be found unassociated with inflammatory cells, lying free within liver cell plates or sinusoids (see Fig. 15.4C). Acidophil bodies are apoptotic hepatocytes (or fragments of apoptotic hepatocytes) with brightly eosinophilic cytoplasm. They may be devoid of nucleus or may contain a shrunken, hyperchromatic, and often fragmented nucleus. Features suggestive of activation of the apoptotic process in hepatocytes include increased cytoplasmic eosinophilia, angulated cell shape, and nuclear hyperchromasia. In a small minority of cases, adjacent foci of spotty necrosis coalesce to form areas of confluent necrosis, mostly located in centrilobular regions (Fig. 15.5); bridging necrosis is distinctly uncommon in chronic hepatitis C. Successful antiviral therapy leads to disappearance of intralobular necroinflammatory activity.

Steatosis and Other Cytoplasmic Changes of Hepatocytes Macrovesicular or mixed macrovesicular and microvesicular steatosis of mild to moderate degree is a characteristic, but not universally present, feature of chronic hepatitis C (Fig. 15.6). Although steatosis may represent a viral effect, especially in cases resulting from HCV genotype 3,49 prominent steatosis should always raise the possibility of other causes, such as alcohol use, obesity, hyperlipidemia, or diabetes mellitus. Mallory bodies, neutrophilic infiltrates and centrilobular/pericellular fibrosis in liver biopsies with chronic hepatitis C and steatosis may be suggestive of concomitant alcoholic or nonalcoholic steatohepatitis (NASH) (see eSlide 12.5). Hepatic iron stores are frequently increased

Hepatitis C

15

A Figure 15.5  Confluent necrosis in a centrilobular area from a biopsy with chronic hepatitis C.

B

Figure 15.6  Mild steatosis in chronic hepatitis C.

presence of abundant mitochondria and are illustrated in Chapter 14 on hepatitis B.

Large Cell Change and Small Cell Change

C Figure 15.4  Intralobular necroinflammatory activity in chronic hepatitis C. A, There are scattered foci of spotty necrosis, accompanied by Kupffer cell activation. B, Swollen hepatocytes and an acidophil body (arrow) are seen in this field. C, An acidophil body (arrow) lies free within a sinusoid.

in chronic hepatitis C35,50; mild hemosiderin deposits may be present both in hepatocytes and sinusoidal-lining cells. “Oncocytic” hepatocytes (ie, hepatocytes with abundant, finely granular eosinophilic cytoplasm) may be seen in chronic hepatitis C, as well as hepatitis B and other chronic liver diseases. These cells owe their appearance to the

Two cytologic changes that are suggestive of an increased risk of development of HCC may be seen in livers with chronic hepatitis C, usually in the setting of cirrhosis. Large cell change (LCC) of hepatocytes is both frequent and widespread in cirrhotic livers and is characterized by large cell size, nuclear pleomorphism and hyperchromasia, as well as multinucleation; the nucleocytoplasmic ratio is preserved51 (Fig. 15.7). This change is common in cirrhosis caused by chronic viral hepatitis B or C but may also be seen in cirrhosis from other causes. LCC is thought to represent a marker of chronic hepatic injury rather than a precancerous change by most investigators;52-54 however, this entity has also been found to be a marker of increased risk for HCC in cirrhotic patients.55,56 Recent evidence suggests that LCC may be heterogeneous, and a subset occurring in cirrhosis due to chronic hepatitis B may be related to hepatocarcinogenesis.57 Small cell change (SCC) of hepatocytes58 is less common than LCC and is considered to be precancerous.59,60 SCC is characterized by small cell size, nuclear hyperchromasia 227

Practical Hepatic Pathology: A Diagnostic Approach and pleomorphism, increased nucleocytoplasmic ratio, and multinucleation.58 LCC and SCC are discussed in more detail in Chapter 31. Identification of either LCC or SCC should be mentioned in the pathology reports to be taken into account for HCC surveillance.54

Fibrosis and Architectural Distortion

Figure 15.7  Large cell change of hepatocytes in a case of cirrhosis due to chronic hepatitis C.

In the course of time, the necroinflammatory activity of chronic hepatitis C may cause fibrosis, involving portal tracts and extending into the lobules in the form of fibrous septa (Fig. 15.8A). Early “spiky” septa may be difficult to discern on hematoxylin and eosin–stained sections; they are best seen on connective tissue stains, such as Masson trichrome (see Fig. 15.8B). Over time, fibrous septa may link adjacent portal tracts (see Fig. 15.8C), as well as portal tracts with central veins (eSlide 15.2B). Such progressive fibrosis, combined with hepatocyte loss and regeneration, may cause architectural distortion (see Fig. 15.8 D), eventually leading to cirrhosis (eSlide 15.3). Cirrhosis is of the macronodular, or mixed macronodular and micronodular type (Fig. 15.9). Connective tissue stains are valuable in assessing the stage of fibrosis and in differentiating between bridging necrosis and bridging fibrosis. Whereas trichrome stains are usually sufficient for determining the stage, elastic tissue stains

A

B

C

D Figure 15.8  Fibrosis in chronic hepatitis C. A, This portal tract is expanded with chronic inflammation and fibrosis. “Spiky” fibrous septa extend into the lobules. B, Higher power examination shows thin fibrous septa in periportal location. C, Fibrous septa linking adjacent portal tracts. D, Marked fibrosis with architectural distortion. The rounded edge of the lobules is suggestive of transition to cirrhosis (also see eSlide 15.2B). (A–D, Masson trichrome.)

228

Hepatitis C

15

A Figure 15.9  Cirrhosis of mixed macronodular and micronodular type due to chronic hepatitis C.

may also be of assistance because elastic fibers are found only in established septa but not in areas of recent parenchymal collapse.61 Although in the past fibrosis was considered to be an unremitting process, recent studies have shown that fibrosis can regress after successful antiviral treatment (also see Chapters 40 and 41).62,63 At the same time, the molecular mechanisms of fibrosis have become better understood, including the role of chronic inflammation and hepatic stellate cell activation in this process.64-67 HCV eradication by antiviral therapy leads to loss of necroinflammatory activity, which results in inactivation, apoptosis, or senescence of activated hepatic stellate cells; this in turn provides the opportunity for absorption of excess fibrous tissue and improvement of disease stage. Even the fibrosis that is part of cirrhosis may regress after successful antiviral treatment (also see Figs. 40.1 and 40.2); when this happens, parenchymal nodularity may disappear over time, and the hepatic architecture may improve significantly. A recent study of cirrhotic patients (METAVIR stage F4) achieving SVR, who underwent pretreatment and posttreatment liver biopsies, has documented regression of cirrhosis in 23 out of 38 patients; more specifically, the stage became F3 in 14 patients, F2 in 7 patients, and F1 in 2 patients.68 Although the fibrous septa in cirrhotic livers may regress or disappear after successful antiviral treatment, the vascular changes, which are greatly responsible for portal hypertension, are not believed to improve over time, at least according to the current level of knowledge. Therefore, the interpretation of liver biopsies from patients who are clinically thought to have cirrhosis must be made with extreme caution when diagnostic features of cirrhosis are not readily evident on histologic examination. Such biopsy specimens may come from livers with “incomplete septal cirrhosis” (ISC), which is notoriously difficult to diagnose on liver biopsy. The morphologic appearances of ISC may be the result of architectural remodeling due to regression of fibrosis in cirrhotic livers.69 Clues for the presence of ISC include thin, often discontinuous (“perforated”) fibrous septa, isolated thick collagen fibers, portal tract remnants, hepatic vein remnants with prolapsed hepatocytes, aberrant parenchymal veins, and vague nodularity, with presence of compressed and dilated sinusoids rather than fibrous septa at the nodule limits69 (Fig. 15.10A–C). Despite the lack of significant fibrosis, patients with ISC may have portal hypertension, with its attendant clinical consequences. The recent progress in the treatment of the advanced stages of chronic hepatitis C and other chronic liver diseases has made obvious that cirrhosis does not always represent an end stage condition.

B

C Figure 15.10  Incomplete septal cirrhosis in a patient with chronic hepatitis C. A, Thin, often perforated fibrous septa extend from the portal tracts into the lobules, occasionally reaching terminal hepatic venules. There is vague parenchymal nodularity (reticulin). B, Perforated fibrous septa, such as the one illustrated, apparently are caused by regression of fibrosis in a liver that used to have established cirrhosis (Masson trichrome). C, Aberrant parenchymal veins, representing terminal hepatic venules approximated to portal tracts, are characteristic features of incomplete septal cirrhosis (Masson trichrome).

229

Practical Hepatic Pathology: A Diagnostic Approach Box 15.2  Histologic Differential Diagnosis of Chronic Hepatitis C Other causes of chronic hepatitis • Hepatitis B • Autoimmune hepatitis • Drug-induced hepatitis Hereditary metabolic disorders (eg, Wilson disease, alpha-1 antitrypsin deficiency) Chronic biliary diseases Alcoholic liver disease and nonalcoholic steatohepatitis Malignant lymphoma

Therefore, an International Liver Pathology study group have challenged the usefulness of the term “cirrhosis” in modern medicine and suggested that it be discontinued.70

Differential Diagnosis of Chronic Hepatitis C There are no specific (pathognomonic) histologic findings for chronic hepatitis C. Thus, the differential diagnosis includes a variety of pathologic conditions causing chronic hepatic inflammation and fibrosis35,44,71,72 (Box 15.2).

Chronic Hepatitides Distinction between chronic hepatitis C and chronic hepatitides from other causes is often impossible to make on histologic grounds, with the exception of chronic hepatitis B, in which ground-glass cells and sanded nuclei are commonly found, and immunohistochemical stains usually show positivity for hepatitis B surface antigen and hepatitis B core antigen. However, even in cases with findings of chronic HBV infection, the possibility of mixed HBV/HCV infection still exists, and histologic features should be correlated with clinical and serologic findings. Drug-induced hepatitis and autoimmune hepatitis may simulate chronic hepatitis C. As a rule, chronic hepatitis C lacks the prominent plasma cell infiltrates and severe necroinflammatory activity typically seen in autoimmune hepatitis, as well as the cholestatic features often seen in drug-induced hepatitis. On the other hand, the presence of the characteristic triad of steatosis, portal lymphoid aggregates/follicles, and bile duct damage is suggestive of, but not diagnostic for, chronic hepatitis C. Therefore, the distinction between chronic hepatitis C and other causes of chronic hepatitis is established only after careful correlation of pathology with clinical and laboratory findings.

Hereditary Metabolic Disorders Histologic features of chronic hepatitis may be seen in certain metabolic disorders, such as Wilson disease and alpha-1 antitrypsin deficiency. Clinical information is of great importance in making the diagnosis of Wilson disease, as discussed in Chapter 8. Histochemical stains for copper (rhodanine stain) and copper-binding protein (orcein stain) may be useful diagnostic adjuncts in some cases. Confirmation of the diagnosis may require 24-hour urine copper quantitation, before and after d-penicillamine challenge; copper quantitation in dry liver tissue; or genetic testing. Alpha-1 antitrypsin deficiency is characterized by the presence of variably sized eosinophilic globules in the cytoplasm of periportal hepatocytes. These are characteristically periodic acid–Schiff positive and diastase resistant; their identity can be confirmed by immunohistochemical stains for alpha-1 antitrypsin.

Chronic Biliary Diseases Distinction between chronic hepatitis C and chronic biliary diseases may be challenging in some cases. In general, bile duct damage in chronic hepatitis C is mild; bile duct loss, when present, involves a minority of portal tracts. Significant bile duct damage and loss, often accompanied by accumulation of copper and copper-binding protein 230

Box 15.3  Practical Approach in Evaluating Liver Biopsy Specimens from Patients with Chronic Hepatitis C • Is the biopsy specimen adequate? (See Chapter 16 on grading and staging.) • Is the overall hepatic architecture preserved, or is there distortion suggestive of significant fibrosis or cirrhosis? • Is there chronic inflammation in portal tracts? Is it mild, moderate, or severe? • Is there interface hepatitis? Is it mild, moderate, or severe? • Are there foci of spotty necrosis and acidophil bodies? Are they few, moderate in number, or abundant? • Is there confluent necrosis? Bridging necrosis? What is their extent? • Are there features suggestive of hepatitis C virus infection, such as steatosis, portal lymphoid aggregates or follicles, and bile duct damage? Is the steatosis mild, moderate, or severe? • Is there fibrosis? How is the biopsy staged, according to one of the available systems? (See Chapter 16 on grading and staging.) • Are there features suggestive of any other liver disease? If so, which liver disease appears to be predominant Hepatitis C or other? • Are there cytologic changes suggestive of an increased risk of hepatocellular carcinoma, such as large cell change or small cell change?

in periportal hepatocytes, are suggestive of a chronic biliary disease, such as primary biliary cholangitis or primary sclerosing cholangitis. Presence of florid duct lesions is diagnostic of primary biliary cholangitis. Prominent bile ductular reaction, a characteristic feature of large bile duct obstruction, is uncommon in chronic hepatitis C, except in the presence of cirrhosis.

Steatohepatitis Both alcoholic liver disease (ALD) and NASH may show histologic features that overlap with chronic hepatitis C, such as steatosis, chronic inflammation, and fibrosis. Furthermore, ALD or NASH may coexist with chronic hepatitis C and portend a worse prognosis.29,73 Determining the predominant cause of liver damage in patients with such coexisting conditions may be very difficult. However, features suggestive of viral injury include portal lymphoid aggregates/follicles, interface hepatitis, and “spiky fibrosis,” whereas centrilobular/pericellular fibrosis, Mallory bodies and neutrophilic infiltrates are features of ALD or NASH.

Malignant Lymphoma In rare cases of chronic hepatitis C, the possibility of malignant lymphoma may need to be ruled out. Clinical information and review of previous histologic material may be very useful in making the correct diagnosis. Features suggestive of lymphoma rather than hepatitis include a relatively monomorphous cellular infiltrate, immaturity of the lymphoid cells, and absence of significant necroinflammatory activity or fibrosis. As a rule, neoplastic lymphoid cells tend to infiltrate portal tracts and sinusoids without causing the degree of hepatocyte apoptosis and drop-out that would be expected in cases of chronic hepatitis with inflammatory infiltrates of similar intensity. Immunohistochemical stains for lymphoid markers are necessary to confirm the diagnosis of lymphoma.

Practical Approach in Evaluating Liver Biopsy Specimens from Patients with Chronic Hepatitis C It is recommended that the pathologist first examine the slides “blindly” (ie, without knowledge of the clinical history) and address the issues shown in Box 15.3. This blinded approach is probably the best one in assessing the possible etiology of the histologic changes.74 Once the pathologist has an unbiased impression of the histologic features, he or she should read the clinical information, paying attention to length of infection (if known), laboratory findings (such as liver function tests, serum HCV RNA level, and HCV genotype), and treatment. If slides of

Hepatitis C previous liver biopsies are available, they should be reviewed and compared with those of the new biopsy. The final diagnosis should include a statement regarding the grade of necroinflammatory activity and the stage of fibrosis in descriptive terms, with or without semiquantitative values. In patients with more than one biopsy specimen over time (with or without antiviral treatment), a comment regarding progression or regression of the histologic changes is appropriate. Suggested Readings D’Ambrosio R, Aghemo A, Rumi MG, et al. A morphometric and immunohistochemical study to assess the benefit of a sustained virological response in hepatitis C virus patients with cirrhosis. Hepatology. 2012;56:532–543. Hytiroglou P, Snover DC, Alves V, et al. Beyond “cirrhosis”: a proposal from the International Liver Pathology Study Group. Am J Clin Pathol. 2012;137:5–9. Ishak KG. Pathologic features of chronic hepatitis. A review and update. Am J Clin Pathol. 2000;113:40–55. Lee YA, Wallace MC, Friedman SL. Pathobiology of liver fibrosis: a translational success story. Gut. 2015;64:830–841. Lefkowitch JH. Liver biopsy assessment in chronic hepatitis. Arch Med Res. 2007;38:634–643.

References 1. Guidelines for the Screening. Care and Treatment of Persons with Hepatitis C Infection. Geneva: World Health Organization; 2014. 2. Tillman HL, McHutchison JG. Hepatitis C. In: Boyer TD, Manns MP, Sanyal AJ, Zakim D, eds. Zakim and Boyer’s Hepatology: A Textbook of Liver Disease. 6th ed. Philadelphia: Saunders/ Elsevier; 2012:564–598. 3. Centers for Disease Control and Prevention. Summary of notifiable diseases, United States, 1998. Morb Mortal Wkly Rep. 1998;47:1–39. 4. Terrault NA. Sexual activity as a risk factor for hepatitis C. Hepatology. 2002;36(suppl 1):S99–S105. 5. Thomas DL, Seef LB. Natural history of hepatitis C. Clin Liver Dis. 2005;9:383–398. vi. 6. Eyster ME, Alter HJ, Aledort LM, et al. Heterosexual co-transmission of hepatitis C virus (HCV) and human immunodeficiency virus (HIV). Ann Intern Med. 1991;115:764–768. 7. Roberts EA, Yeung L. Maternal transmission of hepatitis C virus infection. Hepatology. 2002;36(suppl 1):S106–S113. 8. Mast EE, Hwang LY, Seto DS, et al. Risk factors for perinatal transmission of hepatitis C virus (HCV) and the natural history of HCV infection acquired in infancy. J Infect Dis. 2005;192:1880–1889. 9. Lerat H, Hollinger FB. Hepatitis C virus (HCV) occult infection or occult HCV RNA detection? J Infect Dis. 2004;189:3–6. 10. Penin F, Dubuisson J, Rey FA, et al. Structural biology of hepatitis C virus. Hepatology. 2004;39:5–19. 11. Chevaliez S, Pawlotsky JM. Hepatitis C virus: virology, diagnosis and management of antiviral therapy. World J Gastroenterol. 2007;13:2461–2466. 12. Moradpour D, Penin F, Rice C. Replication of hepatitis C virus. In: Boyer TD, Manns MP, Sanyal AJ, Zakim D, eds. Zakim and Boyer’s Hepatology: A Textbook of Liver Disease. 6th ed. Philadelphia: Saunders/Elsevier; 2012:97–110. 13. Wedemeyer H. Hepatitis C. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease. 10th ed. Philadelphia: Saunders/Elsevier; 2016:1332–1352. 14. Pawlotsky JM. Hepatitis C virus genetic variability: pathogenic and clinical implications. Clin Liver Dis. 2003;7:45–66. 15. Neumann AU, Lam NP, Dahari H, et al. Hepatitis C viral dynamics in vivo and the antiviral efficacy of interferon-alpha therapy. Science. 1998;282:103–107. 16. Farci P, Shimoda A, Coiana A, et al. The outcome of acute hepatitis C is predicted by the evolution of the viral quasispecies. Science. 2000;288:339–344. 17. Orland JR, Wright TL, Cooper S. Acute hepatitis C. Hepatology. 2001;33:321–327. 18. Sherlock S, DooleyJ. Diseases of the Liver and Biliary System. 10th ed. Oxford, UK: Blackwell Science; 1997. 19. Strader DB, Wright TL, Thomas DL, et al. Diagnosis, management, and treatment of hepatitis C. Hepatology. 2004;39:1147–1171. 20. Pawlotsky JM. Use and interpretation of virological tests for hepatitis C. Hepatology. 2002;36(suppl 1):S65–S73. 21. Pawlotsky JM. Molecular diagnosis of viral hepatitis. Gastroenterology. 2003;122:1554–1568. 22. Seeff LB. Natural history of chronic hepatitis C. Hepatology. 2002;36(suppl 1):S35–S46. 23. Bjoro K, Froland SS, Yun Z, et al. Hepatitis C infection in patients with primary hypogammaglobulinemia after treatment with contaminated immune globulin. N Engl J Med. 1994;331:1607–1611. 24. Poynard T, Bedossa P, Opolon P, et al. Natural history of liver fibrosis progression in patients with chronic hepatitis C. Lancet. 1997;349:825–832. 25. Benhamou Y, Bochet M, Di Martino V, et al. Liver fibrosis progression in human immunodeficiency virus and hepatitis C virus coinfected patients. The Multivirc Group. Hepatology. 1999;30:1054–1058.

26. Poynard T, Ratziu V, Charlotte F, et al. Rates and risk factors of liver fibrosis progression in patients with chronic hepatitis C. J Hepatol. 2001;34:730–739. 27. Wiley TE, Brown J, Chan J. Hepatitis C virus infection in African Americans: its natural history and histological progression. Am J Gastroenterol. 2002;97:700–706. 28. Monto A, Bostrom A, Pianko S, et al. Risks of a range of alcohol intake on hepatitis C-related fibrosis. Hepatology. 2004;39:826–834. 29. Sanyal AJ. Non-alcoholic fatty liver disease and hepatitis C—risk factors and clinical implications. Aliment Pharmacol Ther. 2005;22(suppl 2):48–51. 30. Kim AY, Chung RT. Coinfection with HIV-1 and HCV—a one-two punch. Gastroenterology. 2009;137:795–814. 31. Potthoff A, Manns MP, Wedemeyer H. Treatment of HBV/HCV coinfection. Expert Opin Pharmacother. 2010;11:919–928. 32. Degos F, Christidis C, Ganne-Carrie N, et al. Hepatitis C virus related cirrhosis: time to occurrence of hepatocellular carcinoma and death. Gut. 2000;47:131–136. 33. El-Serag HB. Hepatocellular carcinoma and hepatitis C in the United States. Hepatology. 2002;36(suppl 1):S74–S83. 34. Morgan RL, Baack B, Smith BD, et al. Eradication of hepatitis C virus infection and the development of hepatocellular carcinoma: a meta-analysis of observational studies. Ann Intern Med. 2013;5;158(5 Pt 1):329–337. 35. Theise ND, Bodenheimer Jr HC, Ferrell LD. Acute and chronic viral hepatitis. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 6th ed. Philadelphia: Churchill Livingstone; 2012:361–401. 36. Roboz GJ. Hepatitis C and B-cell lymphoma. AIDS Patient Care STDS. 1998;12:605–609. 37. Cacoub P, Poynard T, Ghillani P, et al. Extrahepatic manifestations of chronic hepatitis C. MULTIVIRC Group. Multidepartment Virus C. Arthritis Rheum. 1999;42:2204–2212. 38. Manns MP, McHutchison JG, Gordon SC, et al. Peginterferon alfa-2b plus ribavirin compared with interferon alfa-2b plus ribavirin for initial treatment of chronic hepatitis C: a randomised trial. Lancet. 2001;358:958–965. 39. Fried MW, Shiffman ML, Reddy KR, et al. Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection. N Engl J Med. 2002;347:975–982. 40. European Association for the Study of the Liver. EASL recommendations on treatment of hepatitis C 2015. J Hepatol. 2015;63:199–236. 41. Swain MG, Lai MY, Shiffman ML, et al. A sustained virologic response is durable in patients with chronic hepatitis C treated with peginterferon alfa-2a and ribavirin. Gastroenterology. 2010;139:1593–1601. 42. AASLD/IDSA HCV Guidance Panel. Hepatitis C Guidance: AASLD-IDSA Recommendations for Testing, Managing, and Treating Adults Infected with Hepatitis C Virus. Hepatology. 2015;62:932–954. 43. Scheuer PJ, Ashrafzadeh P, Sherlock S, et al. The pathology of hepatitis C. Hepatology. 1992;15:567–571. 44. Ishak KG. Pathologic features of chronic hepatitis. A review and update. Am J Clin Pathol. 2000;113:40–55. 45. Lefkowitch JH. Liver biopsy assessment in chronic hepatitis. Arch Med Res. 2007;38:634–643. 46. Kaji K, Nakanuma Y, Sasaki M, et al. Hepatitic bile duct injuries in chronic hepatitis C: histopathologic and immunohistochemical studies. Mod Pathol. 1994;7:937–945. 47. Kumar KS, Saboorian MH, Lee WM. Cholestatic presentation of chronic hepatitis C: a clinical and histological study with a review of the literature. Dig Dis Sci. 2001;46:2066–2073. 48. Falkowski O, An HJ, Ianus IA, et al. Regeneration of hepatocyte “buds” in cirrhosis from intrabiliary stem cells. J Hepatol. 2003;39:357–364. 49. Hezode C, Roudot-Thoraval F, Zafrani ES, et al. Different mechanisms of steatosis in hepatitis C virus genotypes 1 and 3 infections. J Viral Hepat. 2004;11:455–458. 50. Corengia C, Galimberti S, Bovo G, et al. Iron accumulation in chronic hepatitis C: relation of hepatic iron distribution, HFE genotype, and disease course. Am J Clin Pathol. 2005;124:846–853. 51. Anthony PP, Vogel CL, Barker LE. Liver cell dysplasia: a premalignant condition. J Clin Path. 1973;26:217–223. 52. Natarajan S, Theise ND, Thung SN, et al. Large-cell change of hepatocytes in cirrhosis may represent a reaction to prolonged cholestasis. Am J Surg Pathol. 1997;21:312–318. 53. Lee RG, Tsamandas AC, Demetris AJ. Large cell change (liver cell dysplasia) and hepatocellular carcinoma in cirrhosis: matched case-control study, pathological analysis, and pathogenetic hypothesis. Hepatology. 1997;26:1415–1422. 54. Hytiroglou P, Park YN, Krinsky G, et al. Hepatic precancerous lesions and small hepatocellular carcinoma. Gastroenterol Clin North Am. 2007;36:867–887. 55. Borzio M, Bruno S, Roncalli M, et al. Liver cell dysplasia is a major risk factor for hepatocellular carcinoma in cirrhosis: a prospective study. Gastroenterology. 1995;108:812–817. 56. Ganne-Carrié N, Chastang C, Chapel F, et al. Predictive score for the development of hepatocellular carcinoma and additional value of liver large cell dysplasia in Western patients with cirrhosis. Hepatology. 1996;23:1112–1118. 57. Kim H, Oh BK, Roncalli M, et al. Large liver cell change in hepatitis B virus-related liver cirrhosis. Hepatology. 2009;50:752–762. 58. Watanabe S, Okita K, Harada T, et al. Morphologic studies of the liver-cell dysplasia. Cancer. 1983;51:2197–2205. 59. Hytiroglou P. Morphological changes of early human hepatocarcinogenesis. Semin Liver Dis. 2004;24:65–75.

15

231

Practical Hepatic Pathology: A Diagnostic Approach 60. Theise ND, Curado MP, Franceschi S, et al. Hepatocellular carcinoma. In: Bosman FT, Carneiro F, Hruban RH, Theise ND, eds. WHO Classification of Tumours of the Digestive System. 4th ed. Lyon: IARC; 2010:205–216. 61. Scheuer PJ, Maggi G. Hepatic fibrosis and collapse: histological distinction by orcein staining. Histopathology. 1980;4:487–490. 62. Poynard T, McHutchison J, Manns M, et al. Impact of pegylated interferon alfa-2b and ribavirin on liver fibrosis in patients with chronic hepatitis C. Gastroenterology. 2002;122:1303–1313. 63. Everson GT, Balart L, Lee SS, et al. Histological benefits of virological response to peginterferon alfa-2a monotherapy in patients with hepatitis C and advanced fibrosis or compensated cirrhosis. Aliment Pharmacol Ther. 2008;27:542–551. 64. Bonis PA, Friedman SL, Kaplan MM. Is liver fibrosis reversible? N Engl J Med. 2001;344:452–454. 65. Bedossa P, Paradis V. Liver extracellular matrix in health and disease. J Pathol. 2003;200:504–515. 66. Friedman SL, Bansal MB. Reversal of hepatic fibrosis—fact or fantasy? Hepatology. 2006;43(suppl 1):S82–S88. 67. Lee YA, Wallace MC, Friedman SL. Pathobiology of liver fibrosis: a translational success story. Gut. 2015;64:830–841.

232

68. D’Ambrosio R, Aghemo A, Rumi MG, et al. A morphometric and immunohistochemical study to assess the benefit of a sustained virological response in hepatitis C virus patients with cirrhosis. Hepatology. 2012;56:532–543. 69. Wanless IR, Nakashima E, Sherman M. Regression of human cirrhosis. Morphologic features and the genesis of incomplete septal cirrhosis. Arch Pathol Lab Med. 2000;124:1599–1607. 70. Hytiroglou P, Snover DC, Alves V, et al. Beyond “cirrhosis”: a proposal from the International Liver Pathology Study Group. Am J Clin Pathol. 2012;137:5–9. 71. Hytiroglou P, Thung SN, Gerber MA. Histological classification and quantitation of the severity of chronic hepatitis: keep it simple! Semin Liver Dis. 1995;15:414–421. 72. Thung SN, Gerber MA. Differential Diagnosis in Pathology: Liver Disorders. New York: IgakuShoin; 1995. 73. Shiomi S, Kuroki T, Minamitani S, et al. Effect of drinking on the outcome of cirrhosis in patients with hepatitis B or C. J Gastroenterol Hepatol. 1992;7:274–276. 74. Thung SN, Schaffner F. Liver biopsy. In: MacSween NM, Anthony PP, Scheuer PJ, eds. Pathology of the Liver. 3rd ed. Edinburgh: Churchill Livingstone; 1994:787–796.

16 Chronic Hepatitis: Grading and Staging Maria Guido, MD, PhD

Need for Grading and Staging  233 General Principles of Grading and Staging  234 Grading and Staging Systems  234 Histologic Activity Index  235 Grading Systems  235 Staging Systems  236 Which Is the Best Grading and Staging System?  238 Limitations of the Liver Biopsy in Grading and Staging: Sampling Error  238 Limitations of Semiquantitative Scoring: Interobserver Variability 240 Semiquantitative Scoring versus Morphometric Analysis  241 Noninvasive Non–Biopsy-Based Staging Systems  242

Abbreviations ALT  alanine aminotransferase AST  aspartate aminotransferase AUC  area under the curve CPA   collagen proportionate area HAI   histologic activity index HCV   hepatitis C virus MIA  morphometric image analysis

The concepts of grading and staging have been borrowed from the world of clinical oncology, where they give an idea of how quickly, or aggressively, a tumor is growing (its grade of differentiation) and how far it has spread through the body (its stage). This information is both a powerful indicator of prognosis as well as an important determinant of the most appropriate therapy. By analogy, the “aggressiveness” of chronic hepatitis, in terms of progression to fibrosis/cirrhosis, is indicated by the degree of necroinflammation, also called the “activity” or the grade of hepatitis1–3; the more severe the necroinflammation, the more “aggressive” the disease. The stage is a measure of the extent of fibrosis and architectural disruption indicating how far the hepatitis has come along the path to cirrhosis.

In this chapter, grading and staging systems developed for chronic viral hepatitis are described. Other chronic inflammatory processes (eg, primary biliary cholangitis, primary sclerosing cholangitis) that might have histologic features similar to chronic hepatitis warrant separate consideration and are discussed in Chapters 26 and 27 respectively. The pattern of damage and fibrosis in nonalcoholic steatohepatitis is distinct from that of chronic viral hepatitis. Grading and staging systems specific for this condition are discussed in Chapter 12.

Need for Grading and Staging In the past, the term chronic active hepatitis was used to label biopsies with interface hepatitis (formerly known as piecemeal necrosis), whereas the term chronic persistent/chronic lobular hepatitis referred to biopsies with portal/lobular inflammation without significant interface hepatitis.4,5 This distinction was based on the assumption that chronic persistent/lobular hepatitis were relatively benign processes without progression to cirrhosis. Identification of the hepatitis C virus (HCV) and elucidation of its natural history has made it clear that interface hepatitis does not represent the “conditio sine qua non” for the onset of cirrhosis, which can also evolve from morphologic chronic persistent/lobular hepatitis; therefore, the old nomenclature has been abandoned.6–9 However, in terms of histologic severity, necroinflammation and fibrosis remain powerful prognostic parameters, associated with the risk of progression to cirrhosis. In chronic viral hepatitis, the extent of fibrosis in the baseline biopsy is a strong predictor of further fibrotic progression.10,11 Discovering of HCV along with the progress in therapeutic options gave rise to the need for assessing the severity of chronic hepatitis in a more objective and reproducible way, possibly amenable to statistical analysis, to facilitate testing of drug efficacy in clinical trials. In the last two decades, staging, and at a lesser extent, grading, have been the main indications to perform a liver biopsy in subjects with chronic viral hepatitis.12-15 This information is useful in predicting short-term and long-term prognosis, deciding treatment options and their timing, and assessing changes occurring during or after any treatment. Nowadays, the need to perform a liver biopsy in subjects with chronic viral hepatitis, particularly chronic HCV infection has decreased because of the availability of direct 233

Practical Hepatic Pathology: A Diagnostic Approach Table 16.1  Comparison of Grading Systems Grading Scheme

Parameters Scored

Scale Used

Overall Grade

Scheuer24 (1991)

Portal/periportal activity Lobular activity

0–4 0–4

Reported as a sum of individual scores with a range of 0–8

Batts and Ludwig25 (1995)

Lymphocytic piecemeal necrosis Lobular inflammation and necrosis

No activity, minimal, mild, moderate, severe No activity, minimal, mild, moderate, severe

Severity of lesion (piecemeal or lobular) determines grade

Ishak19 (1995)

Periportal or periseptal interface hepatitis (piecemeal necrosis) Confluent necrosis Focal lytic necrosis, apoptosis, focal inflammation Portal inflammation

0–4

Reported as a sum of individual scores with a range of 0–18

Piecemeal necrosis Lobular necrosis

0–3 (none, mild, moderate, severe) 0–2 (none, mild, moderate, severe)

Bedossa and Poynard26 (METAVIR, 1996)

0–6 0–4 0–4 Overall histologic activity determined by algorithm combining piecemeal and lobular necrosis: A0 = none, A1 = mild, A2 = moderate, A3 = severe

Table 16.2  Comparison of Staging Systems Staging Scheme Scheuer24

Stage 0

(1991)

No fibrosis

Batts and Ludwig25 (1995)

No fibrosis

Bedossa and Poynard26 (METAVIR, 1996)

No fibrosis

Stage 1

Stage 2

Enlarged, fibrotic portal tracts

Portal fibrosis

Stage 3

Periportal fibrosis or portal-portal septa but intact architecture Periportal fibrosis (including rare portal-portal septa)

Portal fibrosis without septa (eSlide 16.1, eSlide 16.2)

Portal fibrosis with rare septa (eSlide 16.3)

Septal fibrosis (with architectural distortion) Numerous septa without cirrhosis

Cirrhosis Cirrhosis

Stage 0

Stage 1

Stage 2

Stage 3

Stage 4

Stage 5

Ishak19

No fibrosis

Fibrous expansion of some portal tracts, with or without short septa (eSlide 16.1, eSlide 16.2)

Fibrous expansion of most portal tracts, with or without short fibrous septa (eSlide 16.3)

Fibrous expansion of most portal tracts with occasional portal-portal bridging

Fibrous expansion of Marked bridging with portal tracts with occasional nodules marked portal-portal (incomplete cirrhosis) as well as portalcentral bridging (eSlide 16.4)

(1995)

acting antivirals that allow sustained viral response (SVR) in the majority of treated individuals.16 Nevertheless, including grade and stage in the final pathology report on cases of chronic viral hepatitis remains mandatory.

General Principles of Grading and Staging Several schemes of varying complexity have been proposed for grading and staging chronic viral hepatitis. The simplest method, familiar to most pathologists, consists of classifying both grade and stage in descriptive terms such as mild, moderate, and severe.17 The overall severity of necroinflammation and fibrosis is considered, but there are no specific rules to guide this evaluation, which remains highly subjective. In the more complex methods, the final grade and stage emerge from combining numerical scores attributed to each histologic lesion; all methods are based on similar principles, regardless of the specific criteria used (Tables 16.1 and 16.2). Grading is performed semiquantitatively by assessing necroinflammatory lesions, both in the portal-periportal area (ie, portal inflammation and interface hepatitis) and in the lobular parenchyma (ie, lobular necrosis/apoptosis and inflammation). Each lesion is scored, with higher numbers coinciding with more severe lesions. The sum of the scores gives the grade of hepatitis. Bear in mind that these numbers represent ordered categories and not genuine mathematic measurements; therefore, general mathematic rules are not always applicable for statistical analysis. 234

Stage 4

Fibrosis with architectural distortion Cirrhosis, probable or definite but no obvious cirrhosis

Stage 6 Cirrhosis, probable or definite

Staging is an assessment of the extent and location of fibrosis and of accompanying changes in parenchymal architecture. All systems express stage on a linear numerical scale, with stage 0 (zero) corresponding to no fibrosis and the highest stage to a diagnosis of cirrhosis; definitions of the intermediate stages differ with the staging systems. Even more so than with grading, these numbers do not reflect measurements but rather progressive pathologic stages such as portal fibrosis or septal fibrosis, which are qualitative rather than quantitative parameters. Clinicopathologic studies have demonstrated that formation of fibrous bands linking adjacent portal tracts, or portal tracts to central veins, the so-called septal fibrosis or bridging fibrosis, carries the highest risk of further fibrotic progression and cirrhosis in chronic viral hepatitis. Septal or bridging fibrosis is therefore referred to as clinically significant fibrosis. The use of special stains for collagen is strongly recommended for proper staging of fibrosis; in the absence of universal guidelines, the choice of stain is a matter of personal preference.

Grading and Staging Systems The initial attempt at a semiquantitative scoring system was made by Knodell and colleagues,18 who proposed the histologic activity index (HAI), which combined the scores for grade and stage. Subsequent methods scored the stage and grade separately. The four systems currently in use include the Scheuer system; the Batts and Ludwig system, which is a modification of the Scheuer system; the

Chronic Hepatitis: Grading and Staging METAVIR system; and the Ishak system, which is a modification of the HAI.

Histologic Activity Index The HAI, proposed in a well-known study by Knodell and colleagues,18 was the first attempt to “(semi)quantify” the “aggressiveness” of chronic hepatitis. Developed to assess the efficacy of interferon in clinical trials on chronic viral hepatitis, it aimed to provide information in a format amenable to statistical analysis. The HAI is a total of the scores for periportal inflammation with or without bridging necrosis, lobular hepatocyte degeneration and focal necrosis, portal inflammation, and fibrosis (Table 16.3). It has a wide range of values (0–22), thus providing discriminatory sensitivity for study of large cohorts as well as comparison of paired biopsies. Furthermore, the HAI uses weighted scores, thus assigning greater significance to numeric values but also giving rise to missing numbers. As an example, piecemeal necrosis may be assigned scores of 0, 1, 3, 4, 5, 6, or 10, whereas there are no scores 2, 7, 8, and 9. Thus, although marked piecemeal necrosis with bridging necrosis (6) is slightly worse than moderate piecemeal necrosis with bridging necrosis (5), the presence of multilobular necrosis (10) is much worse, thus deserving a score of 10 rather than 7, 8, or 9, which are therefore missing. The Knodell score has been criticized for two main reasons. First, as initially designed, HAI combines necroinflammation with fibrosis. This is not biologically accurate and although fibrosis (stage) may be a consequence of liver cell damage and necroinflammation (grade), the two are not necessarily parallel processes. Furthermore, sequential liver biopsies may show an improvement in necroinflammation even as there is worsening of fibrosis. Second, the HAI scheme has missing numbers because of the formulation of weighted scores as explained previously. The Knodell HAI is now rarely used in its original version. A modified HAI19 and several other systems have been proposed, not just to overcome limitations of the HAI, but also to create systems simple enough for routine practice. A detailed analysis of advantages and disadvantages of the Knodell scoring system can be found in several authoritative publications.20-23

Table 16.3  Comparison of Ishak’s and Knodell’s Systems for Scoring Necroinflammatory Lesions Ishak Score

Knodell Score

Periportal or periseptal interface hepatitis (piecemeal necrosis)

Periportal ± bridging necrosis (piecemeal necrosis)

Absent

0

Absent

Mild (focal, few portal areas)

1

Mild piecemeal necrosis

Mild/moderate (focal, most portal areas)

2

Moderate (continuous around less than 50% of tracts or septa)

3

Moderate piecemeal necrosis (involves less than 50% of circumference of most portal tracts)

Severe (continuous around more than 50% of tracts or septa)

4

Marked piecemeal necrosis (involves more than 50% of circumference of most portal tracts)

Confluent necrosis Absent

0

Focal confluent necrosis

1

Zone 3 necrosis in some areas

2

Zone 3 necrosis in most areas

3

Zone 3 necrosis plus occasional P-C bridging

4

Zone 3 necrosis plus multiple P-C bridging 5

Moderate piecemeal necrosis plus bridging necrosis

Panacinar or multiacinar necrosis

Marked piecemeal necrosis plus bridging necrosis Multilobular necrosis

6

Focal (spotty) lytic necrosis, apoptosis and focal inflammation

Intralobular degeneration and focal necrosis

Absent

0

Absent

One focus or less per ×10 objective

1

Mild (acidophilic bodies, ballooning degeneration, and/or scattered foci of necrosis in less than one third of lobules or nodules)

Two to four foci per ×10 objective

2

Five to ten foci per ×10 objective

3

Moderate (involvement of one third to two thirds of lobules or nodules)

More than ten foci per ×10 objective

4

Marked (involvement of more than two thirds of lobules or nodules)

Grading Systems

Scheuer System Scheuer was the first to suggest that necroinflammation and fibrosis should be scored separately, proposing a simple scheme that is readily applicable in daily practice.24 The Scheuer system grades activity of chronic hepatitis by separately scoring portal-periportal activity (ie, interface hepatitis) and lobular lesions, each on a scale from 0 to 4 (Figs. 16.1 and 16.2). This range is too narrow for monitoring responses to therapy in clinical trials, but it is appropriate for routine practice, where it is more reproducible. The Scheuer system does not score the degree of portal inflammation, in line with the conviction that, regardless of the severity of portal inflammation, absence of interface hepatitis (corresponding to the old category of chronic persistent hepatitis) coincides with low risk of fibrosis progression. As mentioned earlier, this concept has been challenged by the model of HCV hepatitis. The criteria used to define the severity of piecemeal necrosis and lobular changes are not clearly stated in Scheuer’s original paper. The severity of lesions can vary from one portal tract or lobule to the next, which means that an average grade of severity or the worst grade in the biopsy may be used. I prefer the latter option because it is more reproducible. Batts and Ludwig System The Batts and Ludwig system25 is a modified version of the Scheuer system, in which numbers have been translated into verbal descriptors. The overall grade is based on separate assessment of piecemeal necrosis

16

Portal inflammation

Portal inflammation

Absent

0

Absent

Mild, some or all portal areas

1

Mild (sprinkling of inflammatory cells in less than one third of portal tracts)

Moderate, some or all portal areas

2

Moderate/marked, all portal areas

3

Moderate (increased inflammatory cells in one third to two thirds of portal tracts)

Marked, all portal areas

4

Marked (dense packing of inflammatory cells in more than two thirds of portal areas)

P-C, Portal-central.

235

Practical Hepatic Pathology: A Diagnostic Approach None

0

Absent

Portal inflammation alone

1

Inflammation but no necrosis

Mild piecemeal necrosis

2

Focal necrosis or acidophil bodies

Moderate piecemeal necrosis

3

Severe focal cell damage

Severe piecemeal necrosis

4

Damage includes bridging necrosis

Figure 16.1  Schematic showing the four grades of portal-periportal activity (left panel) and lobular activity (right panel) according to Scheuer’s grading system. For both categories, the score is assigned according to the highest grade observed in the biopsy as a whole.

and lobular inflammation and is expressed on a five-point scale ranging from no activity to minimal, mild, moderate, or severe activity. The authors recommend that when portal-periportal and lobular activities do not correspond in severity, the final grade should indicate the more severe lesion. Ishak System The Ishak system,19 a modification of the HAI system, was generated by an international panel of pathologists led by Ishak, who was also the senior author of the Knodell system. The Ishak system grades confluent necrosis separately from periportal necrosis on a scale of 0 to 6, thus emphasizing its independent contribution to the progression of fibrosis (see Table 16.3). The Ishak system restricts the term bridging to portal-central bridging necrosis (Fig. 16.3) and excludes portal-portal necrosis from this descriptor because these two types of bridging are thought to have distinct prognostic and pathogenic significance. This is a fundamental distinction because the presence of confluent necrosis and portal-central bridging necrosis identifies severe disease with adverse clinical outcomes. The modified HAI also assigns sequential numbers so that there are no missing numbers. The “quantitative” indicators such as “few,” “some,” and “most” used in the Ishak system have not been well defined, introducing a level of subjectivity. Furthermore, the distinction between “few” versus “some” or “most” clearly depends on the size of the specimen: three involved portal tracts are “few” in a long sample with numerous (>11) portal tracts but “most” if only four portal tracts are included in the biopsy specimen. In my routine practice, I adopt the following rule: the terms “few” and “some” are used to indicate less than half of the portal tracts or central areas present in a biopsy, regardless of number, whereas “most” is used to indicate more than half of the portal tracts and/or central areas present in the biopsy. Focal lobular changes are graded by the Ishak system by the exact number of inflammatory foci per ×10 objective; mononuclear cells in sinusoids do not constitute lobular inflammation. It has been noted that using the ×10 objective may be a cause of poor reproducibility because the size of the field varies with different microscopes.22 Fig. 16.4 shows schematically how interface hepatitis and confluent lobular necrosis are scored by the Ishak system. Fig. 16.5 shows histologic examples of “focal” and “continuous” interface hepatitis. METAVIR Algorithm This algorithm was designed specifically to grade the activity of chronic hepatitis C26 by a panel of 10 French pathologists who scored a large series of biopsies from HCV subjects. The panel agreed that the overall activity grade they awarded was influenced significantly by the severity 236

of piecemeal necrosis, which is hardly surprising because this lesion was thought to distinguish progressive from nonprogressive chronic hepatitis. However, chronic HCV hepatitis may lack piecemeal necrosis, with lobular activity, thus explaining the onset of cirrhosis in these cases. Piecemeal necrosis and lobular necrosis were combined in an algorithm for classifying the activity of hepatitis into four grades of severity. These grades are A0: no activity; A1: mild activity; A2: moderate activity; and A3: severe activity (Fig. 16.6). Portal inflammation was excluded from the algorithm based on the observation that it correlated significantly and positively with the degree of piecemeal necrosis and lobular necrosis, despite discriminant analysis suggesting that this lesion is independently associated with the grade of activity. The terms focal and diffuse in the scoring of piecemeal necrosis are not clarified, but it is reasonable to apply the same criteria as for the Ishak system. The cutoff between “at least one” and “several” in scoring lobular necrosis is not very clear, and it is not certain whether bridging necrosis includes only portal-central bridges or portal-portal bridges as well.

Staging Systems

Scheuer System Scheuer24 proposed a four-stage system on a scale of 0 to 4 for evaluating the extent of fibrosis (see Table 16.2). Problems encountered with this system include the difficulty of distinguishing between enlarged portal tracts (stage 1) and periportal fibrosis (stage 2), as well as the real meaning of “architectural distortion, but no obvious cirrhosis” (stage 3 versus stage 4). Distinction of periportal fibrosis from portal fibrosis can be made by observing the contours of the portal tracts; the former results in irregular stellate-shaped portal tracts, whereas the contour remains smooth when the portal tracts are enlarged by fibrosis (Figs. 16.7 and 16.8). However, the prognostic significance of this distinction is not entirely clear. It should also be remembered that this distinction applies largely to terminal and small portal tracts, as segmental and hilar portal tracts may normally have an irregular shape. As for architectural distortion, stage 3 should be designated when several portal-central septa are seen delineating nodular portions of parenchyma, in the absence of true complete nodules or other signs of established cirrhosis (see Fig. 16.8). A major drawback of the Scheuer system is that it includes periportal fibrosis and complete portal-portal septa formation in the same category, even though only the latter has been recognized as “clinically significant” fibrosis. Ishak System The Ishak system19 (modified HAI) stages fibrosis on a scale from 0 to 6, making it more discriminatory than others in comparing paired

Chronic Hepatitis: Grading and Staging Portal-Periportal Activity

Grade

Lobular Activity

16

1

A

E

2

B

F

3

G

C

4

D

H Figure 16.2  Panels that represent the four grades of portal-periportal activity (left) and lobular activity (right) according to Scheuer’s grading system. In both categories, the score is assigned according to the highest grade observed in the biopsy as a whole. Portal inflammation without piecemeal necrosis (A), portal inflammation with mild piecemeal necrosis (arrow) (B), portal inflammation with moderate piecemeal necrosis (arrows) (C), portal inflammation with severe piecemeal necrosis (D), intrasinusoidal lymphocytic inflammation (arrows) but no necrosis (E), focal (spotty) necrosis (arrows) (F), severe focal necrosis (G), and bridging necrosis (arrows) (H).

237

Practical Hepatic Pathology: A Diagnostic Approach is not clear from the original description whether “septa” should include both incomplete and bridging septa. I only assign a score of 2 when there is evidence of complete bridging fibrosis because stage 2 according to the METAVIR scoring system is considered as clinically significant fibrosis in the vast majority of clinicopathologic studies. (see eSlide 16.3). Fig. 16.11 is a schematic representation of my approach to staging fibrosis with the METAVIR system; the similarity with Scheuer stages 1 and 3 is clearly evident. A comparison between METAVIR, Ishak, and Scheuer stages is shown in Figs. 16.12 to 16.15.

biopsies. The Ishak system clearly distinguishes incomplete septa (ie, “short” = stages 1 and 2) (Fig. 16.9) (eSlide 16.1, eSlide 16.2) from complete septa formation (stages 3 and 4) (eSlide 16.3). In addition, it differentiates between portal-portal and portal-central septa formation (stage 4 versus stage 5) (eSlide 16.4) (see Table 16.3). As in grading, the meaning of “some” and “most” is ambiguous, and I would recommend the same criteria described previously for grading (Fig. 16.10). It is not clear from the original paper whether “fibrous expansion of portal tracts” also includes the “periportal fibrosis” indicated in the Scheuer system. This distinction has not been shown to have real clinical meaning, so it is reasonable to assume that stages 1 and 2 of the modified HAI system should include both portal and periportal fibrosis. Stage 3 should be awarded when no more than one or two portal-portal septa are detected in an adequate biopsy sample. In the original paper, the authors suggest noting the presence of any additional patterns of fibrosis such as perivenular “chicken-wire” fibrosis or sclerosis of the terminal hepatic venules, even though these are not scored. This is important because such patterns indicate the presence of concomitant causes of liver damage.

Which Is the Best Grading and Staging System? Although a uniform, universally applied system is highly desirable because it would facilitate comparison of different clinicopathologic studies and improve interobserver reproducibility, there is no general consensus regarding which is the best system for grading and staging chronic hepatitis in routine practice.27 In the absence of agreement, I share the opinion of most authoritative liver pathologists that it does not matter which system is used in daily practice.27,28 Bearing in mind that any scoring system has its drawbacks, there are a few crucial considerations regardless of the system used: • At least two histologic stains (hematoxylin-eosin and a good collagen stain) should be available for assessment. • It is not advisable to replace descriptive terms with numbers because adjectives such as mild, moderate, and severe are easier for both clinicians and patients to understand. • The name of the system used must be clearly stated in every diagnostic report, without which the scores lose their significance. Patients may consult different clinicians; therefore this information is crucial for proper interpretation of the report. • Remember that all scoring systems were designed for uncomplicated hepatitis and may not be accurate in the presence of comorbidities.43

METAVIR System The METAVIR system26 stages fibrosis on a scale of 0 to 4 (see Table 16.2). Portal-portal and portal-central septa are not separate categories, and it

Limitations of the Liver Biopsy in Grading and Staging: Sampling Error In current practice, percutaneous needle biopsy, performed most often under ultrasound guidance, is used for assessing diffuse liver diseases, as well as for grading and staging chronic hepatitis.15,29,30 A subcapsular wedge biopsy is not recommended for this purpose because fibrous septa extending from the capsule into the underlying parenchyma may prompt an overestimation of fibrosis, and nonspecific inflammation related to the surgical procedure may influence assessment of the grade of inflammation.31 Two types of biopsy needles are in general use: large

Figure 16.3  Portal-central bridging necrosis (arrows) (van Gieson stain).

Mild (focal around few portal areas) Mild/moderate (focal around most portal areas) Moderate (continuous around 50% of tracts or septa)

1

Focal confluent necrosis

2

Zone 3 necrosis in some areas

3

Zone 3 necrosis in most areas

4

Zone 3 necrosis + occasional P-C bridging

5

Zone 3 necrosis + multiple P-C bridging

6

Panacinar or multiacinar necrosis

Figure 16.4  Schematic showing the four grades of portal-periportal activity (piecemeal necrosis) (left panel) and confluent lobular necrosis (right panel) according to Ishak’s scoring system. P-C, portal-central. 238

Chronic Hepatitis: Grading and Staging needles, with a minimum core diameter of 1.0 mm, for assessing diffuse disease, and thin (40° C), relative bradycardia, and a left-shift of the white blood cell count. Severe cases are usually associated with renal insufficiency, rhabdomyolysis, and disseminated intravascular coagulation.12 The severity of illness in individuals with salmonellosis is determined by virulence factors of the infecting strain as well as host properties. Virulence factors of salmonellae are complex and encoded on chromosomes and plasmids. Major host risk factors are immunodeficiency due to human immunodeficiency virus (HIV) infection or immunosuppressive therapy, neoplasms, diabetes and prior

Nonviral Infections of the Liver

18

B

A

C Figure 18.2  Liver abscesses. A, Pyogenic abscess on a contrast-enhanced computed tomography scan showing liquefied area in segment VII of the liver with an adjacent perfusional defect. B, Recurrent pyogenic cholangitis on a T2-weighted magnetic resonance image, showing stones in intrahepatic dilated bile ducts. C, Several liver abscesses are seen in this patient, who died of bacterial sepsis. (A and B, Courtesy Manoel Rocha, MD, University of Sáo Paulo, Sáo Paulo, Brazil.)

antimicrobial therapy. Sickle cell disease, malaria, schistosomiasis, bartonellosis, and pernicious anemia are among the major comorbidities that predispose to salmonellosis.

epithelioid granulomas (typhoid nodules) are interspersed within the parenchyma, with varying degrees of macrovesicular or predominantly microvesicular steatosis.

Pathogenesis The bacilli gain entry by attaching to specialized epithelial cells (M cells) of the Peyer patches by fimbriae or pili. This is followed by endocytosis leading to bacterial internalization and transport to the lamina propria, where they attract macrophages (typhoidal strains) or neutrophils (nontyphoidal strains). S. typhi disseminate through the mononuclear phagocyte system, mainly to the liver, spleen, and bone marrow. Infection of the gallbladder may lead to a long-term carrier state in which the bacilli are present in bile and secreted to the stool. Nontyphoidal salmonellae generally precipitate a localized response, whereas S. typhi and other especially virulent strains invade deeper tissues via lymphatics and capillaries and elicit a major immune response.

Diagnosis Specific diagnosis can be made by culture and/or serology. Treatment includes antibodies (fluoroquinolones) and metabolic support. Longterm therapy may be necessary to eradicate the carrier state.14

Liver Disease in Salmonellosis Although clinical hepatitis is evident in less than 25% of cases, liver involvement is almost always present.12,13 Jaundice is less frequent (33%) than in acute viral hepatitis. Liver histology shows nonspecific hepatitis with variable degrees of portal tract infiltration13 by lymphocytes and macrophages. Necroinflammatory foci and nonnecrotizing

Brucellosis Brucellosis, a zoonosis acquired from bovines, is a continuing public health concern in developing countries. Most at risk are workers exposed to animals or animal products infected with gram-negative bacilli from the genus Brucella, most commonly Brucella melitensis, Brucella suis, Brucella canis, and Brucella abortus. General malaise is commonly followed by fever, chills, and headache. Prolonged infection leads to weight loss, pleural effusion, orchiepididymitis, arthritis, meningitis, and hepatosplenomegaly.15 Liver Involvement in Brucellosis Liver involvement is suspected in patients with severe abdominal pain and/or jaundice with abnormalities in serum biochemical markers of liver injury. However, because brucellosis is a systemic infection and 267

Practical Hepatic Pathology: A Diagnostic Approach most frequent, followed by intraabdominal lesions; thoracic involvement is relatively rare.

Liver Involvement in Actinomycosis Liver involvement occurs as a complication of intraabdominal infection, especially after surgery or trauma, pancreatitis, pelvic abscesses related to intrauterine devices, and infections of the appendix, anus, and rectum. Infection is evident as an abscess or, more frequently, as a large, solitary mass of confluent abscesses; these abscesses are more frequent at right lobe. Review of the literature found that these lesions are often misdiagnosed as malignancy (20/28, 71.4% cases) on imaging studies because they often appear as a mass lesion.19 Furthermore, because cultures are positive in only about half of all cases, histologic identification of colonies of long, branching filamentous bacilli (“grains”) is critical for precise diagnosis. The bacterial colonies are associated with an abundant neutrophilic infiltrate and extensive tissue necrosis (eSlide 18.1). The organisms may also be demonstrated with the Brown-Brenn stain and Gomori silver stain. Figure 18.3  Brucellosis in a contrast-enhanced computed tomography scan. This characteristic focal liver lesion has a central calcification surrounded by a hypoattenuating halo (arrow). (Courtesy Manoel Rocha, MD, University of Sáo Paulo, Sáo Paulo, Brazil.)

bacteria survive within mononuclear phagocytes, the liver, being a major organ of reticuloendothelial system, is probably involved in all cases, even if transaminase levels are normal or only mildly elevated.16 Diffuse liver enlargement is rather frequent, whereas hepatic abscesses may sometimes occur (Fig. 18.3). Liver histology may be nonspecific, with focal intraparenchymal collections of lymphocytes and/or macrophages, which may form microgranulomas. Epithelioid granulomas may be present, which when fully developed, may show fibrinoid necrosis.15,16 In a prospective Iranian series of 20 cases of acute brucellosis published from Iran,16 mild (8 cases) or moderate (2 cases) portal inflammation was present in half of all cases (10 cases). Lobular inflammation was found in 12 cases (60%), being mild in 7, moderate in 4 and severe in 1 case respectively. Two cases showed epithelioid granulomata, whereas microgranulomata were identified in 2 other cases. Steatosis was detected in 4 cases (20%). Diagnosis Brucellosis is diagnosed by detection of gram-negative coccobacilli from blood cultures incubated in Castaneda medium 6 weeks and agglutination with specific antiserum in patients with occupational exposure to animal products and compatible clinical features.16

Legionellosis Legionellosis, also known as Legionnaire disease, is a pneumonia caused by Legionella pneumophila and characterized by systemic involvement. It has been associated with bilirubin increases in 15% of cases and with slight elevations of aminotransferases.17 Liver histology reveals minimal changes, with steatosis and focal necrosis.18 Specific diagnosis can be made by direct immunofluorescence in tissue, by serology or by identification of bacilli in respiratory secretions. Treatment with antibiotics (fluoroquinolones or macrolides) is associated with resolution of the hepatic dysfunction.

Actinomycosis At least six species of the anaerobic gram-positive bacteria of the genus Actinomyces may infect humans; Actinomyces israelii is the most common. Although frequently found as a saprophyte in palatine tonsils or in the intestines, Actinomyces may lead to blood-borne infections, especially after surgical interventions. Cervicofacial lesions are the 268

Syphilis Liver involvement in syphilis is now much less common than in the past. Even so, congenital syphilis must be considered when there is prominent hepatosplenomegaly in cases of neonatal jaundice or intrauterine death. Histologically, there is giant cell hepatitis with miliary necrosis containing numerous spirochetes, which can be visualized by the Warthin-Starry stain or immunohistochemical staining. Progressive sinusoidal fibrosis ensues, leading to compression and atrophy of hepatocytes (Fig. 18.4) (eSlide 18.2).20 In adults, secondary syphilis may present with neutrophilic cholangitis, epithelioid granulomas, or nonspecific focal hepatocyte necrosis. Although rare, tertiary syphilis may involve the liver, presenting as a hepatitic or cholestatic disease. A major finding is the “syphilitic gumma,” an epithelioid granuloma with a necrotic center and thick fibrous wall; these may be single or numerous and may measure up to several centimeters in diameter (eSlide 18.3).21 An increase in the number of cases of syphilis has been reported in the United States, especially in homosexual individuals, many of whom are HIV positive.22 Cholestasis with portal and lobular hepatitis, which may be rich in giant cell hepatocytes, plasma cells and neutrophils is seen. A recent report of three cases depicting syphilitic inflammatory tumors from Massachusetts General Hospital discusses that the abundance of fibroblastic proliferation and plasma cells raises differential diagnoses with immunoglobulin G4 inflammatory pseudotumor, angiomyolipoma, and other spindle cell tumors, including sarcomas.21 The presence of neutrophilic and plasmacytic infiltrate within the mass lesion, as well as the portal edema and neutrophilic cholangitis in the background liver are important clues favoring the diagnosis of syphilis, which can be confirmed by immunohistochemical staining and serologic tests.21,23

Leptospirosis Leptospirosis is a worldwide zoonosis caused by bacteria of the family Leptospiraceae, gram-negative spirochetes that comprise 24 serogroups and 250 serovars.24 Members of the Leptospiraceae infect domestic and wild animals and are transmitted by the urine of rodents and, less commonly, by the urine of other animals. Humans are infected when broken skin or mucous membranes come in contact with contaminated water. Leptospirosis is highly endemic in tropical areas of all continents with an estimated 900,000 new cases each year; epidemics occur in these regions during floods. High-risk groups include workers exposed to contaminated water, such as miners, sewer workers, soldiers, and farmers, mainly on rice and sugar cane plantations. Workers who handle animal tissues or fluids such as veterinarians, butchers, fishermen,

Nonviral Infections of the Liver

18

A

B

C

D Figure 18.4  Congenital syphilis. A, Extensive area of parenchymal necrosis with mixed but predominantly neutrophilic inflammatory infiltrate. B, Higher magnification shows edema and intercellular matrix deposition, causing compression and atrophy of liver cell trabeculae. C, Early sinusoidal deposition of collagen is already seen (Masson trichrome stain) (also see eSlide 18.2). D, Silver stains demonstrate abundant Treponema pallidum (Warthin-Starry stain).

slaughterhouse workers, and laboratory personnel are also at risk. Exposure to Leptospira may also occur during recreational activities. Clinical Manifestations The severity of the clinical picture varies with the serovar of Leptospira interrogans, the most common of which are Leptospira icterohaemorrhagiae, Leptospira canicola, Leptospira autumnalis, Leptospira hebdomadis, Leptospira australis, and Leptospira pomona. Most natural infections appear 7 to 13 days after exposure. The clinical picture is protean, and the severity of illness varies widely. At one end of the spectrum, leptospirosis can be entirely asymptomatic, whereas at the other, it can cause a severe illness called Weil disease characterized by jaundice, renal failure, and hemorrhage. Many anicteric infections go undetected, although mild forms of the disease are increasingly recognized.24 Muscle pain may be severe in leptospirosis and is usually localized to the calves. Muscular lesions are responsible for a striking increase in serum creatine phosphokinase, a valuable biochemical clue to the disease.25 The second phase (immune phase or period of localization) generally appears after a relatively asymptomatic interval of 1 to 3 days. It is characterized by marked individual variability of the clinical picture. This phase lasts from 2 to 4 days in most patients. It is characterized by lower fever, less severe myalgia, and milder gastrointestinal symptoms. Meningitis and iridocyclitis are more common. Severe leptospirosis, or Weil disease, is characterized by jaundice, usually associated with renal damage, changes in hemostasis, anemia,

and neurologic disturbances, which begin on the second or third day of the illness and reach their peak during the second week.24 Simultaneous occurrence of renal impairment and jaundice is an important diagnostic clue and also indicates a poor prognosis. Death may result from acute renal failure caused by interstitial nephritis and acute tubular necrosis and, rarely, from acute liver failure.24,25 Acute coronary arteritis, myocarditis and inflammation of the conductive system are frequent.25 Pulmonary involvement affects up to 70% of patients, including alveolar hemorrhage presenting as dyspnea and hemoptysis. Indeed, acute respiratory distress syndrome has emerged as a major cause of death attributed to leptospirosis.26 Patients with the severe forms of leptospirosis who survive have an excellent prognosis, with complete recovery and without long-term sequelae. Some patients may continue to harbor leptospires and excrete them in urine, thus acting as a reservoir for the microorganism.24 Because leptospirosis is a tropical infection, other infections prevalent in hot and humid regions that cause similar acute manifestations should be excluded. These include the icteric hemorrhagic fevers such as dengue hemorrhagic fever, yellow fever, and hantavirus infection (discussed in Chapter 13). Pathogenesis Active movement of leptospires and their ability for adhesion to extracellular matrix and to endothelial and epithelial cells of target organs is considered essential to their pathogenicity. Comparative genomic 269

Practical Hepatic Pathology: A Diagnostic Approach analyses of transport proteins encoded within the genomes of various Leptospira species revealed that the saprophyte L. biflexa possesses a disproportionately high number of secondary carriers for metabolite uptake and environmental adaptability as well as an increased number of inorganic cation transporters providing ionic homeostasis and effective osmoregulation in a rapidly changing environment. In contrast, the virulent L. interrogans and L. borgpetersenii were found to possess far fewer transporters. These two Leptospira pathogens also possess intact sphingomyelinases, holins, and virulence-related outer membrane porins, thus suggesting that pathogenicity might be related to the emergence of a limited set of proteins responsible for host invasion.27 The liver and renal lesions probably derive from the direct action of the large numbers of leptospires and the products of their lysis. Leptospires seem to attach themselves directly to cells, initiating cellular injury.28 Lung tissue in patients with leptospirosis usually shows much lower numbers of leptospires; thus pulmonary abnormalities may be a result of circulating toxins produced by the pathogen at distant sites such as the liver combined with the action of cytokines (eg, tumor necrosis factor-alpha). Although Leptospira is not a classical intracellular pathogen, pathogenic leptospires may reside, at least temporarily, inside both phagocytic and nonphagocytic cells; an understanding of this interaction might lead to better insight into pathogenesis of the disease.29 The multiorgan dissemination of leptospires is probably a result of rapid cell translocation.26,29,30 Pathology Light microscopic alterations are less striking than in the kidney and often disproportionately mild compared with the severity of the clinical picture. The lobular architecture and the limiting plate are always preserved. Liver cells are either swollen or shrunken, and acidophilic bodies are seen. A prominent feature of leptospirosis in the liver is the mitotic activity of hepatocytes, a rare finding in normal livers and in other liver diseases.31 However, regeneration as evidenced by twin liver cell plates is moderate. Cholestasis is prominent and found both as granules of bile within swollen hepatocytes and Kupffer cells as well as bile plugs in slightly dilated canaliculi. Kupffer cells are usually hypertrophied and hyperplastic throughout the lobule and may show erythrophagocytosis and scanty hemosiderin. In portal tracts, edema is mild or moderate; the inflammatory infiltrate is composed mainly of lymphocytes and histiocytes with smaller numbers of neutrophils and eosinophils (Fig. 18.5). In autopsy studies, the liver is enlarged, is congested, and shows a mottled green appearance due to cholestasis. A common finding is the disarray of liver cell plates with a loss of cohesion between hepatocytes (eSlide 18.4). This feature has been variably attributed to severe cellular damage, terminal change, and an artifact caused by autolysis; however, evidence suggests that this feature is an effect of the leptospires or their toxins.32,33 Major histopathologic findings in leptospirosis are similar to the findings in bacterial septicemia, especially those caused by toxin-producing gram-negative microorganisms. Although not pathognomonic, liver cell disarray is very common in leptospirosis, and when present in the appropriate epidemiologic and clinical background, should lead to a search for leptospiral antigen by immunohistochemistry, the gold standard for etiologic diagnosis. Besides the liver, Leptospira may be seen in other organs, especially the kidneys, lungs, and heart, which may all be involved with variable severity, thus giving rise to variability in the clinical presentation.26,32,29

Rickettsial Infections Rickettsiae are obligatory intracellular gram-negative bacilli or coccobacilli transmitted from mammalian reservoirs through insects or ticks to humans; these bacteria have a great affinity for human endothelium. Of the several illnesses related to rickettsial infections, Rocky Mountain spotted fever and Q fever may lead to major liver involvement. 270

A

B

C Figure 18.5 Leptospirosis. A, Low magnification shows preserved architecture and expansion of portal tracts by edema and a moderate inflammatory infiltrate with lymphocytes, macrophages, and polymorphonuclear cells. This autopsy specimen shows trabecular disarray and focal macrovesicular steatosis. B, A distinctive finding in the lobules is loss of cohesion of hepatocytes and disarray of trabeculae. Occasional apoptotic bodies, frequent binucleated hepatocytes, and hypertrophic Kupffer cells with erythrophagocytosis are seen (also see eSlide 18.4). C, Immunohistochemical demonstration of leptospiral antigen, essential for the etiologic diagnosis, shows numerous phagocytosed granules within Kupffer cells. Occasionally, granules may be seen adherent to the plasma membrane of discohesive hepatocytes (Leptospira interrogans antigen, short polymer-peroxidase amplification).

Nonviral Infections of the Liver Liver Involvement in Q Fever When there is a tender, enlarged liver, histologic findings include lobular granulomas, which may be fibrin-ring granulomas or epithelioid granulomas; the former consist of a central fat vacuole surrounded by a ring of fibrin followed by groups of macrophages. Epithelioid granulomas, whether or not they are necrotic, are also found and necessitate the exclusion of tuberculosis and other infections. Although characteristic, the fibrin-rich granuloma is not specific for Q fever,40 diagnosis relies on serologic demonstration of rising titers of complement-fixing antibodies 2 to 3 weeks after the infection. Reverse transcription polymerase chain reaction has been found to be promising in centers where it is available.41

18

Chlamydial Infection Figure 18.6  Rocky Mountain spotted fever. Immunohistochemical cytoplasmic positivity for rickettsial antigen in infected endothelial cells (Rickettsia sp. antigen, short polymer–alkaline phosphatase amplification).

Rocky Mountain Spotted Fever This disease, caused by Rickettsia rickettsii, occurs in all areas of the American continent, and it is transmitted to humans through tick bites. After an incubation period of about 7 days, an initial nonspecific flulike illness occurs with exanthematous rash, fever, and malaise, lasting about 3 days. This is followed by more severe vascular infection, which may lead to petechial or purpuric hemorrhage. Increased vascular permeability may lead to loss of plasma volume, hypotension, and even shock syndrome.34 Liver Disease in Rocky Mountain Spotted Fever Liver involvement is reported in up to one-third of infected patients, usually presenting as moderately increased aminotransferase levels. Jaundice is rare in cases from the United States, but a study of 118 cases from Brazil found jaundice in 31% of patients. Remarkably, lethality in this study was 37%, in many cases because of major respiratory and vascular involvement.35 Recent phylogenetic analysis revealed that the Central/South American isolates showed low polymorphism and formed a clade distinct from two North American clades, with the latter clades demonstrating greater in-branch polymorphism.36 As in all organs, endothelial cells are directly infected by rickettsiae.37 Edematous portal spaces are infiltrated by lymphocytes, macrophages, and polymorphs. Vasculitis characterized by a predominantly mononuclear infiltration of vessel walls and intravascular fibrin thrombi is seen. Nonspecific parenchymal lesions encompass focal necrosis of hepatocytes and hypertrophy of Kupffer cells, which may show erythrophagocytosis.37,38 Specific diagnosis may be achieved by detection of rickettsial antigen in the cytoplasm of infected endothelial cells in the liver or in other organs, including the skin (Fig. 18.6).38 Q Fever Coxiella burnetii, the causative agent of Q fever, is found worldwide but is more prevalent in dry regions. Peridomiciliary animals such as cows and goats are major reservoirs, although cats and dogs may also transmit the agent. Humans are infected by inhalation, leading to systemic dissemination through the blood circulation.39 Most infections are asymptomatic. Symptomatic infections present abruptly with high fever, chills, headache, myalgia, anorexia, and, frequently, cutaneous rash. Pneumonia, endocarditis, meningitis, and osteomyelitis may ensue, and liver involvement may be found in up to one-third of patients.39

Peritonitis involving the Glisson capsule may complicate genital infection with Chlamydia trachomatis (or, less frequently, by Neisseria gonorrhoeae), especially in younger women. This condition clinically simulates biliary tract disease, with high fever and right hypochondrial pain.42 Histopathologic findings are nonspecific, with focal hepatocytic necrosis and minor mixed infiltrate with lymphocytes and neutrophils.42,43 Similar minor liver involvement may occur in infections with Chlamydia psittaci, which causes pneumonia.42

Mycobacterial and Fungal Infections Liver infection by Mycobacterium species, especially Mycobacterium tuberculosis, Mycobacterium avium, and Mycobacterium leprae, as well as by fungi such as Aspergillus species, Candida species, Cryptococcus neoformans, Blastomyces dermatitidis, Paracoccidioides brasiliensis, and Histoplasma capsulatum lead to granulomatous hepatitis. These are discussed in Chapter 19.

Protozoal Infections Amebiasis

Amebiasis is caused by Entamoeba histolytica, a worldwide protozoan, which is most prevalent in tropical regions, where it is a major public health problem, especially in conditions of poor sanitation. About 10% of the world population may be infected with E. histolytica, and about 8.5% of infected patients are estimated to harbor hepatic pseudoabscesses.44 Infection is transmitted by the oral-fecal route through contaminated water and food or even from person to person.45 Diagnosis of intestinal amebiasis is made by serology or by morphologic and antigenic identification of E. histolytica cysts or trophozoites in feces, aspirated samples, touch preparations, or mucosal biopsies. Ultrasound imaging supported by serologic enzyme-linked ­immunosorbent assay (ELISA) tests is presently the preferred diagnostic tool; it is positive in 90% to 95% of patients with extraintestinal amebiasis.46,47 Life Cycle in Relation to Liver Disease Infection occurs through ingestion of food contaminated with cysts, which progress to metacysts and trophozoites in the intestinal lumen. Trophozoites proliferate and invade the underlying mucosa, leading to the flask-shaped ulcers with a narrower mucosal opening and a broader submucosal base.45 Amebic ulcers are especially common in the cecum and proximal colon. Colonic perforation, peritonitis, and sepsis may complicate severe cases. Hematogenous infection frequently involves the liver and the lungs, where it can progress to abscess formation. Liver abscesses occur more frequently in the right lobe. They may rupture through the diaphragm, leading to empyema and pneumonia. Abscesses of the left hepatic lobe are less numerous, but occasionally they may rupture into the pericardial sac with fatal pericarditis. 271

Practical Hepatic Pathology: A Diagnostic Approach Pathology Trophozoites carried by the venous blood invade portal tracts and induce liquefactive necrosis, thus leading to single or multiple inflammatory nodules; these are more accurately designated pseudoabscesses because the necrotic areas contain many lymphocytes, plasma cells, and macrophages, in addition to polymorphonuclear leucocytes. This contrasts with pyogenic abscesses (discussed earlier) which are comprised predominantly of neutrophils and contain bacterial colonies. As the lesion enlarges, trophozoites are present at the leading edge, leaving only necrotic debris in the center. As the lesion evolves, fibroblasts produce a fibrotic, progressively thicker capsule at the periphery. Older, long-standing lesions may show only granulation tissue or even cicatricial fibrosis.45 Diagnosis Imaging features and serology are usually diagnostic for amebic liver abscess. Although not pathognomonic, ultrasonography demonstrates a round, well-defined hypoechoic mass. Healing leads to calcification at the periphery of the abscess. The cyst contains a thick, brownish fluid (“anchovy paste”) which is acellular on fine-needle aspiration samples. Trophozoites are seen in a minority of aspirates (1000 flukes) typically have acute, intermittent right upper quadrant abdominal pain, tender hepatomegaly, anorexia, and weight loss. Fever and rash may also be present. Laboratory findings include eosinophilia and elevated liver function tests.73 Chronic infestation by clonorchiasis or opisthorchiasis is sometimes complicated by cholelithiasis, cholecystitis, abscesses in the liver and biliary tract, or even pancreatitis, because of biliary obstruction caused by the presence of mucin, parasites, and eggs, which serve as a nidus for extra or intrahepatic pigmented stones rich in bilirubin carbonate. Secondary infection by gram-negative enteric bacteria, especially E. coli, may lead to recurrent pyogenic cholangitis, a major complication. This clinical setting has also been known as oriental cholangiohepatitis127 and may clinically and radiologically resemble primary sclerosing cholangitis (eSlide 18.8). Clonorchiasis and opisthorchiasis lead to gradual tapering of the peripheral hepatic ducts, whereas recurrent pyogenic cholangitis shows decreased branching and abrupt tapering of the peripheral hepatic ducts from stenosis. Primary sclerosing cholangitis leads to stenosis and beading of intrahepatic ducts, with more irregularity than in clonorchiasis.71 Cholangiocarcinoma, peripheral type, is associated with these infestations and typically presents with a palpable liver mass, which is more frequent in the right lobe. Although this is an uncommon neoplasm in the West, accounting for only 7.7% of malignant liver tumors in the United States, it is much more prevalent in parts of Southeast Asia, being more frequent than hepatocellular carcinoma in some areas such as Thailand. The geographic distribution of peripheral cholangiocarcinoma worldwide coincides with endemic areas of liver flukes, O. viverrini, and C. sinensis.128 A large control study from Korea129 found that C. sinensis infection (odds ratio, 13.6), hepatolithiasis (odds ratio, 50.0), and choledochal cysts (odds ratio, 10.7) were significantly related to intrahepatic cholangiocarcinoma. Other significant risk factors for intrahepatic cholangiocarcinoma in Korea were liver cirrhosis (odds ratio, 13.6), heavy alcohol consumption (odds ratio, 6.6), diabetes (odds ratio, 3.2), and hepatitis B virus infection (odds ratio, 2.3) (not hepatitis C virus infection). Pathology In most cases of surgery or in necropsy specimens, the flukes can be found throughout the biliary system. Macroscopic dilatation of fibrous and thickened bile ducts is usually found with variable degrees of peribiliary fibrosis. Bile stasis due to bile duct obstruction may lead to bile lakes. The biliary epithelium lining dilated ducts containing the parasite may present variable degrees of adenomatous hyperplasia, with pseudostratification and infoldings.123,130 Ascending cholangitis from enteric gram-negative bacteria may lead to hepatic abscesses. Remnants of the parasites may be found in the center of biliary calculi. Ductular reaction, usually associated with fibrosis, might be the site of malignant transformation. Cholangiocarcinomas related to these worm infestations are multicentric in many instances; the right lobe is more frequently reported to be involved. Mucin-secreting adenocarcinoma

Nonviral Infections of the Liver is the most common type, with variable degrees of desmoplasia. Sripa et  al. have proposed that progression of human disease from fluke infection to chronic opisthorchiasis, advanced periductal fibrosis, and cholangiocarcinoma has molecular parallels to wound healing, chronic inflammation, and cancer development.131 Chronic hepatitis B and C infections are also common in the countries where these flukes are endemic; therefore, cirrhosis might indeed result from chronic viral hepatitis in coinfected patients rather than from the parasitic infestation.128,129 Diagnosis Flukes collected from biliary lumina are good specimens for identification of the specific parasite; adult C. sinensis is 8 to 25 mm long and 2 to 5 mm wide, whereas O. viverrini is 11 to 20 mm long and 3 mm wide. The oval eggs have a small operculum and are more commonly found in fluid collected from the duodenum by endoscopy or in feces.85 Histologic sections usually depict only parts of an adult worm. When the anterior extremity is represented, the sucker, sometimes the esophagus and part of the cecum, and the ovary in the center may provide hints for identification.

Hydatid Cyst

The germinating cyst capsule and daughter cysts develop from the inner aspect of the germinal layer. When the capsule ruptures, viable protoscoleces are released as white sediments that float in the cyst.134 Rupture of the cyst leads to multifocal new cyst formation (daughter cysts), which may present exophytic growth, biliary communication, and peritoneal seeding. E. multilocularis and E. vogeli produce multilocular alveolar cysts (1 to 10 mm in diameter) that resemble alveoli and grow by exogenous proliferation, with the cysts progressively invading the host tissue by peripheral extension of the process originating in the germinal layer. The metacestodes can proliferate to diameters of 15 to 20 cm in the human host. In addition, a very strong reactive fibrosis can lead to pronounced enlargement of the lesion. The larva causes invasive and destructive changes in the infected liver, with images that mimic a malignant neoplasm (Fig. 18.14A). As the lesion heals, it invariably becomes calcified, initially as isolated points of calcium and then evolving into multiple points toward its periphery, eventually leading to a large homogeneously calcified mass. Host reaction to the growing of intact hydatid cysts may only present granulation tissue and a fibrotic wall. Only when a larva dies or a cyst ruptures does a more prominent inflammation ensue, with abundant eosinophils and macrophages, frequently forming foreign body–type granulomas.

18

Echinococcus (hydatid) cyst is caused by infestation of the liver and lung by the larval stage of animal tapeworms from the genus Echinococcus. Echinococcus granulosus produces unilocular cystic lesions, whereas Echinococcus multilocularis and Echinococcus vogeli produce multilocular alveolar cysts. E. granulosus is found in Mediterranean countries; the Middle East; Eastern Europe; Africa; subtropical and temperate areas of South America, including southern Brazil, Argentina, and Chile; China; Australia; and New Zealand. E. multilocularis is widely distributed in the Northern Hemisphere, including the United States and Canada, and central and northern Eurasia, including China and Japan. Infection by E. vogeli is seen in Central and South America.132 Life Cycle in Relation to Liver Disease The dog and sheep serve as definitive and intermediate hosts for E. granulosus, whereas foxes and rodents serve as definitive and intermediate hosts for E. multilocularis. The definitive hosts pass eggs in the feces. The eggs, which are ingested by the intermediate host, hatch to release embryos that penetrate the intestinal mucosa, enter the portal circulation, and travel to various organs,133 most commonly the liver and lungs, in which larvae develop into fluid-filled cysts. When a dog or fox ingests raw tissues of sheep or mice containing parasitic cysts, the parasite enters the definitive host and matures in the small intestine. Humans become infected as an intermediate host by ingesting plants or water contaminated with eggs of the parasites or by direct contact with the definitive host. Clinical Manifestations Patients infected with E. granulosus are more commonly asymptomatic, whereas E. multilocularis leads to a more aggressive clinical picture. Cysts progressively grow over a period of 5 to 20 years and are discovered either incidentally or because of abdominal pain or a palpable mass in the right upper abdomen.133 Cysts may compress the bile ducts and result in obstructive jaundice. Rupture of a cyst may produce fever, pruritus, eosinophilia, or fatal anaphylaxis. Pathology The larvae of E. granulosus develop into fluid-filled unilocular cysts that consist of an external acellular membrane (compressed liver tissue), middle laminated layer, and inner germinal layer (eSlide 18.9).132

A

B Figure 18.14 Hydatid cyst. A, Polycystic echinococcosis on a contrast-enhanced computed tomography scan, showing multiple cystic lesions in the liver mimicking metastatic disease. B, Protoscoleces of Echinococcus granulosus may be found as “snowflakes” in the hydatid cyst. (A, Courtesy Manoel Rocha, MD, University of Sáo Paulo, Sáo Paulo, Brazil.) 283

Practical Hepatic Pathology: A Diagnostic Approach Diagnosis Diagnosis should be performed by ultrasound or computed tomography scan in conjunction with serology. Imaging findings of infestation by E. granulosus are single, unilocular, or multiseptated cysts, showing wheel-like or honeycomb-like appearances. Free-floating protoscoleces may be found as “snowflakes” in the cavity (Fig. 18.14B). Degenerating cysts show wavy bands or floating membranes. Dead cysts show a calcified cyst wall. Echinococcosis caused by E. multilocularis produces multilocular alveolar cysts, progressively invading the liver parenchyma and other tissues of the body, thus requiring differential diagnosis with malignancies.133,135 On sonography, lesions are heterogeneous with indistinct margins. Multiple small round cysts with solid components are frequent. Large lesions show a “geographic map” appearance. Calcifications are very frequent, appearing as peripheral calcifications or punctuate scattered calcific foci. Invasion into the bile ducts, portal vein, or hepatic vein may occur. Direct spread of infected tissue may result in cysts in the peritoneal cavity, kidneys, adrenal gland, or bones.134,135 Liver biopsy should not be used in the diagnosis of liver cysts suspicious for echinococcosis because of the risk of leakage of antigens that might lead to anaphylactic shock. Fine-needle aspiration is reported as a safe procedure, useful for simultaneous diagnosis and treatment, although the polemics about this issue persist. 136,137,138





Suggested Readings



Andrade ZA. Schistosomiasis and liver fibrosis. Parasite Immunol. 2009;31:656–663. DeBrito T, Menezes LF, Lima DM, et al. Immunohistochemical and in situ hybridization studies of the liver and kidney in human leptospirosis. Virchows Arch. 2006;448:576–583. Hotez PJ, Brindley PJ, Bethony JM, et al. Helminth infections: the great neglected tropical diseases. J Clin Invest. 2008;118:1311–1321. Koskinas J, Gamatos IP, Tiniakos DG, et al. Liver histology in ICU patients dying from sepsis: a clinicopathological study. World J Gastroentrol. 2008;14:1389–1393. Szabo G, Romics Jr L, Frendl G. Liver in sepsis and systemic inflammatory response syndrome. Clin Liver Dis. 2002;6:1045–1066.



References





284

1. Chand N, SanyalAJ. Sepsis-induced cholestasis. Hepatology. 2007;45:230–241. 2. Nesseler N, Launey Y, Aninat C, Morel F, Mallédant Y, Seguin P. Clinical review: the liver in sepsis. BioMedCentral-Crit Care. 2012;16:235. 3. Franson TR, Hierholzer Jr WJ, LaBrecque DR. Frequency and characteristics of hyperbilirubinemia associated with bacteremia. Rev Infect Dis. 1985;7:1–9. 4. Szabo G, Romics Jr L, Frendl G. Liver in sepsis and systemic inflammatory response syndrome. Clin Liver Dis. 2002;6:1045–1066. 5. Abdala E, Baia CE, Mies S, et al. Bacterial translocation during liver transplantation: a randomized trial comparing conventional with venovenous bypass vs. piggyback methods. Liver Transpl. 2007;13:488–496. 6. Koskinas J, Gomatos IP, Tiniakos DG, et al. Liver histology in ICU patients dying from sepsis: a clinicopathological study. World J Gastroenterol. 2008;14:1389–1393. 7. Sugiyama M, Atomi Y. Pyogenic hepatic abscess with biliary communication. Am J Surg. 2002;183:205–208. 8. Lefkowitch JH. Bile ductular cholestasis: an ominous histopathologic sign related to sepsis and “cholangitis lenta”. Hum Pathol. 1982;13:19–24. 9. Jha AK, Das A, Chowdhury F, Biswas MR, Prasad SK, Chattopadhyay S. Clinicopathological study and management of liver abscess in a tertiary care center. J Nat Sci Biol Med. 2015;6:71–75. 10. Cheng HC, Chang WL, Chen WY, et al. Long-term outcome of pyogenic liver abscess: factors related with abscess recurrence. J Clin Gastroenterol. 2008;42:1110–1115. 11. Crump JA, Luby SP, Mintz ED. The global burden of typhoid fever. Bull World Health Organ. 2004;82:346–353. 12. Boyle EC, Bishop JL, Grassl GA, et al. Salmonella: from pathogenesis to therapeutics. J Bacteriol. 2007;189:1489–1495. 13. Morgenstern R, Hayes PC. The liver in typhoid fever: always affected, not just a complication. Am J Gastroenterol. 1991;86:1235–1239. 14. Gonzalez-Escobedo G, Marshall JM, Gunn JS. Chronic and acute infection of the gall bladder by Salmonella typhi: understanding the carrier state. Nat Rev Microbiol. 2011;9:9–14. 15. Akritidis N, Tzivras M, Delladetsima I, et al. The liver in brucellosis. Clin Gastroenterol Hepatol. 2007;5:1109–1112. 16. Young EJ, Hasanjani Roushan MR, Shafae S, Genta RM, Taylor SL. Liver histology of acute brucellosis caused by Brucella melitensis. Hum Pathol. 2014;45:2023–2028.





























17. Kirby BD, Snyder KM, Meyer RD, et al. Legionnaires’ disease: report of sixty-five nosocomially acquired cases of review of the literature. Medicine (Baltimore). 1980;59:188–205. 18. Kirby BD, Snyder KM, Meyer RD, et al. Legionnaires’ disease: clinical features of 24 cases. Ann Intern Med. 1978;89:297–309. 19. Yang XX, Lin JM, Xu KJ, et al. Hepatic actinomycosis: report of one case and analysis of 32 previously reported cases. World J Gastroenterol. 2014;20:16372–16376. 20. Guarner J, Greer PW, Bartlett J, et al. Congenital syphilis in a newborn: an immunopathologic study. Mod Pathol. 1999;12:82–87. 21. Hagen CE, Kamionek M, McKinsey DS, Misdraji J. Syphilis presenting as inflammatory tumors of the liver in HIV-positive homosexual men. Am J Surg Pathol. 2014;38:1636–1643. 22. Cohen SE, Klausner JD, Engelman J, Philip S. Syphilis in the modern era: an update for physicians. Infect Dis Clin North Am. 2013;27:705–722. 23. (NOVO): Chan JK. Newly available antibodies with practical applications in surgical pathology. Int J Surg Pathol. 2013;21:553–572. 24. Kobayashi Y. Clinical observation and treatment of leptospirosis. J Infect Chemother. 2001;7: 59–68. 25. de Brito T, Morais CF, Yasuda PH, et al. Cardiovascular involvement in human and experimental leptospirosis: pathologic findings and immunohistochemical detection of leptospiral antigen. Ann Trop Med Parasitol. 1987;81:207–214. 26. Nicodemo AC, Duarte MI, Alves VA, et al. Lung lesions in human leptospirosis: microscopic, immunohistochemical, and ultrastructural features related to thrombocytopenia. Am J Trop Med Hyg. 1997;56:181–187. 27. Buyuktimkin B, Saier Jr MH. Comparative genomic analyses of transport proteins encoded within the genomes of Leptospira species. Microb Pathog. 2015;88:52–64. 28. De Brito T, Menezes LF, Lima DM, et al. Immunohistochemical and in situ hybridization studies of the liver and kidney in human leptospirosis. Virchows Arch. 2006;448:576–583. 29. Adler B. Pathogenesis of leptospirosis: cellular and molecular aspects. Vet Microbiol. 2014;27;172:353–358. 30. Athanazio DA, Santos CS, Santos AC, et al. Experimental infection in tumor necrosis factor alpha receptor, interferon gamma and interleukin 4 deficient mice by pathogenic Leptospira interrogans. Acta Trop. 2008;105:95–98. 31. De Brito T, Machado MM, Montans SD, et al. Liver biopsy in human leptospirosis: a light and electron microscopy study. Virchows Arch Pathol Anat Physiol Klin Med. 1967;342:61–69. 32. Zaki SR, Shieh WJ. Leptospirosis associated with outbreak of acute febrile illness and pulmonary haemorrhage, Nicaragua, 1995. The Epidemic Working Group at Ministry of Health in Nicaragua. Lancet. 1996;347:535–536. 33. Alves VA, Vianna MR, Yasuda PH, et al. Detection of leptospiral antigen in the human liver and kidney using an immunoperoxidase staining procedure. J Pathol. 1987;151:125–131. 34. Adams JS, Walker DH. The liver in Rocky Mountain spotted fever. Am J Clin Pathol. 1981;75:156–161. 35. Angerami RN, Câmara M, Pacola MR, et al. Features of Brazilian spotted fever in two different endemic areas in Brazil. Ticks Tick Borne Dis. 2012;3:346–348. 36. Labruna MB, Santos FC, Ogrzewalska M, et al. Genetic identification of rickettsial isolates from fatal cases of Brazilian spotted fever and comparison with Rickettsia rickettsii isolates from the American continents. J Clin Microbiol. 2014;52:3788–3791. 37. Walker DH, Ismail N. Emerging and re-emerging rickettsioses: endothelial cell infection and early disease events. Nat Rev Microbiol. 2008;6:375–386. 38. Chapman AS, Bakken JS, Folk SM, et al. Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever, ehrlichioses, and anaplasmosis—United States: a practical guide for physicians and other health-care and public health professionals. MMWR Recomm Rep. 2006;55:1–27. 39. Zaidi SA, Singer C. Gastrointestinal and hepatic manifestations of tickborne diseases in the United States. Clin Infect Dis. 2002;34:1206–1212. 40. Tjwa M, De Hertogh G, Neuville B, et al. Hepatic fibrin-ring granulomas in granulomatous hepatitis: report of four cases and review of the literature. Acta Clin Belg. 2001;56: 341–348. 41. Ughetto E, Gouriet F, Raoult D, Rolain JM. Three years experience of real-time PCR for the diagnosis of Q fever. Clin Microbiol Infect. 2009;15(suppl 2):200–201. 42. Parolini I, Blanc P, Larrey D. Bacterial perihepatitis. Rev Prat. 2001;51:2081–2085. 43. Piton S, Marie E, Parmentier JL. Chlamydia trachomatis perihepatitis (Fitz Hugh-Curtis syndrome). Apropos of 20 cases. J Gynecol Obstet Biol Reprod (Paris). 1990;19:447–454. 44. Doyle DJ, Hanbidge AE, O’Malley ME. Imaging of hepatic infections. Clin Radiol. 2006;61: 737–748. 45. Connor DH, Neafie RC, Meyers WM. Amebiasis. In: Binford CH, Ash JE, Connor DH, eds. Pathology of Tropical and Extraordinary Diseases. Washington, DC: Armed Forces Institute of Pathology; 1976:308–316. 46. Pawlowski SW, Warren CA, Guerrant R. Diagnosis and treatment of acute or persistent diarrhea. Gastroenterology. 2009;136:1874–1886. 47. Chacín-Bonilla L. An update on amebiasis. Rev Med Chil. 2013;141:609–615. 48. Ready PD. Epidemiology of visceral leishmaniasis. Clin Epidemiol. 2014;6:147–154. 49. Magill AJ, Grogl M, Gasser Jr RA, et al. Visceral infection caused by Leishmania tropica in veterans of Operation Desert Storm. N Engl J Med. 1993;328:1383–1387. 50. Herrador Z, Gherasim A, Jimenez BC, Granados M, San Martín JV, Aparicio P. Epidemiological changes in leishmaniasis in Spain according to hospitalization-based records, 1997-2011: raising awareness towards leishmaniasis in non-HIV patients. PLoS Negl Trop Dis. 2015;9: e0003594.

Nonviral Infections of the Liver





















51. Martins-Melo FR, Lima Mda S, Ramos Jr AN, Alencar CH, Heukelbach J. Mortality and case fatality due to visceral leishmaniasis in Brazil: a nationwide analysis of epidemiology, trends and spatial patterns. PLoS One. 2014;9. e93770. 52. Stanley AC, Engwerda CR. Balancing immunity and pathology in visceral leishmaniasis. Immunol Cell Biol. 2007;85:138–147. 53. Seixas Duarte MI, Tuon FF, Pagliari C, et al. Human visceral leishmaniasis expresses Th1 pattern in situ liver lesions. J Infect. 2008;57:332–337. 54. el Hag IA, Hashim FA, el Toum IA, et al. Liver morphology and function in visceral leishmaniasis (kala-azar). J Clin Pathol. 1994;47:547–551. 55. Andrade ZA, Andrade SG. Some new aspects of the kala-azar pathology. (Morphologic study of 13 autopsy cases). Rev Inst Med Trop Sáo Paulo. 1966;8:259–266. 56. Duarte MI, Corbett CE. Histopathological patterns of the liver involvement in visceral leishmaniasis. Rev Inst Med Trop Sáo Paulo. 1987;29:131–136. 57. Corbett CE, Duarte MI, Bustamante SE. Regression of diffuse intralobular liver fibrosis associated with visceral leishmaniasis. Am J Trop Med Hyg. 1993;49:616–624. 58. Mansueto P, Seidita A, Vitale G, Cascio A. Leishmaniasis in travelers: a literature review. Travel Med Infect Dis. 2014;12:563–581. 59. Boelaert M, Bhattacharya SK, Chappuis F, El Safi SH, Hailu A, Mondal D, et al. Evaluation of rapid diagnostic tests: visceral leishmaniasis. Nat Rev Micro. 2007:S30–S39. 60. Pintado V, Martin-Rabadan P, Rivera ML, et al. Visceral leishmaniasis in human immunodeficiency virus (HIV)-infected and non-HIV-infected patients. A comparative study. Medicine (Baltimore). 2001;80:54–73. 61. World Malaria Report. Genève: WHO; 2014:227. 62. White NJ, Pukrittayakamee S, Hien TT, Faiz MA, Mokuolu OA, Dondorp AM. Malaria. Lancet. 2014;383:723–735. 63. Wassmer SC, Taylor TE, Rathod PK, et al. Investigating the pathogenesis of severe malaria: a multidisciplinary and cross-geographical approach. Am J Trop Med Hyg. 2015;93(suppl 3):42–56. 64. Deller Jr JJ, Cifarelli PS, Berque S, et al. Malaria hepatitis. Mil Med. 1967;132:614–620. 65. De Brito T, Barone AA, Faria RM. Human liver biopsy in P. falciparum and P. vivax malaria. A light and electron microscopy study. Virchows Arch A Pathol Pathol Anat. 1969;348:220–229. 66. Rupani AB, Amarapurkar AD. Hepatic changes in fatal malaria: an emerging problem. Ann Trop Med Parasitol. 2009;103:119–127. 67. Crane GG. Hyperreactive malarious splenomegaly (tropical splenomegaly syndrome). Parasitol Today. 1986;2:4–9. 68. Wilson ML. Laboratory diagnosis of malaria: conventional and rapid diagnostic methods. Arch Pathol Lab Med. 2013;137:805–811. 69. Bethony J, Brooker S, Albonico M, et al. Soil-transmitted helminth infections: ascariasis, trichuriasis, and hookworm. Lancet. 2006;367:1521–1532. 70. Malik AH, Saima BD, Wani MY. Management of hepatobiliary and pancreatic ascariasis in children of an endemic area. Pediatr Surg Int. 2006;22:164–168. 71. Khandelwal N, Shaw J, Jain MK. Biliary parasites: diagnostic and therapeutic strategies. Curr Treat Options Gastroenterol. 2008;11:85–95. 72. Lim JH, Kim SY, Park CM. Parasitic diseases of the biliary tract. AJR Am J Roentgenol. 2007;188:1596–1603. 73. Bradley JE, Jackson JA. Immunity, immunoregulation and the ecology of trichuriasis and ascariasis. Parasite Immunol. 2004;26:429–441. 74. Gayotto LC, Muszkat RM, Souza IV. Hepatobiliary alterations in massive biliary ascariasis. Histopathological aspects of an autopsy case. Rev Inst Med Trop Sáo Paulo. 1990;32:91–95. 75. Hotez PJ. Neglected infections of poverty in the United States of America. PLoS Negl Trop Dis. 2008;2:e256. 76. Kwon NH, Oh MJ, Lee SP, et al. The prevalence and diagnostic value of toxocariasis in unknown eosinophilia. Ann Hematol. 2006;85:233–238. 77. Ehrhard T, Kernbaum S. Toxocara canis et toxocarose humaine. Bulletin de l’Institut Pasteur. 1979;77:225–287. 78. Huntley CC, Costas MC, Lyerly A. Visceral larva migrans syndrome: clinical characteristics and immunologic studies in 51 patients. Pediatrics. 1965;36:523–536. 79. da Silva AM, Chieffi PP, da Silva WL, et al. The hamster (Mesocricetus auratus) as an experimental model of toxocariasis: histopathological, immunohistochemical, and immunoelectron microscopic findings. Parasitol Res. 2015;114:809–821. 80. Musso C, Castelo JS, Tsanaclis AM, et al. Prevalence of Toxocara-induced liver granulomas, detected by immunohistochemistry, in a series of autopsies at a Children’s Reference Hospital in Vitoria, ES. Brazil. Virchows Arch. 2007;450:411–417. 81. Despommier D. Toxocariasis: clinical aspects, epidemiology, medical ecology, and molecular aspects. Clin Microbiol Rev. 2003;16:265–272. 82. Jacob CM, Pastorino AC, Peres BA, et al. Clinical and laboratorial features of visceral toxocariasis in infancy. Rev Inst Med Trop Sáo Paulo. 1994;36:19–26. 83. Lynch NR, Wilkes LK, Hodgen AN, et al. Specificity of Toxocara ELISA in tropical populations. Parasite Immunol. 1988;10:323–337. 84. Fuehrer HP, Igel P, Auer H. Capillaria hepatica in man—an overview of hepatic capillariosis and spurious infections. Parasitol Res. 2011;109:969–979. 85. Cooke R. Infectious Diseases: atlas, Cases, Text. Brisbane, Australia: McGraw-Hill; 2008. 86. Peres LC, Saggioro FP, Dias Jr LB, et al. Infectious diseases in paediatric pathology: experience from a developing country. Pathology. 2008;40:161–175. 87. Assis BC, Cunha LM, Baptista AP, et al. A contribution to the diagnosis of Capillaria hepatica infection by indirect immunofluorescence test. Mem Inst Oswaldo Cruz. 2004;99:173–177.































88. Valerio L, Roure S, Fernández-Rivas G, et al. Strongyloides stercoralis, the hidden worm. Epidemiological and clinical characteristics of 70 cases diagnosed in the North Metropolitan Area of Barcelona, Spain, 2003-2012. Trans R Soc Trop Med Hyg. 2013;107:465–470. 89. CDC, DPDx. Parasites and health: strongyloidiasis. Centers for Disease Control & Prevention. www.cdc.gov/parasites/strongyloides/epi.html; 2014. 90. Puthiyakunnon S, Boddu S, Li Y, et al. Strongyloidiasis—an insight into its global prevalence and management. PLoS Negl Trop Dis. 2014;14(8):e3018. 91. Voehringer D, Shinkai K, Locksley RM. Type 2 immunity reflects orchestrated recruitment of cells committed to IL-4 production. Immunity. 2004;20:267–277. 92. Finkelman FD, Shea-Donohue T, Morris SC, et al. Interleukin-4- and interleukin-13-mediated host protection against intestinal nematode parasites. Immunol Rev. 2004;201:139–155. 93. Pinlaor S, Mootsikapun P, Pinlaor P, et al. Detection of opportunistic and non-opportunistic intestinal parasites and liver flukes in HIV-positive and HIV-negative subjects. Southeast Asian J Trop Med Public Health. 2005;36:841–845. 94. Bachur TP, Vale JM, Coelho IC, et al. Enteric parasitic infections in HIV/AIDS patients before and after the highly active antiretroviral therapy. Braz J Infect Dis. 2008;12:115–122. 95. Hotez PJ, Brindley PJ, Bethony JM, et al. Helminth infections: the great neglected tropical diseases. J Clin Invest. 2008;118:1311–1321. 96. Marcos LA, Terashima A, Dupont HL, et al. Strongyloides hyperinfection syndrome: an emerging global infectious disease. Trans R Soc Trop Med Hyg. 2008;102:314–318. 97. Andrade ZA. Schistosomiasis and hepatic fibrosis regression. Acta Trop. 2008;108:79–82. 98. Poltera AA, Katsimbura N. Granulomatous hepatitis due to Strongyloides stercoralis. J Pathol. 1974;113:241–246. 99. Buonfrate D, Formenti F, Perandin F, Bisoffi Z. Novel approaches to the diagnosis of Strongyloides stercoralis infection. Clin Microbiol Infect. 2015;21:543–552. 100. Paula FM, Malta Fde M, et al. Molecular diagnosis of strongyloidiasis in tropical areas: a comparison of conventional and real-time polymerase chain reaction with parasitological methods. Mem Inst Oswaldo Cruz. 2015;110:272–274. 101. Martins-Melo FR, Pinheiro MC, Ramos Jr AN, Alencar CH, Bezerra FS, Heukelbach J. Trends in schistosomiasis-related mortality in Brazil, 2000-2011. Int J Parasitol. 2014;44: 1055–1062. 102. Kamal S, Madwar M, Bianchi L, et al. Clinical, virological and histopathological features: long-term follow-up in patients with chronic hepatitis C co-infected with S. mansoni. Liver. 2000;20:281–289. 103. Silva LC, Maciel PE, Ribas JG, et al. Treatment of schistosomal myeloradiculopathy with praziquantel and corticosteroids and evaluation by magnetic resonance imaging: a longitudinal study. Clin Infect Dis. 2004;39:1618–1624. 104. Andrade ZA. Schistosomal hepatopathy. Mem Inst Oswaldo Cruz. 2004;99:51–57. 105. Pereira TA, Syn WK, Machado MV, et al. Schistosome-induced cholangiocyte proliferation and osteopontin secretion correlate with fibrosis and portal hypertension in human and murine schistosomiasis mansoni. Clin Sci (Lond). 2015;129:875–883. 106. Bina JC, Prata A. Regressão da hepatoesplenomegalia pelo tratamento específico da esquistossomose. Rev Soc Bras Med Trop. 1983;16:213–218. 107. Vianna MR, Gayotto LC, Telma R, et al. Intrahepatic bile duct changes in human hepatosplenic schistosomiasis mansoni. Liver. 1989;9:100–109. 108. Mohamed-Ali Q, Doehring-Schwerdtfeger E, Abdel-Rahim IM, et al. Ultrasonographical investigation of periportal fibrosis in children with Schistosoma mansoni infection: reversibility of morbidity seven months after treatment with praziquantel. Am J Trop Med Hyg. 1991;44:444–451. 109. Richter J. The impact of chemotherapy on morbidity due to schistosomiasis. Acta Trop. 2003;86:161–183. 110. Andrade ZA. Morphological features of collagen degradation in advanced hepatic schistosomiasis of man. Mem Inst Oswaldo Cruz. 1992;87(suppl 4):129–138. 111. Rutitzky LI, Bazzone L, Shainheit MG, et al. IL-23 is required for the development of severe egg-induced immunopathology in schistosomiasis and for lesional expression of IL-17. J Immunol. 2008;180:2486–2495. 112. Cerri GG, Alves VA, Magalhaes A. Hepatosplenic schistosomiasis mansoni: ultrasound manifestations. Radiology. 1984;153:777–780. 113. Vezozzo DC, Farias AQ, Cerri GG, et al. Assessment of portal hemodynamics by Doppler ultrasound and of liver morphology in the hepatosplenic and hepatointestinal forms of Schistosomiasis mansoni. Dig Dis Sci. 2006;51:1413–1419. 114. Smith JA, Oladiran B, Lagundoye SB, et al. Pentastomiasis and malignancy. Ann Trop Med Parasitol. 1975;69:503–512. 115. Prathap K, Lau KS, Bolton JM. Pentastomiasis: a common finding at autopsy among Malaysian aborigines. Am J Trop Med Hyg. 1969;18:20–27. 116. Hopps HC, Keegan HL, Price DL, et al. Pentastomiasis. In: Marcial-Rojas RA, ed. Pathology of Protozoal and Helminthic Diseases with Clinical Correlation. Baltimore: Williams & Wilkins; 1971:970–989. 117. Machado MA, Makdissi FF, Canedo LF, et al. Unusual case of pentastomiasis mimicking liver tumor. J Gastroenterol Hepatol. 2006;21:1218–1220. 118. Ma KC, Qiu MH, Rong YL. Pathological differentiation of suspected cases of pentastomiasis in China. Trop Med Int Health. 2002;7:166–177. 119. Mas-Coma S. Epidemiology of fascioliasis in human endemic areas. J Helminthol. 2005;79: 207–216. 120. Ashrafi K, Bargues MD, O’Neill S, Mas-Coma S. Fascioliasis: a worldwide parasitic disease of importance in travel medicine. Travel Med Infect Dis. 2014;12(6 Part A):636–649.

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285

Practical Hepatic Pathology: A Diagnostic Approach 121. Marcos LA, Terashima A, Gotuzzo E. Update on hepatobiliary flukes: fascioliasis, opisthorchiasis and clonorchiasis. Curr Opin Infect Dis. 2008;21:523–530. 122. Rana SS, Bhasin DK, Nanda M, et al. Parasitic infestations of the biliary tract. Curr Gastroenterol Rep. 2007;9:156–164. 123. Lim JH, Mairiang E, Ahn GH. Biliary parasitic diseases including clonorchiasis, opisthorchiasis and fascioliasis. Abdom Imaging. 2008;33:157–165. 124. Hong ST, Fang Y. Clonorchis sinensis and clonorchiasis, an update. Parasitol Int. 2012;61: 17–24. 125. Sithithaworn P, Haswell-Elkins MR, Mairiang P, et al. Parasite-associated morbidity: liver fluke infection and bile duct cancer in northeast Thailand. Int J Parasitol. 1994;24:833–843. 126. Rim HJ. Clonorchiasis: an update. J Helminthol. 2005;79:269–281. 127. Parray FQ, Wani MA, Wani NA. Oriental cholangiohepatitis—is our surgery appropriate? Int J Surg. 2014;12:789–793. 128. Srivatanakul P, Sriplung H, Deerasamee S. Epidemiology of liver cancer: an overview. Asian Pac J Cancer Prev. 2004;5:118–125. 129. Lee TY, Lee SS, Jung SW, et al. Hepatitis B virus infection and intrahepatic cholangiocarcinoma in Korea: a case-control study. Am J Gastroenterol. 2008;103:1716–1720. 130. Kim KH, Kim CD, Lee HS, et al. Biliary papillary hyperplasia with clonorchiasis resembling cholangiocarcinoma. Am J Gastroenterol. 1999;94:514–517.

286

131. Sripa B, Brindley PJ, Mulvenna J, et al. The tumorigenic liver fluke Opisthorchis viverrini— multiple pathways to cancer. Trends Parasitol. 2012;28:395–407. 132. Eckert J, Deplazes P. Biological, epidemiological, and clinical aspects of echinococcosis, a zoonosis of increasing concern. Clin Microbiol Rev. 2004;17:107–135. 133. Pedrosa I, Saiz A, Arrazola J, et al. Hydatid disease: radiologic and pathologic features and complications. Radiographics. 2000;20:795–817. 134. Czermak BV, Akhan O, Hiemetzberger R, et al. Echinococcosis of the liver. Abdom Imaging. 2008;33:133–143. 135. Ozkok A, Gul E, Okumus G, et al. Disseminated alveolar echinococcosis mimicking a metastatic malignancy. Intern Med. 2008;47:1495–1497. 136. Saenz-Santamaria J, Moreno-Casado J, Nunez C. Role of fine-needle biopsy in the diagnosis of hydatid cyst. Diagn Cytopathol. 1995;13:229–232. 137. Safioleas M, Safioleas C, Misiakos EP. Why fine-needle aspiration cytology is not an adequate diagnostic method for liver hydatid cyst—reply. Arch Surg. 2007;142:690–691. 138. Nunnari G, Pinzone MR, Gruttadauria S, et al. Hepatic echinococcosis: clinical and therapeutic aspects. World J Gastroenterol. 2012;18:1448–1458.

19 Hepatic Granulomas: Differential Diagnosis Evandro Sobroza de Mello, MD, PhD, and Venancio Avancini Ferreira Alves, MD, PhD

Histologic Patterns of Hepatic Granulomas  290 Epithelioid Granulomas  290 Suppurative Granulomas (Granulomas with Central Microabscess)  291 Microgranulomas 291 Lipogranulomas 291 Foamy Macrophage Aggregates  291 Fibrin-Ring Granulomas  292 Specific Granulomatous Diseases  292 Tuberculosis 292 Other Mycobacteria  293 Brucellosis 294 Q-Fever 294 Systemic Mycoses  294 Candidiasis 294 Histoplasmosis 295 Other Mycoses  295 Parasitic Infections  295 Other Infectious Agents  295 Sarcoidosis 297 Drug-Induced Granulomas  297 Neoplasia-Associated Granulomas  298

dilemma because of their frequency and nonspecificity. Most systemic granulomatous diseases involve the liver, possibly reflecting the high hepatic content of mononuclear phagocytes, including Kupffer cells and other macrophages. Besides systemic conditions, some primary liver diseases demonstrate granulomas as the main pathologic finding. Immunogenetically, two main types of granulomas can be recognized1: foreign body–type granulomas, induced by a material that is nonimmunogenic; and immune or hypersensitivity granulomas that are induced by antigenic substances that elicit an immune response. The latter type of granulomas predominates in the liver and can be morphologically classified as shown in Table 19.1. Foreign body–type granulomas are usually found in a subcapsular location as a reaction to talc or suture material, or surrounding extravasated bile around large bile ducts at the hilum in conditions that cause extrahepatic biliary obstruction (Fig. 19.2A–B). Familiarity with the different types of granulomas and their mode of presentation in various diseases helps tremendously in narrowing the pathologic differential diagnosis.2

Idiopathic Hepatic Granulomas  298 Abbreviations CMV cytomegalovirus EBV Epstein-Barr virus HIV human immunodeficiency virus MAI Mycobacterium avium-intracellulare PAS periodic acid–Schiff PCR polymerase chain reaction TB tuberculosis

A granuloma is a focus of chronic inflammation consisting of a microscopic aggregation of epithelioid macrophages with or without the participation of other cell types (Fig. 19.1). Granulomas are found in 2% to 15% of routine liver biopsies,1,2 and are a constant source of diagnostic

Figure 19.1  An epithelioid granuloma located in the hepatic lobule. Epithelioid cells are characterized by abundant homogeneous cytoplasm and elongated curved nuclei, which are frequently peripherally located. In this case, multinucleated giant cells and a rim of lymphocytes are seen. 289

Practical Hepatic Pathology: A Diagnostic Approach Table 19.1  Morphologic Patterns of Liver Granulomas and Their Major Etiologic Associations Epithelioid

Suppurative

Microgranuloma

Infectious

Tuberculosis, fungal infections, brucellosis, schistosomiasis

Candida infection, actinomycosis, nocardia infection

Listeria, other (rare)

Lipogranuloma

Noninfectious

Primary biliary cholangitis, sarcoidosis, foreign body reaction, drug reaction

Chronic granulomatous disease

Nonspecific reaction to liver injury or systemic disease

—

Foamy

Fibrin-ring

Mycobacterium avium-intracellulare infection, leprosy, Whipple disease

Q-fever, rarely other infections (viral, salmonella)

Fatty liver disease, mineral oil

—

Drug reaction

Adapted from Lamps LW. Hepatic granulomas: a review with emphasis on infectious causes. Arch Pathol Lab Med. 2015;139:867–875.

Table 19.2  Geographic Variation in the Etiology of Hepatic Granulomas Saudi Turkey Arabia Turkey Scotland Greece Germany Iran 20076 20085 20119 201410 19904 20018 20037

A

Number of cases

59

74

63

68

442

72

35

Incidence of granulomas (%)

14.6

1.6

3.8

3.7

3.6

2.3

1.31

Tuberculosis (%)

34

20

9

1.5

—

51.4

6

Schistosomiasis (%)

54

—

—

1.5

—

—

—

Hepatitis C (%)

—

1.3

9.5

4.4

—

4.2

6

Other infections (%)

8

31

—

1.5

—

18.1

14.5

Primary biliary ­cholangitis/overlap syndromes (%)

—

—

30.1

62

48.6

4.2

45

Sarcoidosis (%)

—

36

11.1

7.5

8.4

1.4

17

Drugs (%)

3

1.3

7.9

3

—

1.4

—

Other causes (%)

—

13.5

—

12.6

—

6.8

11.5

Idiopathic (%)

0

20

11.1

6

36

12.5

—

granulomas is very large, Table 19.1 is a summarized practical version listing the main diagnostic possibilities associated with the major morphologic patterns. The uncommon causes, mentioned under other categories, will be discussed only briefly. An algorithmic approach to differential diagnosis of liver granulomas is shown in Fig. 19.3.

Histologic Patterns of Hepatic Granulomas

B Figure 19.2  Foreign body granuloma associated with extravasated bile. A, Multinucleated foreign body cells containing bile pigment (arrows) are surrounded by loosely arranged xanthomatous macrophages. B, A more compact arrangement of epithelioid cells is shown, but the diagnostic phagocytosed bile pigment (arrows) can be seen.

Hepatic granulomas may be found within the lobule, within portal tracts or at both sites. In the lobules, granulomas may be present in a perivenular location or be distributed randomly. In portal tracts, they may have periductal, perivascular or a random distribution. The site of involvement together with the granuloma type (see Table 19.1) provides important clues to the etiology of the granulomatous process and must be included in all pathology reports even when the cause cannot be easily defined (see Fig. 19.3).

Epithelioid Granulomas The frequency of the different causes of liver granulomas varies with different case series, reflecting geographic variations in patient populations and epidemiologic factors (Table 19.2). The majority of cases worldwide have been ascribed to mycobacterial infections, a high number of cases occurring in developing countries,3 whereas schistosomiasis is a major cause in regions endemic for this infection.4 In Western populations, the majority of cases are arising from autoimmune disease (primary biliary cirrhosis, recently renamed primary biliary cholangitis), followed by sarcoidosis.4-8 Drug-related granulomas and idiopathic granulomas complete the list. Granulomas have been described in only rare cases of chronic hepatitis C virus and hepatitis B virus infections. Although the list of possible causes of hepatic 290

These are focal collections of specialized histiocytes, known as epithelioid cells, which have mainly secretory (not phagocytic) activity, a phenotypic modulation which occurs in response to antigenic stimulation. Epithelioid cells are distinguished from regular macrophages by their abundant homogeneous cytoplasm, which is free of ingested particulate matter, and their elongated curved nuclei, which are frequently located at the periphery of the cell11 (Fig. 19.1 and eSlide 19.1). Multinucleated giant cells, lymphocytes, other inflammatory cells, and fibroblasts may be seen in and around the groups of epithelioid cells; inclusions such as asteroid and Schaumann bodies may also be present (Fig. 19.4). Necrosis is a common finding in epithelioid granulomas and different types of necrosis can be identified.12 The most well-recognized

Hepatic Granulomas: Differential Diagnosis GRANULOMA IN LIVER BIOPSY

19

Describe histologic pattern

Look for specific agents

Group 1. See the cause Specific cause can be seen on morphologic examination (e.g., parasite ova, mycobacteria, fungus)

Correlate histologic pattern with clinical data

Group 2. Know the cause Morphologic pattern and knowledge of clinical data can indicate a very probable etiology (e.g., granuloma with caseous necrosis in a patient with known active tuberculosis; granulomatous damage of bile duct in a middle-aged woman with pruritus and antimitochondrial antibodies)

Group 3. Suspect the diagnosis The diagnosis is not clear but histologic pattern suggests possible etiology (eg, suppurative granuloma suggests Yersinia, Candida, or cat-scratch disease even if not clinically suspected)

Group 4. Case unknown Histology establishes the presence of granulomas but there are no further clues (histologic or clinical) for determination of etiology. Consider tuberculosis. Figure 19.3 Algorithmic approach for the diagnosis and interpretation of hepatic granulomas. (Data from Denk H, Scheuer PJ, Baptista A, et al. Guidelines for the diagnosis and interpretation of hepatic granulomas. Histopathology 1994;25:209-218.)

is caseous necrosis (Figs. 19.5A–B), which is very typical of tuberculosis; caseous necrosis can, however, also be seen in histoplasmosis and other fungal infections as well as occasionally in other diseases such as sarcoidosis. Histologically, caseous necrosis appears as eosinophilic, granular, acellular material characterized by complete loss of tissue structure, in contrast with coagulative necrosis, which preserves some ghost tissue outline (eSlide 19.2). Granulomas with fibrinoid necrosis are typical of rheumatoid arthritis (Fig. 19.5C), whereas suppurative necrosis is indicative of Yersinia infection13 and candidiasis.14 Granulomas with a prominent infiltrate of eosinophils are frequently associated with parasites and less frequently with drugs.

Suppurative Granulomas (Granulomas with Central Microabscess) This is an uncommon granulomatous inflammation pattern, characterized by a central abscess surrounded by a rim of epithelioid or foamy histiocytes. Fungi, including Candida sp. and Histoplasma sp.,15 but also actinomycosis and Nocardia infections, are associated with this type of inflammation. Sometimes, especially if some degree of immunosuppression is present,

Figure 19.4  Multinucleated giant cells containing asteroid bodies in a patient with sarcoidosis. Asteroid bodies provide a useful clue to the diagnosis of sarcoidosis but can be seen in other conditions.

the reaction is more diffuse, with smaller focus of suppurative inflammation interspersed with a histiocytic reaction.

Microgranulomas These are minute collections of typically three to seven macrophages within the hepatic lobule (Fig. 19.6). They are often admixed with other inflammatory cells, mainly lymphocytes, or associated with apoptotic hepatocytes (see Fig. 19.6, inset). Hemosiderin or ceroid pigment may be present. Microgranulomas are generally seen in any chronic inflammatory disease of the liver as a nonspecific change to cellular injury and hepatocyte necrosis16 and do not have any specific diagnostic connotation.2 They therefore need to be distinguished from epithelioid granulomas, which have distinct diagnostic significance. An important exception is the nodular form of leishmaniasis (eSlide 19.3), which may demonstrate numerous very small epithelioid granulomas (Fig. 19.7).

Lipogranulomas These are focal, loose collections of macrophages or epithelioid cells surrounding single or multiple droplets of neutral lipid. When neutral fat escapes the confines of the hepatocyte cell membrane and enters the extracellular compartment, histiocytes settle around it, and a lipogranuloma is formed. Ultrastructurally, remnants of the liver cell may be seen between the fat droplet and the histiocytes.17 Some of these macrophages can adopt a foamy appearance and lymphocytes and plasma cells may be interspersed between them. They are often associated with a little fibrous tissue (Fig. 19.8A–B). Lipogranulomas are characteristically found in zone 3, in the vicinity of the central vein, and are most often seen in fatty livers, as part of nonalcoholic fatty liver disease and, even more frequently, in alcoholic liver disease.18 Lipogranulomas have been associated with the ingestion of mineral oil; these are morphologically similar to those associated with fatty livers.19 Aside from rare exceptions, lipogranulomas are not believed to progress and are therefore not clinically significant.20-22 In addition to the liver, they may also be found in the spleen, lymph nodes, and lungs.

Foamy Macrophage Aggregates This pattern is associated with infections, mostly in immunocompromised patients. Besides foamy cells, there is very little additional inflammatory response. The most commonly implicated microorganisms are atypical mycobacteria in patients with acquired immunodeficiency syndrome and some fungi such as Cryptococcus (Fig. 19.9). 291

Practical Hepatic Pathology: A Diagnostic Approach

A Figure 19.6  Microgranuloma represented by a small group of histiocytes within the lobules, with an inset that shows a microgranuloma associated with an apoptotic hepatocyte.

B

Figure 19.7  Nodular form of leishmaniasis that showed numerous small nonnecrotizing epithelioid cell granulomas (microgranulomas) (eSlide 19.3).

C Figure 19.5  A and B, Caseous necrosis in tuberculous granulomas characterized by complete loss of tissue architecture. A thin rim of palisaded epithelioid histiocytes is present (eSlide 19.2). C, Fibrinoid necrosis is seen in granulomas caused by rheumatoid arthritis.

292

form a complete ring. Besides Q-fever, other causes of hepatic fibrinring granulomas include infectious agents such as cytomegalovirus,25 Epstein-Barr virus (EBV),26 hepatitis A virus,21 hepatitis C virus,22 and leishmaniasis.23 Noninfectious causes include hypersensitivity to medication (mainly allopurinol24), malignancy (eg, Hodgkin and non-Hodgkin lymphoma27) and, exceptionally, giant cell arteritis.28 Infections are the most common causes of fibrin-ring granulomas; therefore, differential diagnosis hinges on serologic tests. However, associated histopathologic features may help in the differential diagnosis; the presence of eosinophils may suggest a possible drug reaction whereas sinusoidal lymphocytosis raises the possibility of EBV infection. The pathogenesis of the fibrin-ring is not clear, but injury to sinusoidal endothelium might be an important factor.29

Fibrin-Ring Granulomas

Specific Granulomatous Diseases

The fibrin-ring or doughnut granuloma is a very unusual but distinctive type of granuloma first described in Q-fever.23,24 It is characterized by a ring of fibrin around a central core of fat, both of which are surrounded by epithelioid cells or neutrophils; the fibrin may not always

Although common in both patients with pulmonary and extrapulmonary tuberculosis (TB), liver involvement by tuberculosis is usually clinically silent; only occasional cases show local signs and symptoms

Tuberculosis

Hepatic Granulomas: Differential Diagnosis

A

B Figure 19.8  A, A lipogranuloma consisting of a collection of histiocytes and other inflammatory cells surrounding a lipid droplet. B, Lipogranulomas occur most often near the central vein and are associated with a small amount of fibrosis (trichrome stain).

Figure 19.9  Large collections of macrophages with abundant, slightly foamy macrophages. Special stains showed the cytoplasm to be filled with cryptococcal yeast forms (eSlide 19.6).

of hepatic involvement, or constitute the initial or sole presenting feature of the disease. A miliary pattern is the most common form and is said to occur in 50% to 80% of all patients dying of pulmonary tuberculosis.30 An extensive review of the world literature in 195231 documented only 80 cases of hepatic tuberculosis with large abscesses and

nodules or tuberculomas and classified tuberculosis of the liver into miliary tuberculosis (part of generalized disease) and localized disease, which could be further divided into focal or nodular tuberculosis (including hepatic abscess or tuberculomas) and into the tubular form (intrahepatic duct involvement). Since then, isolated case reports or case series of localized hepatic tuberculosis appear in literature, with varied nomenclature ranging from tuberculous liver abscess32 to tuberculous pseudo-tumor,33 primary hepatic tuberculosis,34 tuberculous hepatitis,35 tuberculous cholangitis, and tuberculosis of the bile duct,36,37 generating some confusion in classification and clinical significance of this disease. A useful classification of hepatic tuberculosis was proposed by Alvarez in 199838: 1. Miliary tuberculosis, consisting of hepatic involvement as part of generalized miliary TB, usually with no signs or symptoms relevant to the liver. 2. Tuberculous hepatitis, which presents with unexplained fever, with or without mild jaundice and hepatomegaly, caseating or noncaseating granulomas on liver biopsy and improvement with antituberculous therapy. 3. Hepatobiliary tuberculosis, presenting with signs and symptoms relevant to the hepatobiliary tract and including two subtypes: the first without bile duct involvement, presenting as solitary or multiple nodules, tuberculomas and tuberculous hepatic abscesses; and the second with bile duct involvement causing obstructive jaundice, either because of enlarged nodes surrounding the bile ducts or granulomatous involvement of the ductal wall producing inflammatory strictures. Mass forming primary hepatic tuberculosis that mimics intrahepatic carcinoma or hilar cholangiocarcinoma presents a significant clinical problem that requires a liver biopsy to reach the correct diagnosis.39,40

19

Pathology Hepatic granulomas in tuberculosis are most frequently found in portal and periportal areas but may occasionally occur in centrilobular areas (see Fig. 19.5A–B) (eSlide 19.2). Both caseating and noncaseating granulomas may be seen.41 In the localized form of disease, multiple granulomas may coalesce to form a large tumorlike lesion called a tuberculoma. A tuberculoma that has undergone extensive caseating and liquefaction necrosis forms a tuberculous abscess. Diagnosis As in other organs, the final diagnosis of liver tuberculosis rests on the demonstration of acid-fast bacilli on direct examination or culture of tissue specimens. In needle liver biopsies, epithelioid granuloma formation can be demonstrated in 80% to 100% of cases; and caseation necrosis in 30% to 83%. Nine percent to 60% of cases show the presence of acid-fast bacilli on culture of biopsy material, more in the presence of caseating necrosis; Ziehl-Neelsen staining on tissue sections demonstrates bacilli in 0% to 45% cases. Polymerase chain reaction assays from paraffin embedded liver tissue have a sensitivity of 58% to 88% and a specificity of 96% to 100% for the detection of mycobacterial DNA42,43; however, polymerase chain reaction (PCR) has its own limitations. Some patients with tuberculosis may have negative PCR results from liver tissue because of the paucity of mycobacteria or because of the possible reactive nature of liver granulomas.43

Other Mycobacteria The liver is the most frequently affected visceral organ in leprosy, particularly in the multibacillary type. Elevation of hepatic enzymes, especially of the aminotransferases, occurs mainly during the reactions and 293

Practical Hepatic Pathology: A Diagnostic Approach is related to deposition of immune complexes in the liver; in most cases, hepatic involvement is associated with no or only mild increase in the levels of aminotransferases. The entire spectrum of granulomatous lepromatous lesions can be seen in the liver. In a clinicopathologic study of liver disease conducted in Taiwan,44 hepatic granulomas (epithelioid or foam-cell) were found in 21 of 28 patients, and they correlated with the cutaneous reactions in lepromatous leprosy and intensity of bacteremia. Tuberculoid leprosy shows epithelioid noncaseating granulomas in up to 29% of cases, whereas the lepromatous form depicts foam-cell granulomas in up to 76% of cases.45 Neutrophilic infiltration in foam-cell granulomas is seen in some cases of lepromatous leprosy with reaction.46 As we and others have shown, immunohistochemical detection of mycobacterial antigens may be a useful tool, especially in paucibacillary cases.47 Mycobacterium avium-intracellulare (MAI) is usually responsible for pulmonary and/or visceral disease in patients infected with human immunodeficiency virus (HIV) (eSlide 19.1). Rarely, MAI may cause disease in other immunocompromised conditions (eg, hematologic malignancies48 or use of immunosuppressive therapy49). Nontuberculous mycobacteria are also reported very infrequently in the setting of end-stage liver disease.50,51 Animal models have shown that an increased susceptibility to MAI may depend on impaired macrophage function, and this mechanism may also underlie infection in patients with severe liver disease. Histologically, clusters or loose granulomas of clear or blue-gray foamy macrophages are dispersed diffusely throughout the lobule and portal tracts unaccompanied by necrosis or other inflammatory cells. The macrophages are packed with a large number of acid-fast bacilli, which stain with the Ziehl-Neelsen and periodic acid–Schiff (PAS)-diastase stains. Infections with other species of mycobacteria are reported in individuals who are HIV positive and often involve the liver.52,53 Granulomas are the usual histologic presentation, and culture is required for correct species identification.

Brucellosis Brucellosis is a zoonotic infection of ruminants, caused by gram-negative bacilli of Brucella species (Brucella melitensis, Brucella abortus, or Brucella suis). It is transmitted to humans by ingestion of infected milk products, direct contact with an infected animal, or inhalation of aerosols. As pasteurization of milk has eliminated that potential reservoir, infection nowadays generally occurs via occupational exposure in cattlemen, veterinarians, and slaughterhouse workers. Symptoms of brucellosis are protean and nonspecific with somatic complaints often predominating: these consist mainly of fever and weakness, but fatigue, malaise, body aches, depression, and anorexia may also occur. The liver is affected as part of hematogenous dissemination to the lymphoreticular system in 10% to 50% of cases. Altered liver enzymes and hepatomegaly are common. Pathology Nonspecific reactive hepatitis is the most common histologic finding with variable lobular and portal inflammation, lytic necrosis of hepatocytes, prominent Kupffer cells, and microgranulomas (see Fig. 19.6). Rare cases may have liver abscesses. Epithelioid granulomas may be present in chronic brucellosis. They are typically small, poorly delineated, and nonnecrotizing, distributed haphazardly in the lobule and also in portal tracts (Fig. 19.10).54 However, large necrotizing granulomas have also been reported.55 Diagnosis As isolation of the organism from blood or tissue can be difficult, serology remains the mainstay for establishing the diagnosis. 294

Figure 19.10  Multiple randomly distributed lobular microgranulomas in brucellosis.

Q-Fever Q-fever is a worldwide zoonotic infection caused by Coxiella burnetii with numerous reservoirs that include arthropods, birds, and mammals. The usual sources of human infection are farm animals (cattle, sheep, goats), but there have been reports of transmission of disease through contact with other animals, such as dogs, cats, rabbits, pigeons, and rats.56 C. burnetii is transmitted to humans by inhalation or ingestion of aerosols or dust contaminated with urine, feces, or milk of infected animals. The true prevalence of Q-fever may be underestimated because this disease can be subclinical.57 Symptomatic patients present with general symptoms including sweats, fever, myalgia, and chills. Cough, shortness of breath, and sputum production are often seen as signs of lung affection. Although the liver is affected in more than 85% of cases, it predominates the clinical picture only in a minority of cases. More frequently, asymptomatic hepatomegaly may be present with only modestly abnormal liver tests. Pathology Liver histology typically shows lobular fibrin-ring granulomas, present in up to 80% of cases.58 These are small granulomas characterized by a peripheral rim of histiocytes with a central fat vacuole and an intermediate ring of fibrin, besides a variable population of neutrophils. At times, however, only regular epithelioid granulomas may be present, or fibrin may appear as an irregular mass or strand, rather than a defined ring. Diagnosis The diagnosis of Q-fever is not straightforward; serum antibody titers provide definitive diagnosis and are highly reliable, although it may take a few months for antibody titers to develop.59

Systemic Mycoses Fungal infection can involve the liver in the course of hematogenous dissemination of a usually primary pulmonary infection. Visceral disease, including liver involvement, is precipitated by some kind of immunosuppression. Proper morphologic identification of the fungus is often possible in tissue sections stained with the Grocott and PAS stains.

Candidiasis Hepatic candidiasis affects mainly patients undergoing remission induction chemotherapy or bone marrow transplantation for acute

Hepatic Granulomas: Differential Diagnosis

Histoplasmosis Histoplasmosis is possibly the most common of the systemic mycosis and is seen in the liver as a scar or an old fibrotic subcapsular granuloma resulting from transient hematogenous spread during initial infection. Disseminated histoplasmosis occurs primarily in immunocompromised persons, especially in patients with HIV infection and a low CD4 lymphocyte count.62 Patients with lymphoreticular neoplasms, who are receiving corticosteroids, cytotoxic therapy, or immunosuppressive agents are also predisposed to disseminated histoplasmosis.63 Disseminated histoplasmosis is characterized by widespread infection of the lymphoreticular organs, including the liver. Hepatic involvement can lead to major clinical manifestations with hepatosplenomegaly and elevation of liver enzymes.15

A

19

Pathology Liver biopsy usually shows poorly formed granulomas with loose aggregates of histiocytes, often with central necrosis, especially in immunocompromised individuals. At the opposite end of spectrum are well-formed epithelioid granulomas, sometimes with caseous necrosis and fibrosis that may be difficult to differentiate from the scar of primary infections noted earlier (eSlides 19.4 and 19.5).

Other Mycoses Liver involvement can also occur with variable frequency in ­disseminated forms of other fungal diseases such as c­ ryptococcosis (eSlide 19.6), blastomycosis, paracoccidioidomycosis, or ­ coccidioidomycosis. In these cases, liver disease does not dominate the clinical picture and is usually identified in autopsy findings as a c­ omponent of more widespread disease. In most cases, a liver biopsy shows granulomas or suppurative lesions. Special stains are useful to further characterize the specific organism involved.

Parasitic Infections B Figure 19.11  Candidiasis. A geographic granuloma with a rim of palisaded histiocytes and a suppurative center (A), which shows necrosis and abundant neutrophils (B).

leukemia, on recovery following prolonged episodes of bone marrow dysfunction and neutropenia. In a study of 562 adult patients with leukemia, 7% of patients had hepatic candidiasis.60 Hepatosplenic candidiasis also occasionally develops in patients who are immunosuppressed for other conditions such as aplastic anemia and malignancies and in recent years has been an important cause of posttransplant mortality in recipients of solid-organ allografts.61 Pathology The usual histologic lesion is a suppurative granuloma consisting of a central area of necrosis rich in neutrophils and surrounded by histiocytes arranged in a palisading fashion (Fig. 19.11A–B).11 In the early stage, necrosis or microabscesses may be the only finding. Fungal organisms are usually found in the center of the granulomas or necrotic foci. Diagnosis A proper diagnosis is essential to initiate treatment but blood cultures are often negative; demonstration of the characteristic lesion and/or fungal elements on liver biopsy is crucial to establishing the diagnosis. The absence of fungal organisms within a granuloma does not rule out the disease, particularly when the patient has already received antifungal treatment.

Liver involvement by schistosoma is common in areas endemic for Schistosoma mansoni, Schistosoma japonicum, and Schistosoma mekongi; the main histopathologic findings consist of portal fibrosis and a granulomatous inflammation centered on schistosomal eggs. The granulomas consist of variable proportions of epithelioid cells and lymphocytes with numerous eosinophils (Fig. 19.12A); the latter are especially prominent in the early stages of the granulomatous response. Characteristic ova are usually found within the granulomas, but if absent (Fig. 19.12B), the combination of extensive portal fibrosis obliterating portal vein branches and granulomas with eosinophils is highly suggestive of the diagnosis (eSlide 18.7) (also discussed in Chapter 18). Visceral larva migrans is caused by larval forms of helminths for which humans are accidental hosts; the larvae do not develop into adult worms but instead migrate through host tissues, mainly of the liver and lungs. The most common agent is the larval form of Toxocara canis, but may also result from infection by Strongyloides stercoralis,64 Ascaris,65 and other round worms. The histologic picture comprises large epithelioid granulomas with geographic central necrosis and numerous eosinophils, the necrotizing eosinophilic granuloma (Fig. 19.13A).66 Charcot-Leyden crystals are often detected. Characteristically, the granulomas are centered on large bile ducts, destroying their walls (Fig. 19.13B) and in rare instances, the parasite may be detected within the inflamed bile duct. Parasitic infections are discussed in greater detail in Chapter 18.

Other Infectious Agents Many additional pathogens can lead to granulomatous inflammation in the liver, although frequently as an incidental finding superimposed on other histologic patterns. Cytomegalovirus (CMV) and 295

Practical Hepatic Pathology: A Diagnostic Approach

A

B Figure 19.12 Schistosomiasis. A, Portal granuloma with a rim of fibrosis, lymphocytes, and eosinophils. B, Portal granuloma with nonviable ova of Schistosoma mansoni (eSlide 18.7).

A Figure 19.14  Incidental lobular epithelioid granulomas in an otherwise typical case of hepatitis C virus.

B Figure 19.13  A, Eosinophil-rich palisading granuloma in Larva migrans infection. B, L. migrans granuloma destroying a bile duct wall.

296

EBV commonly develop microgranulomas and, rarely, an epithelioid granulomatous response. The same is true of rickettsial, chlamydial, and disseminated bacterial infections, in which ill-defined granulomas may be variably combined with other inflammatory lesions. Hepatic granulomas are neither characteristic nor frequent in cases of chronic hepatitis C, but have been recognized since routine serologic testing was introduced in 1991; their reported incidence is from 1.3%67 to 10%68 in needle biopsies, 8% in posttransplant liver biopsies,69 and up to 10% in explanted livers.70 Usually, a single or, at the most, a few, lobular or portal epithelioid granulomas are found in an otherwise histologically typical picture of chronic viral hepatitis (Fig. 19.14), apparently occurring more commonly in patients receiving interferon therapy.71 Similar isolated granulomas have been reported in up to 1.5% of chronic hepatitis B biopsies.72 As a result, the presence of granulomas in biopsies of patients with hepatitis B virus, or hepatitis C virus under treatment, is possibly

Hepatic Granulomas: Differential Diagnosis an incidental finding that does not warrant an extensive etiologic work-up for granulomatous diseases unless otherwise indicated clinically.71 Molecular Methods in Paraffin-Embedded Tissues for Detection of Microorganisms Polymerase chain reaction on paraffin-embedded liver tissue is potentially useful in identifying infectious causes of hepatic granulomas. In practical terms, this is commonly applied for specific diagnosis of M. tuberculosis as granulomas are often an incidental finding on biopsy and no tissue has been collected for culture, which remains the gold standard for diagnosis. Accuracy is variable in fixed tissues, but some commercially available tests approach sensitivity and specificity of 90% and more than 95%, respectively.5,73,74 Other rare causes of hepatic granulomas such as Bartonella henselae, Yersinia pseudotuberculosis, EBV, or CMV can be detected by molecular methods, although in a small number of cases.5

19

A

Sarcoidosis Sarcoidosis is a chronic, multisystemic, noncaseous, granulomatous disease of unknown origin that most commonly affects the lung but can involve almost any organ. Gastrointestinal tract involvement is rare; however, 60% to 90% of these cases show liver granulomas on biopsy. Liver involvement without lung disease is less frequent, documented in only about 13% of patients with systemic sarcoidosis.75 On the other hand, sarcoidosis is one of the most common causes of noncaseating hepatic granulomas. As in tuberculosis, liver involvement is usually asymptomatic, but hepatosplenomegaly, increased liver enzymes, intrahepatic cholestasis,76 and even portal hypertension77,78 as a consequence of fibrosis may be present. Fever correlates with hepatic manifestations of the disease and constitutes an additional indication for liver biopsy. Hepatic sarcoidosis is discussed in detail in Chapter 20. Pathology Granulomas in hepatic sarcoidosis are small in size and typically occur in the portal and periportal areas. They are usually numerous and are regularly distributed in the liver parenchyma, providing a histologic diagnosis in most cases. Sarcoid granulomas consist of very compact aggregates of epithelioid cells, sometimes with multinucleated giant cells and a sparse rim of lymphocytes (Fig. 19.15A) (eSlides 20.1 and 20.2). Reticulin fibers can be seen within the granulomas, especially in older lesions, when a prominent cuff of fibrosis may occur (Fig. 19.15B). Large confluent granulomas ultimately lead to hyalinized scar formation. Intrahepatic cholestasis is found in up to half of biopsy specimens, possibly because of progressive interlobular bile duct injury due to inflammatory infiltration of basement membranes and portal granuloma formation. This kind of granulomatous cholangitis is often seen in African Americans and Jamaicans and is sometimes difficult to differentiate from primary biliary cholangitis.

Drug-Induced Granulomas Drugs are increasingly identified as causes of hepatic granulomas with about 100 therapeutic and toxic substances being recorded as potential agents. A large review of hepatic granulomas incriminated drugs as a likely etiologic factor in up to 29% of cases.79 However, this may well be an underestimate because liver biopsy is not routinely performed in patients with drug reactions characterized by nonspecific liver dysfunction following a short period of drug ingestion. In addition, there have recently been reports of hepatic granulomas induced by drugs that had not previously been considered

B Figure 19.15  A, Large, compact epithelioid granulomas surrounded by dense fibrosis are very typical of liver involvement of sarcoidosis. B, These granulomas are rich in reticulin fibers (also see eSlides 20.1 and 20.2).

causal; therefore, many more drugs may potentially play a role in the development of hepatic granuloma than have been recognized so far. Pathology Granulomatous injury is an idiosyncratic delayed hypersensitivity reaction and therefore may be associated with other manifestations of hypersensitivity, such as rashes or autoimmune phenomena.80 In general, drug-induced granulomas are almost always nonnecrotizing and may be well or poorly formed. Although highly variable, eosinophils are prominent in the early granulomatous drug-induced reaction in many cases and are frequently accompanied by plasma cells and lymphocytes (Fig. 19.16A). On the other hand, except for parasitic infections, eosinophils are rare or absent in the other, more common causes of hepatic granulomas such as tuberculosis or sarcoidosis; therefore, when present in significant numbers, eosinophils mitigate strongly against these diagnoses. Another useful clue is the presence of a significant degree of parenchymal injury accompanying the granulomatous reaction, which is frequent in drug-induced injury but rarely seen in other conditions (Fig. 19.16B) (eSlide 19.7).2 Table 19.381-120 lists some of the more common drugs associated with the presence of hepatic granulomas.

297

Practical Hepatic Pathology: A Diagnostic Approach Table 19.3  Drugs Frequently Associated with Hepatic Granulomas

A

B Figure 19.16  A, Lobular granuloma with eosinophils in a drug-induced lesion. B, Multiple lobular granulomas combined with parenchymal injury is a clue to drug injury (see eSlide 19.7).

Diagnosis The principles of diagnosis are the same as applied to other forms of druginduced liver injury as discussed in Chapter 23. Exclusion of other causes of granulomatous inflammation, especially infectious agents, is vital.

Neoplasia-Associated Granulomas Granulomas have been reported in association with many benign and malignant neoplasms. This includes primary and metastatic neoplasms ranging from leukemias and gastrointestinal carcinomas to hepatocellular carcinomas and hepatocellular adenomas.121-124 The highest incidence is with Hodgkin disease, in which granulomas are present in 8% to 17% of liver biopsies (eSlide 19.8).

Idiopathic Hepatic Granulomas In spite of all histologic criteria and currently available ancillary techniques, up to 36% of patients with hepatic granulomas remain without etiologic diagnosis.5 These patients may present with nonspecific features as anorexia, weight loss, and fever or the granulomas may appear as an incidental finding in a liver biopsy with other clear-cut diseases. When patients are kept under regular medical review, a more precise diagnosis is achieved during follow up in a substantial number of cases.3,125 Clinical wisdom must rely on the

298

Drug

References

Additional Histologic Findings

Acetaminophen

81

Cholestatic hepatitis Lobular hepatitis with spotty or extensive necrosis

Albendazole

127

Portal inflammation with interface hepatitis

Allopurinol

82-85

Sporadically reported: bile duct lesion; ductopenia; fibrin-ring granulomas

Amoxicillin-clavulanic acid

86-88

Cholestatic hepatitis; eosinophils, destructive cholangiopathy

Carbamazepine

89-91

Bile duct injury and eosinophils in portal tracts

Chlorpromazine

92

—

Copper sulfate

93

Inclusions of copper in granulomas

Diltiazem

94,95

Lobular hepatitis

Diphenylhydantoin

96

Hepatocellular injury and vasculitis

Glyburide

97

Necrotizing granuloma; hepatitis

Halothane

98,99

Lobular hepatitis

Hydralazine

100

—

Mebendazole

101

—

Methyldopa

102-104

Eosinophils

Mesalamine

105

—

Norfloxacin

106

Necrotizing granuloma

Oral contraceptives

107

Liver adenoma

Phenylbutazone

108,109

Minor hepatocellular injury and cholestatic hepatitis

Phenytoin

110,111

Vasculitis

Pyrazinamide

112

—

Quinidine

113-115

—

Quinine

116-119

Vasculitis

Rosiglitazone

120

—

concept that patients with persisting idiopathic hepatic granulomas are more likely to be suffering from unusual manifestations of a common disorder than from an obscure disease.126 As an example, liver granulomas in tuberculosis often do not have central necrosis and acid-fast bacilli are demonstrable in only a small percentage of cases on appropriate special stains; in this situation, when clinical suspicion for tuberculosis is strong, it is prudent to acquire a second liver biopsy specimen for culture or consider a trial of therapy for tuberculosis. Suggested Readings Amarapurkar A, Agrawal V. Liver involvement in tuberculosis—an autopsy study. Trop Gastroenterol. 2006;27:69–74. Denk H, Scheuer PJ, Baptista A, et al. Guidelines for the diagnosis and interpretation of hepatic granulomas. Histopathology. 1994;25:209–218. Drebber U, et al. Hepatic granulomas: histological and molecular pathological approach to differential diagnosis—a study of 442 cases. Liver Int. 2008;28:828–834. Devaney K, Goodman ZD, Epstein MS, et al. Hepatic sarcoidosis. Clinicopathologic features in 100 patients. Am J Surg Pathol. 1993;17:1227–1280. Kleiner DE. Granulomas in the liver. Semin Diagn Pathol. 2006;23:161–169. Lamps LW. Hepatic granulomas, with an emphasis on infectious causes. Adv Anat Pathol. 2008;15:309–318.

Hepatic Granulomas: Differential Diagnosis References 1. Majno G, Joris I. Chronic inflammation, in cells, tissues and disease, G.M.I. New York: Oxford University Press; 2004. 2. Kleiner DE. Granulomas in the liver. Semin Diagn Pathol. 2006;23:161–169. 3. Guckian JC, Perry JE. Granulomatous hepatitis. An analysis of 63 cases and review of the literature. Ann Intern Med. 1966;65:1081–1100. 4. Satti MB, al-Freihi H, Ibrahim EM, et al. Hepatic granuloma in Saudi Arabia: a clinicopathological study of 59 cases. Am J Gastroenterol. 1990;85:669–674. 5. Drebber U, Kasper HU, Ratering J, et al. Hepatic granulomas: histological and molecular pathological approach to differential diagnosis-a study of 442 cases. Liver Int. 2008;28:828–834. 6. Dourakis SP, Saramadou R, Alexopoulou A, et al. Hepatic granulomas: a 6-year experience in a single center in Greece. Eur J Gastroenterol Hepatol. 2007;19:101–104. 7. Gaya DR, Thorburn D, Oien KA, Morris AJ, Stanley AJ. Hepatic granulomas: a 10 year single centre experience. J Clin Pathol. 2003;56:850–853. 8. Mert A, Ozaras R, Bilir M, et al. The etiology of hepatic granulomas. J Clin Gastroenterol. 2001;32:275–276. 9. Geramizadeh B, Jahangiri R, Moradi E. Causes of hepatic granuloma: a 12-year single center experience from southern Iran. Arch Iran Med. 2011;14:288–289. 10. Sahin M, Yılmaz G, Arhan M, Sen I. Hepatic granulomas in Turkey: a 6-year clinicopathological study of 35 cases. Turk J Gastroenterol. 2014;25:524–528. 11. Lamps LW. Hepatic Granulomas: a review with emphasis on infectious causes. Arch Pathol Lab Med. 2015;139:867–875. 12. Denk H, Scheuer PJ, Baptista A, et al. Guidelines for the diagnosis and interpretation of hepatic granulomas. Histopathology. 1994;25:209–218. 13. Worthington MG, O’Donnell KF, Dowling JJ, Murphy T, Whitmore EL. Granulomatous hepatitis in Yersinia enterocolitica bacteraemia. J Infect. 1984;9:170–173. 14. Johnson TL, Barnett JL, Appelman HD, Nostrant T. Candida hepatitis. Histopathologic diagnosis. Am J Surg Pathol. 1988;12:716–720. 15. Barrera L, Alvarez J, Tapias M, Idrovo V, López R. Granulomatous hepatitis secondary to histoplasma infection after treatment with infliximab. Case Reports Hepatol. 2013;2013:807537. 16. Ferrell LD, Lee R, Brixko C, et al. Hepatic granulomas following liver transplantation. Clinicopathologic features in 42 patients. Transplantation. 1995;60:926–933. 17. Petersen P, Christoffersen P. Ultrastructure of lipogranulomas in human fatty liver. Acta Pathol Microbiol Scand. 1979;87:45–49. 18. Morita Y, Ueno T, Sasaki N, et al. Comparison of liver histology between patients with nonalcoholic steatohepatitis and patients with alcoholic steatohepatitis in Japan. Alcohol Clin Exp Res. 2005;29(suppl 12):277S–281S. 19. Miller MJ, Lonardo EC, Greer RD, et al. Variable responses of species and strains to white mineral oils and paraffin waxes. Regul Toxicol Pharmacol. 1996;23:55–68. 20. Fleming KA, Zimmerman H, Shubik P. Granulomas in the livers of humans and Fischer rats associated with the ingestion of mineral hydrocarbons: a comparison. Regul Toxicol Pharmacol. 1998;27:75–81. 21. Ponz E, Ishii M, Nagura H, et al. Hepatic fibrin-ring granulomas in a patient with hepatitis A. Gastroenterology. 1991;100:268–270. 22. Glazer E, Ejaz A, Coley 2nd CJ, Bednarek K, Theise ND. Fibrin ring granuloma in chronic hepatitis C: virus-related vasculitis and/or immune complex disease? Semin Liver Dis. 2007;27:227–230. 23. Moreno A, Marazuela M, Yebra M, et al. Hepatic fibrin-ring granulomas in visceral leishmaniasis. Gastroenterology. 1988;95:1123–1126. 24. Stricker BH, Blok AP, Babany G, Benhamou JP. Fibrin ring granulomas and allopurinol. Gastroenterology. 1989;96:1199–1203. 25. Lobdell DH. ‘Ring’ granulomas in cytomegalovirus hepatitis. Arch Pathol Lab Med. 1987;111:881–882. 26. Nenert M, Mavier P, Dubuc N, Deforges L, Zafrani ES. Epstein-Barr virus infection and hepatic fibrin-ring granulomas. Hum Pathol. 1988;19:608–610. 27. Raya Sanchez JM, Argüelles HA, Brito Barroso ML, Nieto LH. Bone marrow fibrin-ring (doughnut) granulomas and peripheral T-cell lymphoma: an exceptional association. Haematologica. 2001;86:112. 28. de Bayser L, Roblot P, Ramassamy A, Silvain C, Levillain P, Becq-Giraudon B. Hepatic fibrinring granulomas in giant cell arteritis. Gastroenterology. 1993;105:272–273. 29. Marazuela M, Moreno A, Yebra M, Cerezo E, Gómez-Gesto C, Vargas JA. Hepatic fibrin-ring granulomas: a clinicopathologic study of 23 patients. Hum Pathol. 1991;22:607–613. 30. Veiga Gonzalez M, Riestra Martínez M, Fresno Forcelledo M, et al. Miliary tuberculosis. Autopsy study of 29 cases. An Med Interna. 1995;12:17–20. 31. Leader SA. Tuberculosis of the liver and gall-bladder with abscess formation: a review and case report. Ann Intern Med. 1952;37(3):594–606. 32. Rahmatulla RH, al-Mofleh IA, al-Rashed RS, al-Hedaithy MA, Mayet IY. Tuberculous liver abscess: a case report and review of literature. Eur J Gastroenterol Hepatol. 2001;13:437–440. 33. Xing X, Li H, Liu WG. Hepatic segmentectomy for treatment of hepatic tuberculous pseudotumor. Hepatobiliary Pancreat Dis Int. 2005;4:565–568. 34. Levine C. Primary macronodular hepatic tuberculosis: US and CT appearances. Gastrointest Radiol. 1990;15:307–309. 35. Fernandes JD, Nebesar R, Wall S, Minihan P. Report of tuberculous hepatitis presenting as metastatic disease. Clin Nucl Med. 1984;9:345–347.

36. Aggarwal S, Guleria S, Hussain T. Biliary stricture due to tuberculosis of the common bile duct. Trop Gastroenterol. 2001;22:28–29. 37. Behera A, Kochhar R, Dhavan S, Aggarwal S, Singh K. Isolated common bile duct tuberculosis mimicking malignant obstruction. Am J Gastroenterol. 1997;92:2122–2123. 38. Alvarez SZ. Hepatobiliary tuberculosis. J Gastroenterol Hepatol. 1998;13:833–839. 39. Park JI. Primary hepatic tuberculosis mimicking intrahepatic cholangiocarcinoma: report of two cases. Ann Surg Treat Res. 2015;89:98–101. 40. Hung YM, Huang NC, Wang JS, Wann SR. Isolated hepatic tuberculosis mimicking liver tumors in a dialysis patient. Hemodial Int. 2015;19:344–346. 41. Amarapurkar A, Agrawal V. Liver involvement in tuberculosis—an autopsy study. Trop Gastroenterol. 2006;27:69–74. 42. Alcantara-Payawal DE, Matsumura M, Shiratori Y, et al. Direct detection of Mycobacterium tuberculosis using polymerase chain reaction assay among patients with hepatic granuloma. J Hepatol. 1997;27:620–627. 43. Diaz ML, Herrera T, Lopez-Vidal Y, et al. Polymerase chain reaction for the detection of Mycobacterium tuberculosis DNA in tissue and assessment of its utility in the diagnosis of hepatic granulomas. J Lab Clin Med. 1996;127:359–363. 44. Chen TS, Drutz DJ, Whelan GE. Hepatic granulomas in leprosy. Their relation to bacteremia. Arch Pathol Lab Med. 1976;100:182–185. 45. Karat AB, Job CK, Rao PS. Liver in leprosy: histological and biochemical findings. Br Med J. 1971;1:307–310. 46. Patnaik JK, Saha PK, Satpathy SK, Das BS, Bose TK. Hepatic morphology in reactional states of leprosy. Int J Lepr Other Mycobact Dis. 1989;57:499–505. 47. Barbosa Junior Ade A, Silva TC, Patel BN, Santos MI, Wakamatsu A, Alves VA. Demonstration of mycobacterial antigens in skin biopsies from suspected leprosy cases in the absence of bacilli. Pathol Res Pract. 1994;190:782–785. 48. Gaur S, Trayner E, Aish L, Weinstein R. Bronchus-associated lymphoid tissue lymphoma arising in a patient with bronchiectasis and chronic Mycobacterium avium infection. Am J Hematol. 2004;77:22–25. 49. Patel R, Roberts GD, Keating MR, Paya CV. Infections due to nontuberculous mycobacteria in kidney, heart, and liver transplant recipients. Clin Infect Dis. 1994;19:263–273. 50. Adal KA, Wispelwey B. Mycobacterium avium complex peritonitis in a patient with alcoholic liver disease. J Clin Gastroenterol. 1996;22:245–246. 51. Fernandez-Miranda C, Medina J, Palenque E, Martinez-Antonio E, Gonzalez-Gomez C. Peritonitis with Mycobacterium avium in a patient with hepatic cirrhosis. Am J Gastroenterol. 1993;88:615. 52. Bottger EC, Teske A, Kirschner P, et al. Disseminated “Mycobacterium genavense” infection in patients with AIDS. Lancet. 1992;340:76–80. 53. Smith MB, Molina CP, Schnadig VJ, Boyars MC, Aronson JF. Pathologic features of Mycobacterium kansasii infection in patients with acquired immunodeficiency syndrome. Arch Pathol Lab Med. 2003;127:554–560. 54. Akritidis N, Tzivras M, Delladetsima I, Stefanaki S, Moutsopoulos HM, Pappas G. The liver in brucellosis. Clin Gastroenterol Hepatol. 2007;5:1109–1112. 55. Cervantes F, Bruguera M, Carbonell J, Force L, Webb S. Liver disease in brucellosis. A clinical and pathological study of 40 cases. Postgrad Med J. 1982;58:346–350. 56. Raoul D, Marrie T. Q fever. Clin Infect Dis. 1995;20:489–495. 57. Fournier PE, Marrie TJ, Raoult D. Diagnosis of Q fever. J Clin Microbiol. 1998;36:1823–1834. 58. Pellegrin M, Delsol G, Auvergnat JC, et al. Granulomatous hepatitis in Q fever. Hum Pathol. 1980;11:51–57. 59. Watanabe A, Takahashi H. Diagnosis and treatment of Q fever: attempts to clarify current problems in Japan. J Infect Chemother. 2008;14:1–7. 60. Sallah S, Semelka RC, Wehbie R, Sallah W, Nguyen NP, Vos P. Hepatosplenic candidiasis in patients with acute leukaemia. Br J Haematol. 1999;106:697–701. 61. Shi SH, Lu AW, Shen Y, et al. Spectrum and risk factors for invasive candidiasis and nonCandida fungal infections after liver transplantation. Chin Med J (Engl). 2008;121:625–630. 62. Mora DJ, dos Santos CT, Silva-Vergara ML. Disseminated histoplasmosis in acquired immunodeficiency syndrome patients in Uberaba, MG, Brazil. Mycoses. 2008;51:136–140. 63. Oh YS, Lisker-Melman M, Korenblat KM, Zuckerman GR, Crippin JS. Disseminated histoplasmosis in a liver transplant recipient. Liver Transpl. 2006;12:677–681. 64. Doeglas HM, ten Berg JA. Larva currens (migrans) caused by Strongyloides stercoralis. Dermatologica. 1972;144:350–352. 65. Sakakibara A, Baba K, Niwa S, et al. Visceral larva migrans due to Ascaris suum which presented with eosinophilic pneumonia and multiple intra-hepatic lesions with severe eosinophil infiltration—outbreak in a Japanese area other than Kyushu. Intern Med. 2002;41:574–579. 66. Kaplan KJ, Goodman ZD, Ishak KG. Eosinophilic granuloma of the liver: a characteristic lesion with relationship to visceral larva migrans. Am J Surg Pathol. 2001;25:1316–1321. 67. Ozaras R, Tahan V, Mert A, et al. The prevalence of hepatic granulomas in chronic hepatitis C. J Clin Gastroenterol. 2004;38:449–452. 68. Goldin RD, Levine TS, Foster GR, Thomas HC. Granulomas and hepatitis C. Histopathology. 1996;28:265–267. 69. Vakiani E, Hunt KK, Mazziotta RM, et al. Hepatitis C-associated granulomas after liver transplantation: morphologic spectrum and clinical implications. Am J Clin Pathol. 2007;127:128–134. 70. Emile JF, Sebagh M, Féray C, David F, Reynès M. The presence of epithelioid granulomas in hepatitis C virus-related cirrhosis. Hum Pathol. 1993;24:1095–1097.

19

299

Practical Hepatic Pathology: A Diagnostic Approach 71. Fiel MI, Shukla D, Saraf N, Xu R, Schiano TD. Development of hepatic granulomas in patients receiving pegylated interferon therapy for recurrent hepatitis C virus post liver transplantation. Transpl Infect Dis. 2008;10:184–189. 72. Tahan V, Ozaras R, Lacevic N, et al. Prevalence of hepatic granulomas in chronic hepatitis B. Dig Dis Sci. 2004;49:1575–1577. 73. Seo AN, Park HJ, Lee HS, et al. Performance characteristics of nested polymerase chain reaction vs real-time polymerase chain reaction methods for detecting Mycobacterium tuberculosis complex in paraffin-embedded human tissues. Am J Clin Pathol. 2014;142:384–390. 74. Drews SJ, Eshaghi A, Pyskir D, et al. The relative test performance characteristics of two commercial assays for the detection of Mycobacterium tuberculosis complex in paraffin-fixed human biopsy specimens. Diagn Pathol. 2008;3:37. 75. Harder H, Büchler MW, Fröhlich B, et al. Extrapulmonary sarcoidosis of liver and pancreas: a case report and review of literature. World J Gastroenterol. 2007;13:2504–2509. 76. Pereira-Lima J, Schaffner F. Chronic cholestasis in hepatic sarcoidosis with clinical features resembling primary biliary cirrhosis. Report of two cases. Am J Med. 1987;83:144–148. 77. Deniz K, Ward SC, Rosen A, Grewal P, Xu R. Budd-Chiari syndrome in sarcoidosis involving liver. Liver Int. 2008;28:580–581. 78. Moreno-Merlo F, Wanless IR, Shimamatsu K, Sherman M, Greig P, Chiasson D. The role of granulomatous phlebitis and thrombosis in the pathogenesis of cirrhosis and portal hypertension in sarcoidosis. Hepatology. 1997;26:554–560. 79.  McMaster 3rd KR, Hennigar GR. Drug-induced granulomatous hepatitis. Lab Invest. 1981;44:61–73. 80. Ishak KG, Zimmerman HJ. Drug-induced and toxic granulomatous hepatitis. Baillieres Clin Gastroenterol. 1988;2:463–480. 81. Lindgren A, Aldenborg F, Norkrans G, Olaison L, Olsson R. Paracetamol-induced cholestatic and granulomatous liver injuries. J Intern Med. 1997;241:435–439. 82. Swank LA, Chejfec G, Nemchausky BA. Allopurinol-induced granulomatoushepatitis with cholangitis and a sarcoid-like reaction. Arch Intern Med. 1978;138:997–998. 83. Tam S, Carroll W. Allopurinol hepatotoxicity. Am J Med. 1989;86:357–358. 84. Yoon JY, Min SY, Park JY, et al. A case of allopurinol-induced granulomatous hepatitis with ductopenia and cholestasis. Korean J Hepatol. 2008;14:97–101. 85. Chawla SK, Patel HD, Parrino GR, Soterakis J, Lopresti PA, D’Angelo WA. Allopurinol hepatotoxicity. Case report and literature review. Arthritis Rheum. 1977;20:1546–1549. 86. Silvain C, Fort E, Levillain P, Labat-Labourdette J, Beauchant M. Granulomatous hepatitis due to combination of amoxicillin and clavulanic acid. Dig Dis Sci. 1992;37:150–152. 87. Ryley NG, Fleming KA, Chapman RW. Focal destructive cholangiopathy associated with amoxycillin/clavulanic acid (Augmentin). J Hepatol. 1995;23:278–282. 88. Larrey D, Vial T, Micaleff A, et al. Hepatitis associated with amoxycillin-clavulanic acid combination—report of 15 cases. Gut. 1992;33:368–371. 89. Rodríguez Hernández H, Dehesa Violante M, Vega Ramos B, Méndez Gutiérrez TH. Granulomatous hepatitis secondary to ingestion of carbamazepine. Report of a case. Rev Gastroenterol Mex. 1989;54:239–241. 90. Soffer EE, Taylor RJ, Bertram PD, Haggitt RC, Levinson MJ. Carbamazepine-induced liver injury. South Med J. 1983;76:681–683. 91. Levander HG. Granulomatous hepatitis in a patient receiving carbamazepine. Acta Med Scand. 1980;208:333–335. 92. Ben-Yehuda A, Bloom A, Lijovetzky G, Flusser D, Tur-Kaspa R. Chlorpromazine-induced liver and bone marrow granulomas associated with agranulocytosis. Isr J Med Sci. 1990;26:449–451. 93. Pimentel JC, Menezes AP. Liver granulomas containing copper in vineyard sprayer’s lung. A new etiology of hepatic granulomatosis. Am Rev Respir Dis. 1975;111:189–195. 94. Toft E, Vyberg M, Therkelsen K. Diltiazem-induced granulomatous hepatitis. Histopathology. 1991;18:474–475. 95. Sarachek NS, London RL, Matulewocz TJ. Diltiazen and granulomatous hepatitis. Gastroenterology. 1985;88:1260–1262. 96. Mullick FG, Ishak KG. Hepatic injury associated with diphenylhydantoin therapy. A clinicopathologic study of 20 cases. Am J Clin Pathol. 1980;74:442–452. 97. Saw D, Pitman E, Maung M, Savasatit P, Wasserman D, Yeung CK. Granulomatous hepatitis associated with glyburide. Dig Dis Sci. 1996;41:322–325. 98. Shah IA, Brandt H. Halothane-associated granulomatous hepatitis. Digestion. 1983;28: 245–249.

300

99. Dordal E, Glagov S, Orlando RA, Platz C. Fatal halothane hepatitis with transient granuloma. N Engl J Med. 1970;283:357–359. 100. Jori GP, Peschile C. Hydralazine disease associated with transient granulomas in the liver. A case report. Gastroenterology. 1973;64:1163–1167. 101. Colle I, Naegels S, Hoorens A, Hautekeete M. Granulomatous hepatitis due to mebendazole. J Clin Gastroenterol. 1999;28:44–45. 102. Bezahler GH. Fatal methyldopa-associated granulomatous hepatitis and myocarditis. Am J Med Sci. 1982;283:41–45. 103. Miller Jr AC, Reid WM. Methyldopa-induced granulomatous hepatitis. JAMA. 1976;235: 2001–2002. 104. Mirada Canals A, Monteagudo Jimenez M, Sole Villa J, Rodriguez Moreno C. Methyldopainduced granulomatous hepatitis. DICP. 1991;25:1269–1270. 105. Braun M, Fraser GM, Kunin M, Salamon F, Tur-Kaspa R. Mesalamine-induced granulomatous hepatitis. Am J Gastroenterol. 1999;94:1973–1974. 106. Björnsson E, Olsson R, Remotti H. Norfloxacin-induced eosinophilic necrotizing granulomatous hepatitis. Am J Gastroenterol. 2000;95:3662–3664. 107. Malatjalian DA, Graham CH. Liver adenoma with granulomas. The appearance of granulomas in oral contraceptive-related hepatocellular adenoma and in the surrounding nontumorous liver. Arch Pathol Lab Med. 1982;106:244–246. 108. Benjamin SB, Ishak KG, Zimmerman HJ, Grushka A. Phenylbutazone liver injury: a clinicalpathologic survey of 23 cases and review of the literature. Hepatology. 1981;1:255–263. 109. Ishak KG, Kirchner JP, Dhar JK. Granulomas and cholestatic—hepatocellular injury associated with phenylbutazone. Report of two cases. Am J Dig Dis. 1977;22:611–617. 110. Gaffey CM, Chun B, Harvey JC, Manz HJ. Phenytoin-induced systemic granulomatous vasculitis. Arch Pathol Lab Med. 1986;110:131–135. 111. Cook IF, Shilkin KB, Reed WD. Phenytoin induced granulomatous hepatitis. Aust N Z J Med. 1981;11:539–541. 112. Knobel B, Buyanowsky G, Dan M, Zaidel L. Pyrazinamide-induced granulomatous hepatitis. J Clin Gastroenterol. 1997;24:264–266. 113. Bramlet DA, Posalaky Z, Olson R. Granulomatous hepatitis as a manifestation of quinidine hypersensitivity. Arch Intern Med. 1980;140:395–397. 114. Geltner D, Chajek T, Rubinger D, Levij IS. Quinidine hypersensitivity and liver involvement. A survey of 32 patients. Gastroenterology. 1976;70(5 Part 1):650–652. 115. Chajek T, Lehrer B, Geltner D, Levij IS. Quinidine-induced granulomatous hepatitis. Ann Intern Med. 1974;81:774–776. 116. Hou M, Horney E, Stockelberg D, Jacobsson S, Kutti J, Wadenvik H. Multiple quinine-dependent antibodies in a patient with episodic thrombocytopenia, neutropenia, lymphocytopenia, and granulomatous hepatitis. Blood. 1997;90:4806–4811. 117. Katz B, Weetch M, Chopra S. Quinine-induced granulomatous hepatitis. Br Med J(Clin Res Ed). 1983;286:264–265. 118. Mathur S, Dooley J, Scheuer PJ. Quinine induced granulomatous hepatitis and vasculitis. BMJ. 1990;300:613. 119. Nirodi NS. Quinine induced granulomatous hepatitis. Br Med J(Clin Res Ed). 1983;286:647. 120. Dhawan M, Agrawal R, Ravi J, et al. Rosiglitazone-induced granulomatous hepatitis. J Clin Gastroenterol. 2002;34:582–584. 121. Alirhayim Z, Dyal H, Alarhayem A, Donthireddy V. Non-Hodgkin’s lymphoma: a cause of paraneoplastic cholestasis. BMJ Case Rep. 2013. 122. Aderka D, Kraus M, Avidor I, Sidi Y, Weinberger A, Pinkhas J. Hodgkin’s and non-­Hodgkin’s lymphomas masquerading as “idiopathic” liver granulomas. Am J Gastroenterol. 1984;79:642–644. 123. Kazi KC, Deshpande R, Soman R, Lala M, Shah S. Liver cell adenoma with co-existing hepatic granulomas in an HIV-positive patient. Indian J Gastroenterol. 2005;24:274–275. 124. Li T, Fan M, Shui R, Hu S, Zhang Y, Hu X. Pathology-confirmed granuloma mimicking liver metastasis of breast cancer. Int J Biol Markers. 2014;24(29):e93–e97. 125. Cunnigham D, Mills PR, Quiqley EM, et al. Hepatic granulomas: experience over a 10-year period in the west of Scotland. Q J Med. 1982;51:162–170. 126. Mills PR, Russell RI. Diagnosis of hepatic granulomas: a review. J R Soc Med. 1983;76:393–397. 127. Marin Zuluaga JI, Marin Castro AE, Perez Cadavid JC, Restrepo Gutierrez JC. Albendazoleinduced granulomatous hepatitis: a case report. J Med Case Rep. 2013;26(7):201.

20 Hepatic Sarcoidosis Arief Antonius Suriawinata, MD

Incidence and Demographics  301 Clinical Manifestations  301 Radiologic Features  302 Microscopic Pathology  302 Differential Diagnosis  304 Treatment and Prognosis  304

Sarcoidosis is a systemic granulomatous disease of unknown etiology that primarily affects the lungs and lymphoid tissues of the body. The term sarcoidosis stems from a case report by a Norwegian dermatologist, Caesar Boeck, who in describing “multiple benign sarkoid of the skin” coined the term for skin lesions that resembled sarcoma but were benign.1 Sarcoid liver disease was first described in detail by Maddrey and colleagues in 1970, when they reported 20 patients with known sarcoidosis who had hepatic granulomas and biochemical or clinical evidence of liver disease.2 Although a liver affected by sarcoidosis may contain up to 75 million granulomas,3 the vast majority of patients are asymptomatic or show only minimal biochemical hepatic dysfunction.4 When symptomatic, the clinical presentation can be very disparate as documented in several studies.2,5–8

Incidence and Demographics A population-based study of sarcoidosis in the United States reported an incidence of 5.9 per 100,000 person-years for men and 6.3 per 100,000 person-years for women.9 In the United States, the incidence is higher in African Americans,1,4 and the lifetime risk of sarcoidosis is estimated at 0.85% for Caucasians and 2.4% for African Americans.10 Most studies show a slight predilection in women.1 Although the disease may occur in any age group, sarcoidosis is a disease of young adults, with a peak incidence in the second and third decades of life.1,4–11 In Scandinavian countries and Japan, a second peak occurs in women older than 50 years.1 Liver involvement by sarcoidosis is common, and it follows lymph nodes and lungs in the frequency of involvement.8 It is estimated that liver biopsy specimens demonstrate granulomas in up to 90% of patients with systemic sarcoidosis.1,2 The reported incidence of liver

involvement varies in different series because of differing criteria used to define sarcoid liver disease. In a review of 10 series comprising slightly more than 1200 patients with sarcoidosis, liver involvement as determined by hepatomegaly was found in 21% of cases.4 A separate study of 125 patients found a 35% incidence of liver involvement, which was defined as abnormal liver tests in patients with known sarcoidosis.12 A 4% incidence of liver involvement was found among 500 patients with sarcoidosis when defined as presence of granulomas in the liver along with biochemical or clinical evidence of liver disease.2 Finally, an incidence of 11.5% was reported in a series of 736 patients with liver involvement being defined by a combination of clinical history, physical findings, and laboratory studies.11 Although a significant number of patients may have abnormal liver tests and even granulomas in the liver, symptomatic liver disease is consistently low in all series2,4,12,13 and is estimated to be below 5% in patients with sarcoidosis. A predilection for liver disease among African Americans has been reported in some studies2,11,12 but not in others.4 Sarcoidosis accounts for 8% to 22% of liver biopsies with granulomatous inflammation.14–17

Clinical Manifestations Liver involvement may be the first manifestation of sarcoidosis or may be discovered several years after the initial diagnosis. In one study, the mean time between the initial diagnosis of sarcoidosis and recognition of liver disease was reported to be 3.3 years.8 Pulmonary disease may be inactive at presentation of hepatic sarcoidosis, and therefore, a normal chest x-ray (pulmonary stage 0) does not exclude sarcoidosis. Hepatic sarcoidosis is clinically silent in the most cases and often overshadowed by involvement of other organ systems.5 When liver involvement does come to clinical attention, the presentation of the disease is highly variable.6 A large number of patients present with liver test abnormalities with or without hepatomegaly or splenomegaly. This has been attributed to inflammatory changes around the hepatic granulomas.2 In one study, there was a high association of male gender and splenomegaly with liver involvement by sarcoidosis. Splenomegaly in the absence of cirrhosis and portal hypertension reflects the propensity of sarcoidosis to involve lymphatic tissue.8 Chronic cholestasis with jaundice, abdominal pain, and elevated alkaline phosphatase levels may rarely occur in hepatic sarcoidosis, resembling primary biliary cholangitis or sclerosing cholangitis.2,5,18–22 Cirrhosis with portal hypertension and its complications is thought 301

Practical Hepatic Pathology: A Diagnostic Approach to manifest in about 1% of patients with sarcoidosis.2,6 When portal hypertension develops in the absence of cirrhosis, it is thought to be secondary to presinusoidal obstruction as the result of extensive portal tract granulomas, which may be superimposed by sinusoidal block because of fibrosis and/or as the result of nodular regenerative hyperplasia.7,23 Rare manifestations of liver sarcoidosis include extrahepatic biliary obstruction by large granulomatous lymph nodes24 and the Budd-Chiari syndrome25–28 resulting from obstruction of hepatic venous tributaries by granulomatous inflammation. Liver involvement may present with nonspecific symptoms such as fever and fatigue and is an important differential of fever of unknown origin. In a series of 30 patients who presented with fever of unknown origin and had granulomas on liver biopsy, 15 were subsequently found to have extrahepatic manifestations of sarcoidosis.29

Radiologic Features Imaging findings of hepatic sarcoidosis are nonspecific. Marked abdominal changes are uncommon on computed tomography, and although they correlate with disease activity, there is no correlation with pulmonary disease stage on chest x-ray.30 In one study, extensive abdominal adenopathy was seen in 10% of patients, and marked hepatomegaly and splenomegaly were seen in 8% and 6% of patients, respectively.30 Large coalescing granulomas with associated fibrosis may produce multiple nodular lesions mimicking metastatic disease. Similarly, extensive hepatic hilar involvement may mimic hilar cholangiocarcinoma. Radiologic findings of cirrhosis as a result of sarcoidosis do not differ appreciably from those caused by other diseases.31 Magnetic resonance imaging showed no characteristic signal intensity changes. In conclusion, no imaging modality allows for precise identification of hepatic sarcoidosis.

A

Microscopic Pathology Sarcoid granulomas occur diffusely throughout the liver but tend to be more frequent in the portal tracts or in the periportal area. They consist of a well-defined, compact/rounded aggregate of epithelioid histiocytes with occasional multinucleated giant cells surrounded by lymphocytes and macrophages with occasional plasma cells and eosinophils (Fig. 20.1A–B) (eSlide 20.1). Schaumann and asteroid bodies that are usually seen in pulmonary sarcoidosis are rarely found in hepatic sarcoidosis (Fig. 20.2). Central granular fibrinoid necrosis may occur, but true caseation is never found (Fig. 20.3). As the granulomas age, they undergo fibrosis, with formation of concentric layers of dense hyalinized collagen (Fig. 20.4). Special stain for reticulin demonstrates an abundance of reticulin fibers in older granulomas (Fig. 20.5). Multiple granulomas often coalesce to form conglomerates of granulomas and incite an extensive irregular fibrous scar. Nodular fibrous scars in the liver may represent remnants of this process. Different stages of the evolution of granulomas may be observed in the same liver. Significant fibrosis is usually not a feature of this disease. When present, fibrosis generally tends to be limited to portal areas and in relation to the presence of granulomas. Portal fibrosis, occlusion of the portal venules, and the resulting nodular regenerative hyperplasia are the basis of portal hypertension in the absence of true cirrhosis. Bridging fibrosis and even cirrhosis have however been recognized in hepatic sarcoidosis (Fig. 20.6) (eSlide 20.2). In addition to the dominant histologic findings of granulomas, hepatic sarcoidosis presents with three other histologic changes: necroinflammatory (hepatitis-like), biliary, and vascular changes. Hepatitis-like changes are the second most common pattern and include spotty parenchymal necrosis, presence of apoptotic bodies, portal inflammation, and interface hepatitis. Chronic nonspecific 302

B Figure 20.1  A, Sarcoid granuloma characterized by a well-defined, compact aggregate of epithelioid histiocytes with a rim of lymphocytes. There is no necrosis. B, A multinucleated giant cell is present (also see eSlide 20.1).

Figure 20.2  Asteroid body in a sarcoid granuloma (arrow).

Hepatic Sarcoidosis

20

Figure 20.6  Bridging fibrosis and cirrhosis related to the presence of coalescent fibrosing granulomas (trichrome stain). Figure 20.3  Foci of fibrinoid necrosis (arrows) in a sarcoid granuloma; there is no true caseation.

Figure 20.7  Sarcoid granuloma involving a bile duct (arrow), mimicking the florid duct lesion of primary biliary cholangitis. Figure 20.4  Older sarcoid granuloma surrounded by concentric fibrosis (trichrome stain).

Figure 20.5  Reticulin fibers in an older sarcoid granuloma (reticulin stain).

inflammatory infiltrate is predominantly periportal in location but may also involve the lobule with varying degrees of severity. Occasionally, isolated multinucleated giant cells may be found in the hepatic sinusoids of patients with sarcoidosis, even in the absence of sarcoid granulomas. Biliary changes manifest as ductopenia in up to 50% of cases with sarcoid granulomas.19–22 Bile duct damage may be seen in some portal tracts and may resemble the florid duct lesion of primary biliary cholangitis (Fig. 20.7). Granulomatous involvement of the bile ducts results in bile duct obliteration, which then gives rise to a primary sclerosing cholangitis-like histologic picture. Hepatic vascular changes, which occur in a relatively small number of patients, include sinusoidal dilatation, nodular regenerative hyperplasia, and Budd-Chiari syndrome. Obstruction of the intrahepatic vein branches and sinusoidal infiltration by granulomas are known to cause sinusoidal dilatation, whereas hepatocyte atrophy caused by the incomplete vascular occlusion of the portal venules may result in compensatory parenchymal hyperplasia. Four cases of Budd-Chiari syndrome in sarcoidosis have been reported to date.25–28 Extrinsic compression of the hepatic veins leading to vascular narrowing or thrombosis, or intrinsic granulomatous infiltration of the vascular wall 303

Practical Hepatic Pathology: A Diagnostic Approach (Fig. 20.8), were the suggested mechanisms for development of the Budd-Chiari syndrome in these cases. Finally, the diagnosis of sarcoidosis cannot be ascertained by histologic examination alone because similar lesions may be found in other granulomatous diseases (see the following Differential Diagnosis section).

Differential Diagnosis Although sarcoidosis is a common cause of hepatic granulomas, these lesions are almost always part of a systemic disease and the diagnosis is often one of exclusion. In addition, the importance of hepatic granulomas lies in the opportunity to diagnose the underlying disease. Thus

other granulomatous diseases, mainly systemic infections such as tuberculosis, should be excluded before treatment because long-standing corticosteroid administration, the mainstay of therapy in sarcoidosis, would be deleterious in an infection.32 Other causes of granuloma formation in the liver include infectious diseases (tuberculosis, viral and fungal infection), schistosomiasis, immunologic disorders (­primary biliary cholangitis), and drug reactions (Table 20.1). Hepatic granulomatous inflammation due to causes other than sarcoidosis is discussed in detail in Chapter 19. Sarcoidosis is often associated with elevations in angiotensin-converting enzyme and serum calcium levels. Because hepatic sarcoidosis is clinically silent in most cases, elevated liver function tests leading to a liver biopsy in a patient with hepatic sarcoidosis may be caused by concurrent liver diseases such as drug-induced injury, fatty liver disease (Fig. 20.9) (eSlide 20.2), or other chronic liver diseases.

Treatment and Prognosis

Figure 20.8  A large tributary of the hepatic vein involved by sarcoidosis; granulomatous inflammation with multinucleated giant cells (arrows) is noted. (Courtesy Swan Thung, MD, Professor of Pathology, Mount Sinai School of Medicine, New York.)

Sarcoidosis can cause end-stage chronic liver disease, which is often unrecognized until examination of the explanted liver. A variety of immunosuppressive agents have been used, such as corticosteroids, azathioprine, cyclosporine, and methotrexate, but response to these agents is variable and unpredictable.33 In addition, there is no evidence that corticosteroids prevent disease progression in asymptomatic patients.12 In advanced cases, liver transplantation represents the ultimate therapeutic option. In a recent study by Lipson and associates,34 0.3% of adult liver transplantations were performed for sarcoidosis. Graft and patient survival rates were comparable with those of patients transplanted for other diseases. Recurrent sarcoidosis has been seen as early as 8 months following transplantation in the engrafted liver.35 Cyclosporine and corticosteroids are useful for controlling disease activity but do not appear to prevent disease recurrence following transplantation.

Table 20.1  Differential Diagnoses of Common Causes of Hepatic Granulomas Conditions

Granuloma Characteristics

Location

Fibrosis

Sarcoidosis

Noncaseating round, compact epithelioid granulomas with occasional multinucleated giant cells that may contain Schaumann bodies, asteroid bodies, or calcium oxalate crystals (eSlide 20.1)

More frequent in portal tracts than in hepatic lobules

Yes, with abundant reticulin Different stages of granuloma evolution and fibers and concentric layers fibrosis are seen simultaneously of dense hyalinized collagen around older granulomas

Tuberculosis

Caseating granulomas with Langhans’ giant cells, central Portal tracts and hepatic lobules necrosis, and caseation may be absent. Special stains for acid-fast bacilli are positive in less than 10% of cases. In AIDS patients, granulomas are poorly formed or entirely absent (eSlide 19.2)

No

All granulomas are at the same stage of development. In AIDS patients, Kupffer cells and portal macrophages may be filled with acid-fat bacilli

Drug reactions

Noncaseating granulomas; may be accompanied by lobular or cholestatic hepatitis (eSlide 19.7)

Portal tracts and hepatic lobules

No

Associated with sulfonamides, allopurinol, carbamazepine, quinine, and phenylbutazone

Primary biliary cholangitis

Poorly defined noncaseating granulomas. Giant cells are usually absent (eSlide 26.1)

Predominantly in portal tracts, cen- No tered around or adjacent to bile ducts with epithelial damage

Granulomas are more readily seen in early stages (stage 1 and 2) of the disease than in late ones

Schistosomiasis

Granulomas with eosinophils, multinucleated giant cells, and fibrosis. Multiple sections may be needed to find ova and lateral spine of Schistosoma mansoni or the spherical ova of Schistosoma japonicum (eSlide 18.7)

Portal tracts and often associated with portal fibrosis

Yes

Kupffer cells and portal macrophages may contain fine, brown to black, iron-negative pigment

Lipogranuloma

Not a true granuloma because epithelioid cells are usually absent (Fig 1.34D)

Lobules, particularly adjacent to central venules; and portal tracts

Yes, focal

Little diagnostic or prognostic significance

Hepatitis C– associated granuloma

Noncaseating small round/compact epithelioid granuloma. No multinucleated giant cell or rim of chronic inflammatory cells. Usually solitary granuloma in a biopsy

Lobules

No

No diagnostic or prognostic significance. Usually seen in patients receiving pegylated interferon

AIDS, Acquired immunodeficiency syndrome.

304

Other Findings

Hepatic Sarcoidosis

Figure 20.9  Biopsy from a patient with suspected fatty liver disease shows steatohepatitis and incidental sarcoidosis (eSlide 20.2). Suggested Readings Alam I, Levenson SD, Ferrell LD, et al. Diffuse intrahepatic biliary strictures in sarcoidosis resembling sclerosing cholangitis. Case report and review of the literature. Dig Dis Sci. 1997;42:1295–1301. Deniz K, Ward SC, Rosen A, et al. Budd-Chiari syndrome in sarcoidosis involving liver. Liver Int. 2008;28:580–581. James DG, Sherlock S. Sarcoidosis of the liver. Sarcoidosis. 1994;11:2–6. Kahi CJ, Saxena R, Temkit M, et al. Hepatobiliary disease in sarcoidosis. Sarcoidosis Vase Diffuse Lung Dis. 2006;23:117–123. Pereira-Lima J, Schaffner F. Chronic cholestasis in hepatic sarcoidosis with clinical features resembling primary biliary cirrhosis. Report of two cases. Am J Med. 1987;83:144–148.

References 1. Statement on sarcoidosis. Joint Statement of the American Thoracic Society (ATS), the European Respiratory Society (ERS), and the World Association of Sarcoidosis and Other Granulomatous Disorders (WASOG) adopted by the ATS Board of Directors and by the ERS Executive Committee, February 1999. Am J Respir Crit Care Med. 1999;160:736–755. 2. Maddrey WC, Johns CJ, Boitnott JK, et al. Sarcoidosis and chronic hepatic disease: a clinical and pathologic study of 20 patients. Medicine (Baltimore). 1970;49:375–395. 3. Klatskin G. Hepatic granulomata: problems in interpretation. Mt Sinai J Med. 1977;44: 798–812. 4. Mayock RL, Bertrand P, Morrison CE, et al. Manifestations of sarcoidosis. Analysis of 145 patients, with a review of nine series selected from the literature. Am J Med. 1963;35:67–89. 5. Bass NM, Burroughs AK, Scheuer PJ, et al. Chronic intrahepatic cholestasis due to sarcoidosis. Gut. 1982;23:417–421. 6. Blich M, Edoute Y. Clinical manifestations of sarcoid liver disease. J Gastroenterol Hepatol. 2004;19:732–737. 7. Devaney K, Goodman ZD, Epstein MS, et al. Hepatic sarcoidosis. Clinicopathologic features in 100 patients. Am J Surg Pathol. 1993;17:1272–1280. 8. Kahi CJ, Saxena R, Temkit M, et al. Hepatobiliary disease in sarcoidosis. Sarcoidosis Vase Diffuse Lung Dis. 2006;23:117–123.

9. Henke CE, Henke G, Elveback LR, et al. The epidemiology of sarcoidosis in Rochester, Minnesota: a population-based study of incidence and survival. Am J Epidemiol. 1986;123:840–845. 10. Rybicki BA, Major M, Popovich Jr J, et al. Racial differences in sarcoidosis incidence: a 5-year study in a health maintenance organization. Am J Epidemiol. 1997;145:234–241. 11. Baughman RP, Teirstein AS, Judson MA, et al. Clinical characteristics of patients in a case control study of sarcoidosis. Am J Respir Crit Care Med. 2001;164:1885–1889. 12. Vatti R, Sharma OP. Course of asymptomatic liver involvement in sarcoidosis: role of therapy in selected cases. Sarcoidosis Vasc Diffuse Lung Dis. 1997;14:73–76. 13. Lynch III JP, Sharma OP, Baughman RP. Extrapulmonary sarcoidosis. Semin Respir Infect. 1998;13:229–254. 14. Dourakis SP, Saramadou R, Alexopoulou A, et al. Hepatic granulomas: a 6-year experience in a single center in Greece. Eur J Gastroenterol Hepatol. 2007;19:101–104. 15. Gaya DR, Thorburn D, Oien KA, et al. Hepatic granulomas: a 10-year single centre experience. J Clin Pathol. 2003;56:850–853. 16. McCluggage WG, Sloan JM. Hepatic granulomas in Northern Ireland: a thirteen-year review. Histopathology. 1994;25:219–228. 17. Sartin JS, Walker RC. Granulomatous hepatitis: a retrospective review of 88 cases at the Mayo Clinic. Mayo Clin Proc. 1991;66:914–918. 18. Alam I, Levenson SD, Ferrell LD, et al. Diffuse intrahepatic biliary strictures in sarcoidosis resembling sclerosing cholangitis. Case report and review of the literature. Dig Dis Sci. 1997;42:1295–1301. 19. Murphy JR, Sjogren MH, Kikendall JW, et al. Small bile duct abnormalities in sarcoidosis. J Clin Gastroenterol. 1990;12:555–561. 20. Nakanuma Y, Kouda W, Harada K, et al. Hepatic sarcoidosis with vanishing bile duct syndrome, cirrhosis, and portal phlebosclerosis. Report of an autopsy case. J Clin Gastroenterol. 2001;32:181–184. 21. Pereira-Lima J, Schaffner F. Chronic cholestasis in hepatic sarcoidosis with clinical features resembling primary biliary cirrhosis. Report of two cases. Am J Med. 1987;83:144–148. 22. Rudzki C, Ishak KG, Zimmerman HJ. Chronic intrahepatic cholestasis of sarcoidosis. Am J Med. 1975;59:373–387. 23. Kakar S, Kamath PS, Burgart L J. Sinusoidal dilatation and congestion in liver biopsy: is it always due to venous outflow impairment? Arch Pathol Lab Med. 2004;128:901–904. 24. Rezeig MA, Fashir BM. Biliary tract obstruction due to sarcoidosis: a case report. Am J Gastroenterol. 1997;92:527–528. 25. Deniz K, Ward SC, Rosen A, et al. Budd-Chiari syndrome in sarcoidosis involving liver. Liver Int. 2008;28:580–581. 26. Melear JM, Goldstein RM, Levy MF, et al. Hematologic aspects of liver transplantation for Budd-Chiari syndrome with special reference to myeloproliferative disorders. Transplantation. 2002;74:1090–1095. 27. Nataline MR, Goyette RE, Owensby LC, et al. The Budd-Chiari syndrome in sarcoidosis. JAMA. 1978;239:2657–2658. 28. Russi EW, Bansky G, Pfaltz M, et al. Budd-Chiari syndrome in sarcoidosis. Am J Gastroenterol. 1986;81:71–75. 29. Israel HL, Goldstein RA. Hepatic granulomatosis and sarcoidosis. Ann Intern Med. 1973;79:669–678. 30. Warshauer DM, Dumbleton SA, Molina PL, et al. Abdominal CT findings in sarcoidosis: radiologic and clinical correlation. Radiology. 1994;192:93–98. 31. Mergo PJ, Ros PR, Buetow PC, et al. Diffuse disease of the liver: radiologic-pathologic correlation. Radiographies. 1994;14:1291–1307. 32. Karagiannidis A, Karavalaki M, Koulaouzidis A. Hepatic sarcoidosis. Ann Hepatol. 2006;5:251–256. 33. Kennedy PT, Zakaria N, Modawi SB, et al. Natural history of hepatic sarcoidosis and its response to treatment. Eur J Gastroenterol Hepatol. 2006;18:721–726. 34. Lipson EJ, Fiel MI, Florman SS, et al. Patient and graft outcomes following liver transplantation for sarcoidosis. Clin Transplant. 2005;19:487–491. 35. Cengiz C, Rodriguez-Davalos M, deBoccardo G, et al. Recurrent hepatic sarcoidosis post-liver transplantation manifesting with severe hypercalcemia: a case report and review of the literature. Liver Transpl. 2005;11:1611–1614.

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305

21 Autoimmune Hepatitis and Overlap Syndromes Lisa M. Yerian, MD

Definitions and Synonyms  309

Definitions and Synonyms

Incidence and Demographics  309

Autoimmune hepatitis (AIH) is a progressive, immune-mediated inflammatory liver disease characterized by a combination of clinical and laboratory findings and histologic evidence of hepatitis.1-5 Described more than 60 years ago as a persistent hepatitis of young women, autoimmune hepatitis has since been referred to as lupoid hepatitis, autoimmune or autoimmune-type chronic active hepatitis, lupus or plasma cell hepatitis, and active juvenile cirrhosis.6 AIH came to represent the prototype histologic pattern of liver injury termed chronic active hepatitis based on the characteristic finding of interface activity (or so-called “piecemeal necrosis”) that distinguished it from chronic persistent hepatitis. The benefit of immunosuppressive therapy was demonstrated in multiple studies in the 1960s and 1970s, and the disease became known as autoimmune hepatitis with solidification of the concept of autoimmunity.3,5-6 Disease presentation is highly variable, and the diagnosis should be considered in any patient with elevated liver enzymes or other evidence of acute or chronic liver disease, or graft dysfunction.1,5 The International Autoimmune Hepatitis Group published and later revised a detailed scoring system for establishing the diagnosis primarily for research purposes,7,8 and a simplified version for clinical use was put forth in 2008.9 These scoring systems and the principles therein have been widely adopted for use in the diagnosis of AIH before and after treatment. Although usually not required to establish a diagnosis of AIH in routine clinical practice, they are frequently used in research studies and can be clinically helpful in difficult cases. A minority of patients with classic features of AIH also exhibit objective evidence of primary biliary cholangitis (PBC) and/or primary sclerosing cholangitis (PSC).10 Recurrent and de novo forms of AIH are recognized to occur after liver transplantation.2

Clinical Manifestations  310 Laboratory Findings  310 Microscopic Pathology  310 Portal Changes and Interface Hepatitis  310 Lobular Inflammation and Damage  311 Cholestasis 312 Fibrosis 312 Overlap Syndromes  312 Overlap with Primary Biliary Cholangitis  312 Overlap with Primary Sclerosing Cholangitis  312 Grading and Staging of Autoimmune Hepatitis  313 Differential Diagnosis  313 Acute or Chronic Viral Hepatitis  314 Celiac Disease  314 Drug-Induced Liver Injury  314 Hereditary Metabolic Diseases  314 Primary Biliary Cholangitis  314 Genetics 314 Treatment and Prognosis  314 Abbreviations AIH autoimmune hepatitis AIH-PBC autoimmune hepatitis–primary biliary cholangitis AIH-PSC autoimmune hepatitis–primary sclerosing cholangitis ALT alanine aminotransferase ANA antinuclear antibodies AST serum asparate ASMA antismooth muscle antibodies GGT gamma-glutamyl transpeptidase HLA human leukocyte antigen IgG immunoglobulin G LKM1 liver-kidney microsomal type 1 antibodies PBC primary biliary cholangitis PSC primary sclerosing cholangitis

Incidence and Demographics AIH affects patients of both genders, all ethnicities, and all ages. The disease occurs more frequently in females, with a male-to-female ratio of approximately 1:3.6.2 Worldwide prevalence and incidence of AIH are unknown and appear to vary regionally, being more common in North America and Northern European populations than in Asia.6,11 The reported mean annual incidence of AIH ranges from 0.08 to 3.5 per 100,000 people per year in adult populations and 0.23 to 4 per 100,000 in pediatric populations.6,11,12 309

Practical Hepatic Pathology: A Diagnostic Approach

Clinical Manifestations

Portal Changes and Interface Hepatitis

The clinical manifestations of AIH are highly variable, ranging from insidious, asymptomatic disease to features of acute or chronic liver disease with or without cirrhosis, or even fulminant hepatic failure.2,3 Although 34% to 45% of patients are entirely asymptomatic at the time of diagnosis, many patients complain of nonspecific symptoms such as fatigue and arthralgias, or flulike symptoms (lethargy, nausea, anorexia, and/or abdominal pain).2,3 Jaundice may signify advanced chronic liver disease, an acute hepatitis picture, or the presence of hemolysis or other disease.3 Approximately one-third of patients have cirrhosis at the time of diagnosis and may exhibit complications of cirrhosis and portal hypertension.4 Many patients have manifestations of extrahepatic autoimmune diseases such as arthritis, thyroid disease, inflammatory bowel disease, diabetes, vasculitis, connective tissue disease, and others.2,3

The characteristic histologic picture of AIH is a chronic hepatitis, a histologic pattern of injury characterized by dense portal inflammatory cell infiltrates and portal-based fibrosis (Fig. 21.1 and eSlides 21.2 and 21.3).16 The degree of inflammation and hepatocyte injury may be severe, especially in untreated patients. The portal inflammatory cell infiltrates are typically dense and composed of lymphocytes, histiocytes, and plasma cells (Fig. 21.2); the latter component may be striking, with plasma cells aggregating in large clusters or sheets. However, plasma cells are not a constant nor pathognomonic feature of the disease; their absence does not exclude AIH and their presence does not exclude other diseases.16 In fact, moderate to severe plasma cell infiltration of portal tracts is only seen in two-thirds of patients with AIH.17 Interface hepatitis is often prominent in untreated patients and at presentation. Also termed interface activity, or “piecemeal necrosis,” interface hepatitis denotes the extension of portal inflammation beyond the limiting plate and into the adjacent lobule where it surrounds and injures periportal hepatocytes (Fig. 21.3). This inflammation and the resultant hepatocyte injury may extend deeply into the hepatic lobules and may even extend across

Laboratory Findings Laboratory testing is used to document features of AIH and exclude other potential causes of liver disease such as viral hepatitis, Wilson disease, and others. The characteristic laboratory findings in AIH include elevated transaminase (serum aspartate [AST] and alanine [ALT] aminotransferase) levels, increased serum immunoglobulin G (IgG) concentration, and detectable autoantibodies.1,2 Transaminases are consistently elevated in untreated AIH and normalize in most patients after conventional therapy.1 Polyclonal elevated serum globulin (particularly gamma globulin) levels are common, mainly because of elevated IgG. As nearly all patients exhibit elevated serum IgG levels at the time of diagnosis, detection of hypergammaglobulinemia can be particularly useful in patients in whom AIH is suspected but autoantibodies cannot be detected.1 In most patients antismooth muscle antibodies (ASMA), antinuclear antibodies (ANA), and/or antiliver/ kidney microsomal 1 antibodies (anti-LKM1) or other autoantibodies can be detected.1 However, ASMA and ANA are neither organ nor disease specific; either autoantibody can be present in other conditions including alcoholic liver disease, nonalcoholic fatty liver disease, PBC and PSC, and even viral hepatitis C, among others.1,4,5 Hepatitis C antibodies can be falsely positive in this population; confirmatory ribonucleic acid (RNA) testing is recommended in individuals with positive hepatitis C antibodies.13 Hyperbilirubinemia and alkaline phosphatase elevations may be seen but are usually less marked than the transaminase elevations.5 The mainly clinical designation of two types of AIH is based on autoantibody profiles.1,5 Type 1 AIH is more common and is characterized by the presence of serum ANA and/or ASMA. Type 2 AIH is much less common, is defined by detection of anti-LKM1 antibodies and/ or antiliver cytosol type 1 autoantibodies (LC-1) and tends to present at an earlier age, occurring nearly exclusively in female children and adolescents.3,11

Figure 21.1  Autoimmune hepatitis presents a chronic hepatitis pattern of injury, with portal-based inflammation and fibrosis.

Microscopic Pathology Liver biopsy is essential in the workup and management of patients for possible AIH.1,2,4 Histologic evaluation is used for diagnosis, therapeutic guidance, and exclusion of concurrent forms of liver disease or alternative diagnoses, some of which can present with similar clinical and laboratory findings.1,2 There are no pathognomonic histologic features of AIH.14,15 The histologic picture is variable among patients and in a given patient depending on its presentation, treatment, and disease evolution. The characteristic histologic features of inflammation and hepatocyte injury abate after immunosuppressive therapy in most patients (eSlide 21.1). Therefore, a posttreatment biopsy may not show typical AIH findings and may in fact be entirely normal. 310

Figure 21.2  Dense portal inflammatory cell infiltrates in autoimmune hepatitis composed of lymphocytes and plasma cells.

Autoimmune Hepatitis and Overlap Syndromes hepatic lobules from portal tracts to central veins as “bridging necrosis” (see later) (eSlide 21.3). Posttreatment biopsies often show a marked decline in both portal inflammation and extent of interface hepatitis. The bile ducts may show focal infiltration by lymphocytes in AIH; this feature does not exclude a diagnosis of AIH. However, definite bile duct destruction is not a feature of AIH and warrants consideration of primary biliary cholangitis, overlap syndrome, drug-induced liver injury, or other form of liver disease.

Lobular Inflammation and Damage Although portal inflammation and interface hepatitis are characteristic features of AIH, the hepatic lobules often also exhibit evidence of inflammation and injury. In mild cases the hepatic lobules contain only scattered foci of inflammation and hepatocyte injury. As in portal areas, the inflammation consists of lymphocytes, histiocytes, and often plasma cells. Kupffer cell hyperplasia may be prominent in areas of extensive hepatocyte injury, but granulomas are not a feature of AIH. As in the portal areas, plasma cells may be prominent but are not a required nor specific feature of AIH (Fig. 21.4).

Figure 21.3  Periportal interface activity is a characteristic feature and may be exuberant in autoimmune hepatitis (also see eSlides 21.2 and 21.3).

Figure 21.4  The lobular inflammatory cell infiltrates of autoimmune hepatitis are similar to portal infiltrates, composed of lymphocytes, histiocytes, and plasma cells, which may be numerous. The lobular inflammation is associated with diffuse hepatocyte swelling and numerous acidophil bodies (also see eSlide 21.2).

Hepatocyte injury is evidenced by hepatocyte swelling and necrosis. Individual necrotic hepatocytes, also known as acidophil bodies, are commonly seen. The frequency and size of these necroinflammatory foci increases with disease activity. In more severe cases they aggregate as larger areas of confluent hepatocyte necrosis and may extend across the acinus as areas of “bridging necrosis.” Centrilobular perivenular inflammation and necrosis can occur in association with the typical portal inflammation and interface hepatitis or, rarely, in isolation (Fig. 21.5).16,18 This appears to be a feature of more severe disease and is more commonly seen in patients with acute disease onset.18 Plasma cells again may be prominent in these centrilobular infiltrates, which are not specific for AIH and may be seen in drug-induced liver injury or vascular insults. In some patients, the lobular inflammation and injury outstrip that in the portal/periportal regions, presenting a pattern of injury more suggestive of an acute (lobular-predominant) hepatitis (Fig. 21.6), but some portal inflammation is nearly always present. Patients presenting with a clinical picture of acute hepatitis can show more diffuse hepatocyte injury with hepatocyte swelling and disruption of hepatocyte cords resulting in an overall picture “lobular disarray” similar

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Figure 21.5 Centrilobular, perivenular inflammation and necrosis (centrilobular “piecemeal necrosis”) can be seen in combination with portal and periportal hepatitis or as the predominant feature in autoimmune hepatitis.

Figure 21.6  Some patients with autoimmune hepatitis exhibit a lobular-predominant pattern of inflammation and injury, with necrotic hepatocytes and lobular disarray similar to that seen with acute hepatitis (see eSlide 21.2). 311

Practical Hepatic Pathology: A Diagnostic Approach to that seen in patients with acute viral hepatitis. The necrotic areas may extend between hepatic lobules (“bridging necrosis”) in severely affected patients (Fig. 21.7). Patients with fulminant AIH may show large areas of confluent hepatocyte necrosis with parenchymal collapse. In addition to the loss of hepatocytes and residual debris, close approximation of portal areas can be a helpful feature of extensive lobular injury and parenchymal collapse. When lobular hepatocyte injury is extensive, regenerative features with bile ductular proliferation or hepatocyte rosetting may be seen. Transformation of hepatocytes into syncytial multinucleated giant cells is seen in a minority of affected patients (Fig. 21.8). This histologic finding, also termed postinfantile giant cell hepatitis or syncytial giant cell hepatitis, is not specific to AIH and may represent an idiosyncratic response to hepatic injury.19 The extent of lobular inflammation and hepatocyte injury is usually markedly reduced or absent after treatment.

in those who experience a period of subclinical or asymptomatic chronic disease followed by an acute exacerbation. The cholestasis is hepatocellular and/or canalicular and is associated with lobular inflammation and features of lobular injury such as apoptotic hepatocytes and regenerative features. The characteristic portal and periportal inflammation and interface hepatitis are also present in these cases.

Cholestasis

Overlap Syndromes

Hepatocanalicular cholestasis may be seen. In some patients, a histologic picture of cholestatic hepatitis may predominate, particularly

A minority of patients with AIH also exhibit clinical, serologic, and histologic features of one or more other autoimmune liver disease such as PBC or PSC.4,10,20 In these “overlap” syndromes, the two diseases may present concurrently in an individual patient, or one may follow the other after a variable period. Standardized diagnostic criteria are lacking, and therefore reported prevalence of overlap syndromes remain controversial.4,20 In general, diagnosis requires clear, objective features of AIH in combination with those of PBC or PSC.10,20

Fibrosis Fibrosis is a frequent feature of AIH, typically present even at initial presentation. The pattern of fibrosis follows that described for other forms of chronic hepatitis. Fibrosis develops in the portal and periportal areas, extending to form bridging fibrous septa and ultimately, cirrhosis. Approximately 33% of patients have cirrhosis at the time of diagnosis.4

Overlap with Primary Biliary Cholangitis

Figure 21.7  In severe cases of autoimmune hepatitis, confluent areas of hepatocyte necrosis involve adjacent lobules. This finding is termed bridging necrosis (also see eSlide 21.3).

Autoimmune hepatitis–primary biliary cholangitis (AIH-PBC) overlap syndrome describes patients with clear clinical and histologic evidence of both AIH and PBC.20 Delineation of an overlap syndrome has proven difficult and controversial, as overlap exists in the clinical and histologic features of otherwise typical AIH and PBC (see eSlide 26.3). For example, mild lymphocytic infiltration of bile ducts and cholestatic features can be seen in AIH, and autoantibodies (ANA and ASMA) and plasma cells are detected in most patients with PBC. The presence of any of these features in isolation does not indicate the presence of an overlap syndrome. Diagnostic criteria are not standardized, but the European Association for the Study of Liver disease guidelines requires at least two of three specific criteria for each diagnosis, AIH and PBC, with interface hepatitis a mandatory feature.21 The criteria for AIH include alanine transaminase (ALT) levels at least five times the upper limit of normal, IgG levels at least twice the upper limit of normal or positive ASMA, and a liver biopsy with moderate or severe periportal or periseptal lymphocytic piecemeal necrosis. The criteria for PBC are: (1) alkaline phosphatase levels at least twice the upper limit of normal or gamma-glutamyl transpeptidase (GGT) levels at least five times the upper limit of normal; (2) positive AMA; and (3) liver biopsy showing a florid duct lesion. The pathologist’s role in the diagnosis AIH-PBC overlap syndrome lies in the confirmation or exclusion of the histologic features previously described; moderate to severe interface activity and florid duct lesions (Figs. 21.9 and 21.10), with or without granulomas. The AIHPBC overlap syndrome is also discussed in Chapter 26.

Overlap with Primary Sclerosing Cholangitis

Figure 21.8  Autoimmune hepatitis with numerous enlarged hepatocytes containing multiple nuclei. This feature is sometimes described as postinfantile giant cell hepatitis and is probably an indicator of hepatocyte injury that is not specific for any etiology. 312

Autoimmune hepatitis–primary sclerosing cholangitis (AIH-PSC) overlap syndrome is uncommon but recognized to occur, particularly in children, adolescents, and young adults with autoimmune liver disease.10 As in AIH-PBC overlap syndrome, the diagnosis requires the presence of codified diagnostic criteria for AIH, in addition to evidence of PSC on histology or cholangiography. The two diseases may

Autoimmune Hepatitis and Overlap Syndromes occur concurrently but are more often sequential in adults, with AIH presenting first with subsequent detection of PSC. Histologic features of AIH-PSC overlap syndrome include those of AIH combined with the “onion skin” lesion of periductal concentric fibrosis, although diagnosis of the PSC component is often based on cholangiography rather than identifying the histologic features of PSC on biopsy specimens (Figs. 21.11 and 21.12). The AIH-PSC overlap syndrome in children is discussed in Chapter 5.

Grading and Staging of Autoimmune Hepatitis The extent of inflammatory activity and fibrosis is reported in AIH with the same grading and staging schemes applied in other forms of chronic hepatitis. These schemes are discussed in detail in Chapter 16. One potential staging difficulty in AIH lies in the assessment of liver biopsies with extensive necrosis. Areas of confluent necrosis and hepatocyte dropout are evident as areas of pale, gray-blue staining on the trichrome stain (Fig. 21.13) and may be mistaken for fibrous

septa, leading to overstaging. This occurs because the reticulin framework remains and collapses after loss of the intervening hepatocytes. Although the reticulin fibers are composed primarily of type III collagen and appear paler blue on a trichrome stain than the predominantly type 1 collagen fibers of hepatic, this distinction may be subtle, causing diagnostic difficulty that may lead to overstaging.

21

Differential Diagnosis The clinical and histologic differential diagnosis for AIH varies with the disparate clinical and histologic pictures of AIH as described previously. Depending on the overall histologic picture, the histologic differential diagnosis may include other forms of acute or chronic hepatitis, or even causes of cholestatic liver disease.

Figure 21.11 Autoimmune hepatitis–primary sclerosing cholangitis overlap syndrome. Although the periductal “onion skin” fibrosis may not be seen in needle biopsies, other features of bile duct obstruction, including duct proliferation and neutrophilic response, may be present. Figure 21.9  Autoimmune hepatitis–primary biliary cholangitis overlap syndrome. This portal tract contains a dense lymphoplasmacytic inflammatory cell infiltrate associated with bile duct injury and granulomatous inflammation.

Figure 21.10 Autoimmune hepatitis–primary biliary cholangitis overlap syndrome (same case as Fig. 21.9). Other areas demonstrate periportal interface activity.

Figure 21.12 Autoimmune hepatitis–primary sclerosing cholangitis overlap syndrome. The presence of dense plasma cell infiltrates within portal tracts supports the overlap of autoimmune hepatitis in this patient with typical endoscopic retrograde cholangiopancreatography findings of primary sclerosing cholangitis. 313

Practical Hepatic Pathology: A Diagnostic Approach considered, particularly in younger patients, and can be excluded on the basis of clinical testing for serum ceruloplasmin levels and 24-hour urine copper, and by liver tissue copper quantitation. Alpha-1 antitrypsin deficiency can be distinguished in children and adults by the presence of characteristic cytoplasmic globules with periodic acid–Schiff staining after diastase digestion or by serum protease inhibitor isotype testing. Isotype testing is required in infants younger than 12 weeks of age.

Primary Biliary Cholangitis

Figure 21.13  Areas of confluent necrosis with parenchymal collapse may exhibit pale, gray-blue staining with trichrome stain, but this feature should be distinguished from the bright blue staining of hepatic fibrosis.

Acute or Chronic Viral Hepatitis Chronic viral hepatitis (hepatitis B virus, hepatitis C virus, or hepatitis D virus infection) can all exhibit a chronic hepatitis with or without interface activity and portal-based fibrosis. Acute viral hepatitis can present a lobular hepatitis and, again, may enter the differential diagnosis for patients with clinical evidence of an acute hepatitis (see eSlide 13.1 and 13.2). As noted previously, neither plasma cells nor the other histologic findings typically seen in AIH are sensitive or specific for the diagnosis. Thus, all can appear histologically similar to AIH and should be excluded by serologic testing in all patients in whom a diagnosis of AIH is entertained.

Celiac Disease Patients with celiac disease may show signs of acute or chronic liver disease that improves with gluten restriction, and 4% of patients with AIH also have concurrent celiac disease.1 Serologic testing for antibodies to tissue transglutaminase and antiendomysial antibodies and, if indicated, small intestinal biopsy can be used to identify concurrent celiac disease in a patient with AIH or celiac as a potential cause of liver disease in patients with acute or chronic liver disease of unknown etiology.

Drug-Induced Liver Injury Drug-induced liver injury may be histologically indistinguishable from AIH, and an AIH-like clinical picture including the detection of autoantibodies and hypergammaglobulinemia has been described with the use of various herbal preparations and certain medications.2,22 This pattern of liver injury, termed drug-induced liver injury with autoimmune features, may occur within a few months or longer after initiating the medication, resolves on withdrawal of the inciting agent and, if immunosuppression is administered, does not recur after withdrawal of the immunosuppression.22 Drugs associated with an AIH-like pattern of injury include nitrofurantoin, minocycline, diclofenac, infliximab, atorvastatin and other statins, hydralazine, methyldopa, and antitumor necrosis factor-α agents, among others.2,12,22 A careful history is warranted in all patients to carefully exclude use of potentially hepatotoxic medications, herbal products, and nutritional supplements.

Hereditary Metabolic Diseases Wilson disease and alpha-1 antitrypsin deficiency can cause similar or identical histologic findings to AIH. Wilson disease should be 314

PBC and AIH share some clinical and histologic features. Both can affect young to middle-aged adult women. ANA and ASMA are characteristic of AIH and are also commonly present in patients with PBC, and both AIH and early PBC are characterized by dense portal inflammatory cell infiltrates including lymphocytes with or without plasma cells (see eSlide 26.2). Patients with PBC are more likely to exhibit AMA positivity, cholestatic clinical features such as jaundice and pruritus as well as biochemical profiles characterized by higher alkaline phosphatase levels with normal or only mildly elevated transaminases. The periductal inflammation and bile duct injury termed the “florid duct lesion” is the characteristic histologic feature of PBC, and in more advanced disease liver histology reveals chronic cholestatic changes with progressive duct loss.16 Although one can see periportal spillover of inflammatory cells beyond the limiting plate and scattered sinusoidal lymphocytes in PBC (eSlide 26.3), these phenomena are not associated with the hepatocyte injury or necrosis that characterize AIH. The distinguishing features of PBC and AIH are also discussed in Chapter 26.

Genetics There is no specific known genetic cause of AIH; both genetic and environmental factors are believed to be involved in its pathogenesis.3 AIH is most strongly associated with certain human leukocyte antigen (HLA) alleles, and both allele frequencies and disease susceptibilities demonstrate ethnic and regional variation.2,3,11 Certain alleles within the HLA-DRB1 locus, HLA DR3 (DRB1*0301) and HLA DR4 (DRB1*0401), are the major risk factors for AIH in white European and North American populations and are incorporated into the revised International Autoimmune Hepatitis Group diagnostic scoring system.3,5,8 HLA DR7 (DRB1*0701) and DR3 (DRB1*0301) are associated with susceptibility to Type 2 AIH.3,6 The association of these and other HLA alleles with particular populations and clinical features have been described, and non-HLA genes have also been associated with AIH.3,5,6,11

Treatment and Prognosis Standard first-line treatment for AIH is combination immunosuppressive therapy with prednisone or prednisolone alone and azathioprine.1 The next-generation glucocorticoid budesonide is less well studied but may have fewer side effects and be appropriate for use in combination with azathioprine in some patients.1 Other immunosuppressive agents including calcineurin inhibitors (cyclosporine, tacrolimus) or mycophenolate mofetil may be used in patients who cannot tolerate standard therapy or have refractory disease.1 Immunosuppressive therapy results in symptomatic, chemical, and histologic improvement in 80% of patients, prevents or reverses fibrosis, and improves patient 5-year survival from 40% to over 90%.1 A small percentage of compliant patients worsen despite therapy.1 Longterm management involves monitoring both liver tests and histologic findings and titrating medications to minimize disease activity while minimizing side effects, which can be significant.

Autoimmune Hepatitis and Overlap Syndromes Liver transplantation is considered in patients with hepatic decompensation due to acute liver failure or decompensated cirrhosis or in those with hepatocellular carcinoma. The 5-year survival rate after transplant is excellent at 96%. Recurrent AIH occurs in about 8% to 68% of patients who undergo transplantation, although disease progression and graft failure are uncommon.23 Possible risk factors for disease recurrence include premature corticosteroid withdrawal, suboptimal immunosuppression, severe disease prior to transplantation, and episodes of graft rejection.23 The identification of serum autoantibodies (ANA, anti-SMA, or antiLKM1) after transplant is helpful but is not sufficient to diagnose AIH.24 Suggested Readings Czaja AJ. Diagnosis and management of autoimmune hepatitis. Clin Liver Dis. 2015;19:57–79. Hennes EM, Zeniya M, Czaja AJ, et al. Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatology. 2008;48:169–176. Manns MP, Czaja AJ, Gorham JD, et al. Diagnosis and management of autoimmune hepatitis. Hepatology. 2010;51:1–31. Washington MK. Autoimmune liver disease: overlap and outliers. Mod Pathol. 2007;20:S15–S30.

References 1 Czaja AJ. Diagnosis and management of autoimmune hepatitis. Clin Liver Dis. 2015;19:57–79. 2. Manns MP, Czaja AJ, Gorham JD, et al. Diagnosis and management of autoimmune hepatitis. Hepatology. 2010;51:1–31. 3. Manns J, Lohse AW, Vergain D. Autoimmune hepatitis—update 2015. J Hepatology. 2015;62:S100–S111. 4. Vierling JM. Autoimmune hepatitis and overlap syndromes: diagnosis and management. Clin Gastro and Hepatology. 2015;13:2088–2108. 5. Liberal R, Grant CR, Mieli-Vergani G, et al. Autoimmune hepatitis: a comprehensive review. J Autoimmunity. 2013;41:126–139. 6. Liberal R, Vergani D, Mieli-Vergani G. Update on autoimmune hepatitis. J Clin Transl Hepatology. 2015;3:42–52.

7. Johnson PJ, McFarlane IG. Meeting report: International Autoimmune Hepatitis Group. Hepatology. 1993;18:98–1005. 8. Alvarez F, Berg PA, Bianchi FB, et al. International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31:929–938. 9. Hennes EM, Zeniya M, Czaja AJ, et al. Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatology. 2008;48:169–176. 10 Bunchorntavakul C, Reddy KR. Diagnosis and management of overlap syndromes. Clin Liver Dis. 2015;19:81–97. 11 Feld JJ, Heathcote EJ. Epidemiology of autoimmune liver disease. J Gastroenterol Hepatol. 2013;18:1118–1128. 12 Jimenez-Rivera C, Ling SC, Ahmed N, et al. Incidence and characteristics of autoimmune hepatitis. Pediatrics. 2015;136:e1237–e1248. 13  AASLD/IDSA HCV Guidance Panel. Hepatitis C guidance: AASLD-IDSA recommendations for testing, managing, and treating adults infected with hepatitis C virus. Hepatology. 2015;62:932–954. 14. Carpenter HA, Czaja AJ. The role of histologic evaluation in the diagnosis and management of autoimmune hepatitis and its variants. Clin Liver Dis. 2002;6:685–705. 15. Guindi M. Histology of autoimmune hepatitis and its variants. Clin Liver Dis. 2010;14:577–590. 16. Washington MK. Autoimmune liver disease: overlap and outliers. Mod Pathol. 2007;20:S15–S30. 17. Czaja AJ, Carpenter HA. Sensitivity, specificity, and predictability of biopsy interpretations in chronic hepatitis. Gastroenterology. 1993;105:1824–1832. 18. Hofer H, Oesterreicher C, Wrba F, et al. Centrilobular necrosis in autoimmune hepatitis: a histological feature associated with acute clinical presentation. J Clin Pathol. 2006;59:246–249. 19. Bihari C, Rastogi A, Sarin SK. Postinfantile giant cell hepatitis: an etiological and prognostic perspective. Hepat Res Treat. 2013:1–7. 20. Boberg KM, Chapman RW, Hirschfield GM. Overlap syndromes: the International Autoimmune Hepatitis Group (IAIHG) position statement on a controversial issue. J Hepatol. 2011;54:374–385. 21.  EASL Clinical Practice Guidelines. Management of cholestatic liver diseases. J Hepatol. 2009;51:237–267. 22. deLemos AS, Foureau DM, Jacobs C, et al. Drug-induced liver injury with autoimmune features. Semin Liver Dis. 2014;34:194–204. 23. Czaja AJ. Diagnosis, pathogenesis, and treatment of autoimmune hepatitis after liver transplantation. Dig Dis Sci. 2012;57:2248–2266.

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22 Metabolism of Drugs and Xenobiotics Raj Vuppalanchi, MD

General Considerations in Drug Metabolism  319 Factors Affecting Bioavailability of Drugs  320 Enzyme Induction and Inhibition  320 Enzyme Polymorphisms  320 Disease States  321 Clinically Significant Drug-Metabolizing Enzymes and Transporters 321 Cytochrome P450 Enzymes  321 Conjugating Enzymes  322 Drug Transporters/Phase III Enzymes  324 Role of Drug Metabolism in Drug-Induced Liver Injury  324 Alcohol Use and Risk of Drug-Induced Liver Injury  325

Abbreviations ABC adenosine triphosphate (ATP)–binding cassette ATP adenosine triphosphate AUC area under curve Cmax maximum plasma concentration CYP cytochrome P450 enzymes DILI drug-induced liver injury GST glutathione transferase NAT N-acetyltransferase SLC solute carrier SLT Shiga-like toxin SNP single-nucleotide polymorphisms TPMT thiopurine methyltransferase UDP uridine 5′-diphosphate The majority of drugs and xenobiotics (foreign compounds) that enter the systemic circulation undergo biotransformation to more water soluble compounds for elimination through urine or bile. This process was formerly termed detoxification1 as it led to the termination of the physiologic action of these compounds by facilitating elimination from the cell. However, biotransformation of a drug also leads to the formation of active metabolites, as is seen with activation of codeine to morphine; therefore, this process is more appropriately termed metabolism.2

Although the liver is the major site of metabolism in the body, the gut wall, kidney, lungs, and other tissues also make a contribution.3-6 The enzymes that participate in drug metabolism act primarily as catalysts for chemical transformation and can be divided into two categories: phase I enzymes or functionalizing enzymes and phase II enzymes or conjugating enzymes. Transport proteins involved in the movement of drug/metabolites across cell membranes have sometimes been termed phase III enzymes.7,8 These phases do not necessarily occur in a sequential fashion as the numbering might suggest.

General Considerations in Drug Metabolism The plasma concentration of orally administered drugs is often much lower than anticipated. This is called the “first pass” effect and results from the loss of a certain fraction of the absorbed drug because of metabolism in the intestinal wall and the liver.9 Drugs with high firstpass effect thus have low oral bioavailability. Drug metabolism in the liver essentially results in the conversion of a lipophilic parent compound to a more readily excreted hydrophilic (polar) metabolite. This is accomplished in two phases, the first of which results in the formation of an active metabolite that mediates the desired pharmacologic action while the second inactivates and, therefore, terminates the action of this active metabolite. Phase I enzymes “functionalize” the drug through oxidation, reduction, hydrolysis, or hydration, which results in the insertion of reactive groups such as –OH, –COOH, –SH, and –NH2 in the parent compound. These enzymes are a naturally occurring superfamily of hemeprotein isoenzymes collectively termed cytochrome P450 enzymes (CYPs).10 Phase II or conjugating enzymes couple an endogenous molecule to the reactive groups generated in phase I, thus inactivating the compound and creating a larger molecular weight product.10 This pharmacologically and toxicologically inactive product is also water soluble and easily excreted in bile or urine. Phase II reactions are mediated by enzymes such as UDP-glucuronosyltransferase (UGT; glucuronidation), sulfotransferases (sulfonation), glutathione S-transferase (GST; glutathionylation), methyl transferases (methylation) and N-acetyltransferase (NAT; acetylation). There are several more conjugating enzymes whose role in drug metabolism has not yet been characterized. Finally, drug metabolism involves transporter molecules located on basolateral and apical membranes of the hepatocyte; these transporter function in sinusoidal uptake of drug into hepatocytes and secretion into bile, respectively (see Fig 29A.1 and Table 29A.1 in Chapter 29A). 319

Practical Hepatic Pathology: A Diagnostic Approach Liver

Plasma

Tissue Pharmacologic effect

Drug metabolism

Drug concentration in systemic circulation

Drug concentration at site of action

Pharmacodynamics

Gut lumen

Bile

Kidney

Figure 22.1  Schematic representation of drug absorption, distribution, metabolism and excretion.

Excretion

The term pharmacokinetics is used to describe the relationship between the administered dose of a drug and its concentration in plasma.11 A physiologic response to an administered drug occurs when plasma drug concentration equilibrates to the concentration required for the pharmacologic action of the drug at its site of action or receptor site. The term pharmacodynamics is used to describe the relationship between the physiologic effect of a drug and the drug concentration.11 Both pharmacokinetics and pharmacodynamics of a drug are affected by a complex interplay of factors including drug absorption, distribution, metabolism, and excretion (Fig. 22.1).12 Metabolism of drugs is in turn affected by polymorphisms and genetic defects in drug-metabolizing enzymes. The term pharmacogenetics is used to describe the study of the effect of genetics on the pharmacologic response to drugs.

Factors Affecting Bioavailability of Drugs Enzyme Induction and Inhibition

Variability in enzymatic metabolism profoundly affects drug bioavailability and may result from one of three mechanisms: enzyme induction, enzyme inhibition, and enzyme polymorphisms. Enzyme induction occurs when an inducer promotes synthesis of additional enzyme protein, reduces inactivation of the formed protein, or both. Inhibition of enzyme activity occurs when a drug reversibly binds to the substrate binding site, acting as a competitive inhibitor.13 In other cases, an inhibitor may render an enzyme nonfunctional by covalent binding to a substrate site. These are known as suicide inhibitors or mechanism-based inhibitors.14 Several drugs may act as enzyme inducers and inhibitors, thus affecting the bioavailability of other drugs metabolized by the same enzyme. In addition, adverse reactions caused by drug interactions are more likely to occur from an alteration in pharmacokinetic profiles by either induction or inhibition of drug-metabolizing enzymes. They usually occur at the level of phase I metabolism because it is the rate limiting step. However, drug–drug interactions may not necessarily result in adverse events and may even be used to therapeutic advantage as in the successful use of ritonavir, a weak antiviral agent. Ritonavir effectively inhibits the drug-metabolizing enzyme CYP3A (see subsequent discussion of nomenclature), thus increasing the blood concentrations of concomitantly administered protease inhibitors in the treatment of human immunodeficiency virus.15 320

Pharmacokinetics

Enzyme Polymorphisms Enzyme polymorphisms have been best studied in the context of the human CYP superfamily that contains 57 functional genes and 58 pseudogenes (www.cypalleles.ki.se). Each enzyme is considered an isoform because each derives from a different gene and is designated by the letters “CYP” followed by an Arabic numeral indicating family, a letter indicating subfamily, and another Arabic numeral indicating the individual gene; for example, CYP3A4 or CYP2D6.16,17 Proteins included in a family have at least 40% amino acid sequence homology and proteins within subfamilies have at least 55% homology. Genetic polymorphisms from single base pair changes in the DNA sequence are common in drug metabolizing enzymes and contribute to interindividual variability in enzyme activity.18,19 The alleles or gene variants that occur with the lowest frequency at a locus observed in a particular population are termed single-nucleotide polymorphisms (SNPs).12 Based on the location, they are categorized as intragenic or extragenic. Intragenic SNPs that occur in the coding region may result in translation of a different amino acid or give rise to a premature codon resulting in a truncated protein. These are known as a nonsynonymous SNP, and the changes may influence enzyme activity. As a consequence of the redundancy of the genetic code, SNPs may result in the production of the same polypeptide. These are known as synonymous SNPs and are not of any functional consequence. Extragenic SNP are functionally important when they occur in regions that regulate gene expression. In general, the first alleles sequenced is termed “wildtype” and is designated as *1. Thus, the wild-type allele may not necessarily be the major allele in every ethnic group. The in  vivo activity of a drug metabolizing enzyme is assessed by studying systemic clearance of a probe drug that is exclusively metabolized by the target enzyme.20 The metabolic profile of a specific population may be classified as ultrarapid metabolizers, extensive metabolizers, intermediate metabolizers, and poor metabolizers. This interindividual variability in enzyme activity is attributed to the polymorphic expression of the gene. Subjects with ultrarapid metabolizer phenotype often carry more copies of the functional gene, resulting in up to a 1000-fold increase in enzymatic activity. The poor metabolizer phenotype is because of the presence of two nonfunctional (null) alleles or deletion of both alleles, whereas an intermediate phenotype

Metabolism of Drugs and Xenobiotics

22

Disease state

Proinflammatory cytokines (IL-6, IL-1β, or TNF-α)

NOS2, NO

Oxidative stress

Transcription factors (PXR, VDR, CAR, etc.)

CYP gene

CYP mRNA

CYP protein

Drug clearance

is typically found in individuals carrying one null allele. Subjects with extensive metabolizer phenotype have normal enzyme activity with one or two functional alleles.

Disease States The activity of drug metabolizing enzymes and transporters, in general, may be downregulated in disease states such as infection, chronic liver disease, and cancer.21,22 These changes in drug clearance occur because of altered gene expression at the transcriptional and posttranscriptional level mediated by proinflammatory cytokines such as interleukin-6, interleukin-1β, and tumor necrosis factor-α (Fig. 22.2). These alterations in the metabolism and excretion of drugs thus introduce the risk of drug interactions and toxicity in disease states. In advanced liver disease such as cirrhosis, CYP activity may be reduced in a selective and sequential manner depending on the etiology and the severity of the liver disease.23 Studies evaluating CYP activity in cirrhosis have also shown that loss of CYP activity is selective and dependent on the etiology (cholestatic versus noncholestatic) and severity of liver disease.23,24 George et al. observed CYP3A activity and protein reduction only in livers of patients with cirrhosis because of noncholestatic liver disorders.24 In patients with nonalcoholic fatty liver disease without advanced fibrosis, our group has showed a significant negative relationship between severity of steatosis and hepatic CYP3A activity.25 Increased hepatic CYP2E1 activity has been observed in steatohepatitis from both alcoholic liver disease and nonalcoholic liver disease from metabolic syndrome (Fig. 22.3).26,27

? hepatic microRNA

Figure 22.2  Proposed pathway for decrease in CYP activity in disease states through multilevel regulation of gene expression. Pathways and mediators possibly regulated by hepatic microRNA are shown by dashed lines. CAR, Constitutive androstane receptor; IL, interleukin; NO, nitrous oxide, NOS2, nitric oxide synthase2; TNF-α, tumor necrosis factor-alpha; VDR, vitamin D receptor. (Modified from Morgan ET, Goralski KB, Piquette-Miller M et al. Regulation of drug-metabolizing enzymes and transporters in infection, inflammation and cancer. Drug Metab Dispos. 2008;36:205-216.)

and carbon monoxide.17 CYP enzymes can be detected in the smooth endoplasmic reticulum and after high-speed centrifugation in the microsomal fraction. In the liver, the highest levels of CYP activity are seen in hepatocytes around the central vein (zone 3) and the lowest in periportal hepatocytes (zone 1). All venous blood returning from the small intestine, stomach, pancreas, and spleen converges into the portal vein and drains into the hepatic sinusoids toward the central vein; therefore, the distribution of CYPs around the central vein underscores the physiologic role of CYPs in the metabolism of nutrients and detoxification of xenobiotics and environmental toxins. CYP enzymes belonging to families 1, 2, and 3 are responsible for the metabolism of up to 90% of drugs that undergo biotransformation.12

Clinically Significant Drug-Metabolizing Enzymes and Transporters

CYP1A2 CYP1A2 is a member of the CYP1 family and is mainly expressed in the liver. It accounts for about 10% to 15% of the total CYP content of human liver and is responsible for metabolism of 10% to 15% of drugs that undergo metabolism.28 Caffeine is a validated phenotyping agent used to assess the activity of CYP1A2.20 Clinically important drugs dependent on CYP1A2 for elimination include clozapine, cyclobenzaprine, imipramine, mexiletine, and theophylline. Drugs such as cimetidine, fluoroquinolones, and fluvoxamine have been shown to be inhibitors of CYP1A2 activity. Considerable inter-individual variability of up to 15-fold exists in the expression of CYP1A2.28 This has largely been attributed to induction by environmental agents such as tobacco smoke, cruciferous vegetables, and charcoal-grilled meat. However, recent studies indicate that genetic polymorphisms may determine either the basal expression or inducibility of enzyme expression.29,30

CYP450 enzymes are the best-studied and most important phase I drug-metabolizing enzymes. Besides metabolism of drugs, these enzymes are also involved in other biologic pathways, including the metabolism of cholesterol, steroids, and lipids. The number “450” represents the wavelength at which these CYPs show maximum spectral absorbance on spectrophotometry in the presence of a reducing agent

CYP2B6 CYP2B6 is expressed in the liver and constitutes less than 1% of the total hepatic CYP content. The role of CYP2B6 in drug metabolism is being increasingly recognized; bupropion, cyclophosphamide, efavirenz, ifosfamide, and methadone are some of the clinically important drugs that undergo metabolism via CYP2B6. Bupropion is often used as

Cytochrome P450 Enzymes

321

Practical Hepatic Pathology: A Diagnostic Approach

A

antiinflammatory drugs (NSAIDs; diclofenac, ibuprofen, piroxicam), oral hypoglycemics (tolbutamide, glipizide), angiotensin II blockers (losartan, irbesartan), celecoxib, fluvastatin, phenytoin, tolbutamide, torsemide, and rosiglitazone. Tolbutamide has been validated as a phenotyping agent to assess CYP2C9 activity.20 Certain genotypes (CYP2C9*2 and CYP2C9*3) predict lower activity of this enzyme resulting in slower metabolism.34 CYP2C19 processes a wide array of drugs such as proton pump inhibitors (lansoprazole, omeprazole, rabeprazole), antiepileptics (diazepam, phenytoin, phenobarbitone), clopidogrel, and amitriptyline. Omeprazole is often used as a phenotyping agent to assess CYP2C19 activity.20 Several clinically significant CYP2C19 polymorphisms that decrease enzymatic activity have been described.32,35 A recent study also reported that the CYP2C19*17 variant, with a SNP located in the regulatory region, results in increased enzyme activity. This variant is present with a frequency of 15% to 20% in Caucasian populations.36 CYP2D6 CYP2D6 constitutes up to 2% of hepatic CYP content and is responsible for the metabolism of up to 20% of drugs that undergo biotransformation. Compounds of clinical interest include several antidepressants (amitriptyline, clomipramine, desipramine, imipramine, paroxetine), antipsychotics (haloperidol, risperidone, thioridazine), beta-blockers (timolol, s-metoprolol), codeine, dextromethorphan, duloxetine, tramadol, and tamoxifen. Some polymorphisms have been identified, and the frequency of these alleles differ with the specific population examined.37 The majority of poor metabolizers have CYP2D6 *3, *4, *5, and *6 genotype. Ultra-rapid metabolizers have multiple copies of CYP2D6 *1, *2, or *35.38

B Figure 22.3  Immunohistochemical stain using an antibody against the CYP2E1 illustrating expression in (A) normal liver and (B) nonalcoholic steatohepatitis. The larger area and increased intensity of staining indicate upregulation of CYP2E1 in nonalcoholic steatohepatitis.

the probe drug in pharmacokinetic studies to assess CYP2B6 activity.20 Drugs such as phenobarbital, phenytoin, and rifampin induce its activity, and thiotepa and ticlopidine may inhibit it.31 There is wide interindividual variability in the expression of CYP2B6. The role of genetic polymorphisms in this phenomenon is currently under evaluation.32 CYP2C The CYP2C subfamily consists of CYP2C8, CYP2C9, and CYP2C19. These isoenzymes account for 20% of hepatic CYP content and metabolize about 20% of all drugs in current use. CYP2C8 is expressed in various organs, and its role in drug metabolism is increasingly appreciated because of its role in the elimination of clinically important drugs such as paclitaxel, torsemide, amodiaquine, cerivastatin, and repaglinide. Amodiaquine had been proposed as a selective probe substrate to assess enzyme activity.33 Several of the drugs metabolized by CYP2C8 are also metabolized by CYP3A4. Polymorphisms in CYP2C8 with clinically significant effects on the metabolic profile and clinical outcomes have been described in various populations.33 CYP2C9 is the most abundant of the CYP2C enzymes and metabolizes approximately 15% of drugs including nonsteroidal 322

CYP3A Human CYP3A is composed of four functional genes: CYP3A4, CYP3A5, CYP3A7, and CYP3A43.39 Of these, CYP3A 4/5 are responsible for metabolism of up to 50% of the drugs that undergo biotransformation. These drugs include several macrolide antibiotics (erythromycin, telithromycin), benzodiazepines (alprazolam, diazepam, midazolam, triazolam), immune modulators (cyclosporine, tacrolimus), HIV antivirals (indinavir, ritonavir, saquinavir), calcium channel blockers (amlodipine, diltiazem, felodipine, nifedipine, verapamil), statins (atorvastatin, lovastatin, simvastatin), certain directacting antivirals (simeprevir, ombitasvir), sildenafil, vincristine, and buspirone. CYP3A4 is the predominant isoenzyme present in the liver and contributes to the majority of CYP3A activity.39 In addition to the liver, CYP3A5 enzyme may be expressed significantly in the small intestine, kidney, and other organs contributing variably to the total CYP3A activity. Although several polymorphisms have been detected in CYP3A4 and CYP3A5, it appears that clinically relevant pharmacokinetic changes are related to polymorphic expression of CYP3A5 only.40 Midazolam and erythromycin are valid probe substrates for phenotyping purposes.20

Conjugating Enzymes Glucuronidation is perhaps the most important conjugation pathway in humans because of the large number of substrates and the pharmacologic, physiologic, and toxicologic significance of their effects. Glucuronidation is a conjugation reaction whereby glucuronic acid, derived from cofactor UDP-glucuronic acid, is covalently linked to a substrate containing a nucleophilic functional group. The resultant metabolite, called a glucuronide, is excreted in bile and urine. Glucuronidation occurs mostly in the liver and gut and is catalyzed by enzymes present in endoplasmic reticulum, collectively called UGTs.41 Most

Metabolism of Drugs and Xenobiotics Table 22.1  Summary of Pharmacologically Relevant Drug-Metabolizing Enzymes and Transporters Enzyme

Example Substrates

Inducers

Inhibitors

Functional Effects of ­Polymorphisms

22

Functionalizing Enzymes CYP1A2

Imipramine, tacrine, theophylline, caffeine

Tobacco, omeprazole

Cimetidine, fluvoxamine, ciprofloxacin

↓ Induction ↓ Expression

CYP2B6

Efavirenz, bupropion, cyclophosphamide

Phenobarbital, phenytoin, rifampin

Ticlopidine, thiotepa

↓ Activity

CYP2C8

Amodiaquine, cerivastatin, sorafenib

Rifampin

Gemfibrozil

CYP2C9

Diclofenac, tolbutamide, losartan, fluvastatin, phenytoin

Rifampin, secobarbital

Fluconazole, amiodarone, isoniazid

↓ Activity

CYP2C19

Omeprazole, pantoprazole, diazepam, phenytoin, amitriptyline, clopidogrel

Rifampicin

Fluoxetine, fluvoxamine, ticlopidine, omeprazole

↓ Activity ↑ Activity

CYP2D6

Metoprolol, timolol, imipramine, paroxetine, haloperidol, risperidone, codeine, dextromethorphan, duloxetine, tramadol, tamoxifen

Dexamethasone, rifampin

Bupropion, fluoxetine, paroxetine, quinidine

↑ Metabolism ↓ Metabolism

CYP2E1

Chlorzoxazone, ethanol, enflurane, halothane, benzene

Ethanol, isoniazid

Disulfiram

↓ Expression

CYP3A 4,5,7

Clarithromycin, erythromycin, telithromycin, alprazolam, midazolam, cyclosporine, tacrolimus, indinavir, ritonavir, diltiazem, verapamil, atorvastatin, lovastatin, simvastatin, imatinib, trazodone

Rifampin, phenobarbital, carbamazepine, phenytoin, St. John’s wort, troglitazone

Indinavir, nelfinavir, ritonavir, clarithromycin, itraconazole, ketoconazole, telithromycin, grapefruit juice, diltiazem

Polymorphic expression

Conjugating Enzymes TPMT

Mercaptopurine, azathioprine, captopril, omapatrilat

*

*

↓ Activity

COMT

Dopamine, norepinephrine, epinephrine

*

*

↓ Activity

SULT1

Dopamine, minoxidil, resveratrol, beta2-receptor agonists, acetaminophen

*

*

↓ Activity

NAT2

Isoniazid, amonafide, hydralazine, procainamide

*

*

↓ Activity

UGT1A1

Irinotecan, ezetimibe

*

*

↓ Expression

UGT2B7

Morphine, zidovudine

*

GSTM

Several anticancer drugs

*

*

↓ Expression

GSTT

Halogenated hydrocarbons

*

*

↓ Expression

↓ Activity

Fluconazole

Drug Transporters ABCB1

Digoxin, fexofenadine

Rifampin, dexamethasone

Amiodarone, quinidine

Unclear

ABCC2

Indinavir, cisplatin

Rifampin, dexamethasone

Probenecid, glibenclamide

↑ Activity ↑ Expression

ABCG2

Doxorubicin, rosuvastatin

*

SLC01B1

Pravastatin, rifampin

SLC22A1

Metformin, desipramine

* *

*

↓ Expression

Cyclosporine, gemfibrozil

↓ Affinity

Procainamide, quinidine

↓ Affinity

*Data do not exist or are difficult to interpret. Modified from www.drug-interactions.com and Williams JA, Andersson T, Andersson TB, et al. PhRMA white paper on ADME pharmacogenomics. J Clin Pharmacol. 2008;48:849–889.

glucuronides are pharmacologically and toxicologically inactive, but there are some exceptions such as morphine 6-glucoronide. The human UGTs are a superfamily of enzymes composed of 4 families (UGT1, UGT2, UGT3, and UGT8) and several subfamilies.41 UGT1A1 is the primary enzyme responsible for glucuronidation of bilirubin. Mutations in this gene result in hereditary unconjugated hyperbilirubinemia (Crigler-Najjar and Gilbert syndrome).42 UGT2B7 is the major enzyme responsible for glucuronidation of steroids. UGTs in general exhibit overlapping substrate selectivity, particularly with relatively small substrates.41 Examples of UGT substrates are presented in Table 22.1.43 Sulfonation is a major conjugation reaction in human metabolism; substrates include xenobiotics and endogenous compounds such as

hydroxysteroids, estrogens, thyroid hormones, and catecholamines. An endogenous substrate, 3′-phosphoadenosine 5′-phosphosulfate (PAPS), is used as a sulfate donor in the conjugation reaction. There are at least 12 isoforms of the enzymes representing 3 gene families.41,44 The phenol sulfotransferases that are present in the cytosol are predominantly involved in drug metabolism.44 The cytosolic Shiga-like toxin (SLT) gene family consists of 13 isoforms with the SLT1 family primarily involved in sulfonation of xenobiotics such as minoxidil, synthetic steroid hormones, acetaminophen, and 4-hydroxytamoxifen.41 Glutathionylation is mediated by the glutathione transferases (GST), a family of enzymes that are soluble proteins found in the cytosol of hepatocytes. They are abundant and provide diverse protection by catalyzing the conjugation of reduced glutathione with electrophilic 323

Practical Hepatic Pathology: A Diagnostic Approach substrates. They belong to 5 different families with 13 different human GST subfamilies.41 The inhibition of GST activity and depletion of glutathione levels might potentiate the deleterious effects of many environmental toxins as demonstrated in patients who develop acetaminophen toxicity after an overdose.45 Glutathione conjugates are not excreted per se but rather undergo further enzymatic modification of the peptide moiety, resulting in urinary or biliary excretion of mercapturic acids. Methylation is a competing metabolic pathway for other conjugation reactions. Methyltransferases are predominantly cytosolic and use S-adenosyl-L-methionine as the methyl donor for the methylation and inactivation of many neurotransmitters and hormones. Three major types of reactions are recognized, namely the O-methylation, N-methylation, and S-methylation.41 The main enzyme responsible for O-methylation is catechol O-methyltransferase (COMT). In addition to its important role in physiologic functions, it plays a role in the metabolism of xenobiotics such as dopamine, L-DOPA, and carbidopa. Thiopurine S-methyltransferase (TPMT), an S-methylation enzyme, is involved in the metabolism of drugs such as azathioprine and 6-mercaptopurine that are used in the treatment of autoimmune disorders, leukemia, and solid organ transplants. The functional effect of genetic polymorphism of TPMT is a perfect example for the concept of individualized pharmacotherapy when using azathioprine or 6-mercaptopurine.46 These thiopurine drugs undergo biotransformation by TPMT, xanthine oxidase, and aldehyde oxidase. However, the presence of certain polymorphisms (TPMT*3A and *3B) result in a virtual lack of TPMT enzyme activity. Patients who are homozygous for these alleles thus accumulate toxic levels of 6-thioguanine nucleotides and develop severe, life-threatening myelosuppression at standard doses.47 Acetylation is mainly mediated by the acetyl transferase enzymes using acetyl-coenzyme A as acetyl donor for the conjugating reaction.41 Acetyl transferases catalyze both N-acetylation, typically a deactivation reaction, and O-acetylation, typically an activation reaction, of aromatic and heterocyclic amine carcinogens. Acetylation of xenobiotics is mainly mediated by N-acetyl transferase (NAT).41 Two genes, NAT1, and NAT2 exist in humans. The phenotype of “slow, intermediate, and fast acetylators” has been attributed to the polymorphic expression of NAT2 gene.48,49 Isoniazid, a drug used in combination regimens for therapy of tuberculosis, is metabolized by NAT2, and patients with rapid acetylation have been associated with lower INH plasma concentration resulting in treatment failure.50 In contrast, a higher incidence of adverse drug reactions has been seen in some patients with slow acetylators, presumably because of higher isoniazid plasma concentrations.51

Drug Transporters/Phase III Enzymes The clearance of drugs through metabolism may involve an intricate balance between uptake and excretion of xenobiotics by transporter proteins at the basolateral and apical membranes of hepatocytes, respectively. Hepatic drug transporters of the solute carrier (SLC) and adenosine triphosphate (ATP)-binding cassette (ABC) transporter superfamilies can thus significantly affect the duration and intensity of the pharmacologic action of a drug by modulating the drug concentration at the target receptor.52,53 ABC transporters line the bile canaliculi and export a wide variety of drugs into the bile. Key ABC transporters involved in drug metabolism include ABCB1 (P-glycoprotein, MDR1), ABCC1 (MRP1), ABCC2 (MRP2, cMOAT), and ABCG2 (BCRP, MXR, ABCP).54 The SLC transporters involved in drug metabolism belong to OATP subfamilies (gene SLCO), solute carrier peptide transporter family (gene SLC15A1), and organic zwitterion/cation transporters (gene SLC22).7,55 These are present on the basolateral membrane of 324

the hepatocyte and primarily mediate uptake of drugs into the cell. Polymorphisms associated with differences in expression and functions have been identified in many of these transporters proteins. Their clinical significance is still being investigated actively. Adverse reactions from transporter-mediated drug interactions may occur by alterations in absorption and secretion at sites such as the gut lumen, liver, and kidney. However, these types of drug interactions are much less common than those resulting from drug metabolizing enzymes (see Table 22.1).

Role of Drug Metabolism in Drug-Induced Liver Injury The central role of the liver in metabolism and detoxification of drugs and xenobiotics places it at a disproportionate risk for drug-induced injury. The clinical manifestations of drug-induced liver injury (DILI) may range from asymptomatic elevations in liver enzymes to fulminant hepatic failure, resulting in death or requiring liver transplantation.56-58 In general, DILI satisfying the criteria for a modified Hy law (alanine aminotransferase ≥3× the upper limit of normal and total bilirubin ≥2× the upper limit of normal) is considered prognostically significant as initially observed in 1978 by the late Hyman Zimmerman. He noted that the presence of hepatocellular jaundice in DILI was associated with a mortality rate of up to 50%.59 DILI may be clinically classified based on pattern of liver test elevations (hepatocellular, mixed, cholestatic) or by the histologic pattern of injury. Although these clinical and histologic classifications are useful in practice to identify a clinical signature associated with a specific drug (eg, cholestatic hepatitis from amoxicillin-clavulanate), they do not necessarily reflect the underlying mechanism of liver injury. DILI may also be classified as intrinsic or idiosyncratic hepatotoxicity. Whereas intrinsic hepatotoxicity is dose-dependent and generally predictable, idiosyncratic hepatotoxicity is unpredictable and not obviously dose dependent. However, recent studies show that drugs prescribed at doses less than 50 mg per day are less likely to cause idiosyncratic DILI compared with higher doses, suggesting that some level of dose-dependent hepatotoxicity also occurs in idiosyncratic DILI.60,61 The study of drug metabolism is clinically relevant because it provides the framework for understanding the etiopathogenetic mechanisms underlying DILI. Induction of phase I enzymes may result in the rapid production of drug metabolites in amounts that cannot be degraded rapidly enough, causing cellular damage. An example of this is acetaminophen toxicity in alcoholic patients, in whom CYP2E1 induced by chronic alcohol intake results in increased formation of the toxic metabolite N-acetyl-p-benzo-quinone imine (NAPQI) in amounts that overwhelm the detoxifying capacity of glutathione. Rarely, the activity of phase II enzymes may produce toxic drug metabolites (eg, acyl glucuronides) that may cause DILI. Injurious reactive metabolites cause liver injury through various mechanisms, including oxidative stress and impairment of mitochondrial function. In addition to direct toxicity, reactive metabolites may bind to other cellular macromolecules leading to the formation of neoantigens or haptens, triggering a major histocompatibility complex II–dependent immune reaction resulting in immune-mediated hepatocyte injury.62 Drugs that undergo metabolism are more likely to cause idiosyncratic liver injury compared with those that do not.63 Furthermore, reactive metabolites may specifically inhibit hepatic transporters, resulting in intracellular accumulation of toxic substances that lead to hepatocyte damage.64 Enzyme polymorphisms may cause DILI by affecting the nature of metabolites produced or their rate of production. In a study of 36 patients with DILI, Lang and coworkers reported polymorphisms in MDR3 (ABCB4) that were specific for DILI when compared with control patients.65 It is postulated that heterozygous

Metabolism of Drugs and Xenobiotics polymorphisms in MDR3 may increase the risk of drug-induced cholestatic injury by excessive formation of phosphatidylcholinedeficient toxic bile.

Alcohol Use and Risk of Drug-Induced Liver Injury There are three pathways for oxidative metabolism of alcohol (ethanol) in the liver; the major pathway involves the enzyme alcohol dehydrogenase (ADH), which produces acetaldehyde, a highly reactive and toxic byproduct that forms proteins adducts, which adversely affect protein function. The cytochrome P450 isozymes, including CYP2E1, 1A2, and 3A4, and catalase constitute the other two enzymatic pathways of oxidative metabolism in the liver and also produce acetaldehyde. Acetaldehyde is metabolized by aldehyde dehydrogenase 2 (ALDH2) to form acetate, another product that is deleterious for the cellular microenvironment. Collectively, these pathways of oxidative alcohol metabolism result in the generation of reactive oxygen species and reduction of the redox potential of the cell.66 Furthermore, ethanol consumption induces CYP2E1, which not only increases oxidative stress in hepatocytes but may affect the metabolism and pharmacokinetics of administered drugs.67 The pharmacokinetics of alcohol and xenobiotics may affect each other, potentially increasing the risk of DILI or accelerating the course of alcoholic liver disease in individuals with moderate to heavy alcohol use. Fortunately, these interactions are often minimized in the real world because of the limited duration of most drug therapies. However, drugs such as statins that are prescribed over a long term could be deleterious in such individuals; current prescribing information for atorvastatin cautions individuals who consume substantial quantities of alcohol; that is, more than two glasses of alcohol daily. This recommendation is based on pharmacokinetic studies performed in alcoholic cirrhosis that showed a four-fold increase in maximum plasma concentration (Cmax) and area under the curve (AUC) of atorvastatin. A further increase in Cmax and AUC by sixteenfold and elevenfold, respectively, was observed in decompensated alcoholic cirrhosis. However, clinical studies in healthy human volunteers examining the effects of acute and 6 weeks of alcohol consumption (20 g/day) with concomitant statin usage on the pharmacokinetics, efficacy, and safety of statin failed to show any significant difference compared with the placebo arm.68 Alcohol may affect the pharmacokinetics of drugs by altering gastric emptying or liver metabolism, the latter by inducing cytochrome P450 2E1. The relationship between alcohol consumption and the risk of acetaminophen hepatotoxicity is well-established,69 but the role of alcohol in causing idiosyncratic DILI is unclear. Alcohol consumption is one of the criteria in the CIOMS causality scale, although there is no evidence that alcohol increases the risk of liver injury from medications other than methotrexate, isoniazid, highly active antiretroviral therapy (HAART), or halothane.70 Heavy alcohol consumption is associated with increased risk of fibrosis and cirrhosis in long-term users of methotrexate.71,72 Chronic alcohol abuse might increase the hepatotoxicity of antituberculosis medications, possibly from alcoholmediated induction of hepatic CYP2E1. However, not all studies have shown a significant relationship between alcohol consumption and hepatotoxicity from antituberculosis medicines.73,74 To reduce the risk of hepatotoxicity, the labeling for duloxetine indicates that individuals with substantial alcohol consumption should not take this medication, but there are no published data to show that alcoholism increases the risk of duloxetine hepatotoxicity. In one study, alcohol consumption showed an inverse relationship with severity of DILI, but because alcohol consumption was defined in this study as any alcohol intake in the preceding 12 months, this surprise finding is of uncertain significance.75

Suggested Readings Al-Ghoul M, Valdes Jr R. Fundamentals of pharmacology and applications in pharmacogenetics. Clin Lab Med. 2008;28:485–497. Fisher K, Vuppalanchi R, Saxena R. Drug-induced liver injury. Arch Pathol Lab Med. 2015;139:876–887. Fontana RJ. Pathogenesis of idiosyncratic drug-induced liver injury and clinical perspectives. Gastroenterology. 2014;146:914–928. Pauli-Magnus C, Meier PJ. Hepatobiliary transporters and drug-induced cholestasis. Hepatology. 2006;44:778–787.

22

References 1. Williams RT. Detoxication mechanisms. London: Chapman and Hall Ltd; 1959. 2. Cooper DY, Levin S, Narasimhulu S, et al. Photochemical action spectrum of the terminal oxidase of mixed function oxidase system. Science. 1965;147:400–402. 3. McKinnon RA, Burgess WM, Hall PM, et al. Characterisation of CYP3A gene subfamily expression in human gastrointestinal tissues. Gut. 1995;36:259–267. 4. Wheeler CW, Guenthner TM. Cytochrome P-450-dependent metabolism of xenobiotics in human lung. J Biochem Toxicol. 1991;6:163–169. 5. Zhang JY, Wang Y, Prakash C. Xenobiotic-metabolizing enzymes in human lung. Curr Drug Metab. 2006;7:939–948. 6. Bieche I, Narjoz C, Asselah T, et al. Reverse transcriptase-PCR quantification of mRNA levels from cytochrome (CYP)1, CYP2 and CYP3 families in 22 different human tissues. Pharmacogenet Genomics. 2007;17:731–742. 7. Yamazaki M, Suzuki H, Sugiyama Y. Recent advances in carrier-mediated hepatic uptake and biliary excretion of xenobiotics. Pharm Res. 1996;13:497–513. 8. Ishikawa T. The ATP-dependent glutathione S-conjugate export pump. Trends Biochem Sci. 1992;17:463–468. 9. Pond SM, Tozer TN. First-pass elimination. Basic concepts and clinical consequences. Clin Pharmacokinet. 1984;9:1–25. 10. Katz DA, Murray B, Bhathena A, et al. Defining drug disposition determinants: a pharmacogenetic-pharmacokinetic strategy. Nat Rev Drug Discov. 2008;7:293–305. 11. Atkinson AJ. ed. Principles of Clinical Pharmacology. San Diego: Academic Press; 2001. 12. Al-Ghoul M, Valdes Jr R. Fundamentals of pharmacology and applications in pharmacogenetics. Clin Lab Med. 2008;28:485–497. 13. Zhang ZY, Wong YN. Enzyme kinetics for clinically relevant CYP inhibition. Curr Drug Metab. 2005;6:241–257. 14. Fontana E, Dansette PM, Poli SM. Cytochrome p450 enzymes mechanism based inhibitors: common sub-structures and reactivity. Curr Drug Metab. 2005;6:413–454. 15. Xu L, Desai MC. Pharmacokinetic enhancers for HIV drugs. Curr Opin Investig Drugs. 2009;10:775–786. 16. Nelson DR. Cytochrome P450 nomenclature, 2004. Methods Mol Biol. 2006;320:1–10. 17. Nelson DR, Koymans L, Kamataki T, et al. P450 superfamily: update on new sequences, gene mapping, accession numbers and nomenclature. Pharmacogenetics. 1996;6:1–42. 18. Weinshilboum R. Inheritance and drug response. N Engl J Med. 2003;348:529–537. 19. Linder MW, Valdes Jr R. Genetic mechanisms for variability in drug response and toxicity. J Anal Toxicol. 2001;25:405–413. 20. Fuhr U, Jetter A, Kirchheiner J. Appropriate phenotyping procedures for drug metabolizing enzymes and transporters in humans and their simultaneous use in the “cocktail” approach. Clin Pharmacol Ther. 2007;81:270–283. 21. Morgan ET. Impact of infectious and inflammatory disease on cytochrome P450-mediated drug metabolism and pharmacokinetics. Clin Pharmacol Ther. 2009;85:434–438. 22. Morgan ET, Goralski KB, Piquette-Miller M, et al. Regulation of drug-metabolizing enzymes and transporters in infection, inflammation, and cancer. Drug Metab Dispos. 2008;36:205–216. 23. Frye RF, Zgheib NK, Matzke GR, et al. Liver disease selectively modulates cytochrome P450— mediated metabolism. Clin Pharmacol Ther. 2006;80:235–245. 24. George J, Murray M, Byth K, et al. Differential alterations of cytochrome P450 proteins in livers from patients with severe chronic liver disease. Hepatology. 1995;21:120–128. 25. Kolwankar D, Vuppalanchi R, Ethell B, et al. Association between nonalcoholic hepatic steatosis and hepatic cytochrome P-450 3A activity. Clin Gastroenterol Hepatol. 2007;5:388–393. 26. Weltman MD, Farrell GC, Hall P, et al. Hepatic cytochrome P450 2E1 is increased in patients with nonalcoholic steatohepatitis. Hepatology. 1998;27:128–133. 27. Novak RF, Woodcroft KJ. The alcohol-inducible form of cytochrome P450 (CYP 2E1): role in toxicology and regulation of expression. Arch Pharm Res. 2000;23:267–282. 28. Landi MT, Sinha R, Lang NP, et al. Human cytochrome P4501A2. IARC Sci Publ. 1999:173–195. 29. Nakajima M, Yokoi T, Mizutani M, et al. Phenotyping of CYP1A2 in Japanese population by analysis of caffeine urinary metabolites: absence of mutation prescribing the phenotype in the CYP1A2 gene. Cancer Epidemiol Biomarkers Prev. 1994;3:413–421. 30. Aklillu E, Carrillo JA, Makonnen E, et al. Genetic polymorphism of CYP1A2 in Ethiopians affecting induction and expression: characterization of novel haplotypes with single-nucleotide polymorphisms in intron 1. Mol Pharmacol. 2003;64:659–669. 31. Rae JM, Soukhova NV, Flockhart DA, et al. Triethylenethiophosphoramide is a specific inhibitor of cytochrome P450 2B6: implications for cyclophosphamide metabolism. Drug Metab Dispos. 2002;30:525–530. 32. Solus JF, Arietta BJ, Harris JR, et al. Genetic variation in eleven phase I drug metabolism genes in an ethnically diverse population. Pharmacogenomics. 2004;5:895–931.

325

Practical Hepatic Pathology: A Diagnostic Approach 33. Totah RA, Rettie AE. Cytochrome P450 2C8: substrates, inhibitors, pharmacogenetics, and clinical relevance. Clin Pharmacol Ther. 2005;77:341–352. 34. Kirchheiner J, Brockmoller J. Clinical consequences of cytochrome P450 2C9 polymorphisms. Clin Pharmacol Ther. 2005;77:1–16. 35. Desta Z, Zhao X, Shin JG, et al. Clinical significance of the cytochrome P450 2C19 genetic polymorphism. Clinical pharmacokinetics. 2002;41:913–958. 36. Sim SC, Risinger C, Dahl ML, et al. A common novel CYP2C19 gene variant causes ultrarapid drug metabolism relevant for the drug response to proton pump inhibitors and antidepressants. Clin Pharmacol Ther. 2006;79:103–113. 37. Ingelman-Sundberg M. Genetic polymorphisms of cytochrome P450 2D6 (CYP2D6): clinical consequences, evolutionary aspects and functional diversity. Pharmacogenomics J. 2005;5:6–13. 38. Gaedigk A, Ndjountche L, Divakaran K, et al. Cytochrome P4502D6 (CYP2D6) gene locus heterogeneity: characterization of gene duplication events. Clin Pharmacol Ther. 2007;81:242–251. 39. Wojnowski L. Genetics of the variable expression of CYP3A in humans. Ther Drug Monit. 2004;26:192–199. 40. Wojnowski L, Kamdem LK. Clinical implications of CYP3A polymorphisms. Expert Opin Drug Metab Toxicol. 2006;2:171–182. 41. Testa B, Kramer SD. The biochemistry of drug metabolism—an introduction: part 4. Reactions of conjugation and their enzymes. Chem Biodivers. 2008;5:2171–2336. 42. Kadakol A, Ghosh SS, Sappal BS, et al. Genetic lesions of bilirubin uridine-diphosphoglucuronate glucuronosyltransferase (UGT1A1) causing Crigler-Najjar and Gilbert syndromes: correlation of genotype to phenotype. Hum Mutat. 2000;16:297–306. 43. Williams JA, Andersson T, Andersson TB, et al. PhRMA white paper on ADME pharmacogenomics. J Clin Pharmacol. 2008;48:849–889. 44. Weinshilboum RM, Otterness DM, Aksoy IA, et al. Sulfation and sulfotransferases 1: sulfotransferase molecular biology: cDNAs and genes. FASEB J. 1997;11:3–14. 45. Zhao P, Kalhorn TF, Slattery JT. Selective mitochondrial glutathione depletion by ethanol enhances acetaminophen toxicity in rat liver. Hepatology. 2002;36:326–335. 46. Weinshilboum R. Thiopurine pharmacogenetics: clinical and molecular studies of thiopurine methyltransferase. Drug Metab Dispos. 2001;29:601–605. 47. Lennard L, Van Loon JA, Weinshilboum RM. Pharmacogenetics of acute azathioprine toxicity: relationship to thiopurine methyltransferase genetic polymorphism. Clin Pharmacol Ther. 1989;46:149–154. 48. Garcia-Martin E. Interethnic and intraethnic variability of NAT2 single nucleotide polymorphisms. Curr Drug Metab. 2008;9:487–497. 49. Fretland AJ, Leff MA, Doll MA, et al. Functional characterization of human N-acetyltransferase 2 (NAT2) single nucleotide polymorphisms. Pharmacogenetics. 2001;11:207–215. 50. Castillejos-Lopez Mde J, Garcia-Sancho MC, Quinones-Falconi F, et al. [Cytochrome P450 and NAT2 polymorphisms and drug metabolism in DOTS]. Rev Invest Clin. 2008;60:47–57. 51. Possuelo LG, Castelan JA, de Brito TC, et al. Association of slow N-acetyltransferase 2 profile and anti-TB drug-induced hepatotoxicity in patients from Southern Brazil. Eur J Clin Pharmacol. 2008;64:673–681. 52. Pauli-Magnus C, Meier PJ. Hepatocellular transporters and cholestasis. J Clin Gastroenterol. 2005;39:S103–S110. 53. Sadee W, Graul RC, Lee AY. Classification of membrane transporters. Pharm Biotechnol. 1999;12:29–58.

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54. Toyoda Y, Hagiya Y, Adachi T, et al. MRP class of human ATP binding cassette (ABC) transporters: historical background and new research directions. Xenobiotica. 2008;38:833–862. 55. Choi MK, Song IS. Organic cation transporters and their pharmacokinetic and pharmacodynamic consequences. Drug Metab Pharmacokinet. 2008;23:243–253. 56. Vuppalanchi R, Liangpunsakul S, Chalasani N. Etiology of new-onset jaundice: how often is it caused by idiosyncratic drug-induced liver injury in the United States? Am J Gastroenterol. 2007;102:558–562. quiz 693. 57. Lee WM. Etiologies of acute liver failure. Semin Liver Dis. 2008;28:142–152. 58. Chalasani N, Bonkovsky HL, Fontana R, et al. Features and outcomes of 899 patients with druginduced liver injury: the DILIN Prospective Study. Gastroenterology. 2015;148:1340–1352. 59. Zimmerman HJ. Drug-induced liver disease. Clin Liver Dis. 2000;4:73–96. vi. 60. Senior JR. What is idiosyncratic hepatotoxicity? What is it not? Hepatology. 2008;47:1813–1815. 61. Lammert C, Einarsson S, Saha C, et al. Relationship between daily dose of oral medications and idiosyncratic drug-induced liver injury: search for signals. Hepatology. 2008;47:2003–2009. 62. Spahn-Langguth H, Benet LZ. Acyl glucuronides revisited: is the glucuronidation process a toxification as well as a detoxification mechanism? Drug Metab Rev. 1992;24:5–47. 63. Lammert C, Bjornsson E, Niklasson A, et al. Oral medications with significant hepatic metabolism at higher risk for hepatic adverse events. Hepatology. 2010;51:615–620. 64. Pauli-Magnus C, Meier PJ. Hepatobiliary transporters and drug-induced cholestasis. Hepatology. 2006;44:778–787. 65. Lang C, Meier Y, Stieger B, et al. Mutations and polymorphisms in the bile salt export pump and the multidrug resistance protein 3 associated with drug-induced liver injury. Pharmacogenet Genomics. 2007;17:47–60. 66. Cederbaum AI. Alcohol metabolism. Clin Liver Dis. 2012;16:667–685. 67. Wu D, Cederbaum AI. Oxidative stress mediated toxicity exerted by ethanol-inducible CYP2E1. Toxicol Appl Pharmacol. 2005;207:70–76. 68. Smit JW, Wijnne HJ, Schobben F, et al. Effects of alcohol consumption on pharmacokinetics, efficacy, and safety of fluvastatin. American J Cardiol. 1995;76:89A–96A. 69. Schmidt LE, Dalhoff K, Poulsen HE. Acute versus chronic alcohol consumption in acetaminophen-induced hepatotoxicity. Hepatology. 2002;35:876–882. 70. Zimmerman HJ. Hepatotoxicity: the adverse effects of drugs and other chemicals on the liver. 2nd ed. Philadelphia: Lippincott, Williams & Wilkins; 1999. 71. Whiting-O’Keefe QE, Fye KH, Sack KD. Methotrexate and histologic hepatic abnormalities: a meta-analysis. American J Med. 1991;90:711–716. 72. Malatjalian DA, Ross JB, Williams CN, et al. Methotrexate hepatotoxicity in psoriatics: report of 104 patients from Nova Scotia, with analysis of risks from obesity, diabetes and alcohol consumption during long term follow-up. Can J Gastroenterol. 1996;10:369–375. 73. Saukkonen JJ, Cohn DL, Jasmer RM, et al. An official ATS statement: hepatotoxicity of antituberculosis therapy. Am J Respir Critic Care Med. 2006;174:935–952. 74. Hussain Z, Kar P, Husain SA. Antituberculosis drug-induced hepatitis: risk factors, prevention and management. Indian J Exp Biol. 2003;41:1226–1232. 75. Chalasani N, Fontana RJ, Bonkovsky HL, et al. Causes, clinical features, and outcomes from a prospective study of drug-induced liver injury in the United States. Gastroenterology. 2008;135:1924–1934. 1934 e1921–1924.

23 Liver Injury Due to Drugs and Herbal Agents David E. Kleiner, MD, PhD

Brief Historical Overview  327 Incidence and Demographics  328 Clinical Manifestations  330 Microscopic Pathology  331 Necroinflammatory Patterns  331 Cholestatic Patterns  353 Steatotic Patterns  357 Vascular Injury Patterns  361 Pigments and Other Cytoplasmic Changes  363 Neoplasms 364 Grading and Staging  364 Differential Diagnosis  365 Establishing Causality  365 Ancillary Diagnostic Studies  366 Genetics 367 Treatment and Prognosis  367

Abbreviations ALT alanine aminotransferase AST aspartate aminotransferase CDER Center for Drug Evaluation and Research CDS clinical diagnostic scale DILIN Drug-Induced Liver Injury Network DRESS drug reaction with eosinophilia and systemic symptoms FDA United States Food and Drug Administration HLA human leukocyte antigen NAFLD nonalcoholic fatty liver disease NAT2 N-acetyltransferase-2 NRH nodular regenerative hyperplasia PAS periodic acid–Schiff PBC primary biliary cholangitis PSC primary sclerosing cholangitis

RUCAM ULN UNOS VOD/SOS

Roussel Uclaf Causality Assessment Method upper limit of normal United Network of Organ Sharing veno-occlusive disease/sinusoidal obstruction syndrome

Brief Historical Overview In 1965, Hans Popper and his coworkers published a landmark paper entitled “Drug-Induced Liver Disease: A Penalty for Progress.”1 He reviewed 155 cases of apparent liver toxicity, related to 30 different agents, and recognized that the information on the clinical and pathologic characteristics of drug- and toxin-induced injury was poorly organized and would benefit from a systematic attempt at classification. He therefore proposed dividing the pathologic changes into six basic categories: zonal injury, uncomplicated cholestasis, nonspecific drug-induced hepatitis with or without cholestasis, reactions simulating viral hepatitis, nonspecific reactive hepatitis, and drug-induced steatosis. To a large extent the classifications used today are the intellectual children of Popper’s classification, reorganized and expanded. The major additions include the spectrum of drug-induced vascular injury, mainly a consequence of chemotherapy and certain natural products, subcategories of cholestatic liver disease related to primary or secondary destruction of the ducts and the category of drug-induced hepatic neoplasms. Identification of the pattern of injury under the microscope is the first job of the pathologist, because the pattern of injury will determine the pathologic differential diagnosis and help determine the mechanism of injury. A significant barrier to gaining a comprehensive understanding of drug-induced liver injury is the medical literature itself. The primary literature of human drug-induced liver injury is mainly in the form of case reports and small series scattered across the full breadth of the medical literature. There is huge variation in the quality of individual articles both in terms of the data being presented (including descriptions of pathologic changes) and the extent to which other causes of liver injury are excluded. In addition, because of advances in hepatology over the last forty years, physicians are now better able to diagnose a number of conditions that could be mistaken for drug injury. For example, before 1988 chronic hepatitis C may have been present and

327

Practical Hepatic Pathology: A Diagnostic Approach been mistaken for chronic drug-induced injury (a factor to consider in reading older literature). Beyond the primary literature are a host of review articles, some of which are highlighted at the end of the chapter. These can be helpful, but most are written from a clinical point-ofview and are published in a wide range of clinical subspecialty journals. There are also a number of recent monographs devoted to drug- and toxin-induced liver injury, and while these are also written from a clinical point-of-view, they can offer significant insight into the pathology of drug-induced liver injury.2-4 In recognition of the need to bring structure to what is essentially an anecdotal science, there have been a number of efforts in the last several decades to scientifically evaluate drug-induced liver injury in humans. Beginning in 1985, the European pharmaceutical company Roussel Uclaf organized a series of consensus meetings in France on adverse drug effects where participants considered fundamental questions of injury classification and causality. These efforts culminated in 1993 with the publication of the Roussel Uclaf Causality Assessment Method (RUCAM), which is a numeric scoring system designed to assist clinicians in assigning a degree of certainty as to whether or not a particular agent is responsible for a particular case of hepatotoxicity.5 This system is further considered later. In the United States, the Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER) has organized annual meetings since 2001 between the FDA, academia, and the pharmaceutical industry to discuss various aspects of drug-induced liver injury. Documents relating to these meetings are freely available on the FDA’s website (www.fda.gov/Drugs/ScienceResearch/ResearchAreas/ucm07147 1.htm). Another recent development has been the establishment of regional and multicenter clinical networks devoted to gathering cases of drug-induced liver injury. Networks exist in France6 and Spain,7,8 in the United States,9,10 and in other countries. The Acute Liver Failure Study Group prospectively collects cases of acute liver failure in the United States, a significant percentage of which are due to druginduced liver injury.11,12 An important online resource is the LiverTox website (http://livertox.nlm.nih.gov/), maintained by the National Library of Medicine. LiverTox is oriented towards the clinical manifestations of liver injury from drugs and herbal supplements, but also has some information on the pathology of drug-induced liver injury as well as an extensive annotated drug-by-drug bibliography.13 Given the relatively low incidence of drug-induced liver injury (discussed later), one may justifiably wonder why it is so important to correctly identify and classify cases. One of the main reasons is that the subtle clinical presentation coupled with a potentially fatal outcome is of great concern to doctors and patients alike. Confirmed hepatotoxicity sometimes leads to regulatory action. Table 23.1 shows the drugs that have been either removed from the US market or flagged by blackbox warnings by the FDA for liver injury. A review of FDA regulatory actions over a 25-year period showed that liver injury was the most common reason for a drug to be withdrawn or have its use curtailed.14 Furthermore, every year reports of first instances of hepatotoxicity of new drugs appear (Box 23.1), reinforcing the fact that we are unable to completely screen for potential hepatotoxicity in preclinical or clinical trial settings. Correct causal association of a drug with an injury coupled with properly reporting the injury is an important part of protecting patients and can lead to limiting the use of or removing potentially harmful medications.

Incidence and Demographics It is difficult to accurately assess the true incidence of drug-induced liver injury for any particular agent. To know the incidence, one must have some information about the exposed population as well as some method

328

Table 23.1  Hepatotoxicity Resulting in Food and Drug Administration Regulatory Actions Drugs Withdrawn

Black Box Warnings

Safety Alerts

Benoxaprofen

Dacarbazine

Acetaminophen

Bromfenac

Danazol

Dronedarone

Ticrynafen

Felbamate

Leflunomide

Troglitazone

Ketoconazole

Nefazodone

Pemoline

Nevirapine

Propylthiouracil

Ombitasvir/paritaprevir/ritonavir and dasabuvir

Tolcapone

Orlistat

Trovafloxacin

Pyrazinamide/Rifampin

Valproate

Telithromycin

Zalcitabine

Terbinafine

Zidovudine

Tolvaptan Zafirlukast

Dietary Supplements Kava Lipokinetix Data from Lasser KE, Allen PD, Woolhandler SJ, et al. Timing of new black box warnings and withdrawals for prescription medications. JAMA. 2002;287:2215–2220; Watkins PB. Idiosyncratic liver injury: challenges and approaches. Toxicol Pathol. 2005;33:1–5; and Norris W, Paredes AH, Lewis JH. Drug-induced liver injury in 2007. Curr Opin Gastroenterol. 2008;24:287–297 and www. fda.gov/Drugs/DrugSafety/default.htm.

Box 23.1  Drugs with Recently Reported Hepatotoxicity Anastrozole161 Atomoxetine162 Ipilimumab163 Dronedarone164 Telithromycin165 Temozolomide166 Tolvaptan167 Tumor necrosis factor alpha antagonists168 Tyrosine-kinase inhibtors169

of identifying all of the cases of injury. A recent population-based survey from Iceland made use of that country’s nationalized health care system to estimate the injury incidence for hepatotoxic agents over a 2-year period.15 They estimated the proportion of prescriptions that led to liver injury for 10 drugs. The incidence varied from 6 per 100,000 patients for doxycycline to 675 per 100,000 patients for infliximab. The combination drug amoxicillin-clavulanate had the most number of cases, but also had a very large number of prescriptions filled, resulting in an incidence of 43 per 100,000 patients. In large, population-based studies the overall incidence of drug-induced liver injury varies from about 2 to 190 per million person-years, depending on the population studied (Table 23.2). Drug classes frequently associated with hepatotoxicity include the antibacterials, particularly amoxicillin-clavulanate and the sulfonamides; the antimycobacterials; nonsteroidal antiinflammatory drugs; and antiseizure medications. Herbals in the form of traditional Chinese medicines make up a significant proportion of cases in Singapore.16,17 The prevalence of injury related to particular agents

Liver Injury Due to Drugs and Herbal Agents Table 23.2  Estimates of the Incidence of Drug-Induced Liver Injury Estimated Incidence per Million Person-Years

Country (ref)

Years

Method of Case Accrual

Total Cases

Top Drugs Identified

United States25

1977–1981

Health maintenance organization (HMO) database

9

Ampicillin

2–4 for patients younger than 40 20–80 for patients older than 60

Spain8

1993–1998

Referral

107

Acetaminophen, aspirin, ranitidine

7.4 (acute serious toxicity)

France6

1997–2000

Population-based

34

Augmentin, nevirapine, atorvastatin

140 (crude rate) 80 (standardized rate)

England148

1994–1999

Practice database

128

Acetaminophen, diclofenac, flucloxacillin

24 (with sixfold increased risk if 2 or more drugs suspected)

Spain7

1994–2005

Referral

461

Amoxicillin-clavulanate, ebrotidine, antimycobacterials

17 (severe toxicity) 34 (overall toxicity)

Sweden149

1995–2005

Practice database

77

Diclofenac, flucloxacillin, azathioprine

23

England150

1998–2004

Referral for jaundice

28

Amoxicillin-clavulanate, flucloxacillin

13 for jaundice-related drug-induced liver injury

Iceland15

2010–2011

Population-based

96

Amoxicillin-clavulanate Diclofenac Azathioprine

191

United States151

2004–2010

HMO database

32

Acetaminophen Herbal supplements

1.6 for drug-induced acute liver failure

23

Table 23.3  Drug-Induced Liver Injury from Surveys of Acute Liver Failure Country (ref)

Years

Method of Accrual

Fraction Due to DILI

Total Cases of DILI

% Due to Acetaminophen

Other Top Drugs

Canada152

1991–1999

Hospital database

27%

22

55%

Isoniazid

1998–2001

Referral

52%

160

75%

1970–1998

Referral

95

0%

Ecarazine, halothane

1990–2002

UNOS database

270

46%

Isoniazid, propylthiouracil, phenytoin, valproate

Sweden153

1966–2002

Adverse drug reports

103

14%

Halothane, flucloxacillin, trimethoprim-sulfa

United States, United Kingdom, Canada24

1999–2004

Pediatric referral

65

74%

Valproate, isoniazid

WHO154

1968–2003

Adverse drug reports

4690

6.5%

Troglitazone, valproate, stavudine

Portugal155

1992–2006

Referral

23%

14

0%

Antimycobacterials, sulfasalazine, nimesulide

2000–2004

Population-based survey

54%

35

77%

2004–2010

HMO database

52%

32

56%

United

States11

Japan22 United

United

States21

States23

United States151

15%

19%

DILI, Drug-induced liver injury; HMO, health maintenance organization; UNOS, United Network of Organ Sharing; WHO, World Health Organization

changes with time. Friis and coworkers examined 1100 adverse drug reactions reported to the Danish surveillance system from 1978 to 1987.18 Herbal usage by persons in the United States has risen progressively over the last 50 years.19 In the most recent summary from the US Drug-Induced Liver Injury Network (DILIN), liver injury was attributed to herbals and dietary supplements in 16% of 899 cases.9 Liver injury accounts for a disproportionate amount of drug-associated mortality. In the Danish study, liver injury accounted for 5.9% of the adverse drug reactions but 14.7% of the deaths. Another study from New Zealand recorded similar findings.20 Surveys of acute liver failure (Table 23.3) show that drug-induced liver injury usually accounts for a significant proportion of cases,

from 15% of cases in the UNOS database21 to just over half of cases reported to the ALF Study Group.11 The proportion of drug-induced liver failure due to acetaminophen also varies considerably, from no cases in a Japanese cohort22 to three-quarters of cases in several US and Canadian studies.11,23,24 Besides acetaminophen, other drugs that commonly top the lists include isoniazid, valproic acid, and halothane. Similar to incidence information, it is difficult to assess the demographic factors that are associated with drug-induced liver injury. Overall, the number of reports of drug-induced liver injury appear to increase with age,18,25 but whether this is due to true differences in susceptibility or increased drug usage is not clear. In terms of specific

329

Practical Hepatic Pathology: A Diagnostic Approach Table 23.4  Classification of Drug-Induced Liver Injury by Toxicity Category Category and Subcategory

Mechanism(s)

Intrinsic

Other Features

Examples

Dose-dependent, experimentally reproducible

Direct

Toxin or metabolite reacts Results in cell necrosis with multiple targets, with usually little resulting in massive inflammation disruption

Carbon tetrachloride (hepatocytes), paraquat (cholangiocytes)

Indirect

Drug metabolite disrupts specific metabolic pathway or selectively affects particular macromolecules

Acetaminophen (necrosis, steatosis), contraceptive steroids (cholestasis)

Idiosyncratic

Effect depends on targets but usually pauci-inflammatory

Low incidence, difficult to reproduce, dose independent

Immunologic

Drug metabolite reacts Systemic symptoms Halothane, with macromolecules to and signs (fever, chlorpromazine, form hapten for B and rash, eosinophilia, nitrofurantoin, T-cell mediated immune autoantibodies), erythromycins, responses prompt recurrence to phenytoin rechallenge

Metabolic

Susceptibility to injury increased by genetic or acquired inability to detoxify or eliminate injurious metabolites

Variable time to onset, Isoniazid, valproic absence of immunoacid, amiodarone logic signs

drugs, children are more likely to be injured by asprin26 and valproic acid27 and less likely to be injured by isoniazid,28 halothane,29 and erythromycin.30 For many drugs there is either insufficient information on age-related incidence or no apparent age effect. With respect to gender, studies show either more reports of liver-related drug injury in women18,20 or similar numbers between men and women.7 Women are much more likely to develop drug-associated autoimmune hepatitis than men, just as in idiopathic autoimmune hepatitis, although the data may be confounded by prescribing bias.31

Clinical Manifestations Hepatotoxic agents are classified clinically in several ways, but a common categorization is to divide them into intrinsic and idiosyncratic hepatotoxins (Table 23.4).32 Intrinsic hepatotoxins cause injury in a dose-dependent, reproducible manner, which is usually testable in animal models. They are further subclassified as either direct, in which the agent itself is the poison, or indirect, in which the agent is metabolized reproducibly to a toxic substance. Examples of direct hepatotoxins include carbon tetrachloride, which causes zone 3 necrosis and steatosis, and the herbicide paraquat, which damages bile duct epithelium. Acetaminophen is a typical example of an indirect intrinsic hepatotoxin. Under normal conditions it is adequately metabolized and excreted by the liver, but with high doses, increased induction of cytochrome P450 2E1, or reduced stores of cellular glutathione, it is metabolized to the active metabolite N-acetyl-p-benzoquinone, which can damage the cell.33 Finally, toxicity is classified by the target of the agent, usually either the hepatocyte, resulting in hepatocyte necrosis (usually along zonal lines), or the cholangiocyte, resulting in duct destruction. The injury caused by idiosyncratic hepatotoxins is classically described as unpredictable, not dose-dependent, and of low incidence compared with the intrinsic hepatotoxins. Some dose dependence has

330

been suggested by data that show a relationship between the potential for toxicity and the overall dose. Drugs that are given at a dose of 50 mg per day or more are much more likely to be the subject of hepatotoxicity reports.34 Pharmacogenomics has provided insights into genetic alterations that increase the risk of hepatotoxicity for certain drugs.35 Idiosyncratic hepatotoxins are subdivided by mechanism of action into metabolic and immunologic hepatotoxins. Immunologic reactions to drugs have been divided into two more categories: autoimmune reactions that resemble idiopathic autoimmune hepatitis and immunoallergic reactions that are accompanied by systemic sign of hypersensitivity. Autoimmune drug reactions present clinically with elevated aminotransferases, elevated immunoglobulin, and autoantibodies, typically antinuclear antibodies.31 The onset is insidious and may develop months to years after the drug is started. Arthralgias and rash may be present and biopsies usually show a chronic hepatitis-like pattern of injury with plasma cells (see later). Nitrofurantoin, minocycline, and hydralazine are classic examples of drugs associated with autoimmune injury. More recently, the statins have been implicated in drug-induced autoimmune hepatitis.36 Immunoallergic reactions differ in that they are usually associated with systemic symptoms of hypersensitivity, including fever, rash, and eosinophilia. The rash can be very severe and some patients will have Stevens-Johnson syndrome. The latency time between starting the drug and the development of symptoms is usually less than 2 months. The symptoms will recur quickly if the patient is rechallenged with the medication. A particular type of hypersensitivity drug reaction termed DRESS (drug reaction with eosinophilia and systemic symptoms), may have liver injury as a component, often mild in comparison with the other symptoms. Liver biopsies are more likely to have eosinophils or granulomas37 and the injury can lead to vanishing bile duct syndrome. Drugs associated with immunoallergic reactions include many types of antibiotics (including sulfonamides, penicillins, and fluoroquinolone among others), certain anticonvulsants, and allopurinol. Metabolic hepatotoxins differ from the immunologic hepatotoxins in several important respects. There is a widely variable latent period before the development of jaundice and rechallenge does not cause immediate recurrence of the injury. The systemic features of hypersensitivity are absent in metabolic idiosyncrasy. Mechanisms of metabolic hepatotoxicity include genetic variation in pathways that process and detoxify drugs, competition for metabolic pathways by other drugs, or induction of pathways that lead to more toxic metabolites.38 The clinical presentations of drug-induced liver injury are almost as varied as the pathology. Patients may present in fulminant hepatic failure, with painless jaundice that mimics obstruction, with signs and symptoms of portal hypertension, with a mass lesion or with asymptomatic enzyme abnormalities. The onset may be sudden or insidious. Because most drug reactions fall into either the necroinflammatory or cholestatic categories, the biochemical changes in aminotransferases, bilirubin, and alkaline phosphatase are used to categorize the injury into a limited number of categories. In general, injuries that present mainly with aminotransferase (either alanine aminotransferase [ALT] or aspartate aminotransferase [AST]) elevations are categorized as hepatocellular injury whereas injuries characterized by elevated alkaline phosphatase are categorized as cholestatic. Injuries in which both transaminases and alkaline phosphatase are elevated are classified as mixed injuries. The ratio of ALT to alkaline phosphatase after normalization to the upper limit of normal (ULN) for each test is used to categorize this biochemical injury pattern (Table 23.5).5,39 In reports of drug injury, the ratio is obtained from the time of onset of

Liver Injury Due to Drugs and Herbal Agents Table 23.5  Biochemical Classification of Drug Injury

Table 23.6  Histologic Features That Should Prompt a Search for Drug Injury

Drug-induced liver injury is categorized based on the ratio (R) of alanine aminotransferase (ALT) to alkaline phosphatase (AP) normalized by the upper limit of normal (ULN) for each test: R = (Alt/Uln)/(Ap/Uln) Injury Category

Minimum Abnormality

R Values

Hepatocellular

ALT/ULN ≥2

R≥5

Mixed

ALT/ULN≥ 2

250%), but jaundice and splenomegaly occur late in the disease reflecting failing liver function and portal hypertension respectively. Portal hypertension can develop before the onset of cirrhosis. Primary biliary cholangitis may be associated with other autoimmune disease; the most common associations are Sjögren syndrome, CREST (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia) syndrome, scleroderma, and autoimmune thyroiditis.1,6 The majority of the patients (50% to 60%) are asymptomatic at diagnosis.1,5,7 The detection of hepatomegaly, elevated alkaline phosphatase, or antimitochondrial antibodies may provide the initial clue in these cases. Most of these patients will develop symptomatic disease within 5 years of follow up, although disease progression can be very slow in some instances.

Laboratory Findings

Liver Enzymes and Immunoglobulins The most characteristic liver enzyme abnormality is elevation of alkaline phosphatase, whereas aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels are normal or modestly elevated (typically less than 300 IU/L). Alkaline phosphatase (ALP) can be normal in early disease, and elevation is not necessary for the diagnosis. In cirrhotic cases, ALP elevation strongly correlates with severity of ductopenia and inflammation.8 Total serum immunoglobulins are increased and elevation of immunoglobulin M (IgM) is characteristic of the disease.

Autoantibodies

Antimitochondrial Antibodies AMAs are the serologic hallmark of PBC. AMAs are of several types (M1 to M9) and are directed against different mitochondrial fractions. AMA of M2 type has high specificity for PBC and is directed against the pyruvate hydrogenase complex (E2 subunit) located on the inner mitochondrial membrane.9 Both the sensitivity and specificity of AMA for the diagnosis of PBC is around 90% to 95%. AMA-M2 has been reported in around 20% of autoimmune hepatitis, and rarely in other diseases such as primary sclerosing cholangitis (PSC), Sjögren syndrome, chronic hepatitis C, drug reactions, and infections like tuberculosis and asymptomatic bacteriuria.2,4,10,11 Traditionally, AMA testing has been done by indirect immunofluorescence of distal tubules of rodent kidney and parietal cells of stomach.12 The pattern can be confused with liver-kidney microsomal (LKM) antibodies, which show reactivity in the proximal but not distal tubules or parietal cells. Enzyme-linked immunosorbent assay (ELISA) is now replacing immunofluorescence as the test of choice and measures reactivity of patient’s sera against E2 subunit of pyruvate dehydrogenase complex. The ELISA test is easier to interpret and has superior sensitivity and specificity compared with immunofluorescence.4 410

Antinuclear Antibodies Antinuclear antibodies (ANAs) are present in around 30% of PBC cases. ANAs directed against components of nuclear pore complex (anti-gp210) and nuclear bodies (anti-sp100) have high specificity for PBC (>99%), and can be useful for diagnosis if AMA is negative.13,14 However, these antibodies are present in only 10% to 25% of patients. ANA of the anticentromeric type, characteristically seen in CREST syndrome, occur in up to 10% to 25% of PBC cases.2 Anti-gp210 antibodies have been associated with severe interface hepatitis, ductular reaction, and higher progression to liver failure, whereas anticentromeric antibodies may predict risk for progression to portal hypertension.15 These associations have not been consistently reproduced across studies.16 Other Autoantibodies Smooth muscle antibodies (SMA) can occur in up to two thirds of patients with PBC.2 Antiactin antibodies can also be present but are less common. Other autoantibodies include rheumatoid factor (70%) and antithyroid antibodies (40%).

Radiologic Features Imaging techniques are helpful to exclude large duct obstruction. If PSC is a consideration, endoscopic retrograde cholangiopancreatography (ERCP) with cholangiogram or magnetic resonance cholangiopancreatography (MRCP) can be helpful in delineating the biliary tree. In advanced disease, imaging may demonstrate cirrhosis and features of portal hypertension.

Pathology

Gross Pathology The liver is enlarged in early stages and can be bile stained. Disease evolution results in macronodular cirrhosis. The cirrhotic liver is generally larger than cirrhosis resulting from viral or autoimmune hepatitis.

Microscopic Pathology

Bile Duct Injury Nonsuppurative Cholangitis. Nonsuppurative cholangitis is the hallmark of PBC.17,18 However, the distribution is heterogeneous early in the course of the disease and hence typical findings may not be seen on biopsy. The disease typically affects interlobular bile ducts smaller than 100 μm in diameter. Bile duct injury often manifests as infiltration of lymphocytes within the epithelium (lymphocytic cholangitis) (Fig. 26.1, eSlide 26.1, 26.2). Bile duct epithelial damage can manifest as cytoplasmic vacuolation, dense eosinophilic cytoplasm with shrunken nuclei, or regenerative changes such as epithelial stratification (Figs. 26.2 to 26.4). In addition to lymphocytic infiltration, ill-defined collections of epithelioid cells, or occasionally well-formed granulomas are centered on the bile duct (granulomatous cholangitis). The presence of prominent lymphocytic and/or granulomatous duct destruction is referred to as florid duct lesion (Figs. 26.5 to 26.7, eSlide 26.1, 26.2). Ductular Reaction. Ductular reaction often accompanies the bile duct injury and results from metaplasia of periportal hepatocytes or proliferation of preexisting ductules. Origin of these ductules from stem cells has also been postulated. The seepage of bile acids from the ductules can incite a neutrophilic response (acute cholangiolitis), and does not signify infection (Fig. 26.8, eSlide 26.2). Neutrophilic infiltration of the interlobular duct is uncommon. Bile Duct Loss and Ductopenia. Bile duct loss and ductopenia occur with disease progression, primarily involving the small intrahepatic ducts (Fig. 26.9). Septal and larger bile ducts may show inflammation and epithelial injury but are usually not lost (Fig. 26.10). The site of

Primary Biliary Cholangitis

26

Figure 26.1  Portal inflammation and infiltration of the bile ducts with lymphocytes (lymphocytic cholangitis). Eosinophils are usually present in variable numbers.

Figure 26.4  Lymphocytic cholangitis involving a damaged, irregularly shaped bile duct.

Figure 26.2  Bile duct injury in primary biliary cholangitis. The duct is tortuous with disorderly epithelial cells showing shrunken nuclei and eosinophilic cytoplasm.

Figure 26.5  Florid duct lesion: An inflammatory infiltrate comprising lymphocytes, plasma cells, and epithelioid histiocytes is centered on the damaged bile duct.

Figure 26.3  The damaged duct is nearly obliterated by dense inflammatory cells.

Figure 26.6  Florid duct lesion: ill-defined collections of epithelioid cells surrounding a damaged duct. 411

Practical Hepatic Pathology: A Diagnostic Approach

Figure 26.7  Nonnecrotizing epithelioid granulomas may occur away from the bile duct (right). Florid duct lesion with ill-defined epithelioid histiocytes is also seen (left).

Figure 26.10 Septal bile duct with few infiltrating lymphocytes. These ducts may show injury but are generally not lost.

the original duct can be marked by aggregates of inflammatory cells (Fig. 26.11) or a fibrous scar, and the duct remnants may be visualized by keratin 7 (K7) immunohistochemistry.6

Figure 26.8  Bile ductular reaction associated with mild neutrophilic infiltrate (acute cholangiolitis).

Figure 26.9 Late-stage PBC with ductopenia. The presence of arterioles without accompanying interlobular bile duct helps in establishing ductopenia. 412

Portal Inflammation Bile duct injury is accompanied by portal inflammation that can be intense and is composed chiefly of lymphocytes and plasma cells. The latter can be numerous and do not necessarily indicate autoimmune hepatitis (eSlide 26.2). A variable number of eosinophils is often present (Fig. 26.12). Lymphoid follicles can be seen, occasionally with germinal centers. Loose aggregates of epithelioid cells are present around or in the vicinity of the bile ducts (Fig. 26.13). Well-formed nonnecrotizing granulomas can also be present, especially in early disease. Foamy macrophages are a common finding, perhaps resulting from phagocytosis of lipids released from the damaged ducts. Neutrophils can be seen associated with the ductular reaction at the periphery of the portal tract but typically are absent or rare around the interlobular bile duct. Hepatic Parenchymal Changes A variable degree of inflammation is commonly present, but hepatocellular damage is typically minimal and acidophil bodies are few or absent (Fig. 26.14, eSlide 26.1). Ill-defined epithelioid collections and well-formed nonnecrotizing granulomas can occur. Certain distinctive morphologic features at the portal-parenchymal interface can be an important clue to the diagnosis. These features indicate chronic biliary disease and are not specific for PBC. Encroachment of the Limiting Plate. The inflammatory cells often spill over from the portal tract into the adjacent parenchyma (Fig. 26.15, eSlide 26.3). Despite the spillover, damage to periportal hepatocytes is limited. In some cases, the interface activity can be prominent and can resemble lymphocytic interface activity seen in viral and autoimmune hepatitis (Fig. 26.16). Interface activity may be predictive of development of significant fibrosis.8 Cholate Stasis. This finding becomes more prominent with disease progression but may not be seen in all cases on needle biopsies. The periportal hepatocytes are swollen and show clear cytoplasm with granular strands (feathery degeneration). Mallory hyaline may be seen in the swollen hepatocytes (Fig. 26.17). These changes are probably caused by the detergent effects of retained bile acids.19 This constellation of changes is referred to as cholate stasis and along with the

Primary Biliary Cholangitis

26

Figure 26.11  Bile duct loss marked by a prominent lymphoid aggregate infiltrate.

Figure 26.12  Lymphoplasmacytic inflammation centered on the bile duct. Scattered eosinophils and a prominent ductular reaction are also seen.

Figure 26.13  Lymphoid aggregate and loose aggregates of epithelioid cells. Lymphocytic cholangitis is also present.

Figure 26.14  Scattered foci of lobular lymphocytic inflammation and an ill-defined aggregate of epithelioid macrophages. Despite the inflammation, hepatocellular damage is minimal.

Figure 26.15 The inflammation commonly spills over into the periportal hepatic parenchyma. This interface activity is typically mild.

Figure 26.16  Moderate to marked lymphocytic interface activity is uncommon in primary biliary cholangitis (PBC) and raises the suspicion of PBC–autoimmune hepatitis overlap syndrome. 413

Practical Hepatic Pathology: A Diagnostic Approach

Figure 26.17 Cholate stasis characterized by swollen periportal hepatocytes with clear cytoplasm and cytoplasmic strands (feathery degeneration), which contain illdefined Mallory hyaline.

Figure 26.19  Mild portal inflammation and ductular reaction. The presence of canalicular cholestasis in the hepatic parenchyma makes primary biliary cholangitis unlikely because this occurs late in the course of the disease.

Figure 26.18  Granules of copper in periportal hepatocytes (rhodanine stain).

Figure 26.20  Porto-portal bridging fibrosis with entrapment of hepatocytes (Gomori trichrome stain).

accompanying ductular reaction is described sometimes as biliary interface activity. Copper Deposition. Copper is excreted in the bile and copper accumulation occurs in the liver in chronic cholestasis of any etiology. Copper is bound with proteins and typically accumulates in the lysosomes of periportal hepatocytes. It can be demonstrated by rhodanine stain (Fig. 26.18) or indirectly by orcein stain, which highlights copper-binding protein. When present, the presence of copper and copper-binding protein are helpful pointers of chronic cholestasis in early-stage disease, but they may not always be seen.20 Copper accumulation increases with increasing stage but loses its specificity for diagnosis of biliary disease if significant fibrosis is present. Keratin7 Expression. Periportal hepatocytes may strongly express K7 by immunohistochemistry, reflecting acquisition of a biliary phenotype. In conjunction with copper stain, this can help in confirming chronic cholestasis and can be a helpful feature in distinction from autoimmune hepatitis.21 Cholestasis. Although biochemical cholestasis is present early in the disease, cholestasis at the morphologic level occurs years after 414

onset of symptoms and usually heralds progression of the disease. The presence of morphologic cholestasis in the form of bile plugs (Fig. 26.19) without evidence of advanced disease argues against PBC and may reflect other abnormalities such as obstruction or adverse drug reaction. Fibrosis. Progressive ductular reaction and cholate stasis is accompanied by fibrosis. In early stages, periportal fibrosis may give the appearance of entrapment of hepatocytes in the expanded portal tract. The fibrosis extends to form porto-portal septa in small portal tracts (Fig. 26.20) and eventually leads to micronodular cirrhosis. Unlike other etiologies, cirrhotic nodules in chronic biliary disease are not typically round but are elongated and “garland-shaped” (eSlide 26.4). The nodules are interconnected and have been likened to jigsaw pieces (Fig. 26.21). The cholate stasis and ductular reaction at the periphery of the nodules create a halo effect and separate the cirrhotic nodules from the fibrous septa with dense collagen (Fig. 26.22). This is a valuable clue to biliary etiology. Another helpful pointer is the intact relationship of portal tracts and central vein even when significant fibrosis is present (monolobular fibrosis).6

Primary Biliary Cholangitis Table 26.1  Histologic Findings in Primary Biliary Cholangitis

Figure 26.21  Elongated garland-shaped cirrhotic nodules are typical of chronic biliary disease.

Feature

Significance

Caveat

AMA

Almost pathognomonic in most situations

Can be present in 20% of cases of AIH; rarely in PSC, Sjögren syndrome

Bile duct damage

Characteristic feature

Can be seen in other biliary diseases such as PSC and large duct obstruction; less commonly in chronic hepatitis C and AIH

Florid duct lesion

Nearly pathognomonic

Rarely in PSC, chronic hepatitis C, or adverse drug reaction

Prominent plasma cells

Common

Do not help in distinction from AIH

Hepatocellular damage and lymphocytic piecemeal necrosis

Typically mild

If moderate or severe, raises the possibility of AIH or PBC-AIH overlap

Cholate stasis

Often present in late stages

Nonspecific feature of chronic cholestasis; helpful in distinction from hepatitis but not from other chronic biliary diseases

NRH

Present in one third of cases in early stages

Periportal copper deposition

Often present

K7 immunohistochemistry Expression in periportal hepatocytes

26

Helpful in biliary vs. hepatic etiology in early stage but not if advanced fibrosis is present Can be useful in distinction from AIH but has not been well-studied

AIH, Autoimmune hepatitis; AMA, antimitochondrial antibody; K7, keratin 7; NRH, nodular regenerative hyperplasia; PBC, primary biliary cholangitis; PSC, primary sclerosing cholangitis.

simultaneously.5 The most advanced finding is used to designate stage.

Differential Diagnosis

Mechanical Large Bile Duct Obstruction

Figure 26.22  The elongated cirrhotic nodules are often surrounded by a rim of inflammation and ductular reaction creating an interface between the nodule and the dense fibrous bands, the so-called halo effect.

Diagnosis The diagnosis of PBC is based on three criteria: elevated alkaline phosphatase for more than 6 months, presence of serum AMA, and compatible or diagnostic histologic findings.3,5 A diagnosis can be established if two criteria are met8 (Tables 26.1 and 26.2). Liver biopsy is not considered necessary in adults with positive AMA and otherwise unexplained elevation of ALP.22 Liver biopsy is necessary in unusual settings such as negative AMA and prominent elevation of transaminases or serum IgG. In addition to the diagnosis, the biopsy provides staging information that can serve as a baseline for evaluating progression and response to therapy.2

Staging Of the several systems that have been proposed, Scheuer and Ludwig systems are the most commonly used.23,24 Both systems divide the disease into somewhat comparable four stages (Table 26.3). The disease is not uniformly distributed and all four stages may be present

Obstruction by stones, biliary stricture, and benign or malignant neoplasms can mimic PBC. Both ultrasound and computed tomography are sensitive for detection of extrahepatic biliary obstruction. AMA is negative in obstructive biliary disease. Histologically, the portal tracts show edema and a variable degree of ductular reaction, although lymphoplasmacytic inflammation is not as prominent as in PBC (Fig. 26.19). Cholestasis is generally present, beginning in the centrizonal zone. Cholestasis is not seen in early PBC.

Primary Sclerosing Cholangitis There can be considerable overlap between PBC and PSC, and the diagnosis cannot be irrefutably established on histologic findings alone (Table 26.4). History of inflammatory bowel disease strongly favors PSC. Autoantibodies can be present in PSC, but AMA is negative. On biopsy, PSC is characterized by more prominent ductular reaction and less intense lymphoplasmacytic inflammation. Periductal fibrosis and fibroinflammatory obliteration of medium- and largesized bile ducts are characteristic findings but may not present on the biopsy, as large ducts are usually not sampled (Fig. 26.23). Florid duct lesion has been reported but is rare. Granulomas can also occur but are not associated with bile ducts. Cholate stasis and periportal copper are nonspecific features of chronic cholestasis and do not distinguish PBC and PSC. The gold standard for the diagnosis of PSC is visualization of the biliary tree by cholangiography. Small duct variant of PSC can occur in the setting of inflammatory bowel disease, characterized by clinical and histologic picture compatible with PSC but with normal cholangiography. 415

Practical Hepatic Pathology: A Diagnostic Approach Table 26.2  Interpretation of Histologic Findings in Different Clinical Settings Clinical Setting

Histologic Findings

Biopsy Interpretation

Portal inflammation with no definite bile duct injury, with or without mild lobular inflammation (scenario 1)

• H  istologic findings are not diagnostic for PBC. However, because typical lesions are patchy in early disease, PBC cannot be excluded. Based on positive AMA, typical PBC is likely to develop on follow-up.

Positive AMA • With or without symptoms • W  ith or without elevated alkaline phosphatase • ALT and AST elevations 50 years; does not occur in children

Wide age range: 50% patients 255

or

4

Severe pain and ileus

Indexa

or

Stage (max.)

Volume of Diarrhea (mL/day)

0

20 mg/dL; as high as 45 mg/dL). The high bilirubin levels cause kernicterus and severe neurologic damage. Patients with type II Crigler-Najjar syndrome also present with neonatal jaundice, but they have lower unconjugated bilirubin levels, which range between 7 and 20 mg/dL. Levels may rise during illness or other stressful events and confer a risk of kernicterus, so that adult patients with Crigler-Najjar syndrome may develop new neurologic deficits. Patients with Gilbert syndrome, who have approximately 461

Practical Hepatic Pathology: A Diagnostic Approach

A

B

C FIGURE 29B.10  A, Dubin-Johnson syndrome shows a brown lipofuscin-like pigment that is present not only around the central veins but also around the portal tracts. This pigment is negative for the Prussian blue reaction (B) but stains black with the Fontana-Masson stain (C) (also see eSlide 29B.5).

25% of normal enzyme activity, present at puberty with jaundice; their unconjugated bilirubin levels range from 1 to 6 mg/dL. There is no hemolysis in these patients.91 There are no specific histologic findings. Scant bright yellow bilelike pigment may be seen within bile canaliculi and hepatocytes. Gilbert syndrome may show increased lipofuscin in hepatocytes. Phenobarbital lowers levels of bilirubin by 30% in type II CriglerNajjar syndrome, but has no effect in type I Crigler-Najjar syndrome. Liver transplantation is curative.92 Although gene therapy has resulted in long-term correction of serum bilirubin levels in the Gunn rat, these efforts have not been translated into clinical trials.93

Dubin-Johnson Syndrome Dubin-Johnson syndrome is an autosomal recessive disease that results from mutations in ABBC2 (10q24), which encodes multidrug resistance–associated protein 2 (MRP2).94 MRP2 exports anionic glutathione and glucuronate conjugates of various substances, including bilirubin, from hepatocytes into bile canaliculi. Presentation may occur at any age from infancy well into the sixth decade. Except for conjugated bilirubin in the range of 2 to 5 mg/dL, no 462

other enzyme is elevated and there is no hepatic dysfunction; neonatal Dubin-Johnson syndrome is an exception, in that a neonatal hepatitis, with high GGT, may be seen.95-97 Total urinary coproporphyrin is normal but isomer I is increased, accounting for more than 80% of the total. This in contrast to the 25% seen in normal adults. Microscopically, a coarse brown-black pigment is seen in hepatocytes after infancy; accumulation begins in perivenular hepatocytes and extends to involve the rest of the lobule (eSlide 29.5A). The pigment shares some properties with lipofuscin and melanin and stains black with the Fontana stain (Fig. 29B.10) (eSlide 29.5B). Immunohistochemical stain for MRP2 shows absence of staining in the bile canaliculi. Although extrahepatic tissues express MRP2, signs and symptoms other than conjugated hyperbilirubinemia are not described.

Rotor Syndrome Rotor syndrome is an autosomal disorder that is clinically similar to Dubin-Johnson syndrome. However, there is no pigment deposition in hepatocytes. Urinary coproporphyrin excretion is increased, with isomer I less than 80% of the total. Rotor syndrome is not allelic with Dubin-Johnson syndrome.98 No locus or gene has yet been identified.

Intrahepatic Cholestasis Suggested Readings Evanson K, Bove K, Finegold M, et al. Morphologic findings in progressive familial intrahepatic cholestasis 2 (PFIC2): correlation with genetic and immunohistochemical studies. Am J Surg Pathol. 2011;35:687–696. Floreani A, Gervasi MT. New insights on intrahepatic cholestasis of pregnancy. Clin Liver Dis. 2016;20:177–189. Jacquemin E. Role of multidrug resistance 3 deficiency in pediatric and adult liver disease: one gene for three diseases. Semin Liver Dis. 2001;21:551–562. Morotti RA, Suchy FJ, Magid MS. Progressive familial intrahepatic cholestasis (PFIC) type 1, 2, and 3: a review of the liver pathology findings. Semin Liver Dis. 2011;31:3–10. Morris AL, Bukauskas K, Sada RE, et al. Byler disease: early natural history. JPGN. 2015;60:460–466. Naik J, de Waart DR, Utsunomiya K, et al. ATP8B1 and ATP11C: two lipid flippases important for hepatocyte function. Dig Dis. 2015;33:314–318. Srivastava A. Progressive familial intrahepatic cholestasis. J Clin Exp Hepatol. 2014;4:25–36. van der Woerd WL, van Mil SW, Stapelbroek JM, et al. Familial cholestasis: progressive familial intrahepatic cholestasis, benign recurrent intrahepatic cholestasis and intrahepatic cholestasis of pregnancy. Best Pract Res Clin Gastroenterol. 2010;24:541–553. Vij M, Safwan M, Shanmugan N, et al. Liver pathology in severe multidrug resistant 3 protein deficiency: a series of 10 pediatric cases. Ann Diag Pathol. 2015;19:277–282. Wendum D, Barbu D, Rosmorduc O, et al. Aspects of liver pathology in adult patients with MDR3/ ABCB4 gene mutations. Virchows Arch. 2012;460:291–298.

References 1. de Vree JM, Jacquemin E, Sturm E, et al. Mutations in the MDR3 gene cause progressive familial intrahepatic cholestasis. Proc Natl Acad Sci U S A. 1998;95:282–287. 2. Lang C, Meier Y, Stieger B, et al. Mutations and polymorphisms in the bile salt export pump and the multidrug resistance protein 3 associated with drug-induced liver injury. Pharmacogenet Genomics. 2007;17:47–60. 3. Jacquemin E. Role of multidrug resistance 3 deficiency in pediatric and adult liver disease: one gene for three diseases. Semin Liver Dis. 2001;21:551–562. 4. Gotthardt D, Runz H, Keitel V, et al. A mutation in the canalicular phospholipid transporter gene, ABCB4, is associated with cholestasis, ductopenia, and cirrhosis in adults. Hepatology. 2008;48:1157–1166. 5. Trauner M, Fickert P, Wagner M. MDR3 (ABCB4) defects: a paradigm for the genetics of adult cholestatic syndromes. Semin Liver Dis. 2007;27:77–98. 6. Rosmorduc O, Poupon R. Low phospholipid associated cholelithiasis: association with mutation in the MDR3/ABCB4 gene. Orphanet J Rare Dis. 2007;2:29. 7. Kano M, Shoda J, Sumazaki R, et al. Mutations identified in the human multidrug resistance P-glycoprotein 3 (ABCB4) gene in patients with primary hepatolithiasis. Hepatol Res. 2004;29:160–166. 8. Ziol M, Barbu V, Rosmorduc O, et al. ABCB4 heterozygous gene mutations associated with fibrosing cholestatic liver disease in adults. Gastroenterology. 2008;135:131–141. 9. Jirsa M, Knisely A, Strautnieks S, Thompson RJ. Multidrug resistance protein 3 [MDR3] deficiency / ABCB4 disease: Thirty-four patients in twenty-two families, with clinical, histopathologic, and genetic correlations [abstr]. Hepatology. 2009;50:375A. 10. Vij M, Safwan M, Shanmugam NP, Rela M. Liver pathology in severe multidrug resistant 3 protein deficiency: a series of 10 pediatric cases. Ann Diagn Pathol. 2015;19:277–282. 11. Wendum D, Barbu V, Rosmorduc O, et al. Aspects of liver pathology in adult patients with MDR3/ABCB4 gene mutations. Virchows Arch. 2012;460:291–298. 12. Kubitz R, Droge C, Stindt J, Weissenberger K, Haussinger D. The bile salt export pump (BSEP) in health and disease. Clin Res Hepatol Gastroenterol. 2012;36:536–553. 13. Sambrotta M, Strautnieks S, Papouli E, et al. Mutations in TJP2 cause progressive cholestatic liver disease. Nat Genet. 2014;46:326–328. 14. Zhou S, Hertel PM, Finegold MJ, et al. Hepatocellular carcinoma associated with tight-junction protein 2 deficiency. Hepatology. 2015;62:1914–1916. 15. Alvarez L, Jara P, Sanchez-Sabate E, et al. Reduced hepatic expression of farnesoid X receptor in hereditary cholestasis associated to mutation in ATP8B1. Hum Mol Genet. 2004;13:2451–2460. 16. Frankenberg T, Miloh T, Chen FY, et al. The membrane protein ATPase class I type 8B member 1 signals through protein kinase C zeta to activate the farnesoid X receptor. Hepatology. 2008;48:1896–1905. 17. Cai SY, Gautam S, Nguyen T, et al. ATP8B1 deficiency disrupts the bile canalicular membrane bilayer structure in hepatocytes, but FXR expression and activity are maintained. Gastroenterology. 2009;136:1060–1069. 18. Strautnieks SS, Byrne JA, Pawlikowska L, et al. Severe bile salt export pump deficiency: 82 different ABCB11 mutations in 109 families. Gastroenterology. 2008;134:1203–1214. 19. Bull LN, van Eijk MJ, Pawlikowska L, et al. A gene encoding a P-type ATPase mutated in two forms of hereditary cholestasis. Nat Genet. 1998;18:219–224. 20. Stapelbroek JM, Peters TA, van Beurden DH, et al. ATP8B1 is essential for maintaining normal hearing. Proc Natl Acad Sci USA. 2009;106:9709–9714. 21. Folmer DE, Elferink RP, Paulusma CC. P4 ATPases—lipid flippases and their role in disease. Biochim Biophys Acta. 2009;1791:628–635. 22. Demeilliers C, Jacquemin E, Barbu V, et al. Altered hepatobiliary gene expressions in PFIC1: ATP8B1 gene defect is associated with CFTR downregulation. Hepatology. 2006;43:1125–1134. 23. Jacquemin E. Progressive familial intrahepatic cholestasis. Clin Res Hepatol Gastroenterol. 2012;36(Suppl 1):S26–S35.

24. Clayton RJ, Iber FL, Ruebner BH, McKusick VA. Byler disease. Fatal familial intrahepatic cholestasis in an Amish kindred. Am J Dis Child. 1969;117:112–124. 25. Klomp LW, Bull LN, Knisely AS, et al. A missense mutation in FIC1 is associated with Greenland familial cholestasis. Hepatology. 2000;32:1337–1341. 26. Bull LN, Carlton VE, Stricker NL, et al. Genetic and morphological findings in progressive familial intrahepatic cholestasis (Byler disease [PFIC-1] and Byler syndrome): evidence for heterogeneity. Hepatology. 1997;26:155–164. 27. Strautnieks SS, Kagalwalla AF, Tanner MS, et al. Identification of a locus for progressive familial intrahepatic cholestasis PFIC2 on chromosome 2q24. Am J Hum Genet. 1997;61:630–633. 28. Morris AL, Bukauskas K, Sada RE, Shneider BL. Byler disease: early natural history. J Pediatr Gastroenterol Nutr. 2015;60:460–466. 29. Pawlikowska L, Strautnieks S, Jankowska I, et al. Differences in presentation and progression between severe FIC1 and BSEP deficiencies. J Hepatol. 2010;53:170–178. 30. Knisely AS, Strautnieks SS, Meier Y, et al. Hepatocellular carcinoma in ten children under five years of age with bile salt export pump deficiency. Hepatology. 2006;44:478–486. 31. Scheimann AO, Strautnieks SS, Knisely AS, et al. Mutations in bile salt export pump (ABCB11) in two children with progressive familial intrahepatic cholestasis and cholangiocarcinoma. J Pediatr. 2007;150:556–559. 32. Knisely AS, Portmann BC. Deficiency of BSEP in PFIC with hepatocellular malignancy. Pediatr Transplant. 2006;10:644–645. author reply 646. 33. Iannelli F, Collino A, Sinha S, et al. Massive gene amplification drives paediatric hepatocellular carcinoma caused by bile salt export pump deficiency. Nat Commun. 2014;5:3850. 34. Vilarinho S, Erson-Omay EZ, Harmanci AS, et al. Paediatric hepatocellular carcinoma due to somatic CTNNB1 and NFE2L2 mutations in the setting of inherited bi-allelic ABCB11 mutations. J Hepatol. 2014;61:1178–1183. 35. Miyagawa-Hayashino A, Egawa H, Yorifuji T, et al. Allograft steatohepatitis in progressive familial intrahepatic cholestasis type 1 after living donor liver transplantation. Liver Transpl. 2009;15:610–618. 36. Evason K, Bove KE, Finegold MJ, et al. Morphologic findings in progressive familial intrahepatic cholestasis 2 (PFIC2): correlation with genetic and immunohistochemical studies. Am J Surg Pathol. 2011;35:687–696. 37. Sheridan RM, Gupta A, Miethke A, et al. Multiple dysplastic liver nodules in PFIC2 underscore risk for neoplasia associated with functional BSEP deficiency. Am J Surg Pathol. 2012;36:785–786. 38. El-Guindi MA, Sira MM, Hussein MH, et al. Hepatic immunohistochemistry of bile transporters in progressive familial intrahepatic cholestasis. Ann Hepatol. 2016;15:222–229. 39. Phillips MJ. The Liver: an atlas and text of ultrastructural pathology. New York: Raven Press; 1987. 40. Paulusma CC, Groen A, Kunne C, et al. Atp8b1 deficiency in mice reduces resistance of the canalicular membrane to hydrophobic bile salts and impairs bile salt transport. Hepatology. 2006;44:195–204. 41. Egawa H, Yorifuji T, Sumazaki R, et al. Intractable diarrhea after liver transplantation for Byler’s disease: successful treatment with bile adsorptive resin. Liver Transplant. 2002;8:714–716. 42. Lykavieris P, Crosnier C, Trichet C, et al. Bleeding tendency in children with Alagille syndrome. Pediatrics. 2003;111:167–170. 43. Lykavieris P, van Mil S, Cresteil D, et al. Progressive familial intrahepatic cholestasis type 1 and extrahepatic features: no catch-up of stature growth, exacerbation of diarrhea, and appearance of liver steatosis after liver transplantation. J Hepatol. 2003;39:447–452. 44. Nicastro E, Stephenne X, Smets F, et al. Recovery of graft steatosis and protein-losing enteropathy after biliary diversion in a PFIC 1 liver transplanted child. Pediatr Transplant. 2012;16:E177–E182. 45. Jara P, Hierro L, Martinez-Fernandez P, et al. Recurrence of bile salt export pump deficiency after liver transplantation. N Engl J Med. 2009;361:1359–1367. 46. Keitel V, Burdelski M, Vojnisek Z, et al. De novo bile salt transporter antibodies as a possible cause of recurrent graft failure after liver transplantation: a novel mechanism of cholestasis. Hepatology. 2009;50:510–517. 47. Lin HC, Alvarez L, Laroche G, et al. Rituximab as therapy for the recurrence of bile salt export pump deficiency after liver transplantation. Liver Transplant. 2013;19:1403–1410. 48. Morton DH, Salen G, Batta AK, et al. Abnormal hepatic sinusoidal bile acid transport in an Amish kindred is not linked to FIC1 and is improved by ursodiol. Gastroenterology. 2000;119:188–195. 49. Carlton VE, Harris BZ, Puffenberger EG, et al. Complex inheritance of familial hypercholanemia with associated mutations in TJP2 and BAAT. Nat Genet. 2003;34:91–96. 50. Zhu QS, Xing W, Qian B, et al. Inhibition of human m-epoxide hydrolase gene expression in a case of hypercholanemia. Biochim Biophys Acta. 2003;1638:208–216. 51. Gissen P, Tee L, Johnson CA, et al. Clinical and molecular genetic features of ARC syndrome. Hum Genet. 2006;120:396–409. 52. Gissen P, Johnson CA, Morgan NV, et al. Mutations in VPS33B, encoding a regulator of SNAREdependent membrane fusion, cause arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome. Nat Genet. 2004;36:400–404. 53. Cullinane AR, Straatman-Iwanowska A, Zaucker A, et al. Mutations in VIPAR cause an arthrogryposis, renal dysfunction and cholestasis syndrome phenotype with defects in epithelial polarization. Nat Genet. 2010;42:303–312. 54. Muller T, Hess MW, Schiefermeier N, et al. MYO5B mutations cause microvillus inclusion disease and disrupt epithelial cell polarity. Nat Genet. 2008;40:1163–1165.

29B

463

Practical Hepatic Pathology: A Diagnostic Approach 55. Sato T, Mushiake S, Kato Y, et al. The Rab8 GTPase regulates apical protein localization in intestinal cells. Nature. 2007;448:366–369. 56. Peters J, Lacaille F, Horslen S, et al. Microvillus inclusion disease treated by small bowel transplantation: development of progressive intrahepatic cholestasis with low serum concentrations of γ-glutamyl transpeptidase activity [abstr]. Hepatology. 2001;34:213A. 57. Girard M, Lacaille F, Verkarre V, et al. MYO5B and bile salt export pump contribute to cholestatic liver disorder in microvillous inclusion disease. Hepatology. 2014;60:301–310. 58. Visapaa I, Fellman V, Vesa J, et al. GRACILE syndrome, a lethal metabolic disorder with iron overload, is caused by a point mutation in BCS1L. Am J Hum Genet. 2002;71:863–876. 59. Fellman V, Lemmela S, Sajantila A, et al. Screening of BCS1L mutations in severe neonatal disorders suspicious for mitochondrial cause. J Hum Genet. 2008;53:554–558. 60. De Meirleir L, Seneca S, Damis E, et al. Clinical and diagnostic characteristics of complex III deficiency due to mutations in the BCS1L gene. Am J Med Genet A. 2003;121A:126–131. 61. Hinson JT, Fantin VR, Schonberger J, et al. Missense mutations in the BCS1L gene as a cause of the Bjornstad syndrome. N Engl J Med. 2007;356:809–819. 62. Chagnon P, Michaud J, Mitchell G, et al. A missense mutation (R565W) in cirhin (FLJ14728) in North American Indian childhood cirrhosis. Am J Hum Genet. 2002;71:1443–1449. 63. Drouin E, Russo P, Tuchweber B, et al. North American Indian cirrhosis in children: a review of 30 cases. J Pediatr Gastroenterol Nutr. 2000;31:395–404. 64. Aagenaes O, Sigstad H, Bjorn-Hansen R. Lymphoedema in hereditary recurrent cholestasis from birth. Arch Dis Child. 1970;45:690–695. 65. Fruhwirth M, Janecke AR, Muller T, et al. Evidence for genetic heterogeneity in lymphedemacholestasis syndrome. J Pediatr. 2003;142:441–447. 66. Bull LN, Roche E, Song EJ, et al. Mapping of the locus for cholestasis-lymphedema syndrome (Aagenaes syndrome) to a 6.6-cM interval on chromosome 15q. Am J Hum Genet. 2000;67:994–999. 67. Drivdal M, Trydal T, Hagve TA, et al. Prognosis, with evaluation of general biochemistry, of liver disease in lymphoedema cholestasis syndrome 1 (LCS1/Aagenaes syndrome). Scand J Gastroenterol. 2006;41:465–471. 68. Grammatikopoulos T, Sambrotta M, Strautnieks S, et al. Mutations in DCDC2 (doublecortin domain containing protein 2) in neonatal sclerosing cholangitis. J Hepatol. 2016;65:1179–1187. 69. Girard M, Bizet AA, Lachaux A, et al. DCDC2 mutations cause neonatal sclerosing cholangitis. Hum Mutat. 2016;37:1025–1029. 70. Guigue P, Smahi A, Parsons H, et al. Leucocyte vacuolation in neonatal ichthyosis—sclerosing cholangitis syndrome [NISCH] associated with CLDN1 disease/claudin-1 deficiency: absence after liver transplantation [abstr]. J Pediatr Gastroenterol Nutr. 2009;48:e121–e122. 71. Feldmeyer L, Huber M, Fellmann F, et al. Confirmation of the origin of NISCH syndrome. Hum Mutat. 2006;27:408–410. 72. Hadj-Rabia S, Baala L, Vabres P, et al. Claudin-1 gene mutations in neonatal sclerosing cholangitis associated with ichthyosis: a tight junction disease. Gastroenterology. 2004;127:1386–1390. 73. van Ooteghem NA, Klomp LW, van Berge-Henegouwen GP, Houwen RH. Benign recurrent intrahepatic cholestasis progressing to progressive familial intrahepatic cholestasis: low GGT cholestasis is a clinical continuum. J Hepatol. 2002;36:439–443. 74. van der Woerd WL, van Mil SW, Stapelbroek JM, et al. Familial cholestasis. progressive familial intrahepatic cholestasis, benign recurrent intrahepatic cholestasis and intrahepatic cholestasis of pregnancy. Best Pract Res Clin Gastroenterol. 2010;24:541–553. 75. Kagawa T, Watanabe N, Mochizuki K, et al. Phenotypic differences in PFIC2 and BRIC2 correlate with protein stability of mutant Bsep and impaired taurocholate secretion in MDCK II cells. Am J Physiol Gastrointest Liver Physiol. 2008;294:G58–G67. 76. Lam P, Pearson CL, Soroka CJ, et al. Levels of plasma membrane expression in progressive and benign mutations of the bile salt export pump (Bsep/Abcb11) correlate with severity of cholestatic diseases. Am J Physiol Cell Physiol. 2007;293:C1709–C1716.

464

77. Brenard R, Geubel AP, Benhamou JP. Benign recurrent intrahepatic cholestasis. A report of 26 cases. J Clin Gastroenterol. 1989;11:546–551. 78. Stapelbroek JM, van Erpecum KJ, Klomp LW, et al. Nasobiliary drainage induces long-lasting remission in benign recurrent intrahepatic cholestasis. Hepatology. 2006;43:51–53. 79. Van Mil SW, Milona A, Dixon PH, et al. Functional variants of the central bile acid sensor FXR identified in intrahepatic cholestasis of pregnancy. Gastroenterology. 2007;133:507–516. 80. Mullenbach R, Bennett A, Tetlow N, et al. ATP8B1 mutations in British cases with intrahepatic cholestasis of pregnancy. Gut. 2005;54:829–834. 81. Dixon PH, van Mil SW, Chambers J, et al. Contribution of variant alleles of ABCB11 to susceptibility to intrahepatic cholestasis of pregnancy. Gut. 2009;58:537–544. 82. Meier Y, Zodan T, Lang C, et al. Increased susceptibility for intrahepatic cholestasis of pregnancy and contraceptive-induced cholestasis in carriers of the 1331T>C polymorphism in the bile salt export pump. World J Gastroenterol. 2008;14:38–45. 83. Keitel V, Vogt C, Haussinger D, Kubitz R. Combined mutations of canalicular transporter proteins cause severe intrahepatic cholestasis of pregnancy. Gastroenterology. 2006;131:624–629. 84. Zimmer V, Mullenbach R, Simon E, et al. Combined functional variants of hepatobiliary transporters and FXR aggravate intrahepatic cholestasis of pregnancy. Liver Int. 2009;29:1286–1288. 85. Floreani A, Gervasi MT. New insights on intrahepatic cholestasis of pregnancy. Clin Liver Dis. 2016;20:177–189. 86. Wunsch E, Krawczyk M, Milkiewicz M, et al. Serum autotaxin is a marker of the severity of liver injury and overall survival in patients with cholestatic liver diseases. Sci Rep. 2016;6:30847. 87. Geenes V, Williamson C. Intrahepatic cholestasis of pregnancy. World J Gastroenterol. 2009;15:2049–2066. 88. Kadakol A, Ghosh SS, Sappal BS, et al. Genetic lesions of bilirubin uridine-diphosphoglucuronate glucuronosyltransferase (UGT1A1) causing Crigler-Najjar and Gilbert syndromes: correlation of genotype to phenotype. Hum Mutat. 2000;16:297–306. 89. Zangen S, Kidron D, Gelbart T, et al. Fatal kernicterus in a girl deficient in glucose-6-phosphate dehydrogenase: a paradigm of synergistic heterozygosity. J Pediatr. 2009;154: 616–619. 90. Fretzayas A, Kitsiou S, Tsezou A, et al. UGT1A1 promoter polymorphism as a predisposing factor of hyperbilirubinaemia in neonates with acute pyelonephritis. Scand J Infect Dis. 2006;38:537–540. 91. Powell LW, Hemingway E, Billing BH, Sherlock S. Idiopathic unconjugated hyperbilirubinemia (Gilbert’s syndrome). A study of 42 families. N Engl J Med. 1967;277:1108–1112. 92. Hoffenberg EJ, Narkewicz MR, Sondheimer JM, et al. Outcome of syndromic paucity of interlobular bile ducts (Alagille syndrome) with onset of cholestasis in infancy. J Pediatr. 1995;127:220–224. 93. Miranda PS, Bosma PJ. Towards liver-directed gene therapy for Crigler-Najjar syndrome. Curr Gene Ther. 2009;9:72–82. 94. Wada M, Toh S, Taniguchi K, et al. Mutations in the canilicular multispecific organic anion transporter (cMOAT) gene, a novel ABC transporter, in patients with hyperbilirubinemia II/Dubin-Johnson syndrome. Hum Mol Genet. 1998;7:203–207. 95. Dubin IN, Johnson FB. Chronic idiopathic jaundice with unidentified pigment in liver cells; a new clinicopathologic entity with a report of 12 cases. Medicine (Baltimore). 1954;33:155–197. 96. Lee JH, Chen HL, Ni YH, et al. Neonatal Dubin-Johnson syndrome: long-term follow-up and MRP2 mutations study. Pediatr Res. 2006;59:584–589. 97. Dubin IN. Chronic idiopathic jaundice; a review of fifty cases. Am J Med. 1958;24:268–292. 98. Hrebicek M, Jirasek T, Hartmannova H, et al. Rotor-type hyperbilirubinaemia has no defect in the canalicular bilirubin export pump. Liver Int. 2007;27:485–491.

30 Vascular Disorders of the Liver Natalia Rush, MD, and Romil Saxena, MD, FRCPath

Differential Diagnosis of Sinusoidal Congestion  467 Budd-Chiari Syndrome  468 Congestive Hepatopathy  470 Sinusoidal Obstruction Syndrome/Veno-occlusive Disease  472 Sickle Cell Disease  473 Preeclampsia 474 Hemolysis, Elevated Liver Enzymes and Low Platelets (HELLP) Syndrome 475 Portal Vein Thrombosis  475 Idiopathic Noncirrhotic Portal Hypertension  477 Obliterative Portal Venopathy  477 Nodular Regenerative Hyperplasia  479 Diseases of the Hepatic Artery  479 Ischemic Hepatitis  479 Amyloidosis 480 Abbreviations DIC disseminated intravascular coagulopathy EHPVO extrahepatic portal vein obstruction GSTM1 glutathione S-transferase M1 gene HELLP hemolysis, elevated liver enzymes and low platelets MRI magnetic resonance imaging NRH nodular regenerative hyperplasia SAAG serum-ascites albumin gradient VEGF vascular endothelial growth factor The liver receives blood from the portal vein and hepatic artery, which supply 70% and 30%, respectively, of the total hepatic blood flow. Blood from both these sources flows through and mingles in the hepatic sinusoids from where it drains into the hepatic veins and thereafter into the inferior vena cava. Metabolic exchange between hepatocytes and blood occurs within the sinusoidal bed; “smart features” that facilitate this process include low sinusoidal pressure, lack of a basement membrane, fenestrated endothelial cells, and microvilli on the sinusoidal membranes of hepatocytes that increase the surface area available for exchange.

Vascular diseases affect various components of the hepatic circulatory system with variable clinical and pathologic consequences. The Budd-Chiari syndrome results from obstruction of hepatic veins, which may occur at any level from the small hepatic veins to the junction of the inferior vena cava with the right atrium. Congestive hepatopathy results from congestion of the liver due to impedance of hepatic venous outflow caused by increased right atrial filling pressure in cardiac failure or constrictive pericarditis. Sinusoidal obstruction syndrome/veno-occlusive disease results from damage and destruction of endothelium lining the sinusoids and central veins leading to fibrous occlusion of the central veins. All these conditions share the microscopic features of sinusoidal dilatation and congestion, which is accompanied by variable degrees of hepatic trabecular thinning/atrophy and perisinusoidal fibrosis. Diseases that affect the portal venous system include portal vein thrombosis and obliterative portal venopathy. The hepatic artery may rarely be involved in vasculitides that affect arteries of similar size; overall, however, diseases that primarily affect the hepatic artery are rare. Hepatic artery thrombosis and occlusion of the hepatic artery by foamy macrophages in chronic rejection (arteriopathic rejection or foamy arteriopathy) are conditions specific to the liver allograft. Finally, the liver may be involved by systemic processes such as amyloidosis and sickle cell disease that affect hepatic circulation. Ischemic hepatitis represents anoxic/hypoxic damage to the liver from a variety of systemic causes. Nodular regenerative hyperplasia of the liver is associated with a wide range of systemic conditions that predispose the liver to regional irregularities of blood flow.

Differential Diagnosis of Sinusoidal Congestion A significant number of vascular alterations in the liver result in sinusoidal congestion with or without other accompanying hemorrhage (Box 30.1). Budd-Chiari syndrome, congestive hepatopathy, and sinusoidal obstruction syndrome/veno-occlusive disease all cause sinusoidal congestion with or without hemorrhage, atrophy of the hepatic trabecula, and perisinusoidal fibrosis. The changes are diffuse in congestive hepatopathy whereas they tend to be patchy in BuddChiari syndrome and sinusoidal obstruction syndrome/veno-occlusive disease. Sinusoidal congestion may be present in ischemic hepatitis as many patients have preexisting congestive cardiac failure. The clinical context greatly aids in the distinction of these conditions from each 467

Practical Hepatic Pathology: A Diagnostic Approach Box 30.1  Conditions That Cause Prominent Sinusoidal Congestion With or Without Accompanying Hemorrhage Budd-Chiari syndrome (eSlide 30.1 and eSlide 30.2) Sinusoidal obstruction syndrome/veno-occlusive disease (eSlide 30.5) Congestive hepatopathy (eSlides 30.3 and 30.4) Ischemic hepatitis (eSlide 30.12) Sickle cell disease (eSlide 30.6) Hemophagocytic lymphohistiocytosis (eSlide 1.12) Compression from adjacent space occupying lesion Preeclampsia Hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome

other. Sinusoidal congestion may be the predominant finding in sickle cell disease as well as hemophagocytic lymphohistiocytosis. The latter is characterized by pancytopenia, marked hyperferritinemia, and presence of phagocytosed red blood cells and lymphocytes within Kupffer cells (Fig. 30.1) (see eSlide 1.12). Sinusoidal congestion is seen adjacent to space-occupying lesions and is caused by compression of venous outflow by the mass lesion. Sinusoidal congestion may be accompanied by a ductular reaction in portal tracts if the mass lesion also compresses bile ducts. The combination of sinusoidal congestion and ductular reaction may be the only finding in liver biopsies that miss a targeted lesion and sample the adjacent parenchyma (Fig. 30.2). Sinusoidal congestion with hemorrhage and fibrin deposition is a feature of preeclampsia and hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome, albeit these are most prominent in the periportal regions as opposed to the preferential centrilobular localization in the conditions mentioned earlier.

Figure 30.1  Hemophagocytic lymphohistiocytosis shows activated Kupffer cells, identifiable by their bean-shaped nuclei, some of which contain aggregates of degenerating red blood cells (arrows) (eSlide 1.12).

Budd-Chiari Syndrome Budd-Chiari syndrome results from obstruction of the hepatic venous system at any level from the small hepatic veins to the junction of the inferior vena cava with the right atrium. The level of obstruction can be classified as small hepatic vein obstruction, large hepatic vein obstruction, inferior vena cava obstruction, or variable combination of these sites. In a series of 237 patients from Europe with Budd-Chiari syndrome, obstruction occurred in the hepatic vein, inferior vena cava, or both in 62%, 7%, and 31% of cases, respectively.1 Obstruction of the hepatic veins is common in Western countries whereas obstruction of the inferior vena cava alone or in combination with hepatic veins is more common in Asia. Because of these distinct geographic observations, the term obliterative hepatocavopathy has been preferred for cases that involve the inferior vena cava. However, because hepatic vein thrombosis and thrombophilias are also present in many of these cases, the term Budd-Chiari syndrome is recommended for all cases of hepatic venous outflow obstruction, irrespective of the site of obstruction.2,3 Etiopathogenesis Obstruction to venous outflow in Budd-Chiari syndrome may be caused by pathologic lesions affecting the veins themselves or by compression or invasion from extrinsic lesions; these are referred to as primary and secondary Budd-Chiari syndrome, respectively. Lesions that have been identified in primary Budd-Chiari syndrome include thrombosis, endoluminal webs or membranes, subendothelial thickening, and stenosis in the obstructed segment. Thrombosis is more often reported in Western patients whereas endoluminal webs and membranes predominate in Asia. An underlying prothrombotic state can be identified in the majority of cases.4 In cases where thrombosis cannot be identified but endoluminal webs or stenosis are present, primary endophlebitis and congenital malformations have been suggested as the underlying pathogenetic mechanisms. In some of these cases, however, an underlying prothrombotic state can 468

Figure 30.2  Sinusoidal dilatation and congestion with mild ductular reaction representing effects of venous and biliary compression, respectively by an adjacent large cyst.

be demonstrated suggesting that the webs, membranes, and stenosis represent clinically silent prior thrombi that have been recanalized. The most frequent prothrombotic conditions associated with BuddChiari syndrome are primary myeloproliferative disorders, antiphospholipid syndrome, paroxysmal nocturnal hemoglobinuria, Behcet disease, and deficiencies of antithrombin, protein C, protein S, and Factor V Leiden. Almost half of all patients diagnosed with myeloproliferative disorder have occult disease,5 which is detected by the presence of dystrophic megakaryocytes in the bone marrow, endogenous erythroid colony formation in culture of bone marrow or circulating progenitors and detection of V617F activating mutation of JAK2 tyrosine kinase in blood cells.2,4,5 Budd-Chiari syndrome is also associated with pregnancy, postpartum period, oral contraceptive use, and ulcerative colitis, all of which represent procoagulant states. Incidence and Demographics There are wide geographic variations in the incidence of Budd-Chiari syndrome. One of the highest incidences has been reported from Nepal where Budd-Chiari syndrome accounted for 17.3% of admissions over a 3-year period to a liver unit in Kathmandu.6 The most

Vascular Disorders of the Liver recent statistics from a population-based study from South Korea reported an incidence of 0.87 per million and prevalence of 5.29 per million.7 The estimated incidence in the West is 1 in 2.5 million per person-year.4 Clinical Manifestations Budd-Chiari syndrome usually presents in the third to fourth decades of life; a female preponderance is reported in some series whereas others show no gender preference.1,4,5 The classic presentation is characterized by a triad of abdominal pain, ascites, and hepatomegaly. However, the clinical spectrum of Budd-Chiari syndrome encompasses a range from complete lack of symptoms to fulminant liver failure with asymptomatic presentation accounting for 20% of cases.8 The clinical presentation depends on the extent and rate of progression of venous outflow obstruction and can be classified into fulminant, acute, subacute, and chronic. Fever, edema of the lower extremities, esophageal varices, and hepatic encephalopathy are other manifestations of Budd-Chiari syndrome. Thrombosis of the extrahepatic portal vein has been detected in about 15% of patients with Budd-Chiari syndrome.9,10 Laboratory Findings There are no sensitive or specific set of laboratory tests for diagnosis of Budd-Chiari syndrome or evaluation of its severity. Serum aminotransferase and alkaline phosphatase may be normal or increased. Serum levels of albumin and bilirubin as well as protein levels in ascetic fluid are variable. Ascites protein content above 3.0 g/dL and a concentration of serum-ascites albumin gradient (SAAG) ≥1.1 g/dL are suggestive of Budd-Chiari syndrome; these values overlap with ascites due to cardiac and pericardial disease. Serum creatinine level may be elevated because of prerenal dysfunction. An important goal of laboratory workup is the detection of an underlying prothrombotic condition. While standard laboratory analysis with chemistry and blood panels, liver, and kidney function tests offer little to no help in diagnosis, they provide insight about the severity of the disease, the risk of mortality, and the likelihood of response to therapy. Radiologic Features Budd-Chiari syndrome can be accurately diagnosed on x-ray venography and Doppler sonography. Features characteristic of Budd-Chiari syndrome demonstrable by Doppler sonography include a large hepatic vein with no, reversed, or turbulent blood flow; large intrahepatic or subcapsular collaterals; a spider-web appearance located in the vicinity of hepatic vein ostia, coupled with absence of a normal hepatic vein; absent or flat hepatic vein wave form without fluttering; and presence of a hyperechoic cord in place of a normal hepatic vein.2 The liver parenchyma shows a heterogeneous appearance. Magnetic resonance imaging is not as effective as Doppler sonography in demonstrating intrahepatic collaterals.11 Computed tomography is not a preferred modality because of a very high false positive rate. Gross Pathology The liver is enlarged in early disease when there is congestion without parenchymal atrophy or fibrosis. As the latter sets in, the liver shrinks in size. Patchy areas of atrophy lead to irregularly distributed regenerative nodules of varying sizes. In long-standing cases therefore, the liver may be nodular with irregular contours arising from randomly distributed areas of scarring interspersed with regenerative nodules. Kim et  al. described an explanted liver of a 31-year-old patient with multiple randomly distributed nodules containing fibrous scars that resembled focal nodular hyperplasia.12 The caudate lobe is enlarged in most patients with long-standing Budd-Chiari syndrome because it drains separately into the inferior vena cava, which allows it to undergo compensatory hypertrophy.

30

Figure 30.3  The liver in Budd-Chiari syndrome shows a mottled appearance with areas of congestion alternating with green areas of cholestatic parenchyma. A large sublobular hepatic vein (arrows) is obliterated by organizing fibrous thrombus. Fresh thrombi were present elsewhere in the liver (inset) (eSlide 30.2).

The cut surface of the liver shows a mottled appearance with dark areas of congestion alternating with noncongested parenchyma. The underlying obstructive lesions, such as fresh or organizing thrombi, webs, membranes, or stenosis, may be seen in the hepatic veins (Fig. 30.3). Microscopic Pathology Obstruction of venous outflow leads to sinusoidal dilatation and congestion accompanied by thinning and eventual atrophy of the hepatic trabecula. In severe cases, there may be hemorrhagic necrosis of the hepatic parenchyma. These changes are most prominent around the central veins (Fig. 30.4A–B) (eSlide 30.1). Fibrosis begins in the perivenular regions as thin perisinusoidal fibers and progresses to fibrous septa bridging adjacent central veins or central veins to portal tracts with continuing parenchymal atrophy and extinction. Atrophy of the nondraining portions of the liver lead to compensatory hypertrophy, which appear as trabecular thickening or nodularity, in areas where there is no venous obstruction. Large regenerative nodules, which often appear cholestatic, are commonly seen in advanced Budd-Chiari syndrome. The veins may show fresh or organized thrombi or intimal thickening and fibrosis (Fig. 30.5) (eSlide 30.2). Changes in Budd-Chiari syndrome are not uniform throughout the liver, varying both in severity and localization between different regions in the same liver and between individuals. The findings in a needle biopsy therefore depend on the region that is sampled and do not reliably indicate severity or extent of damage. However, a liver biopsy is the only means to diagnose the small hepatic vein variant of Budd-Chiari syndrome. In these cases, imaging studies demonstrate patent large veins.13 Treatment and Prognosis Therapy is aimed at preserving hepatic function by expediently alleviating venous obstruction and preventing extension of thrombosis. Strategies used to achieve these twin goals include anticoagulant and thrombolytic agents, angioplasty, stenting, insertion of a transjugular intrahepatic portosystemic shunt, and treatment of the underlying prothrombotic state. Orthotopic liver transplantation is indicated for patients with acute liver failure or those who do not respond to placement of a transjugular intrahepatic portosystemic shunt. Overall 5-year survival rates approach 80%.2 469

Practical Hepatic Pathology: A Diagnostic Approach

A

B Figure 30.4  A and B, Perivenular sinusoidal dilatation with congestion and hemorrhage in Budd-Chiari syndrome. There is no inflammation (eSlide 30.1).

Incidence and Demographics The precise incidence and prevalence of passive hepatic congestion are difficult to determine because a significant number of patients are asymptomatic and diagnosis is usually made on autopsy specimens or during workup for cardiac transplantation. In one of the largest series examining histologic features of cardiac hepatopathy in living patients, the median age of the 83 patients was 55 years (range, 14–84 years) and the majority (80%) were men.16

Figure 30.5  Thrombus in a small hepatic (central) vein in a patient with ulcerative colitis who developed Budd-Chiari syndrome (eSlide 30.1).

Congestive Hepatopathy Congestive hepatopathy is also referred to as chronic passive venous congestion, passive hepatic congestion, and cardiac-related venous congestion. Etiopathogenesis As all the above terms indicate, congestive hepatopathy results from passive congestion of the liver in patients with right-sided heart failure because blood fails to drain adequately from the liver because of increased filling pressures in the right ventricle. Poor perfusion due to low cardiac output in patients with cardiac disease is also thought to contribute to liver damage.14 In an experimental murine model of congestive hepatopathy, chronic hepatic congestion was shown to cause sinusoidal thrombosis and mechanic strain, which in turn promoted hepatic fibrosis. Marked fibrin deposition and alpha-smooth muscle actin expression were demonstrated in areas of hepatic fibrosis in both the murine model and in liver specimens of patients with congestive liver disease.15 470

Clinical Manifestations Liver dysfunction in congestive hepatopathy is usually mild and asymptomatic and often detected incidentally on routine biochemical testing. Jaundice and ascites due to portal hypertension may be present in advanced disease when there is significant fibrosis. On physical examination, patients may have tender hepatomegaly, sometimes massive, with a firm and smooth liver edge. Signs and symptoms of heart failure such as jugular venous distention, leg edema, and dyspnea are seen frequently in patients with congestive hepatopathy. Laboratory Findings The most common laboratory finding is elevation of total serum bilirubin level, most of which is unconjugated. Alkaline phosphatase levels may be mildly elevated. Marked elevations in serum aminotransferases may be seen if there is superimposed ischemic hepatitis. Diagnostic paracentesis in patients with congestive hepatomegaly usually reveals high protein content in ascetic fluid and a SAAG greater than 1.1 g/dL. Radiologic Features Imaging studies demonstrate an enlarged, heterogeneous liver in acute or early cardiac disease whereas the liver appears small and nodular with long-standing disease.17 All hepatic veins appear dilated on sonography.18 Computed tomography demonstrates dilatation of the inferior vena cava and hepatic veins in the arterial phase whereas the parenchymal phase shows a heterogeneous, mottled mosaic pattern of enhancement, with linear and curvilinear areas of poor enhancement that correspond to small and medium-sized hepatic veins.17 An echocardiogram demonstrates increased pulmonary artery pressure, dilatation of right side of the heart, tricuspid regurgitation, and abnormal diastolic ventricular filling.18

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Figure 30.8  Perivenular sinusoidal dilatation with dense fibrous septa radiating out from the central zone in a patient with congestive cardiac disease (eSlide 30.4). Table 30.1  Congestive Hepatic Fibrosis Score20

Figure 30.6  Diffuse, evenly spaced dark areas of congestion alternating with normal noncongested parenchyma (“nutmeg” liver) in a patient with congestive cardiac disease.

Figure 30.7  Perivenular sinusoidal dilatation and congestion with delicate perisinusoidal fibrosis in a child with Ebstein anomaly (Masson trichrome stain) (eSlide 30.3).

Gross Pathology On gross examination, the size, texture, and color of the liver depends upon the relative contributions of congestion and fibrosis. When there is little or no fibrosis, the liver is enlarged, with a purple or reddish hue and prominent hepatic veins. The cut surface shows a “nutmeg” appearance, the dark areas reflect centrilobular areas of congestion, which alternate with noncongested periportal areas (Fig. 30.6). As fibrosis sets in, the liver shrinks in size, is harder in consistency, and may have a finely nodular appearance. Microscopic Pathology The venous stasis of congestive hepatopathy is characterized by dilatation and congestion of central veins and perivenular sinusoids. This is accompanied by variable degrees of hepatic trabecular atrophy and

0

No fibrosis

1

Fibrosis in central zone only

2A

Fibrosis in central and portal zones, with accentuation of fibrosis in central zone

2B

Moderate portal fibrosis and central zone fibrosis, with accentuation of fibrosis in portal zone

3

Bridging fibrosis

4

Cirrhosis

perisinusoidal fibrosis (Fig. 30.7) (eSlide 30.3). The degree and extent of these changes depend on the severity and duration of the underlying cardiac disease. As congestion persists, the atrophic hepatocytes disappear and are replaced by fibrous tissue; both cell loss and fibrosis extend between (bridge) adjacent central veins and sometimes between central veins and portal tracts (Fig. 30.8) (eSlide 30.4). Although portal tracts do not show any changes in the early stages, a mild ductular reaction usually appears. Inflammation, portal or lobular, is not a predominant finding. Variable degrees of cholestasis with occasional bile thrombi in the canaliculi may be apparent. Interestingly, perivenular (zone 3) hepatocytes express keratin 7 (K7) in the majority of cases, and in some, K7 expression extends to zone 2 hepatocytes.19 Extensive K7 expression is associated with higher levels of total bilirubin as well as with presence of fibrosis. A liver biopsy is not necessary to make the diagnosis of congestive hepatopathy except in cases with unusual or atypical clinical features. It is most often performed to get an estimate of the extent of parenchymal damage and fibrosis. A histologic fibrosis score for congestive hepatopathy that correlates well with echocardiographic and hemodynamic parameters is shown in Table 30.1.20 Treatment and Prognosis The presence of portal fibrosis is suggestive of more advanced disease, as it correlates with more severe impairment of right heart function, regardless of the underlying etiology.20 Increased serum bilirubin levels have been associated with poor prognosis.21 Overall, liver disease in these patients does not contribute to mortality.18 The primary objective is to treat underlying heart disease. If heart failure is treated successfully, the early histologic changes of congestive hepatopathy may resolve, and cardiac fibrosis may regress histologically and clinically.22 471

Practical Hepatic Pathology: A Diagnostic Approach

Sinusoidal Obstruction Syndrome/Veno-occlusive Disease Pyrrolizidine alkaloids in herbal teas (eg, Jamaican bush tea) extracted from plants of Senecio and Crotalaria species have long been known to cause veno-occlusive disease. However, in the contemporary medical setting, a number of therapeutic interventions constitute the main causes of veno-occlusive disease. Animal models developed to study iatrogenic veno-occlusive disease have revealed that initial toxic damage occurs to sinusoidal endothelial cells with occluded central veins representing sequela of this damage. Therefore, the terms sinusoidal obstruction syndrome or sinusoidal obstruction syndrome/venoocclusive disease are preferred over the term veno-occlusive disease. Etiopathogenesis Sinusoidal obstruction syndrome occurs most commonly after bone marrow transplantation, hemopoietic stem cell transplantation, solid organ transplantation, radiotherapy, and various chemotherapeutic agents, specifically, oxaliplatin for hepatic metastasis of colorectal carcinoma treated by partial hepatectomy. Increasing use of herbal and nutritional supplements, which are often nonstandardized and nontested formulations, cause sporadic cases of sinusoidal obstruction syndrome. Toxic damage to endothelial cells lining sinusoids and central veins causes them to detach and slough off. This leads to extravasation of red blood cells into the space of Disse and obstruction of sinusoids and central veins by clumps of detached endothelial cells mixed with leucocytes and fibrin recruited by activated inflammation and coagulation cascades. As the lesion progresses, there is hemorrhage and necrosis of hepatocytes. Resolution occurs by formation of fibrous tissue along the sinusoids (perisinusoidal fibrosis) and within the central veins leading to venous obliteration.23-25 Individuals with the null phenotype of the glutathione S-transferase M1 (GSTM1) gene or with polymorphisms that decrease its activity are at increased risk of developing sinusoidal obstruction syndrome, underscoring the central role of this enzyme in detoxification of xenobiotics.26,27 Nitric oxide depletion, increased intrahepatic expression of matrix metalloproteinases, and vascular endothelial growth factor (VEGF)23-25 are observed in experimental sinusoidal obstruction syndrome; corrections of these abnormalities leads to alleviation of the pathology in experimental models. Incidence and Demographics A meta-analysis of 135 studies performed between 1979 and 2007 places the overall mean incidence of sinusoidal obstruction syndrome following hematopoietic stem cell transplantation at 13.7%.28 However, the incidence depends greatly on the chemotherapeutic conditioning regimens for hemopoietic stem cell transplantation as evidenced by incidences ranging from 5% to 50% in a multicenter European study.29 Clinical Manifestations The severity of sinusoidal obstruction syndrome ranges from mild to severe with no requirement for treatment to multiorgan failure (respiratory, cardiac, renal) and death, respectively.30 Clinically, sinusoidal obstruction syndrome presents with jaundice, development of right upper-quadrant pain and tender hepatomegaly, ascites, and unexplained weight gain. Liver biopsy provides definitive diagnosis of sinusoidal obstruction syndrome. However, it is risky in patients who are already thrombocytopenic. Diagnosis is thus based primarily on clinical findings outlined in the modified Seattle or Baltimore criteria30-32 (Box 30.2). 472

Box 30.2  Clinical Criteria for Diagnosis of Sinusoidal Obstruction Syndrome/ Veno-occlusive Disease30 Modified Seattle Criteria31 Two of the following three criteria within 20 days of transplant • Bilirubin >34.2 μmol/l (2 mg/dL) • Hepatomegaly or right upper quadrant pain • Weight gain (>2% from pretransplant weight) Baltimore Criteria32 Bilirubin >34.2 μmol/l (2 mg/dL) within 21 d of transplant and two of the following three criteria: • Hepatomegaly • Ascites • Weight gain (>5% from pretransplant weight)

Figure 30.9  Liver with sinusoidal obstruction syndrome shows mottled appearance arising from centrilobular congestion and hemorrhage. The severity of disease is variable across the liver (eSlide 30.5).

Laboratory Findings Hyperbilirubinemia is seen within a few days of onset of sinusoidal obstruction syndrome followed by an increase in transaminases and alkaline phosphatase. Radiologic Features Radiologic studies are useful in excluding other hepatic vascular disorder. Reverse blood flow in a segment of portal vein by color Doppler sonography is a useful feature for early diagnosis of sinusoidal obstruction syndrome.33 Gross Pathology In the acute phase, the liver is enlarged and has a mottled, hemorrhagic appearance (Fig. 30.9). In chronic disease, it may be shrunken and hard because of fibrosis. Microscopic Pathology The observed changes in a liver biopsy depend upon when the specimen was obtained along the natural history of the disease process. In the acute phase, sinusoidal obstruction syndrome shows varying degrees of centrilobular sinusoidal dilatation, congestion, and hemorrhage with damage and loss of hepatocytes. The central veins show intimal edema, detached endothelial cells, and subendothelial extravasation of red blood cells (Fig. 30.10A–C) (eSlide 30.5A–B and eSlide 23.10). Fragmented red blood cells, fibrinogen, and Factor VIII/von Willebrand factor can be demonstrated in the subendothelial space of central veins and perivenular zones of hepatic acini.34 Because of the patchy nature of the disease process, the characteristic pathology may not be encountered in every liver biopsy. Over

Vascular Disorders of the Liver

30

A

B

C Figure 30.10  Sinusoidal obstruction syndrome with extensive and severe perivenular sinusoidal congestion and hemorrhage. Two central veins (arrows) (A) show luminal narrowing due to intimal edema, fibrosis, and extravasation of red blood cells (B and C). C, Masson trichrome stain (eSlide 30.5; also see eSlide 20.10).

days to weeks, collagen deposition occurs in and around the affected terminal hepatic venules. Over the ensuing weeks and months, dense perivenular fibrosis radiates out into the parenchyma from the central veins, which may not be visible any longer (Fig. 30.11). Sinusoidal and venous lumen are obliterated by type I, III, and IV collagen accompanied by an increase in the stellate cells that line the sinusoids.34,35 Congestion is no longer present or is only minimal. Hemosiderin-laden macrophages may be present. Treatment and Prognosis Management of sinusoidal obstruction syndrome consists of supportive care including diuresis, transfusion, and analgesia. Phase III clinical trials demonstrated that defibrotide, an oligonucleotide with local antithrombotic, antiischemic, and antiinflammatory activity, is a promising therapeutic option for severe sinusoidal obstruction syndrome.36

Sickle Cell Disease Etiopathogenesis Sickle cell disease is an autosomal recessive disorder caused by mutation of a single nucleotide in the gene encoding for the globin chain of hemoglobin, which results in the substitution of valine for glutamic acid. The resultant hemoglobin S polymerizes into long chains under

Figure 30.11  Chronic sinusoidal obstruction syndrome showing dense fibrous septa obliterating central veins and perisinusoidal fibrosis in a patient who had received chemotherapy many months earlier.

473

Practical Hepatic Pathology: A Diagnostic Approach conditions of low oxygenation causing red blood cells to acquire an elongated “sickle” shape. Being less flexible than normal red blood cells, sickle cells are unable to pass through small capillaries leading to microvascular occlusion, which causes infarction in various organs including the liver and spleen. The spleen is atrophic by early childhood in most patients with sickle cell disease, increasing their susceptibility to infections, especially by encapsulated bacteria. Parenchymal infarcts, such as in the liver, may get infected leading to abscess formation. Occasionally obstruction of large hepatic or portal veins may occur in sickle cell disease.37 Sickle cells are also fragile with a life span of 10 to 20 days compared to the 120-day life span of normal biconcave red blood cells. This leads to hemolysis, anemia, reticulocytosis, and ineffective hemopoiesis. A constant hemolytic state is responsible for the increased incidence of cholelithiasis in patients with sickle cell disease at a young age. Bilirubin stones being smaller than cholesterol stones easily pass into the bile duct leading to choledocholithiasis. Anemia and hemolysis necessitate blood transfusions setting the stage for hemosiderosis and predisposition to acquiring hepatitis C infection before screening was implemented. Incidence and Demographics Sickle cell disease is estimated to affect 1 out of every 70,000 to 100,000 individuals in the United States, 1 out of every 500 African American births and 1 out of every 36,000 Hispanic American births. The heterozygous sickle trait is found in 8% to 10% of African American population. The frequency of liver involvement is estimated to be 10% to 39% in patients hospitalized with vasoocclusive crises.38 Clinical Manifestations Liver involvement in sickle cell disease may present acutely with right-sided abdominal pain and tender hepatomegaly. Accompanying severe chest pain and joint pain indicate vasoocclusive crisis. Laboratory tests show preserved synthetic function and a cholestatic or mixed rather than purely hepatocellular pattern of injury. Fever and leukocytosis accompanying tender hepatomegaly suggest acute hepatic crisis; transaminases are elevated 1 to 3 times over normal values. Fever and leukocytosis with right upper abdominal pain also herald acute cholecystitis, which is differentiated from acute hepatic crisis by absence of tender hepatomegaly. Acute hepatic sequestration is characterized by a marked drop in hematocrit with appropriate reticulocytosis and jaundice in addition to tender hepatomegaly and right upper quadrant pain. Tender hepatomegaly and right upper quadrant pain may also result from hepatic infarction due to microvascular occlusion. Liver involvement in sickle cell disease may present with features of chronic liver disease in patients with hemosiderosis, chronic viral hepatitis or chronic biliary disease. Sickle cell disease itself seems to cause chronic liver disease as suggested by the high rate of liver cirrhosis in young patients with SCD; this is attributed to parenchymal loss and fibrosis resulting from repeated small, clinically silent microvascular occlusions.39 Rarely, patients present with hepatic abscess resulting from superimposed infection of infarcted tissue. Laboratory Findings The most common laboratory findings are an elevation of unconjugated bilirubin level, anemia, and reticulocytosis. A cholestatic profile is seen in vasoocclusive crisis whereas elevations in transaminases are seen in acute hepatic crisis along with fever and leukocytosis. The latter are also present in cholecystitis with upper quadrant pain but no tender hepatomegaly. A precipitous drop in hematocrit accompanied by an appropriate reticulocytosis signifies hepatic sequestration. 474

Radiologic Features Nonenhanced blood vessels on computed tomography (CT) scan of the liver are due to increased hepatic density from hemosiderosis and decreased blood density from anemia.40 On magnetic resonance imaging (MRI), liver iron concentration is inversely correlated with T2 values as a result of the paramagnetic properties of hemosiderin.41 Gross Pathology The size, weight, and consistency of the liver in sickle cell disease depend on the relative extents of congestion, parenchymal loss due to infarction, and fibrosis. The liver may be cirrhotic in those with chronic hepatitis and hemosiderosis. The cut surface may appear dark because of deposition of hemosiderin or green because of cholestasis. Microscopic Pathology Liver biopsies from patients with sickle cell disease show dilatation of sinusoids that contain clumps and aggregates of sickled red blood cells (Fig. 30.12) (eSlide 30.6). Kupffer cell erythrophagocytosis may be present.42 This may be accompanied by varying degrees of atrophy of the hepatic trabecula, cell loss, and perisinusoidal fibrosis. Variable amount of hemosiderin is present within sinusoidal lining cells and within hepatocytes. Portal or lobular inflammation is not a prominent feature unless there is concomitant hepatitis. Portal tracts may show ductular reaction arising from choledocholithiasis. Varying degrees of portal fibrosis, related to chronic biliary disease, chronic hepatitis or hemosiderosis is present (eSlide 30.7). Infarcts may be seen. Treatment and Prognosis Treatments include blood transfusions, exchange transfusions, iron-chelating agents, hydroxyurea, and allogeneic stem-cell transplantation.39

Preeclampsia The international society for the study of hypertension in pregnancy defines preeclampsia as de novo hypertension (blood pressure 140/90 mm Hg) occurring after the 20th week of pregnancy combined with proteinuria (>300 mg/day) and evidence of maternal organ dysfunction, such as renal insufficiency, liver involvement, neurologic or hematologic complications, uteroplacental dysfunction, or fetal growth restriction.43 Preeclampsia, also known as toxemia, affects 3% to 5% of all pregnancies.44

Figure 30.12  Dilated and congested sinusoids containing clumps of elongated (“sickled”) red blood cells (eSlide 30.6).

Vascular Disorders of the Liver Etiopathogenesis Endothelial dysfunction along with platelet activation and aggregation are considered central to the pathophysiology of preeclampsia, contributing to hypertension and cardiovascular sequelae.45 Liver involvement consists of fibrin deposition within the hepatic sinusoids resulting in sinusoidal obstruction and subsequent hepatic ischaemia.46 Clinical Manifestations The diagnosis may be made in asymptomatic patients during routine antenatal care. Clinical disease presents with right upper quadrant pain, headache, visual changes, nausea, and vomiting. Hypertension, edema, proteinuria, and neurologic deficits are detected on clinical examination.47 Laboratory Findings Abnormal laboratory values include a tenfold to twentyfold elevation in aminotransferases, elevations in alkaline phosphatase levels that exceed those normally observed in pregnancy, and bilirubin elevations of less than 5 mg/dL. Elevated serum transaminases occur in 30% of cases.46,47 Radiologic Features Radiologic findings are rare and include intrahepatic, subcapsular, or extracapsular perihepatic hematomas.48 Gross Pathology Grossly subcapsular hematomas, parenchymal hemorrhage, and hepatic rupture may be observed because of the combination of hepatic sinusoidal obstruction and ischemia resulting from sinusoidal fibrin deposition.45,49 Microscopic Pathology Liver histology generally shows hepatic sinusoidal deposition of fibrin.45 Other common histologic features in patients with preeclampsia include periportal hemorrhage, necrosis, and occasional microvesicular fat.47,49

Hemolysis, Elevated Liver Enzymes and Low Platelets (HELLP) Syndrome

Radiologic Features The life-threatening complications of hepatic hemorrhage, rupture, and infarction, which have been reported in up to 45% of women with HELLP syndrome, need to be investigated by computed tomography or magnetic resonance imaging.51,52 Abnormalities in liver function test results do not accurately reflect the presence of abnormal hepatic imaging findings in HELLP syndrome.50,53 Gross Pathology The liver may show subcapsular hemorrhages, large hematomas, massive infarction, or ruptured capsule. Microscopic Pathology The findings are very similar to those seen in preeclampsia and include periportal hemorrhage with sinusoidal fibrin deposition and hepatocyte necrosis.47,49

Portal Vein Thrombosis Portal vein thrombosis refers to thrombosis that develops in the trunk of the portal vein including its right and left intrahepatic branches, which may extend to the splenic or superior mesenteric veins or towards the liver involving intrahepatic portal branches.54 Portal vein thrombosis is most commonly associated with cirrhosis and primary or metastatic hepatic malignancies. This section is restricted to noncirrhotic, nonmalignant thrombosis of the extrahepatic portal vein, that is, when portal vein thrombosis is the primary disease process. The vast majority of patients with noncirrhotic, nonmalignant portal vein thrombosis present in the chronic stage with a mass of collaterals in the hilum (cavernoma), which develop in an attempt to bypass the obstructed segment. At this stage, thrombosis may not be demonstrable. The term extrahepatic portal vein obstruction (EHPVO) has been proposed for this clinical setting, which is particularly common in the Eastern Hemisphere, particularly India, where a significant number of patients are children. Abdominal infections such as neonatal omphalitis have been implicated as the underlying cause in these cases.

Clinical Manifestations The presenting symptoms are varied and include right upper quadrant or epigastric pain in approximately 65% of cases, nausea and vomiting (35% of cases), and headache (30% of cases). Patients may also present with bleeding and jaundice.50 Patients with hepatic hematoma, infarction, or rupture may present with hypovolemic shock and cardiovascular collapse.46 Manifestations of advanced disease include disseminated intravascular coagulopathy (DIC), pulmonary edema, placental abruption, and retinal detachment.47

Etiopathogenesis In the absence of cirrhosis and malignancy, there are three main risk factors for portal vein thrombosis: (1) local inflammatory lesions such as neonatal omphalitis or inflammation of abdominal organs such as diverticulitis or appendicitis, (2) injury sustained during abdominal surgery, and (3) presence of an underlying prothrombotic state. The conditions in the last group overlap with those mentioned above for Budd-Chiari syndrome including myeloproliferative disorders, antiphospholipid syndrome, paroxysmal nocturnal hemoglobinuria, Behcet disease, deficiencies of protein C, protein S and antithrombin, and mutations of Factor V Leiden or Factor II. A mutation in JAK2 is seen in around 17% to 35% of patients of portal vein thrombosis.54 A high prevalence of nearly 10% of the prothrombin G20210A mutation has been consistently reported in patients with extrahepatic vein occlusion.55-58 Lastly, congenital anomalies of left and right vitelline veins from which the portal vein develops may also result in obstruction of the portal vein.59

Laboratory Findings Laboratory findings include hemolysis with increased bilirubin levels (usually less than 5 mg/dL) and lactate dehydrogenase levels greater than 600 IU/L, moderately elevated transaminases (200 IU/L to 700 IU/L), and thrombocytopenia (less than 100 000/mL).45 Prolonged prothrombin time, low fibrinogen, and presence of fibrin degradation products heralds disseminated intravascular coagulation.46,47 Urinalysis reveals proteinuria.

Incidence and Demographics The prevalence of portal vein thrombosis was reported to be 1% in a cohort of over 23,000 autopsies performed over 12 years, which represented 84% of all in-hospital deaths, in the city of Malmö, Sweden. The leading causes were malignancy and cirrhosis, whereas nonmalignant noncirrhotic portal vein thrombosis accounted for approximately a quarter of the cases.60

HELLP syndrome is considered a severe form of preeclampsia. It occurs in approximately 10% to 20% of women with preeclampsia.44 The pathogenesis of HELLP is thought to involve alterations in platelet activation, increases in proinflammatory cytokines, and segmental vasospasm with vascular endothelial damage.47

30

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Practical Hepatic Pathology: A Diagnostic Approach Clinical Manifestations Portal vein thrombosis may present in the acute or chronic phase; acute presentation is less common as most cases of acute portal vein thrombosis are clinically silent. Acute portal vein thrombosis usually presents with abdominal pain (91%), fever (53%), and ascites (38%), which may be small volume ascites detectable only on imaging (33%) or clinical ascites (5%).58 The abdomen may be distended by ileus but there are no features of intestinal obstruction; the discrepancy between severity of pain and absence of abdominal signs is often helpful in distinguishing abdominal vein thrombosis from peritonitis. If thrombosis extends to superior mesenteric vein and the mesenteric venous arches, causing intestinal ischemia and bowel infarction, patients may present with hematochezia, rebound tenderness, fever, and ascites.54 Patients with acute portal vein thrombosis lack evidence of portal hypertension such as splenomegaly and esophageal varices. Patients with chronic portal vein thrombosis present with complications of portal hypertension such as esophageal varices, splenomegaly, anemia, and thrombocytopenia. Bleeding esophageal varices is the commonest presentation in children with chronic portal vein thrombosis.5,61 Almost 80% of patients with EHPVO demonstrate cholangiographic changes of chronic biliary disease, referred to as portal biliopathy, portal cholangiopathy, or portal cavernoma cholangiopathy. About 20% of these patients are symptomatic,62 presenting with signs and symptoms of chronic obstructive biliary disease such as jaundice, pruritus, cholangitis, and pain. Laboratory Findings Acute portal vein thrombosis shows a marked rise in plasma levels of acute phase reactants in the absence of sepsis. Some patients may show a transient, moderate increase in serum aminotransferases. However, liver function is preserved as increased hepatic arterial blood flow compensates for the decreased portal inflow and there is rapid development of a collateral circulation. When acute portal vein thrombosis occurs because of an abdominal infection, blood cultures will be positive, usually for gram-negative organisms. Liver function test are within normal limits in patients with chronic portal vein thrombosis in the absence of underlying chronic liver disease. Coagulation factors may be decreased. Abnormal liver function tests in patients with portal vein thrombosis are seen as sequelae of chronic portal hypertension. In patients with portal biliopathy, a cholestatic biochemical profile may be seen. Radiologic Features Ultrasound is the modality of choice for detection of portal vein thrombosis; it demonstrates isoechoic or hypoechoic material completely or partially obstructing the lumen.54 Color Doppler ultrasonography reveals decreased or absent flow in the portal vein. Computed tomography and magnetic resonance imaging provide additional valuable information like extent of the thrombus, presence of bowel ischemia, and status of adjacent organs.54 Demonstration of portal cavernoma seen as replacement of portal vein by multiple small collaterals is a sign of chronic portal vein thrombosis. Gross Pathology The liver may appear slightly smaller in size in long-standing portal vein thrombosis because of parenchymal atrophy, but the shape, color, and texture are unaltered. Some cases may show nodular regenerative hyperplasia. A mass of vascular channels is seen at the porta hepatis and a normal portal vein cannot be identified.

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Figure 30.13  Diffuse and severe sinusoidal dilatation in a patient with noncirrhotic, nonmalignant extrahepatic portal vein thrombosis (eSlide 30.8).

Figure 30.14  A dilated hepatic artery with thin walls and muscularized portal vein in a patient with noncirrhotic, nonmalignant extrahepatic portal vein thrombosis (Masson trichrome stain).

Microscopic Pathology A liver biopsy is performed in patients with portal vein thrombosis to rule out cirrhosis or any underlying chronic liver disease. Morphologic changes of noncirrhotic portal vein thrombosis are often minimal and nonspecific. Features on a liver biopsy that should raise suspicion of portal vein thrombosis in a noncirrhotic patient with portal hypertension include diffuse and obvious perivenular sinusoidal dilatation with or without diffuse central venular dilatation; diffuse and obvious perivenular trabecular thinning (Fig. 30.13) (eSlide 30.8); irregular or alternate trabecular thinning and thickening with or without nodularity (eSlide 30.9); attenuated, absent or muscularized portal veins and disproportionately large, thick-walled and/or thin-walled dilated hepatic arterioles (Fig. 30.14).63 Periportal shunt vessels and mild sinusoidal fibrosis may be seen. Ductular reaction, periductal fibrosis, and even biliary cirrhosis may be seen in patients with portal biliopathy (Fig. 30.15).64 Portal vein thrombosis has been associated with nodular regenerative hyperplasia.

Vascular Disorders of the Liver Etiopathogenesis The exact etiopathogenesis of obliterative portal venopathy remains unclear. Suspected causes include genetic predisposition, recurrent bacterial infections, HIV infection, highly active antiretroviral therapy, altered immune response, hypercoagulability, collagen vascular diseases, and exposure to chemicals and certain medications.66 Associations with Turner disease and Adams–Oliver syndrome suggests genetic predisposition. A high frequency of HLA-DR3 phenotype has been reported in Indian patients.62 Frequent association with lower socioeconomic status together with data from experimental animal studies point to an infectious etiology for obliterative portal venopathy.67,68 A case-control study demonstrated an association with didanosine in patients with HIV.69

Figure 30.15  Portal cholangiopathy in a patient with portal vein thrombosis shows ductular reaction and periductal fibrosis around an interlobular bile duct.

Treatment and Prognosis Acute portal vein thrombosis is treated with anticoagulation and thrombolytic therapy. The underlying prothrombotic condition needs identification and treatment. Acute portal vein thrombosis usually has a good prognosis when treated before the occurrence of intestinal infarction.54 Therapy for chronic portal vein thrombosis consists of prevention and treatment of gastrointestinal bleeding due to portal hypertension, prevention of recurrent thrombosis, and treatment of portal cholangiopathy. A multivariate analysis done on determinants of survival in chronic portal vein thrombosis showed that advanced age, malignancy, cirrhosis, mesenteric vein thrombosis, absence of abdominal inflammation, increased serum levels of aminotransferase, and decreased albumin are associated with reduced survival and not due to complications of portal hypertension.59

Idiopathic Noncirrhotic Portal Hypertension Idiopathic noncirrhotic portal hypertension is a well-recognized clinical condition, the pathophysiology of which is not known. The term itself defines the presence of portal hypertension in the absence of cirrhosis and other known causes such as cystic fibrosis, congenital hepatic fibrosis, sarcoidosis, and Budd-Chiari syndrome. The pathologic findings in idiopathic noncirrhotic portal hypertension included nodular regenerative hyperplasia (NRH) on the one hand and varying degrees and patterns of portal fibrosis, with or without accompanying inflammatory and/or obliterative lesions of the smaller intrahepatic branches of the portal vein, on the other. The latter constellation of findings has been described by terms such as hepatoportal sclerosis, phlebosclerosis, noncirrhotic portal fibrosis, obliterative portal venopathy, and incomplete septal fibrosis. Whereas the underlying pathophysiology or exact relationship of these conditions to one another is uncertain, it is possible that all these diseases represent varying manifestations or stages of a fibroinflammatory disease process of the small and medium-sized intrahepatic branches of the portal vein. The term obliterative portal venopathy is preferentially used in this text.

Obliterative Portal Venopathy Obliterative portal venopathy is a disease of uncertain etiology that mainly affects small and medium branches of the portal vein, resulting in portal hypertension in the absence of known causes of portal hypertension.65

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Incidence and Demographics Obliterative portal venopathy is more often reported from developing countries.68 It is responsible for up to 30% of cases of portal hypertension in Japan and 3% to 5% of cases of portal hypertension in Western countries.70 In Western countries and India the disease more often affects middle-aged men while in Japan, obliterative portal venopathy is more common in middle-age women.71,72 Clinical Manifestations Patients usually present with signs of portal hypertension such as variceal hemorrhage, jaundice, ascites, encephalopathy, and hepatopulmonary syndrome. Obliterative portal venopathy has been shown to account for unexplained chronic abnormal liver function tests without portal hypertension.72a The intrasplenic and portal vein pressures are markedly elevated.67 About a quarter of patients present with extrahepatic portal vein thrombosis.73 The development of portal vein thrombosis contributes to a progressive decrease in liver volume and development of hepatic synthetic dysfunction and carries a worse prognosis and increased risk of mortality.65 Laboratory Findings Hepatic synthetic function is near normal in early disease but becomes abnormal as the disease progresses. Splenomegaly may give rise to pancytopenia, which is usually mild. Gastrointestinal bleeding may give rise to microcytic anemia. Abnormalities with coagulation cascade may be seen in advanced disease as liver function declines. Radiologic Features Radiologic investigations assist in excluding known causes of portal hypertension such as cirrhosis and portal vein thrombosis. Imaging findings may demonstrate subcapsular parenchymal atrophy, portal and parenchymal fibrosis, and portal venous thrombosis.74 There may be atrophy of the right lobe with hypertrophy of the caudate lobe.74,75 Liver ultrasonography reveals dilated portal vein and its branches and thickening of the portal vein wall.76 Extrahepatic portal vein thrombosis, intrahepatic portal abnormalities such as reduced caliber, occlusive thrombosis, focal nodular hyperplasia–like nodules, and perfusion disorders are more likely to be seen in obliterative portal venopathy than in cirrhosis on computed tomography.77 Splenorenal shunts may be seen. Gross Pathology The gross appearance of the liver varies with each case, depending on the stage and severity of the disease. In advance disease leading to transplantation, it is common to find parenchymal atrophy with liver weight below 1000 g, often arising from right lobe atrophy with hypertrophic

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Practical Hepatic Pathology: A Diagnostic Approach caudate lobe.75,78 Consistency of atrophic liver, in contrast to cirrhosis, remains soft.78 Capsular thickening, subcapsular septation with increased vascularity, and inflammatory changes are observed.79 The portal veins may be engorged and show sclerotic walls and thrombi in medium- and small-sized vessels.80 Microscopic Pathology Histologic examination is critically important and necessary to establish the diagnosis of obliterative portal venopathy and exclude cirrhosis and other cause of portal hypertension. Although there are no pathognomonic findings of obliterative portal venopathy, characteristic morphologic features of portal tracts, vascular patterns, portal vein, and hepatic parenchyma help establish a morphologic diagnosis of obliterative portal venopathy (Fig. 30.16).81 Endotheliitis of the portal vein branches, central venulitis, lymphocytic infiltration of the portal tracts, and NRH can be seen in early stages of the disease.81 Phlebosclerosis as the hallmark of obliterative portal venopathy demonstrates increased portal connective tissue and luminal narrowing, sclerosis, and obliteration of the small branches of the portal vein82 (eSlide 30.10). Hepatic vein wall thickens to a degree that it resembles hepatic arterioles. An aberrant microvasculature characterized by thinwalled numerous vessels mainly located adjacent to portal tracts and in hepatic lobules may be observed because of vascular alterations in obliterative portal venopathy.79 Herniation of dilated portal veins into

A

the parenchyma (paraportal shunt vessels) can be observed, which are sometimes referred to as megasinusoids.78 Additional morphologic features may include the presence of capillary and necroinflammatory bridging between portal tracts and hepatic terminal veins, abnormally large displaced hepatic vein branches with or without phlebosclerosis, and fibrous septa.83 Collapse of subcapsular parenchyma may be seen in advanced disease.80 In addition to NRH, focal nodular hyperplasia, incomplete septal cirrhosis, and hepatocellular carcinoma as concurrent findings in obliterative portal venopathy have been described.83,84 Nakanuma classified the disease into four stages. The liver is nonatrophic liver without subscapular atrophy in stage I disease. Stage II encompasses nonatrophic hepatic parenchyma with subcapsular atrophy. Stage III disease exhibits parenchymal atrophy, and stage IV shows obstructive thrombosis of the large intrahepatic portal veins. Large vessels thromboembolism causes direct progression from any stage into stage IV.85 Treatment and Prognosis The management of patients with obliterative portal venopathy is mainly symptomatic.66 The most important treatment is adequate management of bleeding varices, either by endoscopic or surgical means. The overall prognosis is good with occasional patients progressing to liver failure. The survival curve of OPV patients is similar to that of the general population of comparable age and sex.86

B

C Figure 30.16  A and B, Obliterative portal venopathy showing absence of portal vein branches in small terminal portal tracts (A and B). There appears to be some hyalinized tissue replacing the portal vein, best seen in A (arrows). A mild lymphocytic inflammatory infiltrate representing phlebitis is present around a vein that appears rounded and narrowed (C) (eSlide 30.10).

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Nodular Regenerative Hyperplasia Nodular regenerative hyperplasia (NRH) refers to diffuse transformation of the hepatic parenchyma into regenerative nodules in the absence of bridging fibrosis or cirrhosis. The diagnosis can only be made on microscopic examination of biopsied or resected liver tissue. Etiopathogenesis NRH appears to represent nonspecific tissue adaptation to heterogeneous distribution of blood flow within the liver parenchyma. It is believed that poor perfusion resulting from obliteration of the small branches of the portal vein causes localized parenchymal atrophy, which is followed by a compensatory hypertrophic response of parenchyma with normal or slightly increased perfusion.87,88 It is pertinent that most conditions associated with NRH represent hypercoagulable states or demonstrate a predisposition to vascular involvement. Vascular obliterative lesions are often not demonstrable because they are subclinical, affect small vessels over several years, and have usually healed by the time clinical disease manifests.87,89 Injury to sinusoidal lining cells appears to trigger NRH caused by chemotherapeutic drugs.90,91 Incidence and Demographics A study of 2500 consecutive autopsies found NRH in 2.6% of cases with an increasing incidence with age.70 In a multiinstitutional French study of 3600 liver biopsies, NRH was diagnosed in 4.4% of cases, and in 15% of patients referred for unexplained liver enzyme abnormalities.184 NRH affects males and females equally.65,92 NRH is associated with a large number of conditions, principal among which are autoimmune, rheumatologic and collagen vascular diseases, myeloproliferative disorders, monoclonal gammopathies, vascular abnormalities, and drugs/medications.87,90 NRH has been associated with congenital cardiac anomalies and portal vein agenesis. However, no associated disease was present in a third of patients in the biopsy series mentioned above.92 NRH also occurs in liver allografts following liver transplantation.90,93-97 Clinical Manifestations Patients present with signs and symptoms of portal hypertension including abdominal pain, ascites, esophageal varices, and splenomegaly. The clinical picture may be dominated by that of the underlying disease. There appears to be a prolonged asymptomatic course. In the autopsy series mentioned above, only 4.7% of patients with NRH had portal hypertension in spite of obliterated portal veins and only 38% of all patients had portal hypertension in the biopsy series.87,92 Laboratory Findings Liver tests are usually normal to slightly elevated. Elevated serum levels may variably involve transaminases, alkaline phosphatase, gamma glutamyl transpeptidase, or bilirubin. Radiologic Features Radiologic findings of NRH are subtle and often mimic cirrhosis,77 therefore NRH cannot be reliably distinguished from cirrhosis on imaging. Because ultrasound is more sensitive than computed tomography or magnetic resonance imaging at detection of parenchymal changes, it easily demonstrates the diffuse nodularity of NRH. By computed tomography, these nodules may appear hypodense with little enhancement while on magnetic resonance imaging, NRH is usually of similar signal intensity to the liver on T1, T2, and gadoliniumenhanced sequences.74

Gross Pathology The liver shows a diffusely micronodular appearance. In contrast to the firm consistency of micronodular cirrhosis, the liver is soft because of absence of fibrosis. It may be a normal tan color or appear green because of cholestasis.

30

Microscopic Pathology Microscopically, NRH is characterized by diffuse nodularity in the absence of bridging fibrosis or cirrhosis. The nodularity is caused by thinned out and atrophic trabecula in the perivenular areas alternating with thickened trabecula in the periportal areas. These changes are best appreciated on a reticulin stain (see Figs. 23.22 and 38.47 and eSlide 23.11). The hepatocytes within the nodules are arranged in plates that are more than one cell thick. They may be enlarged and have large nuclei. The hepatocytes between the nodules are small and atrophic, and are arranged as thin, parallel trabecula. Reticulin stain is essential in establishing diagnosis of NRH, as it highlights expanded liver cell plates alternating with thin, atrophic plates. The portal tracts are evenly and normally spaced. Small portal veins may be absent or occluded. Central veins may appear obliterated. There is usually none to minimal portal and lobular inflammation with intact hepatic arteries and interlobular bile ducts. Keratin 7 may be expressed by atrophic hepatocytes at the periphery of the regenerative nodules.98 Treatment and Prognosis It is not known whether NRH is a reversible condition. Treatment is aimed at removing the offending agent, if applicable, and managing complications of portal hypertension.

Diseases of the Hepatic Artery Diseases of the hepatic artery are more commonly encountered in the liver allograft, the two most common conditions being hepatic artery thrombosis and foamy arteriopathy of chronic (arteriopathic) rejection. These are discussed in Chapter 38. In the native liver, the hepatic artery may be affected by vasculitides, such as polyarteritis nodosa that affects medium-sized muscular arteries. Vasculitis of the hepatic artery may also occur in patients with collagen vascular diseases including systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, polymyositis, or Wegener granulomatosis (Fig. 30.17) (eSlide 30.11). The incidence of hepatic arteritis other than polyarteritis nodosa at autopsy in patients with collagen vascular disease has ranged from 8.3% to 25%.99 A few case reports describe an association between microscopic polyangiitis and primary biliary cholangitis.100 Liver enzyme abnormalities are often present. Reported literature on pathologic changes in the liver is limited reflecting the rarity of hepatic artery vasculitis; the most commonly reported pathologic change is nodular regenerative hyperplasia.65,99

Ischemic Hepatitis Ischemic hepatitis, also known as shock liver, refers to diffuse hepatic injury resulting from acute hypoxia of the liver. Etiopathogenesis Although ischemic hepatitis follows an episode of sudden and profound hypotension in most patients, all cases do not appear to represent a direct consequence of poor hepatic perfusion. In a case control series of 31 cases, hypotension led to ischemic hepatitis only in patients with severe underlying cardiac disease.101 An analysis of 142 episodes in the intensive care unit of a general hospital found

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* Figure 30.17  Granulomatous arteritis with obliteration of a hepatic artery branch in a patient with Wegener granulomatosis. The portal vein is patent (asterisk) (eSlide 30.11).

three main pathophysiologic mechanisms underlying ischemic hepatitis. In decompensated right heart failure and acute cardiac failure, liver hypoxia resulted from decreased blood flow (perfusion). Liver hypoxia in exacerbated chronic respiratory failure was because of hypoxemia, whereas with toxic/septic shock, hypoxia resulted from increased oxygen demand in the liver coupled with inefficient use of available oxygen.102 Incidence and Demographics Ischemic hepatitis is most often seen in the critical care setting. An incidence of 1% was reported in an intensive care unit, 2.6% in a cardiac care unit, and 22% among patients with low cardiac output.102 Ischemic hepatitis was reported in 13.8% of patients with septic shock, in whom it increases the risk of mortality by 247% (OR: 3.47).103 Clinical Manifestations Anorexia, malaise, and jaundice have been reported in patients with ischemic hepatitis. They have tender hepatomegaly, increased central venous pressure, higher pulmonary capillary wedge pressure, and lower cardiac output. The underlying clinical disease may however predominate the clinical picture. Laboratory Findings A sudden and profound elevation of serum aminotransferases of 25 to 250 times the upper limit of normal, which occurs within 1 to 3 days of the hemodynamic insult, is diagnostic of ischemic hepatitis.103 Elevation of aminotransferases is accompanied by only a minimal increase in the alkaline phosphatase.16 The transaminases fall rapidly as hemodynamic stability is restored and return to normal within a few days. Microscopic Pathology Coagulative necrosis of perivenular (zone 3) hepatocytes is characteristic of ischemic hepatitis (Fig. 30.18). Sinusoidal congestion is often an associated finding because many patients have underlying congestive hepatopathy (eSlide 30.12). There is no accompanying portal or lobular inflammation. The portal tracts appear normal without any pathologic change. Acetaminophen toxicity is a differential diagnosis

480

Figure 30.18  Ischemic hepatitis superimposed on congestive changes shows coagulative necrosis in addition to sinusoidal dilatation and congestion. Patient experienced an episode of hypotension and had a history of underlying cardiac disease (eSlide 30.12).

because it also leads to centrilobular coagulative necrosis. Acetaminophen toxicity does not however show the marked elevations in serum transaminases. Treatment and Prognosis Therapy is directed at maintaining cardiac output since vigorous efforts to relieve congestion may further exacerbate or accelerate hepatocellular necrosis.

Amyloidosis Amyloidosis is the extracellular deposition of an insoluble fibrillary material that causes functional compromise of the organs in which it accumulates. The liver is a common site of amyloid deposition and is often involved in systemic amyloidosis. Clinical Manifestations Liver involvement by amyloidosis may remain clinically silent until large amounts of the parenchyma are replaced. Patients present with hepatomegaly, lethargy, right upper quadrant abdominal pain, weight loss, and signs of portal hypertension, including splenomegaly and ascites.104,105 Hepatomegaly disproportionate to the liver enzyme abnormalities was observed in a series of 80 patients with primary amyloidosis.104 Laboratory Findings Proteinuria, elevated alkaline phosphatase, and evidence of hyposplenism were found to be common findings in a series of 98 patients with liver involvement by primary amyloidosis.106 In the series of 80 patients mentioned above, alkaline phosphatase and transaminases were normal in 30% of patients with liver involvement; hepatomegaly disproportionate to the normal levels of liver enzymes was an important observation in this series.104 Radiologic Features Imaging findings are usually nonspecific. Ultrasound demonstrates hepatomegaly with a homogeneous or heterogeneous echogenicity or reduced parenchymal reflectivity.105,107 Computed tomography scan may reveal amyloid as heterogeneous parenchymal enhancement in

Vascular Disorders of the Liver

30

A

Figure 30.19  Cut section of a liver with extensive amyloid deposition appears pale and was “waxy” in texture.

the venous phase of the contrast-enhanced images.107 Magnetic resonance imaging may show decreased signal in T2-weighted images or increased signal in T1-weighted images.108

B

Gross Pathology The size and texture of the liver depends upon the extent of amyloid deposition. When deposition is diffuse, the liver is enlarged and the cut surface is pale with a homogeneous and waxy appearance (Fig. 30.19).

Figure 30.20  A, Vascular amyloid deposition in a patient with primary amyloidosis and end-stage renal disease (also see eSlide 30.13). B, Congo red stain showing the characteristic birefringence under polarized light (also see eSlide 30.13). (From Agaram NP. Liver pathology in systemic diseases and diseases of other organs. In Saxena R. Practical Hepatic Pathology, 1st ed. Philadelphia: Saunders; 2011.)

Microscopic Pathology Three microscopic patterns of amyloid deposition are observed in the liver: (1) perivascular amyloid deposition within the walls of the arteries and veins with or without accompanying deposition within portal stroma (Fig. 30.20), (2) perisinusoidal deposition (Fig. 30.21) and (3) a combination of the two (eSlide 30.13). Perisinusoidal deposition begins in the periportal areas and gradually progresses towards the central veins to diffusely involve the lobules. As in other organs, amyloid appears as a homogeneous, amorphous, lightly eosinophilic material. Examination under polarized light of a section stained with Congo red demonstrates characteristic apple green birefringence. Ultrastructurally, amyloid is arranged in structured arrays, which demonstrate a beta-pleated configuration. Light chain deposition disease mimics amyloid on a hematoxylin-eosin stain but does not stain with the Congo red stain. Ultrastructurally, it lacks the beta-pleated structure of amyloid, and demonstrates instead a haphazard arrangement of globular or fibrillary material. This material also lacks the P-component of amyloid, which can be demonstrated by an immunohistochemical stain in amyloid.109

Figure 30.21  Extensive sinusoidal deposition of amyloid that appears as an amorphous faintly eosinophilic material. The hepatic trabecula are atrophic (also see eSlide 30.13).

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Practical Hepatic Pathology: A Diagnostic Approach Suggested Reading Aggarwal S, Fiel MI, Schiano TD. Obliterative portal venopathy: a clinical and histopathological review. Dig Dis Sci. 2013;58:2767–2776. DeLeve LD, Valla DC, Garcia-Tsao G. Vascular disorders of the liver. Hepatology (Baltimore). 2009;49:1729–1764. Ebert EC, Nagar M, Hagspiel KD. Gastrointestinal and hepatic complications of sickle cell disease. Clin Gastroenterol Hepatol. 2010;8:483–489. Fan CQ, Crawford JM. Sinusoidal obstruction syndrome (hepatic veno-occlusive disease). J Clin Exp Hepatol. 2014;4:332–346. Ogren M, Bergqvist D, Bjorck M, et al. Portal vein thrombosis: prevalence, patient characteristics and lifetime risk: a population study based on 23,796 consecutive autopsies. World J Gastroenterol. 2006;12:2115–2119. Rush N, Sun H, Nakanishi Y, et al. Hepatic arterial buffer response: pathologic evidence in noncirrhotic human liver with extrahepatic portal vein thrombosis. Mod Pathol. 2016;29:489–499. Valla DC. The diagnosis and management of the Budd-Chiari syndrome: consensus and controversies. Hepatology (Baltimore). 2003;38:793–803. Wanless IR, Solt LC, Kortan P, et al. Nodular regenerative hyperplasia of the liver associated with macroglobulinemia. A clue to the pathogenesis. Am J Med. 1981;70:1203–1209.

References 1. Darwish Murad S, Valla DC, de Groen PC, et al. Determinants of survival and the effect of portosystemic shunting in patients with Budd-Chiari syndrome. Hepatology. 2004;39:500–508. 2. DeLeve LD, Valla DC, Garcia-Tsao G. Vascular disorders of the liver. Hepatology. 2009;49:1729–1764. 3. Valla DC. The diagnosis and management of the Budd-Chiari syndrome: consensus and controversies. Hepatology. 2003;38:793–803. 4. Darwish Murad S, Plessier A, Hernandez-Guerra M, et al. Etiology, management, and outcome of the Budd-Chiari syndrome. Ann Intern Med. 2009;151:167–175. 5. Valla DC. Hepatic vein thrombosis (Budd-Chiari syndrome). Semin Liver Dis. 2002;22:5–14. 6. Shrestha SM, Okuda K, Uchida T, et al. Endemicity and clinical picture of liver disease due to obstruction of the hepatic portion of the inferior vena cava in Nepal. J Gastroenterol Hepatol. 1996;11:170–179. 7. Ki M, Choi HY, Kim KA, et al. Incidence, prevalence and complications of Budd-Chiari syndrome in South Korea: a nationwide, population-based study. Liver Int. 2016;36:1067–1073. 8. Hadengue A, Poliquin M, Vilgrain V, et al. The changing scene of hepatic vein thrombosis: recognition of asymptomatic cases. Gastroenterology. 1994;106:1042–1047. 9. Darwish Murad S, Valla DC, de Groen PC, et al. Pathogenesis and treatment of Budd-Chiari syndrome combined with portal vein thrombosis. Am J Gastroenterol. 2006;101:83–90. 10. Mahmoud AE, Helmy AS, Billingham L, Elias E. Poor prognosis and limited therapeutic options in patients with Budd-Chiari syndrome and portal venous system thrombosis. Eur J Gastroenterol Hepatol. 1997;9:485–489. 11. Miller WJ, Federle MP, Straub WH, Davis PL. Budd-Chiari syndrome: imaging with pathologic correlation. Abdom Imaging. 1993;18:329–335. 12. Kim H, Nahm JH, Park YN. Budd-Chiari syndrome with multiple large regenerative nodules. Clin Mol Hepatol. 2015;21:89–94. 13. Riggio O, Marzano C, Papa A, et al. Small hepatic veins Budd-Chiari syndrome. J Thromb Thrombolysis. 2014;37:536–539. 14. Alvarez AM, Mukherjee D. Liver abnormalities in cardiac diseases and heart failure. Int J Angiol. 2011;20:135–142. 15. Simonetto DA, Yang HY, Yin M, et al. Chronic passive venous congestion drives hepatic fibrogenesis via sinusoidal thrombosis and mechanical forces. Hepatology. 2015;61:648–659. 16. Myers RP, Cerini R, Sayegh R, et al. Cardiac hepatopathy: clinical, hemodynamic, and histologic characteristics and correlations. Hepatology (Baltimore). 2003;37:393–400. 17. Torabi M, Hosseinzadeh K, Federle MP. CT of nonneoplastic hepatic vascular and perfusion disorders. Radiographics. 2008;28:1967–1982. 18. Bayraktar UD, Seren S, Bayraktar Y. Hepatic venous outflow obstruction: three similar syndromes. World J Gastroenterol. 2007;13:1912–1927. 19. Pai RK, Hart JA. Aberrant expression of cytokeratin 7 in perivenular hepatocytes correlates with a cholestatic chemistry profile in patients with heart failure. Mod Pathol. 2010;23:1650–1656. 20. Dai DF, Swanson PE, Krieger EV, et al. Congestive hepatic fibrosis score: a novel histologic assessment of clinical severity. Mod Pathol. 2014;27:1552–1558. 21. Shinagawa H, Inomata T, Koitabashi T, et al. Increased serum bilirubin levels coincident with heart failure decompensation indicate the need for intravenous inotropic agents. Int Heart J. 2007;48:195–204. 22. Giallourakis CC, Rosenberg PM, Friedman LS. The liver in heart failure. Clin Liver Dis. 2002;6:947–967. viii–ix. 23. DeLeve LD, Ito Y, Bethea NW, et al. Embolization by sinusoidal lining cells obstructs the microcirculation in rat sinusoidal obstruction syndrome. Am J Physiol Gastrointest Liver Physiol. 2003;284:G1045–G1052. 24. DeLeve LD, Wang X, Kanel GC, et al. Decreased hepatic nitric oxide production contributes to the development of rat sinusoidal obstruction syndrome. Hepatology. 2003;38:900–908. 25. Deleve LD, Wang X, Tsai J, et al. Sinusoidal obstruction syndrome (veno-occlusive disease) in the rat is prevented by matrix metalloproteinase inhibition. Gastroenterology. 2003;125:882–890.

482

26. Srivastava A, Poonkuzhali B, Shaji RV, et al. Glutathione S-transferase M1 polymorphism: a risk factor for hepatic venoocclusive disease in bone marrow transplantation. Blood. 2004;104:1574–1577. 27. Vreuls CP, Olde Damink SW, Koek GH, et al. Glutathione S-transferase M1-null genotype as risk factor for SOS in oxaliplatin-treated patients with metastatic colorectal cancer. Br J Cancer. 2013;108:676–680. 28. Coppell JA, Richardson PG, Soiffer R, et al. Hepatic veno-occlusive disease following stem cell transplantation: incidence, clinical course, and outcome. Biol Blood Marrow Transplant. 2010;16:157–168. 29. Carreras E, Bertz H, Arcese W, et al. Incidence and outcome of hepatic veno-occlusive disease after blood or marrow transplantation: a prospective cohort study of the European Group for Blood and Marrow Transplantation. European Group for Blood and Marrow Transplantation Chronic Leukemia Working Party. Blood. 1998;92:3599–3604. 30. Dignan FL, Wynn RF, Hadzic N, et al. BCSH/BSBMT guideline: diagnosis and management of veno-occlusive disease (sinusoidal obstruction syndrome) following haematopoietic stem cell transplantation. Br J Haematol. 2013;163:444–457. 31. Shulman HM, Hinterberger W. Hepatic veno-occlusive disease–liver toxicity syndrome after bone marrow transplantation. Bone marrow transplant. 1992;10:197–214. 32. Jones RJ, Lee KS, Beschorner WE, et al. Venoocclusive disease of the liver following bone marrow transplantation. Transplantation. 1987;44:778–783. 33. Yoshimoto K, Ono N, Okamura T, Sata M. Recent progress in the diagnosis and therapy for veno-occlusive disease of the liver. Leuk Lymphoma. 2003;44:229–234. 34. Shulman HM, Gown AM, Nugent DJ. Hepatic veno-occlusive disease after bone marrow transplantation. Immunohistochemical identification of the material within occluded central venules. Am J Pathol. 1987;127:549–558. 35. Sato Y, Asada Y, Hara S, et al. Hepatic stellate cells (Ito cells) in veno-occlusive disease of the liver after allogeneic bone marrow transplantation. Histopathology. 1999;34:66–70. 36. Richardson PG, Riches ML, Kernan NA, et al. Phase 3 trial of defibrotide for the treatment of severe veno-occlusive disease and multi-organ failure. Blood. 2016;127:1656–1665. 37. Bramham K, Parnell B, Nelson-Piercy C, et al. Chronic hypertension and pregnancy outcomes: systematic review and meta-analysis. BMJ (Clinical research ed). 2014;348. g2301. 38. Schubert TT. Hepatobiliary system in sickle cell disease. Gastroenterology. 1986;90:2013–2021. 39. Ebert EC, Nagar M, Hagspiel KD. Gastrointestinal and hepatic complications of sickle cell disease. Clin Gastroenterol Hepatol. 2010;8:483–489. quiz e70. 40. Rao VM, Mapp EM, Wechsler RJ. Radiology of the gastrointestinal tract in sickle cell anemia. Semin Roentgenol. 1987;22:195–204. 41. Voskaridou E, Douskou M, Terpos E, et al. Magnetic resonance imaging in the evaluation of iron overload in patients with beta thalassaemia and sickle cell disease. Br J Haematol. 2004;126:736–742. 42. Bauer TW, Moore GW, Hutchins GM. The liver in sickle cell disease. A clinicopathologic study of 70 patients. Am J Med. 1980;69:833–837. 43. Tranquilli AL, Dekker G, Magee L, et al. The classification, diagnosis and management of the hypertensive disorders of pregnancy: A revised statement from the ISSHP. Pregnancy Hypertens. 2014;4:97–104. 44. Mol BW, Roberts CT, Thangaratinam S, et al. Pre-eclampsia. Lancet. 2016;387:999–1011. 45. Agatisa PK, Ness RB, Roberts JM, et al. Impairment of endothelial function in women with a history of preeclampsia: an indicator of cardiovascular risk. Am J Physiol Heart Circ Physiol. 2004;286:H1389–H1393. 46. Westbrook RH, Dusheiko G, Williamson C. Pregnancy and liver disease. J Hepatol. 2016;64:933–945. 47. Lee NM, Brady CW. Liver disease in pregnancy. World J Gastroenterol. 2009;15:897–906. 48. Chan AD, Gerscovich EO. Imaging of subcapsular hepatic and renal hematomas in pregnancy complicated by preeclampsia and the HELLP syndrome. J Clin Ultrasound. 1999;27:35–40. 49. Dani R, Mendes GS, Medeiros Jde L, et al. Study of the liver changes occurring in preeclampsia and their possible pathogenetic connection with acute fatty liver of pregnancy. Am J Gastroenterol. 1996;91:292–294. 50. Sibai BM, Ramadan MK, Usta I, et al. Maternal morbidity and mortality in 442 pregnancies with hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome). Am J Obstet Gynecol. 1993;169:1000–1006. 51. Laivuori H, Lahermo P, Ollikainen V, et al. Susceptibility loci for preeclampsia on chromosomes 2p25 and 9p13 in Finnish families. Am J Hum Genet. 2003;72:168–177. 52. Oudejans CB, Mulders J, Lachmeijer AM, et al. The parent-of-origin effect of 10q22 in preeclamptic females coincides with two regions clustered for genes with down-regulated expression in androgenetic placentas. Mol Hum Reprod. 2004;10:589–598. 53. Barton JR, Sibai BM. Hepatic imaging in HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count). Am J Obstet Gynecol. 1996;174:1820–1825. discussion 5–7. 54. Chawla YK, Bodh V. Portal vein thrombosis. J Clin Exp Hepatol. 2015;5:22–40. 55. Qi X, Ren W, De Stefano V, Fan D. Associations of coagulation factor V Leiden and prothrombin G20210A mutations with Budd-Chiari syndrome and portal vein thrombosis: a systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2014;12:1801–1812. e7. 56. Dentali F, Galli M, Gianni M, Ageno W. Inherited thrombophilic abnormalities and risk of portal vein thrombosis. a meta-analysis. Thromb Haemost. 2008;99:675–682. 57. Martinelli I, Primignani M, Aghemo A, et al. High levels of factor VIII and risk of extra-hepatic portal vein obstruction. J Hepatol. 2009;50:916–922. 58. Plessier A, Darwish-Murad S, Hernandez-Guerra M, et al. Acute portal vein thrombosis unrelated to cirrhosis: a prospective multicenter follow-up study. Hepatology. 2010;51:210–218.

Vascular Disorders of the Liver 59. Janssen HL, Wijnhoud A, Haagsma EB, et al. Extrahepatic portal vein thrombosis: aetiology and determinants of survival. Gut. 2001;49:720–724. 60. Ogren M, Bergqvist D, Bjorck M, et al. Portal vein thrombosis: prevalence, patient characteristics and lifetime risk: a population study based on 23,796 consecutive autopsies. World J Gastroenterol. 2006;12:2115–2119. 61. Poddar U, Thapa BR, Rao KL, Singh K. Etiological spectrum of esophageal varices due to portal hypertension in Indian children: is it different from the West? J Gastroenterol Hepatol. 2008;23:1354–1357. 62. Sarin SK, Mehra NK, Agarwal A, et al. Familial aggregation in noncirrhotic portal fibrosis: a report of four families. Am J Gastroenterol. 1987;82:1130–1133. 63. Rush N, Sun H, Nakanishi Y, et al. Hepatic arterial buffer response: pathologic evidence in noncirrhotic human liver with extrahepatic portal vein thrombosis. Mod Pathol. 2016;29:489–499. 64. Chandra R, Kapoor D, Tharakan A, et al. Portal biliopathy. J Gastroenterol Hepatol. 2001;16:1086–1092. 65. Reshamwala PA, Kleiner DE, Heller T. Nodular regenerative hyperplasia: not all nodules are created equal. Hepatology. 2006;44:7–14. 66. Aggarwal S, Fiel MI, Schiano TD. Obliterative portal venopathy: a clinical and histopathological review. Dig Dis Sci. 2013;58:2767–2776. 67. Kono K, Ohnishi K, Omata M, et al. Experimental portal fibrosis produced by intraportal injection of killed nonpathogenic Escherichia coli in rabbits. Gastroenterology. 1988;94:787–796. 68. Dhiman RK, Chawla Y, Vasishta RK, et al. Non-cirrhotic portal fibrosis (idiopathic portal hypertension): experience with 151 patients and a review of the literature. J Gastroenterol Hepatol. 2002;17:6–16. 69. Kovari H, Ledergerber B, Peter U, et al. Association of noncirrhotic portal hypertension in HIVinfected persons and antiretroviral therapy with didanosine: a nested case-control study. Clin Infect Dis. 2009;49:626–635. 70. Iber FL. Obliterative portal venopathy of the liver and “idiopathic portal hypertension”. Ann Intern Med. 1969;71:660–661. 71. Okuda K, Nakashima T, Okudaira M, et al. Liver pathology of idiopathic portal hypertension. Comparison with non-cirrhotic portal fibrosis of India. The Japan idiopathic portal hypertension study. Liver. 1982;2:176–192. 72. Okuda K. Non-cirrhotic portal hypertension versus idiopathic portal hypertension. J Gastroenterol Hepatol. 2002;17(suppl 3):S204–S213. 72a. Guido M, Sarcognato S, Sonzogni A. Obliterative portal venopathy without portal hypertension: an underestimated condition. Liver Int. 2016;36:454–460. 73. Hillaire S, Bonte E, Denninger MH, et al. Idiopathic non-cirrhotic intrahepatic portal hypertension in the West: a re-evaluation in 28 patients. Gut. 2002;51:275–280. 74. Jha P, Poder L, Wang ZJ, et al. Radiologic mimics of cirrhosis. AJR Am J Roentgenol. 2010;194:993–999. 75. Krishnan P, Fiel MI, Rosenkrantz AB, et al. Hepatoportal sclerosis: CT and MRI appearance with histopathologic correlation. AJR Am J Roentgenol. 2012;198:370–376. 76. Sarin SK, Kumar A. Noncirrhotic portal hypertension. Clin Liver Dis. 2006;10:627–651. x. 77. Glatard AS, Hillaire S, d’Assignies G, et al. Obliterative portal venopathy: findings at CT imaging. Radiology. 2012;263:741–750. 78. Isabel Fiel M, Thung SN, Hytiroglou P, et al. Liver failure and need for liver transplantation in patients with advanced hepatoportal sclerosis. Am J Surg Pathol. 2007;31:607–614. 79. Sarin SK, Kumar A, Chawla YK, et al. Noncirrhotic portal fibrosis/idiopathic portal hypertension: APASL recommendations for diagnosis and treatment. Hepatol Int. 2007;1:398–413. 80. Okudaira M, Ohbu M, Okuda K. Idiopathic portal hypertension and its pathology. Semin Liver Dis. 2002;22:59–72. 81. Schiano TD, Uriel A, Dieterich DT, Fiel MI. The development of hepatoportal sclerosis and portal hypertension due to didanosine use in HIV. Virchows Arch. 2011;458:231–235. 82. Nayak NC, Ramalingaswami V. Obliterative portal venopathy of the liver. Associated with socalled idiopathic portal hypertension or tropical splenomegaly. Arch Pathol. 1969;87:359–369. 83. Ludwig J, Hashimoto E, Obata H, Baldus WP. Idiopathic portal hypertension; a histopathological study of 26 Japanese cases. Histopathology. 1993;22:227–234. 84. Sciot R, Staessen D, Van Damme B, et al. Incomplete septal cirrhosis: histopathological aspects. Histopathology. 1988;13:593–603. 85. Nakanuma Y, Tsuneyama K, Ohbu M, Katayanagi K. Pathology and pathogenesis of idiopathic portal hypertension with an emphasis on the liver. Pathol Res Pract. 2001;197:65–76.

86. Okuda K, Kono K, Ohnishi K, et al. Clinical study of eighty-six cases of idiopathic portal hypertension and comparison with cirrhosis with splenomegaly. Gastroenterology. 1984;86:600–610. 87. Wanless IR. Micronodular transformation (nodular regenerative hyperplasia) of the liver: a report of 64 cases among 2,500 autopsies and a new classification of benign hepatocellular nodules. Hepatology. 1990;11:787–797. 88. Wanless IR, Solt LC, Kortan P, et al. Nodular regenerative hyperplasia of the liver associated with macroglobulinemia. A clue to the pathogenesis. Am J Med. 1981;70:1203–1209. 89. Wanless IR, Liu JJ, Butany J. Role of thrombosis in the pathogenesis of congestive hepatic fibrosis (cardiac cirrhosis). Hepatology. 1995;21:1232–1237. 90. Gane E, Portmann B, Saxena R, et al. Nodular regenerative hyperplasia of the liver graft after liver transplantation. Hepatology. 1994;20:88–94. 91. Force J, Saxena R, Schneider BP, et al. Nodular regenerative hyperplasia after treatment with trastuzumab emtansine. J Clin Oncol. 2016;34:e9–e12. 92. Barge S, Grando V, Nault JC, et al. Prevalence and clinical significance of nodular regenerative hyperplasia in liver biopsies. Liver Int. 2016;36:1059–1066. 93. Coelho R, Rodriguez S, Rodrigues-Pinto E, et al. Nodular regenerative hyperplasia after liver transplantation complicated with inferior vena cava stenosis: a clue for etiopathogenesis? J Gastrointestin Liver Dis. 2015;24:383–385. 94. Grazioli L, Alberti D, Olivetti L, et al. Congenital absence of portal vein with nodular regenerative hyperplasia of the liver. Eur Radiol. 2000;10:820–825. 95. Trenschel GM, Schubert A, Dries V, Benz-Bohm G. Nodular regenerative hyperplasia of the liver: case report of a 13-year-old girl and review of the literature. Pediatr Radiol. 2000;30:64–68. 96. Slapak GI, Saxena R, Portmann B, et al. Graft and systemic disease in long-term survivors of liver transplantation. Hepatology. 1997;25:195–202. 97. Pappo O, Ramos H, Starzl TE, et al. Structural integrity and identification of causes of liver allograft dysfunction occurring more than 5 years after transplantation. Am J Surg Pathol. 1995;19:192–206. 98. Delladetsima I, Sakellariou S, Kokkori A, Tiniakos D. Atrophic hepatocytes express keratin 7 in ischemia-associated liver lesions. Histol Histopathol. 2016;31:1089–1094. 99. Matsumoto T, Kobayashi S, Shimizu H, et al. The liver in collagen diseases. pathologic study of 160 cases with particular reference to hepatic arteritis, primary biliary cirrhosis, autoimmune hepatitis and nodular regenerative hyperplasia of the liver. Liver. 2000;20:366–373. 100. Yamashita H, Suzuki A, Takahashi Y, et al. Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis associated with primary biliary cirrhosis: a case report and literature review. Intern Med. 2015;54:1303–1308. 101. Seeto RK, Fenn B, Rockey DC. Ischemic hepatitis: clinical presentation and pathogenesis. Am J Med. 2000;109:109–113. 102. Henrion J, Schapira M, Luwaert R, et al. Hypoxic hepatitis: clinical and hemodynamic study in 142 consecutive cases. Medicine. 2003;82:392–406. 103. Raurich JM, Perez O, Llompart-Pou JA, et al. Incidence and outcome of ischemic hepatitis complicating septic shock. Hepatol Res. 2009;39:700–705. 104. Gertz MA, Kyle RA. Hepatic amyloidosis (primary [AL], immunoglobulin light chain): the natural history in 80 patients. Am J Med. 1988;85:73–80. 105. Peters RA, Koukoulis G, Gimson A, et al. Primary amyloidosis and severe intrahepatic cholestatic jaundice. Gut. 1994;35:1322–1325. 106. Park MA, Mueller PS, Kyle RA, et al. Primary (AL) hepatic amyloidosis: clinical features and natural history in 98 patients. Medicine. 2003;82:291–298. 107. Srinivasan S, Tan YQ, Teh HS, et al. Primary hepatic amyloidosis presenting as nodular masses on the background of diffuse infiltration and extreme liver stiffness on MR elastography. J Gastrointestin Liver Dis. 2014;23:437–440. 108. Monzawa S, Tsukamoto T, Omata K, et al. A case with primary amyloidosis of the liver and spleen: radiologic findings. Eur J Radiol. 2002;41:237–241. 109. Croitoru AG, Hytiroglou P, Schwartz ME, Saxena R. Liver transplantation for liver rupture due to light chain deposition disease: a case report. Semin Liver Dis. 2006;26:298–303.

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31 Premalignant and Early Malignant Hepatocellular Lesions in Chronic Hepatitis/Cirrhosis Massimo Roncalli, MD, PhD, Young Nyun Park, MD, PhD, Mauro Borzio, MD, Angelo Sangiovanni, MD, Amedeo Sciarra, MD, and Luca Di Tommaso, MD, FIAC

Clinical Setting and Target Population: Surveillance  488 Nomenclature 488 Dysplastic Foci  490 Dysplastic Nodules  490 Small Hepatocellular Carcinoma  491 Dysplastic Nodules as Hepatocellular Carcinoma Precursors 491 Natural History of Premalignant Lesions  493 Dysplastic Nodules and Early Hepatocellular Carcinoma: Role of Imaging 494 Premalignant and Early Malignant Hepatocellular Nodules in Daily Clinical Practice  494 Basic Histopathologic Features (Elementary Lesions)  494 Parenchymal Changes  494 Nonparenchymal Changes  495 Key Diagnostic Points  495 Stromal Invasion  495 Biomarkers 497 Nodule in Nodule  498 Liver Biopsy  499 Diagnostic Criteria in Liver Biopsy  499 Nodule Management  503

Abbreviations AASLD American Association for the Study of Liver Diseases AFP alpha-fetoprotein APASL Asian Pacific Association for Studies of the Liver CT computed tomography CHC clathrin heavy chain DF dysplastic foci DN dysplastic nodule EASL European Association for the Study of the Liver eHCC early hepatocellular carcinoma e/WD HCC early, well-differentiated hepatocellular carcinoma EZH2 enhancer of zeste homolog 2

H&E HBV HCC HGDN HSP70 JSH Ka LI-RAD LCC LGDN LRN MRI pHCC PCNA OATP8 SCC TERT

hemotoxylin and eosin hepatitis B virus hepatocellular carcinoma high-grade dysplastic nodule heat shock protein 70 Japan Society of Hepatology keratin liver imaging reporting and data system large cell change low-grade dysplastic nodule large regenerative nodule magnetic resonance imaging progressed hepatocellular carcinoma proliferating cell nuclear antigen organic anion transporting polypeptide 8 small cell change telomerase reverse transcriptase

Most patients with compensated cirrhosis with “de novo” hepatocellular carcinoma (HCC) at an early stage (single nodule 10 mm Hg.40 When the HVPG is higher than 12 mm Hg, the risk of variceal rupture increases, and there is also a risk of ascites development. Combining clinical and hemodynamic parameters, cirrhotic patients can be classified into four categories: compensated without

Cirrhosis: A Term in Need of a Makeover (stage 1) and with (stage 2) varices, corresponding to HVPG >6 mm Hg and >10 mm Hg, respectively, and decompensated with (stage 3) and without (stage 4) control of the complications: varices bleeding, ascites, and encephalopathy. In the decompensated stages, the HVPG is higher than 12 mm Hg.7,8

41

Pathologic Staging of Cirrhosis The diagnosis of cirrhosis is established on a biopsy, which may be performed to (1) stage a known chronic liver disease, (2) examine histologically a nodular liver discovered incidentally on imaging studies or during surgery, or (3) confirm cirrhosis in a patient with clinical manifestations of portal hypertension or liver failure. Because not all cases of liver nodularity or portal hypertension are due to cirrhosis, a biopsy is paramount to establishing the diagnosis (see Chapter 30). Although microscopic examination is essential to establishing the diagnosis of cirrhosis, attempts at staging the disease, correlating pathologic findings with clinical features, or identifying prognostic and predictive markers have been scarce. Whereas this was acceptable when there were no effective means to treat the underlying etiologic factors or halt progression of the cirrhotic process, contemporary medical necessitates more information. Cirrhosis is represented as a single stage, without further subclassification, in all staging schema for chronic viral hepatitis (see Chapter 16), fatty liver diseases (see Chapter 12), and congestive hepatopathy (see Chapter 30). The Laennec system, a modification of the METAVIR system, is unique in that it subdivides cirrhosis (stage 4) into three substages, namely 4A, 4B, and 4C, on the basis of the number and size of fibrous septa and size of nodules41-43 (Fig. 41.5, see also Figs. 40.3 to 40.6). Stage 4A represents mild cirrhosis (definite or probable), in which most septa are thin (one broad septum allowed) (eSlide 41.2); stage 4B is moderate cirrhosis defined by at least two broad septa but no very broad septa and less than half of biopsy length composed of minute nodules (eSlide 41.3), whereas stage 4C corresponds to severe cirrhosis with at least one very broad septum or many minute nodules43 (eSlide 41.4). The terms “broad septum” and “very broad septum” are defined by comparing the relative thickness of fibrous septa with size of nodules: “broad septum” is defined as septal thickness that is thinner than the size of the nodule, whereas “very broad septum” is defined as septal thickness that is thicker than the size of the nodule.43 When applying the Laennec system, the thickness of the predominant type of septa and the size of smallest nodule should be selected for staging. The Laennec system has been demonstrated to correlate well with both the clinical stage of cirrhosis and grade of portal hypertension41,44,45 as well as with the risk of recurrence of hepatocellular carcinoma after curative resection.46 The study by Kim et  al44 of 175 patients with chronic liver disease who underwent liver biopsy demonstrated that histologic subclassification of cirrhosis using the Laennec stage predicted the development of liver-related events, such as hepatic decompensation, hepatocellular carcinoma, and liver-related mortality. A recent metaanalysis demonstrated that the Laennec system is highly reproducible and confirmed its value in predicting prognosis and complications of portal hypertension.47 Nagula and collaborators described a histologic subclassification of cirrhosis, similar to the Laennec system, based on a combination of nodule size and septal thickness.48 They demonstrated that, as with the Laennec staging system, small nodularity and thick septa were independent predictors of clinical significant portal hypertension and, therefore, predictive of the clinical severity of cirrhosis. The Laennec system and the study by Nagula48 thus demonstrate that cirrhosis does not represent a single homogeneous disease stage. No staging system, however, takes into account features of regression of cirrhosis.

A

B

C FIGURE 41.5 Laennec substaging of cirrhosis. Stage 4A with thin septa and no micronodule (A) (see eSlide 41.2), stage 4B with some broader septa and some micronodules (B) (see eSlide 41.3), and stage 4C with large, thick septa and numerous micronodules (C) (see eSlide 41.4).

Quantification of the amount of liver collagen offers another method to assess the amount of fibrous tissue and therefore the severity of cirrhosis. The principle is to perform an image analysis of digitalized picrosirius red stained slides. The percentage of the stained area is calculated as a proportion of the total area of the biopsy (see Chapter 40). This measurement of the collagen proportionate area (CPA) was shown to better reflect HVPG than the Ishak score.49 Quantification offers the advantage of greater objectivity over semiquantitative assessment of the size and number of septa and nodules. In addition, it reports the result as a continuous variable, which is more conducive to assessing progression or regression of the disease.50 It is however as subject to sampling error as semiquantitative methods. CPA measurement is also time consuming and not easily available in routine practice. Recently, a very sophisticated method to automatically evaluate both the amount of collagen deposition and its specific location called “qFibrosis” has been developed, underscoring the intense efforts currently underway in this field.51,52

Regression of Cirrhosis Clinical demonstration of the reversibility of cirrhosis has been provided in studies involving large cohorts of patients with chronic hepatitis B and chronic hepatitis C, who have been effectively treated with antiviral drugs.12-15 In trials with nucleos(t)ide analogues, regression of cirrhosis is observed in patients achieving long-term suppression of hepatitis B virus replication, after 3 to 6 years of treatment.14 Sustained virologic response is also linked to cirrhosis regression in hepatitis C 683

Practical Hepatic Pathology: A Diagnostic Approach

FIGURE 41.6  Features of regression of cirrhosis. Thin delicate, and sometimes incomplete septa (A); aberrant hepatic vein approximated to portal tract (B); perforated septa with hepatocyte regeneration (C); and portal tract remnant without portal vein (D). Masson trichrome stain (also see eSlide 41.5).

A

B

C

D

virus. A meta-analysis of six studies totaling 443 patients showed that 73 (53%) of 137 patients with chronic hepatitis C achieving sustained virologic response displayed cirrhosis regression.16 The odds ratio of cirrhosis regression was related to the duration of follow up between biopsies, suggesting that the timing of follow-up biopsy should be considered when attempting to assess the reversal of cirrhosis. Reversibility of cirrhosis associated with nonalcoholic steatohepatitis is less certain than in viral hepatitis, since no disease-specific therapies are yet available. Nevertheless, studies comparing degree of fibrosis after bariatric surgery clearly indicate the ability for some regression.10,11 Regression of cardiac cirrhosis has been reported following heart transplantation.17,18 Restoration of glutamine synthetase zonation in addition to regression of fibrosis in paired biopsies from patients treated for chronic hepatitis C suggests that physiologic normalization beyond simple regression of fibrosis is potentially possible.19

Histologic Assessment of Regression of Cirrhosis Features of regression of cirrhosis are easier to identify in resection specimens rather than in biopsy specimens because the nodularity is indistinct and the septa are thin and fragmented. Some of the cases previously called incomplete septal cirrhosis are probably regressed stages of cirrhosis35 and the presence of features of a remodeled parenchyma are the clue that cirrhosis was once present. Obliterated small terminal hepatic veins together with perivenular sinusoidal dilatation reflecting shunting, expanded portal tracts with long and delicate bridging fibrous septa sometimes perforated or incomplete, small fibrotic portal remnant without vein, and scattered collagen fibrils within the parenchyma, are indicative of regression of cirrhosis (Fig. 41.6 and Figs. 40.7–40.13) (eSlides 41.5 and 16.4) (Box 41.1) (also see Chapter 40).35,36,53-55

Is Cirrhosis a Primarily Fibrotic Process? Parenchymal extinction (ie, loss of confluent areas of the liver parenchyma, rather than fibrosis) constitutes the basic pathophysiology of cirrhosis. Loss of parenchymal areas causes vascular remodeling and formation of shunts between afferent and efferent liver vessels leading to portosystemic anastomoses and profound imbalance of blood flow, which is the hallmark of a cirrhotic liver. The parenchymal extinction lesions are progressively replaced by fibrotic scar.36-38,53 684

BOX 41.1  Features of Regression of Cirrhosis35 Thin incomplete mature fibrous septa Perforated septa with hepatocyte regeneration Portal tracts remnants lacking the portal vein Obliterated terminal hepatic veins Sinusoidal dilatation Scattered collagen fibrils within the parenchyma Absence of necroinflammatory activity See Figs. 41.7 and 40.13 and eSlides 16.4 and 41.5.

In conclusion, cirrhosis is not a homogeneous, end-stage or irreversible process. The term cirrhosis thus denotes lacks of precision and a failure to give clear prognostic implication in contemporary times. However, methods to assess cirrhosis regression in different etiologies and schema for substaging of cirrhosis are not yet firmly in place. To reflect the nuanced complexity of cirrhosis and provide an accurate staging for each patient, it has been suggested that the term cirrhosis be replaced by advanced stage of chronic liver disease followed by qualifiers and descriptions that correlate histologic findings with clinical and biological parameters including HVPG.25 An ideal diagnostic tool of the future would assess and quantify features of regression and remodeling such as extracellular matrix and collagen composition, matrix metalloprotease and stellate cell activity in serial biopsies with meaningful correlation with clinical manifestations, HVPG, and other tests of liver function to account for the dynamic disease process in cirrhosis.56,57

Acknowledgments Dr. Sempoux extends very special thanks to Professor Darius Moradpour and Dr. Sabine Schmidt-Kobbe (CHUV, Lausanne, Switzerland) for their critical clinical advice in formulating this chapter. Suggested Readings Garcia-Tsao G, Friedman S, Iredale J, Pinzani M. Now there are many (stages) where before there was one: in search of a pathophysiological classification of cirrhosis. Hepatology. 2010;51:1445–1449. Hytiroglou P, Snover DC, Alves V, et al. Beyond “cirrhosis”: a proposal from the International Liver Pathology Study Group. Am J Clin Pathol. 2012;137:5–9.

Cirrhosis: A Term in Need of a Makeover lQuaglia A, Alves VA, Balabaud C, et al; International Liver Pathology Study Group. Role of aetiology in the progression, regression, and parenchymal remodelling of liver disease: implications for liver biopsy interpretation. Histopathology. 2016;68:953–967. Wanless IR, Nakashima E, Sherman M. Regression of human cirrhosis. Morphologic features and the genesis of incomplete septal cirrhosis. Arch Pathol Lab Med. 2000;124:1599–1607. Quaglia A, Alves VA, Balabaud C, Bhathal PS, Bioulac-Sage P, Crawford JM, Dhillon AP, Ferrell L, Guido M, Hytiroglou P, Nakanuma Y, Paradis V, Snover DC, Theise ND, Thung SN, Tsui WM, van Leeuwen DJ; International Liver Pathology Study Group. Role of aetiology in the progression, regression, and parenchymal remodelling of liver disease: implications for liver biopsy interpretation. Histopathology. 2016;68:953–967.

References 1. Laennec RTH. De l’auscultation médiate. vol. 1. Paris, France: Brosson et Claude; 368–369, 1819. 2. Roguin A. Rene Theophile Hyacinthe Laënnec (1781-1826): the man behind the stethoscope. Clin Med Res. 2006;4:230–252. 3. Jay V. The legacy of Laënnec. Arch Pathol Lab Med. 2000;124:1420–1421. 4. Popper H, Zak FG. Pathologic aspects of cirrhosis. Am J Med. 1958;24:593–619. 5. Anthony PP, Ishak KG, Nayak NC, et al. The morphology of cirrhosis. Recommendations on definition, nomenclature, and classification by a working group sponsored by the World Health Organization. J Clin Pathol. 1978;31:395–414. 6. Ishak KG. Chronic hepatitis: morphology and nomenclature. Mod Pathol. 1994;7:690–713. 7. Garcia-Tsao G, Friedman S, Iredale J, Pinzani M. Now there are many (stages) where before there was one: in search of a pathophysiological classification of cirrhosis. Hepatology. 2010;51:1445–1449. 8. Balabaud C, Bioulac-Sage P. Cirrhosis: what else? Gastroen Clin Biol. 2010;34:252–254. 9. de Franchis R. Evolving consensus in portal hypertension. Report of the Baveno IV consensus workshop on methodology of diagnosis and therapy in portal hypertension. J Hepatol. 2005;43:167–176. 10. Lassailly G, Caiazzo R, Buob D, et al. Bariatric surgery reduces features of nonalcoholic steatohepatitis in morbidly obese patients. Gastroenterology. 2015;149:379–388. quiz e15–e16. 11. Sun M, Kisseleva T. Reversibility of liver fibrosis. Clin Res Hepatol Gastroenterol. 2015;39(Suppl 1):S60–S63. 12. Schiff ER, Lee SS, Chao YC, et al. Long-term treatment with entecavir induces reversal of advanced fibrosis or cirrhosis in patients with chronic hepatitis B. Clin Gastroenterol Hepatol. 2011;9:274–276. 13. Chang TT, Liaw YF, Wu SS, et al. Long-term entecavir therapy results in the reversal of fibrosis/ cirrhosis and continued histological improvement in patients with chronic hepatitis B. Hepatology. 2010;52:886–893. 14. Marcellin P, Gane E, Buti M, et al. Regression of cirrhosis during treatment with tenofovir disoproxil fumarate for chronic hepatitis B: a 5-year open-label follow-up study. Lancet. 2013;381:468–475. 15. Honda K, Seike M, Murakami K. Benefits of nucleos(t)ide analog treatments for hepatitis B virus-related cirrhosis. World J Hepatol. 2015;7:2404–2410. 16. Akhtar E, Manne V, Saab S. Cirrhosis regression in hepatitis C patients with sustained virological response after antiviral therapy: a meta-analysis. Liver Int. 2015;35:30–36. 17. Crespo-Leiro MG, Robles O, Paniagua MJ, et al. Reversal of cardiac cirrhosis following orthotopic heart transplantation. Am J Transplant. 2008;8:1336–1339. 18. Louie CY, Pham MX, Daugherty TJ, et al. The liver in heart failure: a biopsy and explant series of the histopathologic and laboratory findings with a particular focus on pre-cardiac transplant evaluation. Mod Pathol. 2015;28:932–943. 19. D’Ambrosio R, Aghemo A, Rumi MG, et al. A morphometric and immunohistochemical study to assess the benefit of a sustained virological response in hepatitis C virus patients with cirrhosis. Hepatology. 2012;56:532–543. 20. Shouval D, Friedman SL. Focusing on the past, present, and future of hepatology. J Hepatol. 2014;61:1196–1198. 21. Trautwein C, Friedman SL, Schuppan D, Pinzani M. Hepatic fibrosis: concept to treatment. J Hepatol. 2015;62:S15–S24. 22. Friedman SL. Hepatic fibrosis: emerging therapies. Dig Dis. (Basel, Switzerland). 2015;33:504–507. 23. Fallowfield JA. Future mechanistic strategies for tackling fibrosis—an unmet need in liver disease. Clin Med. (London, England). 2015;15(Suppl 6):s83–s87. 24. Goossens N, Nakagawa S, Hoshida Y. Molecular prognostic prediction in liver cirrhosis. World J Gastroenterol. 2015;21:10262–10273. 25. Hytiroglou P, Snover DC, Alves V, et al. Beyond “cirrhosis”: a proposal from the International Liver Pathology Study Group. Am J Clin Pathol. 2012;137:5–9. 25a. Fauerholdt L, Schlichting P, Christensen E, et al. Conversion of micronodular cirrhosis into macronodular cirrhosis. Hepatology. 1983;3:928–931. 26. Suriawinata AA, Thung SN. Diagnosis of cirrhosis. In: Liver Pathology: An Atlas and Concise Guide. New York: Demos Medical; 2011:109–113.

27. Ferrell L. Liver pathology: cirrhosis, hepatitis, and primary liver tumors. Update and diagnostic problems. Mod Pathol. 2000;13:679–704. 28. Tiniakos DG. Liver biopsy in alcoholic and non-alcoholic steatohepatitis patients. Gastroen Clin Biol. 2009;33:930–939. 29. Roskams TA, Theise ND, Balabaud C, et al. Nomenclature of the finer branches of the biliary tree: canals, ductules, and ductular reactions in human livers. Hepatology. 2004;39:1739–1745. 30. Lin WR, Lim SN, McDonald SA, et al. The histogenesis of regenerative nodules in human liver cirrhosis. Hepatology. 2010;51:1017–1026. 31. Bioulac-Sage P, Balabaud C. Human cirrhosis: monoclonal regenerative nodules derived from hepatic progenitor cells abutting ductular reaction. Gastroen Clin Biol. 2010;34:267–269. 32. Gouw AS, Clouston AD, Theise ND. Ductular reactions in human liver: diversity at the interface. Hepatology. 2011;54:1853–1863. 33. Williams MJ, Clouston AD, Forbes SJ. Links between hepatic fibrosis, ductular reaction, and progenitor cell expansion. Gastroenterology. 2014;146:349–356. 34. Stueck AE, Wanless IR. Hepatocyte buds derived from progenitor cells repopulate regions of parenchymal extinction in human cirrhosis. Hepatology. 2015;61:1696–1707. 35. Wanless IR, Nakashima E, Sherman M. Regression of human cirrhosis. Morphologic features and the genesis of incomplete septal cirrhosis. Arch Pathol Lab Med. 2000;124:1599–1607. 36. Wanless IR, Crawford JM. Cirrhosis. In: Odze RD, Goldblum JR, eds. Surgical Pathology of the GI Tract, Liver, Biliary Tract, and Pancreas. 2nd ed. Philadelphia: Saunders Elsevier; 2009:1115–1145. 37. Wanless IR, Wong F, Blendis LM, et al. Hepatic and portal vein thrombosis in cirrhosis: possible role in development of parenchymal extinction and portal hypertension. Hepatology. 1995;21:1238–1247. 38. Wanless IR. Pathogenesis of cirrhosis. J Gastroenterol Hepatol. 2004:369–371. 39. Kamath PS, Wiesner RH, Malinchoc M, et al. A model to predict survival in patients with endstage liver disease. Hepatology. 2001;33:464–470. 40. Albilllos A, Garcia-Tsao G. Classification of cirrhosis: the clinical use of HVPG measurements. Dis Markers. 2011;31:121128. 41. Kutami R, Girgrah N, Wanless IR. The Laennec grading system for assessment of hepatic fibrosis: validation by correlation with wedged hepatic vein pressure and clincal features. Hepatology. 2000;32:407A. 42. Wanless IR, Sweeney G, Dhillon AP, et al. Lack of progressive hepatic fibrosis during longterm therapy with deferiprone in subjects with transfusion-dependent beta-thalassemia. Blood. 2002;100:1566–1569. 43. Kim MY, Cho MY, Baik SK, et al. Histological subclassification of cirrhosis using the Laennec fibrosis scoring system correlates with clinical stage and grade of portal hypertension. J Hepatol. 2011;55:1004–1009. 44. Kim SU, Oh HJ, Wanless IR, et al. The Laennec staging system for histological sub-classification of cirrhosis is useful for stratification of prognosis in patients with liver cirrhosis. J Hepatol. 2012;57:556–563. 45. Rastogi A, Maiwall R, Bihari C, et al. Cirrhosis histology and Laennec staging system correlate with high portal pressure. Histopathology. 2013;62:731–741. 46. Kim SU, Jung KS, Lee S, et al. Histological subclassification of cirrhosis can predict recurrence after curative resection of hepatocellular carcinoma. Liver Int. 2014;34:1008–1017. 47. Kim G, Lee SS, Baik SK, et al. The need for histological subclassification of cirrhosis: a systematic review and meta-analysis. Liver Int. 2016;36:847–855. 48. Nagula S, Jain D, Groszmann RJ, Garcia-Tsao G. Histological-hemodynamic correlation in cirrhosis-a histological classification of the severity of cirrhosis. J Hepatol. 2006;44:111–117. 49. Calvaruso V, Burroughs AK, Standish R, et al. Computer-assisted image analysis of liver collagen: relationship to Ishak scoring and hepatic venous pressure gradient. Hepatology. 2009;49:1236–1244. 50. Standish RA, Cholongitas E, Dhillon A, et al. An appraisal of the histopathological assessment of liver fibrosis. Gut. 2006;55:569–578. 51. Xu S, Wang Y, Tai DC, et al. qFibrosis: a fully-quantitative innovative method incorporating histological features to facilitate accurate fibrosis scoring in animal model and chronic hepatitis B patients. J Hepatol. 2014;61:260–269. 52. Asselah T, Marcellin P, Bedossa P. Improving performance of liver biopsy in fibrosis assessment. J Hepatol. 2014;61:193–195. 53. Wanless IR, Huang W-Y. Vascular disorders. In: Burt AD, Portmann BC, Ferrell L, eds. MacSween’s Pathology of the Liver. 6th ed. Edinburgh: Churchill-Livingstone-Elsevier; 2012:601–643. 54. Ma C, Brunt EM. Histopathologic evaluation of liver biopsy for cirrhosis. Adv Anat Pathol. 2012;19:220–230. 55. Fischer, Guindi M. Regressed cirrhosis case. In: Ferrell LD, Kara S, eds. Liver Pathology. New York: Demos Medical; 2011:199–201. 56. Patel K, Bedossa P, Castera L. Diagnosis of liver fibrosis: present and future. Sem Liver Dis. 2015;35:166–183. 57. Lee YA, Wallace MC, Friedman SL. Pathobiology of liver fibrosis: a translational success story. Gut. 2015;64:830–841.

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685

Index

A ABBC2, in Dubin-Johnson syndrome, 462 ABCB4 disease clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t ABCB11, in “benign” recurrent intrahepatic cholestasis, 460 ABCB11 disease clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t Abdominal wall collaterals, in chronic liver disease, 36, 37f Aberrant parenchymal vein, 674f, 675 Abscess differential diagnosis of, 63t with HIV infection, 249t, 256–257, 257f micro, 256–257 pyogenic hepatic, 256–257 pseudo, due to amebiasis, 271 pyogenic hepatic, 266, 267f Acarbose, hepatotoxicity of, 334t–347t Aceruloplasminemia, hereditary, 157 Acetaldehyde, in drug-induced liver injury, 325

Acetaminophen acute liver disease due to, 34 liver transplantation for, 35t hepatotoxicity of, 334t–347t zonal necrosis due to, 352f Acetohexamide, hepatotoxicity of, 334t–347t Acetylation, in drug metabolism, 324 Acetylsalicylic acid (Aspirin), hepatotoxicity of, 334t–347t Acid lipase deficiency, 112, 115f Acid-α-glucosidase deficiency, 118t Acidophil bodies, 23 in acute viral hepatitis, 193, 195f in autoimmune hepatitis, 311, 311f in chronic hepatitis B, 213 in chronic hepatitis C, 226 Acinar change, 26, 27f Acinar concept, in parenchymal architecture, 4, 5f Acinar growth pattern, of hepatocellular carcinoma, 533, 534f Acinus, anatomy of, 4 Acitretin, hepatotoxicity of, 334t–347t Acquired immunodeficiency syndrome (AIDS), due to cytomegalovirus, 201 Acquired immunodeficiency syndrome (AIDS) cholangiopathy, 249t, 250–251, 430 Actinomyces, 268 Actinomyces israelii, 268 Actinomycin D, hepatotoxicity of, 334t–347t

Actinomycosis, 268 liver involvement, 268 Activity in chronic hepatitis, 233 definition of, 23 Acute cellular rejection, 636–637, 637f in children, 622 grading of, 637–638, 637t loss of intrahepatic bile ducts due to, 438, 438f in recurrent hepatitis C, 646 Acute cholestasis, 332t–333t in drug-induced liver injury, 334t–347t Acute fulminant hepatitis, 348f Acute (fulminant) liver failure, 33 clinical manifestations of, 35 due to autoimmune hepatitis, 35 laboratory investigation of, 46 liver transplantation for, 35, 35t treatment for, 35, 35t Acute intrahepatic cholestasis, in drug-induced liver injury, 353 Acute liver disease, 33–35 clinical manifestations of, 34–35 etiology of, 34, 34t treatment and prognosis for, 35 Acute liver failure (ALF), 123 drug-induced liver injury (DILI) from surveys of, 329t liver transplantation for, 610–611 Acute Liver Failure Study Group, 328

Page numbers followed by f indicate figures; t, tables; b, boxes. 687

Index Acute liver injury, laboratory investigation of, 46–47, 47f, 47t Acute (lobular) hepatitis, 332t–333t Acute renal failure, with acute liver failure, 34–35 Acute viral hepatitis, autoimmune hepatitis and, 314 Acyclovir (Zovirax), for posttransplant prophylaxis, 625 Acylcarnitine profile, collection, storage, and shipping of specimens for, 96t Adalimumab, hepatotoxicity of, 334t–347t Adenocarcinoma colorectal, 598t hepatocellular carcinoma and, 539 pulmonary, 598t Adenoma, bile duct, 547–548 clinical manifestations of, 547 differential diagnosis of, 548 pathology of, 547–548, 548f radiologic features of, 547 Adenomatosis, 508 Adenosine triphosphate (ATP)-binding cassette (ABC) transporter, 323t, 324 Adenovirus acute hepatitis due to, 202–203 diagnosis of, 203 pathology of, 202–203 transmission of, 202 in liver transplantation, 658 Adrenal cortical carcinoma, vs. angiomyolipoma, 591t Adrenal leukodystrophy, X-linked, common findings with, 92t–93t Adverse drug reaction, differential diagnosis of, primary biliary cirrhosis versus, 416 Aflatoxin B1 (AFB1), hepatocellular carcinoma and, 530 African iron overload, 155t, 158 Age-related changes, in liver, 16b Aggressiveness, of chronic hepatitis, 233 AIDS cholangiopathy. see Acquired immunodeficiency syndrome (AIDS) cholangiopathy. AIH. see Autoimmune hepatitis (AIH). AIH-PSC overlap syndrome. see Autoimmune hepatitis-primary sclerosing cholangitis (AIH-PSC) overlap syndrome. Ajmaline, hepatotoxicity of, 334t–347t Alagille syndrome, 77–81 clinical manifestations of, 79–80 differential diagnosis of, 80–81 biliary atresia and, 76f gross pathology of, 80 incidence and demographics of, 78–79 living donor transplantation for, 632 microscopic pathology of, 80, 80f molecular genetics in, 79 prognosis and treatment for, 81 Alanine aminotransferase (ALT) for donor liver, 616 liver tests of, 44 in primary biliary cirrhosis, 410 Alanine aminotransferase-to-aspartate aminotransferase (ALT-to-AST) ratio, for staging of chronic hepatitis, 243 Albumin, serum, 45 688

Alcohol abuse, liver transplantation and, 612–613 Alcohol related liver disease, recurrent, 652–653, 652f Alcohol use, drug-induced liver injury and, 325 Alcoholic fatty liver, 373f, 375–376, 375f Alcoholic foamy degeneration, 375–376, 376f Alcoholic hepatitis, 376 clinical presentation of, 34 Alcoholic liver disease (ALD) clinical manifestations of, 372–373 differential diagnosis of, 383–384 vs. chronic hepatitis C, 230 end-stage, 386 focal liver lesions in, 382–383 genetics of, 384–385 grading and staging of, 382, 382t gross pathology of, 373, 373f hemochromatosis due to, 155t, 159 histologic features of, 383, 384b histologic variants of, 380–382 changes in hepatocytes, 381–382 differential diagnosis, 384 iron overload, 381, 381f portal tract changes in, 380–381 incidence and demographics of, 372 interactions with other liver diseases, 384 liver transplantation for, 609 microscopic pathology of, 373–380, 374t–375t alcoholic fatty liver, 373f, 375–376, 375f alcoholic foamy degeneration, 375–376, 375f alcoholic steatohepatitis, 376–379, 376f cirrhosis, 379–380, 379f lipogranulomas, 376, 376f NAFLD and, 179, 179t noninvasive assessment of, 373 blood tests, 373 imaging studies, 373 role of liver biopsy in, 382 treatment and prognosis of, 385–386 Alcoholic steatonecrosis, 376 Alcohol-induced liver disease, 371–390 ALD. see Alcoholic liver disease (ALD). Alemtuzumab, for posttransplant immunosuppression, 623t, 625 ALF. see Acute liver failure (ALF). Alkaline phosphatase (ALP) liver tests of, 44 in primary biliary cirrhosis, 410, 415 in primary sclerosing cholangitis, 424 Allograft(s) allocation of, 617–618 algorithm for, 614–615, 615t biopsy of, indications of, 630b evaluation of, 614–617, 614b extended criteria donors, 614–617, 614b medical history, 616–617 physiologic, 615–616 with partial liver allografts, 617, 618f implantation of, 619–620 living donor, 617, 618f loss of intrahepatic bile ducts in due to allograft rejection acute, 438, 438f chronic, 438, 438f

Allograft(s) (Continued) due to recurrent primary biliary cirrhosis and primary sclerosing cholangitis, 439 partial liver, 617, 618f pathologic processes occurring in, 630b preparation of, 619 primary nonfunction of, 620 rejection of, 621, 634–642 acute, 438, 438f in children, 622 acute antibody-mediated, microscopic pathology of, 636, 636f cellular, 636–639 acute, 636–637, 637f, 637t–638t differential diagnosis of, 638–639, 639f late, 638, 638f–639f chronic, 438, 438f, 639–641, 640f–641f antibody-mediated, 641, 642b differential diagnosis of, 641 early and late features of, 641t treatment of, 642 clinical manifestations of, 635 common pathways of, 635f differential diagnosis of, 636 ductopenic, 639–640, 640f humoral, 635 hyperacute, 635–636, 636f loss of intrahepatic bile ducts due to, 435f acute, 438–439, 438f chronic, 438, 438f terminology in, 634–642 split liver, 617 Allopurinol, hepatotoxicity of, 334t–347t ALP. see Alkaline phosphatase (ALP). Alpers disease, with valproate-associated liver failure, 108f Alpers-Huttenlocher syndrome, 107 Alpha fetoprotein (AFP), in hepatocellular carcinoma, 531, 535f Alpha methyl acyl-CoA racemase deficiency, 119 Alpha-1 antitrypsin, 133 Alpha-1 antitrypsin deficiency, 133–142 clinical manifestations and natural history of liver disease in, 134–136, 134t diagnosis of, 139, 139f, 140t differential diagnosis of, 139, 139b vs. chronic hepatitis C, 230 genetics and molecular pathology of, 139–140 incidence and demographics of, 134 iron overload with, 157–158 microscopic pathology of, 136–139 intracytoplasmic globules in, 136–137, 136f–137f, 136t of PiMZ, 138 of PiZZ, 137–138 of “S” variant, 138 with PiMZ clinical manifestations and natural history of liver disease in, 134t, 135 incidence and demographics of, 134 pathology of, 138

Index Alpha-1 antitrypsin deficiency (Continued) with PiZZ clinical manifestations and natural history of liver disease in, 134–135, 134t incidence and demographics of, 134 pathology of, 137–138, 137f–138f with “S” allele clinical manifestations and natural history of liver disease in, 134t, 135–136 incidence and demographics of, 134 terminology for, 133–134 treatment and prognosis for, 140 ultrastructural pathology of, 138–139, 138f ALT. see Alanine aminotransferase (ALT). Amebiasis, 271–272 diagnosis of, 272 life cycle in relation to liver disease, 271 pathology of, 272 Amineptine, hepatotoxicity of, 334t–347t Amino acid disorders common findings with, 92t–93t tests, methods, and required biologic samples for, 95t Amino acids methodologies for, 97 quantitative, collection, storage, and shipping of specimens for, 96t Aminoglutethimide, hepatotoxicity of, 334t–347t Amiodarone, hepatotoxicity of, 334t–347t, 360f Amitriptyline, hepatotoxicity of, 334t–347t Amlodipine, hepatotoxicity of, 334t–347t Ammonia, blood, 45 Amodiaquine, hepatotoxicity of, 334t–347t Amoxapine, hepatotoxicity of, 334t–347t Amoxicillin-clavulanate cholestatic injury due to, 354f hepatotoxicity of, 334t–347t Ampicillin, hepatotoxicity of, 334t–347t Ampicillin-sulbactam, hepatotoxicity of, 334t–347t Amsacrine, hepatotoxicity of, 334t–347t Amyloid protein A, serum, in hepatocellular adenomas, 518–520, 521f–522f Amyloidosis, 480–481, 481f Anakinra, hepatotoxicity of, 334t–347t Anaplastic hepatoblastoma, 570, 571f Anaplastic large cell lymphoma, 592t–593t Anastrozole, hepatotoxicity of, 334t–347t Anderson, Dorothy, 143 Androgens, hepatotoxicity of, 334t–347t Anemia of chronic disease, hemochromatosis due to, 158 spur cell, in cirrhosis, 160 Anesthesia, for liver transplantation, 620 Angiomatosis, bacillary, 258, 259f Angiomyolipoma, 590 clinical manifestations of, 590 differential diagnosis of, 589t, 590, 591t gross pathology of, 590 incidence and demographics of, 590 microscopic pathology of, 590, 590f

Angiomyolipoma (Continued) radiologic features of, 590 treatment and prognosis of, 590 Angiopoietin gene 1 (ANGPT1), in focal nodular hyperplasia, 525–526 Angiopoietin gene 2 (ANGPT1), in focal nodular hyperplasia, 525–526 Angiosarcoma, 332t–333t, 587–589 clinical manifestations of, 588 differential diagnosis of, 587t, 588, 589t in drug-induced liver injury, 334t–347t gross pathology of, 588 incidence and demographics of, 587–589 microscopic pathology, 588, 588f radiologic features of, 588 treatment and prognosis of, 588–589 well-differentiated, 585t Aniline blue, 8t Antimitochondrial antibodies (AMAs), in primary biliary cirrhosis, 410, 415, 415t–416t asymptomatic patients with positive, 419 Antimitochondrial antibody (AMA)-negative primary biliary cirrhosis, 416t Antinuclear antibodies, in primary biliary cirrhosis, 410 Antiretroviral therapy, 247 mitochondriopathies with, 259, 260f Antithyroid antibodies, in primary biliary cirrhosis, 410 Apical pole, of hepatocytes, 20 Apoptosis, 23, 25f in acute viral hepatitis, 193, 195f due to yellow fever, 204 in chronic hepatitis B, 213–214, 215f in chronic hepatitis C, 226, 227f Apoptotic bodies, 23 Aprindine, hepatotoxicity of, 334t–347t Architectural changes, in premalignant and early malignant hepatocellular lesions, 495, 495t, 496f Arenaviruses, acute hepatitis due to, 207 Arginase-1, in hepatocellular carcinoma, 534 Argininosuccinic acid lyase deficiency, common findings with, 92t–93t Armillifer (Porocephalus) armillatus, 281 Arterial embolization, for hepatocellular carcinoma, 540 Arterialization, of central zone, 434 Arteriopathic rejection, 639–641 Arthrogryposis-renal dysfunctioncholestasis syndrome (ARC), 459 Ascariasis, 275–276 clinical manifestations of, 275 diagnosis of, 276 life cycle in relation to liver disease, 275 pathology of, 275, 276f Ascaris lumbricoides, 275 Ascites in Budd-Chiari syndrome, 40 causes of, 40 in chronic liver disease, 36, 37f, 39–40 in cirrhosis, 39–40 classification of infected, 40t complications of, 40 epidemiology of, 39

Ascites (Continued) management of, 40 refractory, 40 total protein level, 40 Asparaginase, hepatotoxicity of, 334t–347t Aspartate aminotransferase (AST) for donor liver, 616 liver tests of, 44 in primary biliary cirrhosis, 410 Aspartate aminotransferase (AST)-toplatelet ratio index, for staging of chronic hepatitis, 243 Aspirin, for posttransplant prophylaxis, 623t, 625 AST. see Aspartate aminotransferase (AST). Asterixis, in chronic liver disease, 38 Asteroid bodies in epithelioid granulomas, 291f in sarcoidosis, 302f Atenolol, hepatotoxicity of, 334t–347t Atomoxetine, hepatotoxicity of, 334t–347t, 358f Atorvastatin, hepatotoxicity of, 334t–347t ATP7B, in Wilson disease, 125, 130 ATP8B1, in “benign” recurrent intrahepatic cholestasis, 460 ATP8B1 disease, 456, 456f–457f clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t Autoantibodies in primary biliary cirrhosis, 410 antimitochondrial, 410, 415, 415t–416t antinuclear, 410 other, 410 in primary sclerosing cholangitis, 424 Autoimmune cholangiopathy, 419 Autoimmune cholangitis, 419 Autoimmune diseases, primary sclerosing cholangitis as, 424 Autoimmune hepatitis (AIH), 307–316 in central perivenulitis, 642–643 clinical manifestations of, 310 de novo, 653–654 diagnosis of, 653f in late cellular rejection, 638, 639f definitions and synonyms of, 309 differential diagnosis of, 313–314 primary biliary cirrhosis versus, 416, 417t vs. chronic hepatitides, 219 vs. primary sclerosing cholangitis (PSC), 429 vs. Wilson disease, 130t genetics of, 314 grading and staging of, 313, 314f incidence and demographics of, 309 laboratory findings of, 310 liver transplantation for, 609 microscopic features of, with primary sclerosing cholangitis (PSC), 82, 82f microscopic pathology of, 310–312 overlap of with primary sclerosing cholangitis, 424 clinical manifestations of, 81 microscopic pathology of, 82, 82f 689

Index Autoimmune hepatitis (AIH) (Continued) overlap syndromes in, 312–313 recurrent, 648–649 diagnosis of, 649b differential diagnosis of, 649 microscopic pathology of, 649, 649f treatment and prognosis of, 314–315 Autoimmune hepatitis-primary biliary cirrhosis (AIH-PBC) overlap syndrome, 312, 313f, 413f, 419 Autoimmune hepatitis-primary sclerosing cholangitis (AIH-PSC) overlap syndrome, 312–313, 313f clinical manifestations of, 81 microscopic pathology of, 82, 82f Autoimmune sclerosing cholangitis clinical manifestations of, 81 microscopic pathology of, 82, 82f Autosomal recessive polycystic kidney disease, 397–399 clinical manifestations of, 398–399, 399f macroscopic pathology of, 399, 400f microscopic pathology of, 399, 401f treatment of, 399 Azapropazone, hepatotoxicity of, 334t–347t Azathioprine hepatotoxicity of, 334t–347t for posttransplant immunosuppression, 623t, 624 Azithromycin hepatotoxicity of, 334t–347t toxicity, 355f B Bacillary angiomatosis, 258, 259f Bacille Calmette-Guérin (BCG), hepatotoxicity of, 334t–347t Bacterial infections, 266–271 actinomycosis, 268 liver in, 268 brucellosis, 267–268 diagnosis of, 268 liver in, 267–268 chlamydial, 271 with HIV infection, 249t, 256–257, 257f legionellosis, 268 leptospirosis, 268–270, 270f clinical manifestations of, 269 pathogenesis, 269–270 pathology of, 270 pyogenic hepatic abscess due to, 266, 267f rickettsial, 270–271 Q fever, 271 Rocky mountain spotted fever, 271, 271f salmonellosis as, 266–267 diagnosis of, 267 liver disease in, 267 pathogenesis, 267 sepsis as, 266, 266f pathology of, 266 syphilis as, 268, 269f Bactrim (trimethoprim/sulfamethoxazole), for posttransplant prophylaxis, 625 Ballooned hepatocytes in acute viral hepatitis, 193, 194f in alcoholic liver disease, 374t–375t, 377 in nonalcoholic fatty liver disease, 172–173, 173f 690

Ballooning degeneration/change, 22, 23f Bangui fever, 198 Barakol, hepatotoxicity of, 334t–347t Bartonella henselae, with HIV infection, 258 Bartonella quintana, with HIV infection, 258 Basiliximab, for posttransplant immunosuppression, 623t Basolateral domain, of hepatocytes, 20 Batts and Ludwig system, in chronic hepatitis, for grading, 235–236 B-cell lymphoma extranodal marginal zone, 592t–593t T-cell-rich, 592t–593t Behçet disease (BD), laboratory investigation of, 51 Benign hepatocellular tumor(s), 507–528 clinical manifestations, 508–509 definitions and synonyms, 507–508 differential diagnosis, 511–512 genetics, 525–526 genotype-phenotype classification of, 515–520, 517t gross pathology, 512, 516f–518f histologic variants, 520–522, 524f immunohistochemistry, 520, 523f incidence and demographics, 508 microscopic pathology, 512–515 radiologic features, 509–512, 509f–515f treatment, 526 Benign primary tumors, miscellaneous, 597, 597t “Benign” recurrent intrahepatic cholestasis (BRIC), 460–461 clinical manifestations of, 460 etiopathogenesis of, 460 microscopic findings of, 461, 461f Benign tumors, of bile ducts, 545–551 bile duct hamartoma, 546–547 clinical manifestations of, 546–547 differential diagnosis of, 547 pathology of, 547, 547f prognosis of, 547 radiologic features of, 547 ciliated hepatic foregut cyst, 546 clinical manifestations of, 546 differential diagnosis of, 546, 546t pathology of, 546, 546f intraductal papillary neoplasm of the bile duct, 550–551 clinical manifestations of, 550 differential diagnosis of, 550–551 incidence and demographics of, 550 pathology of, 550, 551f radiologic features of, 550 mucinous cystic neoplasm, 548–549 clinical manifestations of, 548 differential diagnosis of, 548–549 pathology of, 548, 549f–550f radiologic features of, 548, 549f peribiliary gland hamartoma (bile duct adenoma), 547–548 clinical manifestations of, 547 differential diagnosis of, 548 pathology of, 547–548, 548f radiologic features of, 547

Benign tumors, of bile ducts (Continued) solitary bile duct cyst, 545–546 clinical manifestations of, 545 differential diagnosis of, 546, 546t pathology of, 545, 546f Benorylate, hepatotoxicity of, 334t–347t Benoxaprofen, hepatotoxicity of, 334t–347t Benzarone, hepatotoxicity of, 334t–347t 3-Beta hydroxysteroid dehydrogenase deficiency, 118, 119f 5-Beta reductase deficiency, 116–118, 119f Bicaval anastomosis, for liver transplantation, 619, 620f Bile, in hepatocytes, 14–15, 17f Bile acid coenzyme A:amino acid N-acyltransferase (BAAT), in familial hypercholanemia, 459 Bile acid synthetic defects (BASDs), 116–119, 118t, 119f “low-GGT” intrahepatic cholestasis due to, 460 vs. progressive familial intrahepatic cholestasis, 454 Bile canaliculi anatomy of, 15, 18f electron microscopy, 20, 21f in hepatocellular carcinoma, 532 Bile duct adenoma, 547–548 clinical manifestations of, 547 differential diagnosis of, 548 pathology of, 547–548, 548f radiologic features of, 547 Bile duct cyst, solitary, 545–546 clinical manifestations of, 545 differential diagnosis of, 546, 546t pathology of, 545, 546f Bile duct epithelial damage, in primary biliary cirrhosis, 410, 411f Bile duct hamartoma, 546–547 clinical manifestations of, 546–547 differential diagnosis of, 547 pathology of, 547, 547f prognosis of, 547 radiologic features of, 547 Bile duct injury, in primary biliary cirrhosis, 410–412, 415t with bile duct epithelial damage, 410, 411f with bile duct loss and ductopenia, 410–412, 412f–413f with ductular reaction, 410, 412f with florid duct lesion, 410, 411f–412f with granulomas, 410 with lymphocytic cholangitis, 410, 411f nonsuppurative cholangitis due to, 410 Bile duct loss, in primary biliary cirrhosis, 410–412, 413f Bile duct papillomatosis, 550 Bile duct scar, 27, 28f Bile duct tumors, 545–554 benign, 545–551 bile duct hamartoma, 546–547 clinical manifestations of, 546–547 differential diagnosis of, 547 pathology of, 547, 547f prognosis of, 547 radiologic features of, 547 ciliated hepatic foregut cyst, 546 clinical manifestations of, 546

Index Bile duct tumors (Continued) differential diagnosis of, 546 pathology of, 546, 546f intraductal papillary neoplasm of the bile duct (IPNB), 550–551 clinical manifestations of, 550 differential diagnosis of, 550–551 incidence and demographics of, 550 pathology of, 550, 551f radiologic features of, 550 mucinous cystic neoplasm, 548–549 clinical manifestations of, 548 differential diagnosis of, 548–549 pathology of, 548, 549f–550f radiologic features of, 548, 549f peribiliary gland hamartoma (bile duct adenoma), 547–548 clinical manifestations of, 547 differential diagnosis of, 548 pathology of, 547–548, 548f radiologic features of, 547 solitary bile duct cyst, 545–546 clinical manifestations of, 545 differential diagnosis of, 546, 546t pathology of, 545, 546f malignant, 551–553 cholangiocarcinoma, 551–553 clinical manifestations of, 551 differential diagnosis of, 552–553, 553t pathology of, 552, 552f–553f radiologic features of, 552, 552f Bile duct ulceration, in primary sclerosing cholangitis (PSC), 425–426, 425f Bile ductopenia, in primary biliary cirrhosis, 410–412, 412f Bile ducts anatomy of, 8–9, 14f–15f interlobular, 8–9, 14f in primary sclerosing cholangitis (PSC), 427 direct involvement of, 427, 427f periductal fibrosis in, 427, 427f intrahepatic hepatic artery and, 434, 434f paucity of, 433 portal veins and, 434, 434f in metabolic liver disease, 104–105 in primary sclerosing cholangitis (PSC) large (hilar/parahilar), 425–426 bile duct ulceration as, 425–426, 425f bile extravasation as, 425–426, 425f inflammatory myofibroblastic tumor in, 425–426, 426f onion-skin appearance in, 425–426, 426f scar formation in, 426f stones in, 425–426, 426f xanthogranuloma as, 425–426, 425f small peripheral portal tracts, 427 cholate stasis in, 427, 428f copper-associated protein in, 427, 428f early indirect portal changes in, 427, 428f florid ductular reaction in, 427, 428f

Bile ducts (Continued) small septal/interlobular bile ducts, 427 direct involvement of, 427, 427f periductal fibrosis in, 427, 427f septal, 8–9, 427 direct involvement of, 427, 427f periductal fibrosis in, 427, 427f Bile ductular reaction, in primary biliary cirrhosis, 410, 412f Bile ductule, 22 anatomy of, 18f in metabolic liver disease, 104–105, 104f Bile extravasation, in primary sclerosing cholangitis (PSC), 425–426, 425f Bile infarct, 26, 27f Bile salt export pump (BSEP), 447 defect, lobular cholestasis in, 103f Biliary ascariasis, 275, 276f Biliary atresia, 71–76 clinical manifestations of, 71 differential diagnosis of, 74, 75t Alagille syndrome and, 76f, 80f neonatal cholestasis and, 75f neonatal hepatitis and, 74, 75t, 77 nonobstructive conditions and, 74, 75t other nonobstructive conditions and, 74, 75t total parenteral nutrition and, 74, 76f embryonal form of, 71 extrahepatic, 71 incidence and demographics of, 71 intrahepatic, 71 pathology of, 72–74 liver, removed after successful Kasai procedure in, 72, 72f, 75f macroscopic, 72, 72f microscopic, 72–74, 73f–75f porta hepatis in, 73 perinatal form of, 71 radiologic features of, 71–72, 71f–72f treatment and prognosis for, 74–76 Biliary canaliculi anatomy of, 15, 18f electron microscopy, 20, 21f Biliary changes, in sarcoidosis, 303, 303f Biliary channels, intralobular, 15–16, 18f Biliary cirrhosis, primary autoimmune hepatitis and, 314 differential diagnoses of, 304t Biliary complications, in liver transplantation, 621 “Biliary” enzymes, liver tests of, 44–45 Biliary halo, 26, 27f in postnecrotic cirrhosis, 680, 681f Biliary hamartoma, 395, 396f Biliary leak, after liver transplantation, 621 Biliary lesions, terminology for, 26–27 Biliary lobule, anatomy of, 3–4 Biliary microhamartomas, 546–547 clinical manifestations of, 546–547 differential diagnosis of, 547 pathology of, 547, 547f prognosis of, 547 radiologic features of, 547 Biliary papillomatosis, 550 Biliary pole, of hepatocytes, 20

Biliary rosettes, 26, 27f canalicular cholestasis with, in neonatal (giant cell) hepatitis, 77, 78f Biliary strictures in liver transplantation, 655, 656f posttransplant, anastomotic, 621 Bilirubin conjugated and unconjugated, 45 disorders of metabolism conjugated hyperbilirubinemia as, 462 unconjugated hyperbilirubinemia as, 461 liver tests of, 45, 45t Binucleation, in hepatocytes, 12–14, 14f, 16f Bioavailability, of drugs, factors affecting, 320–321 disease states as, 321, 321f–322f enzyme induction and inhibition as, 320 enzyme polymorphisms as, 320–321 Biomarkers, in premalignant and early malignant hepatocellular lesions, 497–498, 499f–500f Bismuth, Henri, 606b Black cohosh, hepatotoxicity of, 334t–347t Black vomiting fever, 198 Bland cholestasis, 17f–18f, 26 Bleeding diathesis, due to acute liver failure, 34 Blood ammonia, 45 Blood plasma, for genetic and biochemical tests, collection, storage, and shipping of specimens for, 96t Blushing hepatocytes, in primary biliary cirrhosis, 435–436, 437f Boeck, Caesar, 301 “Borderline, zone 1 steatohepatitis,” 380 Bortezomib, hepatotoxicity of, 334t–347t Brancher enzyme deficiency, 118t Breast carcinoma, 598t Breast milk jaundice, 69–70 BRIC. see “Benign” recurrent intrahepatic cholestasis (BRIC). Bridging fibrosis in primary biliary cirrhosis, 414, 414f in sarcoidosis, 302, 303f Bridging necrosis, 23 in acute viral hepatitis, 193, 196f in autoimmune hepatitis, 310–311, 312f in chronic hepatitis B, 214, 215f in grading of chronic hepatitis in METAVIR algorithm, 240f in Scheuer system, 237f Bridging septal fibrosis, in staging of chronic hepatitis, 234 in Scheuer system, 241f Broelsch, Christoph, 606b Bromfenac, hepatotoxicity of, 334t–347t Brucella, 294 Brucellosis, 267–268, 268f, 294 diagnosis of, 268, 294 liver in, 267–268 pathology of, 294, 294f Budd-Chiari syndrome, 332t–333t, 468–469, 468b in ascites, 40 clinical manifestation of, 469 in drug-induced liver injury, 334t–347t etiopathogenesis of, 468–469 691

Index Budd-Chiari syndrome (Continued) gross pathology of, 469, 469f incidence and demographics of, 468–469 laboratory findings in, 469 microscopic pathology of, 469, 470f radiologic features of, 469 Bupropion, hepatotoxicity of, 334t–347t Bush tea, hepatotoxicity of, 334t–347t Busulfan, hepatotoxicity of, 334t–347t Byler disease, 454t C C282Y gene, in hereditary hemochromatosis, 156 Calcium hopantenate, hepatotoxicity of, 334t–347t Calne, Roy, 606b Camphor, hepatotoxicity of, 334t–347t Canalicular cholestasis, in neonatal (giant cell) hepatitis, 77, 78f Canalicular domain, of hepatocytes, 20, 21f Canalicular pattern, 15, 18f Canaliculi, biliary anatomy of, 15, 18f electron microscopy, 20, 21f Canals of Hering, 22 anatomy of, 16 Cancer, after liver transplantation, 621–622 Candesartan, hepatotoxicity of, 334t–347t Candidiasis, 294–295 diagnosis of, 295 pathology of, 295, 295f Capillaria hepatica, 277 Capillariasis, 277 clinical manifestations of, 277 diagnosis of, 277 life cycle in relation to liver disease, 277 pathology of, 277 Capillarizations, sinusoidal, 19, 19f Captopril, hepatotoxicity of, 334t–347t Caput medusae, in chronic liver disease, 36, 37f Carbamazepine, hepatotoxicity of, 334t–347t Carbamoyl phosphate synthase deficiency, common findings with, 92t–93t Carbarsone, hepatotoxicity of, 334t–347t Carbenicillin, hepatotoxicity of, 334t–347t Carbetamide, hepatotoxicity of, 334t–347t Carbimazole, hepatotoxicity of, 334t–347t Carbohydrate-deficient glycoprotein syndromes, diagnostic test for, 97 Carboplatin, hepatotoxicity of, 334t–347t Carcinoembryonic antigen (CEA), in hepatocellular carcinoma, 534–535, 535f Carcinoid tumor, vs. angiomyolipoma, 591t Carcinosarcomas, 537 Cardiac death, donation after, 616 Cardiac diseases, liver tests in, 51 Cardiorespiratory abnormalities, in acute liver failure, 34–35 Carmustine, hepatotoxicity of, 334t–347t Carnitine palmitoyltransferase 2 deficiency, 105–106, 106f Carnitine translocase and defects, common findings with, 92t–93t Carnitine-acylcarnitine translocase deficiency, 105–106 692

Caroli disease, 393, 399–402 choledochal cysts and, 393 clinical manifestations of, 400–402, 401f macroscopic pathology of, 402, 402f microscopic pathology of, 402, 402f treatment of, 402 Carrel, Alexis, 606, 606b Cascara sagrada, hepatotoxicity of, 334t–347t Caseous necrosis, in epithelioid granulomas, 290–291, 292f Catechol O-methyltransferase (COMT), in drug metabolism, 323t, 324 β−catenin, in hepatocellular adenoma(s) (HCAs), 511–512, 517t genetics of, 526 immunohistochemistry, 520 inflammatory features, 520 Causality scoring methods, 365t Cavernous hemangioma, 583–585 clinical manifestations, 583 demographics of, 583–585 differential diagnosis of, 584, 585t with focal nodular hyperplasia, 584, 585f gross pathology of, 584, 584f with hemangioma-like vessels, 584 incidence of, 583–585 microscopic pathology of, 584, 584f radiologic features of, 583–584 treatment and prognosis for, 585 CCR5 inhibitor, for HIV infection, 247–248 CD34, in hepatocellular carcinoma, 535 CDG. see Congenital disorders of glycosylation (CDG). Cefadroxil, hepatotoxicity of, 334t–347t Cefalexin, hepatotoxicity of, 334t–347t Cefazolin, hepatotoxicity of, 334t–347t Cefuroxime, chronic cholestatic hepatitis due to, 356f Celecoxib, hepatotoxicity of, 334t–347t Celiac disease (CD), 181 autoimmune hepatitis and, 314 Cell damage, terminology for, 22–23 Cellcept (mycophenolate mofetil), for posttransplant immunosuppression, 624 Cell(s), terminology for, 22 Cellular rejection, 636–639 acute, 636–637, 637f in children, 622 grading of, 637–638, 637t–638t loss of intrahepatic bile ducts due to, 438, 438f in recurrent hepatitis C, 646 differential diagnosis of, 638–639, 639f late, 638, 638f–639f Cellular senescence, 672 Center for Drug Evaluation and Research (CDER), 328 Central perivenulitis, 642–643, 642f–644f diagnosis of, 644f grading of, 642, 643t isolated, 637, 642, 642f–643f Central sclerosing hyaline necrosis, in alcoholic liver disease, 378, 378f Central vein anatomy of, 7f, 11–12 on low power, 4f

Central zone, arterialization of, 434 Centrilobular area, 22 Centrilobular perivenular inflammation, in autoimmune hepatitis, 311, 311f Cerebral edema, due to acute liver failure, 34 Ceruloplasmin, in Wilson disease, 126 Cetirizine, hepatotoxicity of, 334t–347t CEUS. see Contrast-enhanced sonography (CEUS). CF. see Cystic fibrosis (CF). CFTR. see Cystic fibrosis transmembrane conductance regulator (CFTR). Chaparral, hepatotoxicity of, 334t–347t Chaso/Onshido, hepatotoxicity of, 334t–347t Chelation therapy, histologic effects of, 162, 162f Chemical shift imaging, of hepatic steatosis, 60, 64f Chemotherapy associated steatohepatitis (CASH), 180, 180f ‘Chicken-wire’ fibrosis, 672 Childhood, liver diseases of, 67–88 Alagille syndrome as, 77–81 clinical manifestations of, 79–80 differential diagnosis of, 80–81 gross pathology of, 80 incidence and demographics of, 78–79 microscopic pathology of, 80, 80f molecular genetics in, 79 prognosis and treatment for, 81 biliary atresia as, 71–76 clinical manifestations of, 71 differential diagnosis of, 74, 75t Alagille syndrome and, 76f, 80f neonatal cholestasis and, 75f neonatal hepatitis and, 74, 75t, 77 nonobstructive conditions and, 74, 75t other nonobstructive conditions and, 74, 75t total parenteral nutrition and, 74, 76f embryonal form of, 71 extrahepatic, 71 incidence and demographics of, 71 intrahepatic, 71 pathology of, 72–74 liver, removed after successful Kasai procedure in, 72, 72f, 75f macroscopic, 72, 72f microscopic, 72–74, 73f–75f porta hepatis in, 73 perinatal form of, 71 radiologic features of, 71–72, 71f–72f treatment and prognosis for, 74–76 neonatal cholestasis as, 69–71 diagnosis of, 70–71, 70t differential diagnosis of, 70–71, 70t due to Alagille syndrome, 76 due to neonatal hepatitis, 76 incidence and demographics of, 70 liver biopsy in, role of, 70–71 management of, 70–71 neonatal (giant cell) hepatitis as, 76–77 clinical manifestations of, 76–77 differential diagnosis of, 74, 75t, 77 etiology of, 77 pathology of, 77

Index Childhood, liver diseases of (Continued) canalicular cholestasis with biliary rosettes in, 77, 78f focal areas of necrosis in, 77, 77f giant cells in, 76–77, 77f–78f hemosiderin deposition in, 77, 79f treatment and prognosis for, 77 sclerosing cholangitis as autoimmune clinical manifestations of, 81 microscopic pathology of, 82, 82f due to Langerhans cell histiocytosis, 83–85, 84f neonatal, 85 primary, 81–83 clinical manifestations of, 81 diagnosis of, 82 incidence and demographics, 81 microscopic pathology of, 82, 82f–83f radiologic findings in, 82 treatment and prognosis for, 82–83 Child-Pugh Classification, for cirrhosis, 36, 36t Child-Pugh score, for severity of cirrhosis, 682 Chlamydia trachomatis, 271 Chlamydial infection, 271 Chlorambucil, hepatotoxicity of, 334t–347t Chloramphenicol, hepatotoxicity of, 334t–347t Chlordiazepoxide, hepatotoxicity of, 334t–347t Chloride absorption, in cystic fibrosis, 144 Chloroform, hepatotoxicity of, 334t–347t Chloropurine, hepatotoxicity of, 334t–347t Chlorothiazide, hepatotoxicity of, 334t–347t Chlorozotocin, hepatotoxicity of, 334t–347t Chlorpromazine, hepatotoxicity of, 334t–347t Chlorpropamide, hepatotoxicity of, 334t–347t Chlortetracycline, hepatotoxicity of, 334t–347t Chlorthalidone, hepatotoxicity of, 334t–347t Chlorzoxazone, hepatotoxicity of, 334t–347t Cholangioblastic hepatoblastoma, 557t, 561–564 Cholangiocarcinoma (CC), 282, 332t–333t, 551–553 clinical manifestations of, 551 cystic, 549 differential diagnosis of, 63t, 552–553, 553t in drug-induced liver injury, 334t–347t hepatocellular carcinoma and, 539 imaging of, 57f, 59 intrahepatic, differential diagnosis of, 587t pathology of, 552, 552f–553f with primary sclerosing cholangitis, 430 radiologic features of, 552, 552f Cholangiocytes in large bile ducts, 9, 15f in small bile ducts, 8–9, 14f Cholangiolocellular subtype, of hepatocholangiocarcinoma, 665–666, 667f

Cholangiopancreatography endoscopic retrograde for biliary atresia, 72 for primary biliary cirrhosis, 410 for primary sclerosing cholangitis, 424 magnetic resonance for primary biliary cirrhosis, 410 for primary sclerosing cholangitis, 424, 424f Cholangiopathy AIDS, 249t, 250–251, 430 autoimmune, 419 ischemic, loss of intrahepatic bile ducts due to, 440–442, 442f microscopic pathology of, 441–442, 443f Cholangitis autoimmune, 419 ischemic, loss of intrahepatic bile ducts due to, 440–441, 442f microscopic pathology of, 441–442, 443f in primary biliary cirrhosis lymphocytic, 410, 411f nonsuppurative, 410 recurrent pyogenic, 429 sclerosing autoimmune clinical manifestations of, 81 microscopic pathology of, 82, 82f differential diagnosis of, 9, 15f due to Langerhans cell histiocytosis, 83–85, 84f IgG4-related, 429 neonatal, 85 “high-GGT” intrahepatic cholestasis due to, 460 primary. see Primary sclerosing cholangitis; Primary sclerosing cholangitis (PSC). secondary or acquired, 430 causes of, 430b loss of intrahepatic bile ducts due to, 437 primary vs., 429 Cholangitis lenta, 26, 26f, 266, 378 laboratory investigation of, 51 Cholate stasis in primary biliary cirrhosis, 412–414, 414f, 415t in primary sclerosing cholangitis (PSC), 427, 428f Choledochal cysts, 393, 402–405, 403f Caroli disease and, 393 clinical manifestations of, 403–405, 404f macroscopic pathology of, 403, 404f microscopic pathology of, 403, 405f treatment of, 405 Choleohepaton, 4 Cholestasis acute intrahepatic, in drug-induced liver injury, 353 in acute viral hepatitis, 193, 195f in autoimmune hepatitis, 312 bland, 17f–18f, 26 canalicular with biliary rosettes, in neonatal (giant cell) hepatitis, 77, 78f

Cholestasis (Continued) in drug-induced liver injury, 353 chronic, of sarcoidosis, 418, 418f in drug-induced liver injury, 334t–347t lobular, metabolic diseases with prominent, 103–104, 103f, 103t neonatal, 69–71 diagnosis of, 70–71, 70t differential diagnosis of, 70–71, 70t biliary atresia versus, 75f due to Alagille syndrome, 76 due to neonatal hepatitis, 76 incidence and demographics of, 70 liver biopsy in, role of, 70–71 management of, 70–71 neonatal, in cystic fibrosis, 145–146, 145f–146f in primary biliary cirrhosis, 414, 414f sarcoidosis with, 301–302 Cholestasis-lymphedema syndrome, 460 Cholestatic drug-induced liver injury, 332t–333t Cholestatic hepatitis fluvastatin-related, 357f with HIV infection, 249t, 259–260 liver tests for, 44 Cholestatic injury, liver tests for, 44 Cholestatic jaundice, 69–70 diagnosis of, 70–71, 70t differential diagnosis of, 70–71, 70t incidence and demographics of, 70 management of, 70–71 Cholestatic liver disease, liver transplantation for, 609–610 Cholestatic patterns, in drug-induced liver injury, 353–357 Cholesterol ester storage disease, 112, 115f Christoffersen-Poulsen lesion, 416 Chronic cholestasis, 332t–333t Chronic cholestatic hepatitis, due to cefuroxime, 356f Chronic disease, anemia of, hemochromatosis due to, 158 Chronic hepatitis active, 233 grading and staging of, 233–246 aggressiveness (necroinflammation activity) in, 233 general principles of, 234 limitations of liver biopsy in, 238–240 need for, 233–234 semiquantitative scoring for limitations of, 240–241 vs. morphometric analysis, 241–242 systems for, 234–238 Batts and Ludwig, 235–236 best, 238 grading, 235–236, 235t histologic activity index, 235, 235t Ishak, 236, 238f–239f METAVIR, 236, 242f noninvasive nonbiopsy-based, 242–243 Scheuer, 235, 236f–237f staging, 236 idiopathic de novo, 654, 654f in late cellular rejection, 638, 638f 693

Index Chronic hepatitis (Continued) laboratory investigation of, 48 lobular, 233 pattern, 349f persistent, 233 vs. autoimmune hepatitis, 219 Chronic liver disease, 33, 36–41 assessing the severity of cirrhosis, 36, 36t clinical signs of (stigmata), 36–38 abdominal wall collaterals or caput medusae, 36, 37f ascites as, 36, 37f, 39–40 asterixis as, 38 Cruveilhier-Baumgarten murmur as, 38 cutaneous telangiectasia as, 37, 37f digital clubbing and hypertrophic osteoarthropathy as, 38, 38f Dupuytren contracture as, 38, 38f fetor hepaticus as, 38 gynecomastia, 37–38, 37f hepatomegaly as, 36, 36f jaundice as, 36, 36f livedo reticularis as, 38, 38f nail changes as, 38 palmar erythema as, 37, 37f spider angiomas, in chronic liver disease, 37, 37f splenomegaly as, 36 testicular atrophy as, 38 etiology, 36 Chronic liver injury, laboratory investigation of, 47–48, 49f Chronic methotrexate therapy, for collagenvascular diseases, 359f Chronic (portal) hepatitis, 332t–333t Chronic rejection, 639–641, 640f–641f antibody-mediated, 641, 642b differential diagnosis of, 641 early and late features of, 641t loss of intrahepatic bile ducts due to, 438, 438f treatment of, 642 Chronic viral hepatitis, autoimmune hepatitis and, 314 Ciliated hepatic foregut cyst, 546 clinical manifestations of, 546 differential diagnosis of, 546, 546t pathology of, 546, 546f Ciliopathies, 393, 394t Cimetidine, hepatotoxicity of, 334t–347t Cinchophen, hepatotoxicity of, 334t–347t Cinnarizine, hepatotoxicity of, 334t–347t Ciprofloxacin, 351f hepatotoxicity of, 334t–347t Ciprofloxacin hepatitis, 351f CIRH1A disease, 460 Cirrhosis, 33, 675f, 679–686 as advanced stage of chronic liver disease, 684 in alcoholic liver disease, 372, 374t–375t, 379–380 assessing the severity of, 36, 36t in chronic hepatitis B, 217, 218f in chronic hepatitis C, 228–229, 229f incomplete septal, 229 clinical spectrum of, 679 clinical staging of, 681–683, 682t complications of, 38–41 694

Cirrhosis (Continued) ascites, 37f, 39–40, 40t hepatic encephalopathy, 41, 41t hepatopulmonary syndrome, 38f, 41, 41f hepatorenal syndrome, 40–41 portopulmonary hypertension, 41 spontaneous bacterial peritonitis, 40 variceal bleeding, 38–39, 39f cryptogenic, 382 current concept of, 679–680 in cystic fibrosis focal biliary, 146, 147f multilobular, 146–148, 148f in drug-induced liver injury, 334t–347t early childhood, 130 endemic Tyrolean, 130 etiology of, 682f gross morphology of, 680, 680f hemochromatosis in, 160 due to alcoholic liver disease, 160 due to spur cell anemia, 160 genetic/hereditary cause of, 160 related to advanced fibrosis, 160, 160f hepatocellular adenoma with, 522–525 hepatocellular carcinoma and, 530 alcoholic, 530 cryptogenic, 530 imaging of, 55, 56f, 62t primary biliary, 530 imaging of contrast-enhanced sonography for, 62 CT for, 56f differential diagnosis of dominant liver nodules in, 58–59, 62t–63t with hepatocellular carcinoma, 55, 56f, 62t magnetic resonance elastography for, 63, 64f–65f transient elastography, 62–63 Indian childhood, 130 microscopic pathology of, 680–681, 681f pathologic staging of, 683 prognostication of, 681–683 regression of, 672–673, 672f, 683–684, 684f, 684b histologic assessment of, 674–676 Rogers, 272, 273f sarcoidosis with, 301–302 spur cell anemia in, 160 vascular abnormalities in, 671 Cirrhotic liver, hepatocellular carcinoma in, 536f Cirrhotic nodule, 675f Cisplatin, hepatotoxicity of, 334t–347t Citalopram, hepatotoxicity of, 334t–347t Citrin deficiency, 110, 110f common findings with, 92t–93t Citrullinemia, 110, 110f common findings with, 92t–93t Clarithromycin, hepatotoxicity of, 334t–347t Clear cell hepatocellular carcinoma, 537 Clometacin, hepatotoxicity of, 334t–347t Clonelike foci, 494–495 Clonorchiasis, 282–283 clinical manifestations of, 282 diagnosis of, 283

Clonorchiasis (Continued) life cycle in relation to liver disease, 282 pathology of, 282–283 Clonorchis sinensis, 282 Clopidogrel, hepatotoxicity of, 334t–347t Clorazepate, hepatotoxicity of, 334t–347t Cloxacillin, hepatotoxicity of, 334t–347t Clozapine, hepatotoxicity of, 334t–347t Clubbing, digital in chronic liver disease, 38, 38f Coagulation, measures of, 45 Colitis, ulcerative, with primary sclerosing cholangitis, 424 Collagen proportionate area (CPA) measurement, 673–674 Collapse, definition of, 23 Color Doppler ultrasonography, portal vein thrombosis and, 476 Combined hepatocellularcholangiocarcinoma, 553 Comfrey, hepatotoxicity of, 334t–347t Comorbidities, liver transplantation and, 613 Computed tomography (CT), 55 of cholangiocarcinoma, 57f delayed phase, 55, 56f dual phase, 55 of focal nodular hyperplasia, 58 of hemangioma, 57–58 of hepatic metastases, 59, 59f, 63f of hepatic steatosis, 59–60 of hepatocellular carcinoma, 58–59 with cirrhosis, 55, 56f with PET, 55–57, 59f phases of, 55, 57t Concentric fibrosis, in sarcoidosis, 303f Concentric periductal fibrosis, 26–27 Confluent necrosis, 23, 24f in acute viral hepatitis, 193, 196f in chronic hepatitis, 235t, 236, 238f in chronic hepatitis B, 214, 215f in chronic hepatitis C, 227f Congenital alloimmune hepatitis, 77, 79f Congenital disorders of glycosylation (CDG) common findings with, 91–93, 92t–93t tests, methods, and required biologic samples for, 95t Congenital erythropoietic porphyria, 122, 122f Congenital hepatic fibrosis, 397–399 clinical manifestations of, 398–399, 399f macroscopic pathology of, 399, 400f microscopic pathology of, 399, 401f treatment of, 399 Congenital syphilis, 268, 269f Congestive hepatopathy, 468b, 470–471 clinical manifestations of, 470 etiopathogenesis of, 470–471 gross pathology of, 471, 471f incidence and demographics of, 470 laboratory findings in, 470 microscopic pathology of, 471, 471f, 471t radiologic features of, 470 treatment and prognosis of, 471 Conjugated hyperbilirubinemia, 455 Conjugating enzymes, 319, 322–324, 323t Connective tissue diseases, liver tests in, 50–51

Index Continuous venovenous hemofiltration, for hepatorenal syndrome, 35 Contrast agents, for MRI, 58t Contrast-enhanced sonography (CEUS), 55, 56f of focal nodular hyperplasia, 58 of hemangioma, 56f of hepatic fibrosis and cirrhosis, 60–63 Conventional scoring systems, 673 Copper deposition, in primary biliary cirrhosis, 414, 414f, 415t in hepatocytes, 14–15, 17f homeostasis, 125 in progressive familial intrahepatic cholestasis, 457 Copper toxicosis idiopathic, 130 non-Wilson disease forms of, 130 vs. Wilson disease, 130t Copper-associated protein, in primary sclerosing cholangitis (PSC), 427, 428f Corticosteroids, hepatotoxicity of, 334t–347t Councilman bodies, in acute viral hepatitis, 193, 195f due to yellow fever, 204 Cowdry A bodies, in HSV hepatitis, 202, 203f with HIV infection, 254–255, 254f Cowdry B bodies, in HSV hepatitis, 202, 203f Coxiella burnetii, 271, 294 C-reactive protein (CRP), serum, in hepatocellular adenomas, 518–520, 521f–522f Crigler-Najjar syndrome type I, 461–462 type II, 462 Cromolyn, hepatotoxicity of, 334t–347t Cruveilhier-Baumgarten murmur, in chronic liver disease, 38 Cryptococcus spp, granulomas due to, with HIV infection, 256, 257f Cryptogenic cirrhosis, 382 hepatocellular carcinoma and, 530 Cryptosporidium parvum, in AIDS cholangiopathy, 430 CT. see Computed tomography (CT). Cutaneous telangiectasia, in chronic liver disease, 37, 37f Cyamemazine, hepatotoxicity of, 334t–347t Cyanamide, hepatotoxicity of, 334t–347t Cyclic AMP-dependent phosphorylase kinase deficiency, 118t Cyclofenil, hepatotoxicity of, 334t–347t Cyclophosphamide, hepatotoxicity of, 334t–347t Cyclosporine hepatotoxicity of, 334t–347t for posttransplant immunosuppression, 622–623, 623t CYP1A2, in drug metabolism, 321, 323t CYP2B6, in drug metabolism, 321–322, 323t CYP2C, in drug metabolism, 322, 323t CYP2C8, in drug metabolism, 322, 323t CYP2C9, in drug metabolism, 322, 323t CYP2C19, in drug metabolism, 322, 323t CYP2D6, in drug metabolism, 322, 323t

CYP3A, in drug metabolism, 322, 323t CYP3A4, in drug metabolism, 322, 323t CYP3A5, in drug metabolism, 322, 323t Cyproheptadine, hepatotoxicity of, 334t–347t Cyproterone, hepatotoxicity of, 334t–347t Cystadenocarcinoma, 549 Cystadenoma, hepatobiliary, 548–549 clinical manifestations of, 548 differential diagnosis of, 548–549 pathology of, 548, 549f–550f radiologic features of, 548, 549f Cysteamine, hepatotoxicity of, 334t–347t Cystic cholangiocarcinoma, 549 Cystic fibrosis (CF), 143–150 diagnostic studies for, 148–149 genetics of, 143–144 hepatobiliary disease in clinical manifestation of, 144, 144t microscopic pathology of, 145–148 focal biliary cirrhosis in, 146, 147f large bile duct disease in, 148, 149f multilobular cirrhosis in, 146–148, 148f neonatal cholestasis in, 145–146, 145f–146f steatosis in, 145, 145f unusual manifestations of, 148 incidence and demographics of, 143 pathophysiology of, 144 therapy in, 149 Cystic fibrosis transmembrane conductance regulator (CFTR), in cystic fibrosis, 143 genetics of, 143–144 pathophysiology of, 144 Cystic variant, of intraductal papillary neoplasm, 546t, 549 Cystinosis, 115 Cysts choledochal, Caroli disease and, 393 ciliated hepatic foregut, 546 clinical manifestations of, 546 differential diagnosis of, 546 pathology of, 546, 546f differential diagnosis of, 62t hydatid, primary sclerosing cholangitis due to rupture of, 430 hydatid (echinococcal), solitary bile duct cysts and, 546, 546t solitary bile duct, 545–546 clinical manifestations of, 545 differential diagnosis of, 546, 546t pathology of, 545, 546f Cytarabine, hepatotoxicity of, 334t–347t Cytochrome P450 enzymes (CYPs), in drug metabolism, 319, 321–322, 323t CYP1A2, 321, 323t CYP2B6, 321–322, 323t CYP2C, 322, 323t CYP2D6, 322, 323t CYP3A, 322, 323t in disease states, 321, 321f–322f polymorphisms of, 320 Cytokeratin, for loss of intrahepatic bile ducts, 433 Cytomegalovirus (CMV) granulomas and, 295–296

Cytomegalovirus (CMV) (Continued) in liver transplantation, 657, 657f–658f posttransplant, 621 prophylaxis for, 625 Cytomegalovirus (CMV) hepatitis, 200–202 with acquired immunodeficiency syndrome (AIDS), 201 diagnosis of, 201–202 with HIV infection, 254, 254f pathology of, 200–201, 201f transmission of, 200 Cytoplasmic alterations and pigments, 332t–333t Cytoplasmic inclusions, 332t–333t Cytovene (ganciclovir), for posttransplant prophylaxis, 625 D Dacarbazine, hepatotoxicity of, 334t–347t Daclizumab (Zenapax), for posttransplant immunosuppression, 623t, 625 Daily clinical practice, premalignant and early malignant hepatocellular nodules in, 494 Danazol, hepatotoxicity of, 334t–347t Dantrolene, hepatotoxicity of, 334t–347t Dapsone, hepatotoxicity of, 334t–347t Daunorubicin, hepatotoxicity of, 334t–347t D-bifunctional protein deficiency, 119 De novo autoimmune hepatitis, 653–654, 653f in late cellular rejection, 638, 639f De novo diseases, in liver transplantation, 653–655 idiopathic chronic hepatitis as, 654, 654f malignancy as, 654–655, 655f plasma cell hepatitis as, 653–654, 653f viral hepatitis as, 654 Debrancher enzyme deficiency, 118t Delicate periportal fibrous spikes, 674, 676f Delta virus, 198 clinical manifestations and natural history of, 198 pathology of, 198, 199f Dendritic cells, in epithelioid hemangioendothelioma, 586 Dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), 206 Dengue virus (DENV), acute hepatitis due to, 205–206 diagnosis of, 206 pathology of, 206, 206f Desflurane, hepatotoxicity of, 334t–347t Desipramine, hepatotoxicity of, 334t–347t Detajmium tartrate, hepatotoxicity of, 334t–347t Detoxification, 319 Developmental history, for inborn errors of metabolism, 91 Dextropropoxyphene, hepatotoxicity of, 334t–347t Diabetes, type 1 (insulin-dependent), liver tests of, 51 Diazepam, hepatotoxicity of, 334t–347t Dichloromethotrexate, hepatotoxicity of, 334t–347t Diclofenac, hepatotoxicity of, 334t–347t Dicloxacillin, hepatotoxicity of, 334t–347t 695

Index Dicoumarol, hepatotoxicity of, 334t–347t Didanosine, hepatotoxicity of, 334t–347t Dietary effects, NAFLD and, 181 Diethylstilbestrol, hepatotoxicity of, 334t–347t Diffuse hepatic glycogenosis, 363–364 Diffuse large cell lymphoma, 592t–593t Diffuse liver disease, imaging of hepatic fibrosis and cirrhosis as contrast-enhanced sonography for, 62 CT for, 56f differential diagnosis of dominant liver nodules in, 58–59, 62t–63t with hepatocellular carcinoma, 55, 56f magnetic resonance elastography for, 63, 64f–65f transient elastography, 62–63 hepatic steatosis as, 59–60, 64f Diffuse pattern, of hepatocellular carcinoma, 531, 532f Diflucan (fluconazole), for posttransplant prophylaxis, 625 Diflunisal, hepatotoxicity of, 334t–347t Digital clubbing, in chronic liver disease, 38, 38f Dihydralazine, hepatotoxicity of, 334t–347t DILI. see Drug-induced liver injury (DILI). Diltiazem, hepatotoxicity of, 334t–347t Dimethylbusulfan, hepatotoxicity of, 334t–347t DIOS. see Dysmetabolic iron overload syndrome (DIOS). Direct assays, for staging of chronic hepatitis, 242–243 Disease states, drug bioavailability and, 321, 321f–322f Disopyramide, hepatotoxicity of, 334t–347t Disse space, 22 anatomy of, 19–20, 19f electron microscopy, 8, 14f, 20–22 with HIV infection, 249 Disulfiram, hepatotoxicity of, 334t–347t DNA, methodologies for, 97 Dominant stricture, vs. primary sclerosing cholangitis (PSC), 429 Donation after cardiac death (DCD), 616 Donor biopsies, evaluation of, 630–633 with chronic hepatitis C, 631–632, 631f freezing artifact in, 631, 631f indications for, 631t reporting, standard form for, 631–632, 632f steatosis in, 631–632 evaluation of, 614–617, 614b extended criteria donors, 614–617, 614b medical history, 616–617 physiologic, 615–616 with partial liver allografts, 617, 618f extended criteria, 614–617, 614b medical history, 616–617 physiologic, 615–616 living, 617, 618f organ procurement from deceased, 618–619 Doppler sonography, Budd-Chiari syndrome and, 469 Doughnut granuloma, 292 696

Doxidan, hepatotoxicity of, 334t–347t Drug absorption, 320f Drug bioavailability, factors affecting, 320–321 disease states as, 321, 321f–322f enzyme induction and inhibition as, 320 enzyme polymorphisms as, 320–321 Drug distribution, 320f Drug excretion, 320f Drug injury, human leukocyte antigens associated with, 367t Drug metabolism drug-induced liver injury and, 324–325 enzymes, 321–324, 323t conjugating (phase II), 319, 322–324, 323t cytochrome P450 (phase I), 319, 321–322 CYP1A2, 321, 323t CYP2B6, 321–322, 323t CYP2C, 322, 323t CYP2D6, 322, 323t CYP3A, 322, 323t in disease states, 321, 321f–322f polymorphisms of, 320 drug transporter (phase III), 319, 323t, 324 general considerations in, 319–320 schematic representation of, 320f xenobiotics and, 317–326 Drug reactions, vs. Wilson disease, 130t Drug transporter, 319, 323t, 324 Drug-induced granulomas, 297–298 diagnosis of, 298 pathology of, 297, 298f, 298t Drug-induced hepatitis, vs. chronic hepatitis B, 219 Drug-induced liver injury (DILI), 327–328 alcohol use and risk of, 325 ancillary diagnostic studies, 366–367 autoimmune hepatitis and, 314 brief historical overview of, 327–328 classification of biochemical, 331t by histologic pattern, 332t–333t by pattern of injury, 331b, 334t–347t by toxicity category, 330t clinical manifestations of, 330–331, 330t dechallenge/rechallenge of, 366 degree of certainty, 366 differential diagnosis of, 365 direct, 330t drug metabolism and, 324–325 drugs with no record, 366 due to HAART, 248 establishing causality of, 365–366 estimates of incidence of, 329t exclusion of competing causes, 366 genetics of, 367 grading and staging of, 364–365 hepatocellular, 331t histologic features of, 331t incidence and demographics of, 328–330 indirect, 330t information available from liver biopsies in assessment of, 331b known potential for injury and precedent for pathologic injury pattern, 366

Drug-induced liver injury (DILI) (Continued) laboratory investigation of, 46–47 microscopic pathology of, 331–364 histologic features of, 331t necroinflammatory patterns in, 331–353, 334t–347t neoplasms, 364 pigments and other cytoplasmic changes, 363–364 steatotic patterns, 357–359 vascular injury patterns, 361–363 necroinflammatory patterns in steatotic patterns in, macrovesicular, 331t that mimic acute hepatitis, 331–352 practical considerations in, 365b from surveys of acute liver failure, 329t treatment and prognosis of, 367–368 Drug-induced liver injury network (DILIN), 328–329 Drug-induced loss of intrahepatic bile ducts, 442–443 Drug-induced steatosis, NAFLD and, 179–180, 180t, 180b Dual cholate test, 44 Dubin-Johnson syndrome, 462, 462f Ductal plate, 393–395, 394f malformations of, 27, 28f, 394–395, 395f von Meyenburg complex as, 395, 396f Ductal plate tumor, 556t, 564 Ductopenia, 27, 433 idiopathic adulthood, 443 Ductopenic rejection, 639–640, 640f Ductular (cholangiolar) cholestasis, 26, 26f, 378 Ductular reaction, 26, 26f, 672 in alcoholic liver disease, 380–381 differential diagnosis of, 553t in metabolic liver disease, 104, 104f in primary biliary cirrhosis, 410, 412f Ductules, “bud” comprising a hepatocyte in, 674f Duloxetine cholestatic injury with, 355f hepatotoxicity of, 334t–347t Dupuytren contracture, in chronic liver disease, 38, 38f Dyserythropoietic syndromes, hemochromatosis due to, 155t, 157 Dysmetabolic iron overload syndrome (DIOS), 155t, 158–159 Dysplastic foci, 490, 490b iron-free, 490 large cell changes in, 490b, 491f nomenclature for, 490b small cell changes in, 490b, 491f Dysplastic nodules (DNs), 488–490 elementary morphologic features and diagnostic tools in, 495t gross features of, 489f–490f hepatocellular carcinoma and, 539 as hepatocellular carcinoma precursors, 491 high-grade, 488–490, 495–497, 496f low-grade, 488–490, 499–503 natural outcome of, 493t nomenclature for, 490b role of imaging in, 494

Index E Early, well-differentiated HCC (e/WD HCC), 491 Early childhood cirrhosis, 130 Early hepatocellular carcinoma (eHCC), 491, 491t, 492f–493f elementary morphologic features and diagnostic tools in, 495t nodule-in-nodule growth in, 498 role of imaging in, 494 stromal invasion in, 495–497 Ebola and Marburg viruses, acute viral hepatitis due to, 206–207 Ebrotidine, hepatotoxicity of, 334t–347t Echinococcus granulosus, 283 Echinococcus multilocularis, 283 Echinococcus vogeli, 283 ECM. see Extracellular matrix (ECM). Edmondson and Steiner system, for hepatocellular carcinoma, 538 eHCC. see Early hepatocellular carcinoma (eHCC). Elastography of hepatic fibrosis and cirrhosis magnetic resonance, 63, 64f–65f transient, 62–63 for staging of chronic hepatitis, 243 Elderly patients, liver transplantation in, 612 Electrolyte abnormalities, in acute liver failure, 34–35 Electron microscopy, 20–22 Disse space, 20–22 hepatocytes, 14f, 20, 21f in routine diagnostic practice, 22, 22b sinusoidal lining cells, 14f, 20 Enalapril, hepatotoxicity of, 334t–347t Encephalopathy, hepatic due to acute liver failure, 34 due to cirrhosis, 41, 41t grades of, 41, 41t treatment for, 41 types of, 41 Endemic Tyrolean cirrhosis, 130 Endocrine disorders, liver tests for, 51 Endoplasmic reticulum, of hepatocytes, 20, 21f Endoscopic retrograde cholangiopancreatography (ERCP) for biliary atresia, 72 for primary biliary cirrhosis, 410 for primary sclerosing cholangitis, 424 Enflurane, hepatotoxicity of, 334t–347t Entamoeba histolytica, 271 Enzyme induction, drug bioavailability and, 320 Enzyme inhibition, drug bioavailability and, 320 Enzyme polymorphisms, drug bioavailability and, 320–321 Enzymes, methodologies for, 97 Eosinophilic tumor cells, in hepatocellular carcinoma, 532, 532f Eosinophil(s) in drug-induced liver injury, 331t in primary biliary cirrhosis, 412, 413f EPHX1 (epoxide hydroxylase), in familial hypercholanemia, 459

Epithelial hepatoblastoma (E-HB), 556–574, 556b Epithelial pediatric tumor(s), 556–574, 556b cholangiocarcinoma as, 574 fibrolamellar hepatocellular carcinoma as, 570–572 clinical manifestations of, 571 differential diagnosis of, 571 genetics and molecular pathology of, 571–572 incidence and demographics of, 570–571 microscopic pathology of, 571, 572f radiologic features and gross pathology of, 571, 572f treatment and prognosis of, 572 focal nodular hyperplasia, 574 hepatoblastoma as, 556–570 cholangioblastic, 557t, 561–564, 565f classification of, 556b clinical manifestations of, 556 current classification of, 556–557 ductal plate tumor of, 556t, 564 embryonal, 557t, 558 fetal-type, 557–558 genetics and molecular pathology of, 565–568, 569f gross pathology of, 557 incidence and demographics of, 556 macrotrabecular, 558, 560f microscopic pathology of, 557–560, 558f–561f mixed epithelial and mesenchymal, 560, 562f multilineage tumors, 565, 568f nested stromal epithelial tumor of the liver as, 564–565, 567f–568f papillary type, 565, 568f pathology of treated, 560–561, 562f–563f pediatric hepatic stromal tumors, 564, 566f radiologic features of, 557, 557f staging of, 560f, 561, 564f, 564t treatment and prognosis of, 568–570, 570t undifferentiated, 558–560, 561f variants of, 561–565 hepatocellular carcinoma, 572–573 clinical manifestations of, 572 differential diagnosis of, 573 genetics and molecular pathology of, 573 incidence and demographics of, 572 microscopic pathology of, 573, 574f radiologic features and gross pathology of, 572–573, 573f treatment and prognosis of, 573 liver cell adenoma, 573–574 transitional liver cell, 570 clinical manifestations of, 570 differential diagnosis of, 570 microscopic pathology of, 570, 571f radiologic features and gross pathology of, 570 treatment and prognosis of, 570

Epithelioid cells in epithelioid hemangioendothelioma, 586 in primary biliary cirrhosis, 410, 411f, 413f Epithelioid granulomas, 289f, 290 asteroid bodies in, 291f necrosis in, 290–291, 292f Epithelioid hemangioendothelioma, 585–587 cholangiocarcinoma and, 553, 553t clinical manifestations of, 585 differential diagnosis of, 587, 587t gross pathology of, 586, 586f historical overview of, 585–587 incidence and demographics of, 585 microscopic pathology of, 586–587, 586f–587f radiologic features of, 586 treatment and prognosis for, 587 Epithelioid histiocytes, in sarcoidosis, 302, 302f Epithelioid tumors, differential diagnosis of, 591t Epivir (lamivudine), for posttransplant prophylaxis, 623t Epoxide hydroxylase (EPHX1), in familial hypercholanemia, 459 Epstein-Barr virus (EBV), in liver transplantation, 658, 658f Epstein-Barr virus (EBV) hepatitis, 199–200 diagnosis of, 200 pathology of, 200, 200f transmission of, 199 Epstein-Barr virus encoded RNA (EBER) sequences, 200 ERCP. see Endoscopic retrograde cholangiopancreatography (ERCP). Erlotinib, hepatotoxicity of, 334t–347t Erythromycin, hepatotoxicity of, 334t–347t Erythropoietic porphyria, congenital, 122, 122f Escherichia coli, sepsis due to, 266 Esophageal varices, due to cirrhosis, 38–39, 39f Estrogens, synthetic, hepatotoxicity of, 334t–347t Etanercept, hepatotoxicity of, 334t–347t Ethambutol, hepatotoxicity of, 334t–347t Ethionamide, hepatotoxicity of, 334t–347t Etodolac, hepatotoxicity of, 334t–347t Etoposide (VP-16), hepatotoxicity of, 334t–347t Etretinate, hepatotoxicity of, 334t–347t Everolimus, for posttransplant immunosuppression, 624 Extended criteria donors, 614–617, 614b medical history, 616–617 physiologic, 615–616 Extensive metabolizers, 320–321 Extracellular matrix (ECM), 671 Extranodal marginal zone B-cell lymphoma, 592t–593t Ezetimibe, hepatotoxicity of, 334t–347t F Fabry disease, 111 common findings with, 92t–93t Familial hypercholanemia (FHCA), 459 697

Index Family history, for inborn errors of metabolism, 91 Farber lipogranulomatosis, 112, 113f–114f Fasciola hepatica, 281 Fascioliasis, 281–282 clinical manifestations of, 281–282 diagnosis of, 282 life cycle in relation to liver disease, 281 pathology of, 282 Fatty acid oxidation (FAO) common findings with, 92t–93t defects, 105–106 clinical manifestations of, 105–106, 106f diagnosis of, 106 pathology of, 106 diagnosis of, genetic and biochemical tests for, collection, storage, and shipping of specimens for, 96t Fatty change focal, 592 clinical manifestations of, 592 differential diagnosis of, 591t, 592 incidence and demographics of, 592 microscopic pathology of, 592 radiologic features of, 592 treatment and prognosis for, 592 metabolic diseases with, 104–105, 104b, 105f Fatty liver, metabolic diseases with, 104–105, 104b, 105f Fatty liver disease, classification and etiology of, 383b FDG. see Fluorodeoxyglucose (FDG). Feathery degeneration, 22, 23f Felbamate, hepatotoxicity of, 334t–347t Fenofibrate, hepatotoxicity of, 334t–347t Feprazone, hepatotoxicity of, 334t–347t Ferritin, in hereditary hemochromatosis, 158 Ferroportin (FPN) in hereditary hemochromatosis due to gain-of-function mutations, 157 due to loss-of-function mutations, 158 in iron homeostasis, 152–153 Ferrous sulphate, hepatotoxicity of, 334t–347t Fetor hepaticus, in chronic liver disease, 38 Fialuridine, hepatotoxicity of, 334t–347t Fibrinoid necrosis in epithelioid granulomas, 290–291, 292f in sarcoidosis, 302, 303f Fibrin-ring granulomas, 292 Fibroblasts, skin, for genetic and biochemical tests, 94 collection, storage, and shipping of specimens for, 96t Fibrocystic hepatorenal diseases, 393 Fibrocystic liver disease, 391–408, 394t Caroli disease and, 393, 399–402 clinical manifestations of, 400–402, 401f macroscopic pathology of, 402, 402f microscopic pathology of, 402, 402f treatment of, 402 choledochal cysts and, 393, 402–405, 403f clinical manifestations of, 403–405, 404f macroscopic pathology of, 403, 404f microscopic pathology of, 403, 405f treatment of, 405 698

Fibrocystic liver disease (Continued) ductal plate and, 393–395 malformation of, 394–395, 395f miscellaneous hepatorenal ciliopathies, 393 morphologic spectrum of, 393 polycystic in, 396–397 autosomal dominant, 396 clinical manifestations of, 396, 397f macroscopic pathology of, 397, 397f microscopic pathology of, 397, 398f treatment of, 397 autosomal recessive, 397–399 clinical manifestations of, 398–399 macroscopic pathology of, 399, 400f microscopic pathology of, 399, 401f treatment of, 399 solitary (nonparasitic) bile duct cysts and, 397 von Meyenburg complex in, 395, 396f Fibrogenesis mechanisms of, 671–672 process of, 671–672 Fibrolamellar hepatocellular carcinoma, 535, 570–572 clinical manifestations of, 571 differential diagnosis of, 61f, 63t, 571 genetics and molecular pathology of, 571–572 gross examination on, 535, 536f histologic features of, 535, 536f–537f incidence and demographics of, 570–571 microscopic pathology of, 571, 572f prognosis of, 535 radiologic features and gross pathology of, 571, 572f treatment and prognosis of, 572 Fibroma, 597t Fibrosarcoma, 598t Fibroscan, for staging of chronic hepatitis, 243 Fibrosing cholestatic hepatitis (FCH), 644, 647–648, 648f Fibrosis in autoimmune hepatitis, 312 bridging, in primary biliary cirrhosis, 414, 414f in chronic hepatitis B, 217, 217f–218f in chronic hepatitis C, 228–230, 228f with HIV infection, 257 in cystic fibrosis, 146f–147f fragmentation of biopsy material due to, 6–8, 11f–12f in hepatitis D, 198, 199f histologic effects of chelation therapy on, 162 with HIV infection, 249t, 257–258, 258f iron overload related to advanced, 160, 160f morphologic patterns of, 672 in nonalcoholic fatty liver disease, 175–176, 175f pericellular, 257, 258f periportal, 257 in primary biliary cirrhosis, 414 in staging of chronic hepatitis in Ishak system, 238 in Scheuer system, 236, 241f

Fibrosis (Continued) perisinusoidal, 257 portal, 257 in staging of chronic hepatitis, 234 in Ishak system, 238 in Scheuer system, 236 portal, in schistosomiasis, 279 in primary biliary cirrhosis, 414, 414f–415f progression, 671–672 regression of, 672, 673f histologic assessment of, 673–674 septal, in staging of chronic hepatitis, 234 in Scheuer system, 241f Fibrotest, for staging of chronic hepatitis, 243 Fibrous bands, in focal nodular hyperplasia, 520 “Fibrous obliterative lesion”, in primary sclerosing cholangitis, 437 Fibrous septa, 3, 6f in chronic hepatitis C, 228–229 hepatocytes wedged between layers of, 674f Fibrous stroma, in hepatocholangiocarcinoma, 665, 669f FIC1, in progressive familial intrahepatic cholestasis, 454 “First pass” effect, 319 Florid duct lesion, 26, 27f in primary biliary cirrhosis, 410, 411f–412f, 415t Florid ductular reaction, in primary sclerosing cholangitis (PSC), 427, 428f Floxuridine, hepatotoxicity of, 334t–347t Flucloxacillin, hepatotoxicity of, 334t–347t Fluconazole hepatotoxicity of, 334t–347t for posttransplant prophylaxis, 623t, 625 Fluid abnormalities, in acute liver failure, 34–35 Fluorodeoxyglucose (FDG), in PET, 55–57 Fluoxetine, hepatotoxicity of, 334t–347t Fluoxymesterone, hepatotoxicity of, 334t–347t Fluphenazine, hepatotoxicity of, 334t–347t Flurazepam, hepatotoxicity of, 334t–347t Fluroxene, hepatotoxicity of, 334t–347t Flutamide, hepatotoxicity of, 334t–347t Fluvastatin-related cholestatic hepatitis, 357f Foamy macrophage aggregates, 291, 293f Focal biliary cirrhosis, in cystic fibrosis, 146, 147f Focal fatty change, 592 clinical manifestations of, 592 differential diagnosis of, 591t, 592 incidence and demographics of, 592 microscopic pathology of, 592 radiologic features of, 592 treatment and prognosis for, 592 Focal liver lesions in alcoholic liver disease, 382–383 in cirrhosis prevalence of, according to size, 488t ultrasonography detected, prevalence of, 488t in noncirrhotic liver, differential diagnosis of, 63t

Index Focal necrosis, in grading of chronic hepatitis, 235t, 237f Focal nodular hyperplasia atypical, 510, 510f with cavernous hemangioma, 584, 585f clinical manifestations, 508–509 definitions and synonyms for, 507–508, 508t differential diagnosis of, 63t, 511 vs. hepatocellular adenoma, 511–512, 525t genetics, 525–526 gross pathology, 512, 516f histologic variants, 520, 524f imaging of, 58, 61f immunohistochemistry, 520, 523f incidence and demographics of, 508 microscopic pathology, 512–515, 516f mixed adenoma, 508 radiologic features of, 509–510, 509f–510f subtle or pre-, 508, 520, 524f telangiectatic, 518–520 typical, 512, 516f Focal nodular hyperplasia-like lesion, 508 Follicular dendritic cell tumor, 598t Follicular lymphoma, 592t–593t Food and Drug Administration (FDA), on hepatotoxicity, 328, 328t Foreign body granuloma, 290f FPN. see Ferroportin (FPN). Fragmentation, of biopsy material, 6–8, 11f–12f Freezing artifact, in donor biopsies, 631, 631f Fructose 1,6-diphosphatase deficiency, common findings with, 92t–93t Fructose aldolase deficiency, common findings with, 92t–93t Fructose B aldolase deficiency, 111, 111f Fructose intolerance, hereditary, 111, 111f Fulminant hepatic failure etiology of, 34, 34t laboratory investigation of, 46 Fulminant hepatitis, in drug-induced liver injury, 334t–347t Functionalizing enzymes, 319 Fungal infections, granulomas due to, with HIV infection, 255–256, 257f Fusion inhibitors, for HIV infection, 247–248 G Galactosemia, 110–111, 111f Galactose-related enzymes, genetic and biochemical tests for, 96t Gall bladder in biliary atresia, 71 in cystic fibrosis, 148, 149f primary sclerosing cholangitis (PSC) and, 427 Gamma-glutamyl transferase, in primary sclerosing cholangitis, 424 Gamma-glutamyl transpeptidase, intrahepatic cholestasis with “high-GGT”, 460 “low-GGT”, 459–460 Ganciclovir (Cytovene), for posttransplant prophylaxis, 623t, 625

Gas chromatography-mass spectrometry (GC-MS), 97 Gastric adenocarcinoma, 598t Gastrointestinal diseases, liver tests in, 51–52 Gastrointestinal stromal tumor, 598t Gatifloxacin, hepatotoxicity of, 334t–347t Gaucher disease common findings with, 92t–93t pathology of, 112, 113f–114f phenotype-genotype correlation in, 111 Gemcitabine, hepatotoxicity of, 334t–347t Gemtuzumab, hepatotoxicity of, 334t–347t Gene sequencing collection, storage, and shipping of specimens for, 96t tests, methods, and required biologic samples for, 95t Genetic counseling, 98 Genetic hemochromatosis (GH), 152 alcoholic liver disease and, 381 with cirrhosis, 160 classification of, 152t ferroportin in due to gain-of-function mutations, 157 due to loss-of-function mutations, 158 and iron homeostasis, 152–153 hemojuvelin gene in, 153–154 hepcidin in, 152t, 153f HFE gene and, 381 hepcidin and, 152–153, 152t iron homeostasis and, 152–154 liver biopsy, role of, 160–162 SLC40A1 gene in, 152t transferrin receptor 2 (TFR2) gene in, 152t type 4 ferroportin gain-of-function mutations, 157 ferroportin loss-of-function mutations, 158 types 1, 2A, 2B, and 3, 155–156 iron overload pattern in, 152t microscopic pathology of, 156–157 Genetic hemolytic disorders, 121–122, 121f Genetic metabolic diseases of unknown etiology, 123 Germander (Teucrium), hepatotoxicity of, 334t–347t Giant cell hepatitis neonatal, 76, 76f, 78f postinfantile, 76, 311–312, 312f Giant cells, in hepatocellular carcinoma, 537 Giant mitochondria, in alcoholic liver disease, 374t–375t, 377, 377f Gilbert syndrome, 461–462 Gliclazide, hepatotoxicity of, 334t–347t Glucksberg-Seattle criteria (GSC), for acute graft-versus-host disease, 439 Gluconeogenesis, common findings with, 92t–93t Gluconeogenic enzymes, for genetic and biochemical tests, 96t Glucose 6-phosphate translocase deficiency, 118t Glucose-6-phosphatase deficiency, 118t Glucuronidation, in drug metabolism, 322–323 Glucuronide, 322–323

Glutamine synthetase, in focal nodular hyperplasia, 512–515, 523f Glutaric aciduria, common findings with, 92t–93t Glutathione transferases (GST), in drug metabolism, 323, 323t Glutathionylation, in drug metabolism, 323–324 Glyburide (Glibenclamide), hepatotoxicity of, 334t–347t Glycogen, in hepatocytes, 7f, 14, 16f Glycogen storage disease common findings with, 92t–93t tests, methods, and required biologic samples for, 95t treatment of, 98 Glycogen storage disease IIa (Pompe disease), 113f Glycogen synthase deficiency, 118t Glycogenated nuclei, 12–14, 14f Glycogenosis, 332t–333t nonlysosomal, 115–116 diagnosis of, 116, 118t pathology of, 115–116, 117f–118f type II, 112, 114f Glycogenotic hepatopathy, 363–364 Glycosylation, congenital disorders of common findings with, 91–93, 92t–93t tests, methods, and required biologic samples for, 95t Glycyrrhizin, hepatotoxicity of, 334t–347t Glypican 3 (GPC3), for diagnosis, of hepatocellular carcinoma, 539, 539f GM1 gangliosidosis, 113f Gold hepatotoxicity of, 334t–347t pigment, 332t–333t gp130 gene mutation, in hepatocellular adenoma, 520, 526 GRACILE syndrome, 460 Grading, of chronic hepatitis, 233–246 Graft-versus-host disease, loss of intrahepatic bile ducts due to acute, 439, 439t–440t chronic, 439–440 microscopic pathology of, 440, 441f–442f Granular cell tumor, 597t Granuloma(s), 287–300 algorithmic approach for diagnosis and interpretation of, 291f drug-induced, 297–298 in drug-induced liver injury, 331t, 334t–347t epithelioid, 290 etiology of, 290t fibrin-ring, 292 foreign-body type, 289 histologic patterns of, 290–292 with HIV infection, 249t, 255–256 due to mycobacteria, 255, 256f due to mycoses, 255–256, 257f idiopathic hepatic, 298 immune or hypersensitivity, 289 lipo-, in chronic hepatitis C, 226f microin CMV hepatitis, 201, 201f with HIV, 249, 250f 699

Index Granuloma(s) (Continued) morphologic patterns of, 290t neoplasia associated, 298 Granulomatous cholangiodestruction, 26 Granulomatous diseases, 292–298 brucellosis as, 294 diagnosis of, 294 pathology of, 294, 294f candidiasis as, 294–295 diagnosis of, 295 pathology of, 295, 295f histoplasmosis as, 295 pathology of, 295 infectious agents and, 295–297 mycobacteria and, 293–294 parasitic infections and, 295 Q-fever as, 294 sarcoidosis as, 297 pathology of, 297, 297f systemic mycoses and, 294 tuberculosis as, 292–293 diagnosis of, 293 hepatobiliary, 293 miliary, 293 pathology of, 293 Granulomatous inflammation differential diagnosis of, primary biliary cirrhosis versus, 418, 418f with HIV infection, 249t, 255–256 due to mycobacteria, 255, 256f due to mycoses, 255–256, 257f Greater celandine, hepatotoxicity of, 334t–347t Greenland familial cholestasis, 455 Green-lipped mussel (Seatone), hepatotoxicity of, 334t–347t Ground-glass cells/inclusions, 23, 26f in chronic hepatitis B, 214–215, 216f, 219, 219t cytologic changes mimicking, 219 due to HSV hepatitis, 202, 203f in hepatocytes, 381 Ground-glass change, 332t–333t Gumma, syphilitic, 268 Gynecologic tract carcinoma, 598t Gynecomastia, in chronic liver disease, 37–38, 37f H H63D gene, in hereditary hemochromatosis, 156 Hairy cell leukemia, 595 Halo effect, in primary biliary cirrhosis, 414, 415f Haloperidol, hepatotoxicity of, 334t–347t Halothane, hepatotoxicity of, 334t–347t Hamartoma bile duct, 546–547 clinical manifestations of, 546–547 differential diagnosis of, 547 pathology of, 547, 547f prognosis of, 547 radiologic features of, 547 peribiliary gland, 547–548 clinical manifestations of, 547 differential diagnosis of, 548, 553t pathology of, 547–548, 548f radiologic features of, 547 700

Hantavirus, acute hepatitis due to, 207 HCA. see Hepatocellular adenoma (HCA). HCC. see Hepatocellular carcinoma (HCC). HELLP syndrome, laboratory investigation of, 49 Hemangioendothelioma, epithelioid, 585–587 clinical manifestations of, 585 differential diagnosis of, 587, 587t gross pathology of, 586, 586f historical overview of, 585–587 incidence and demographics of, 585 microscopic pathology of, 586–587, 586f–587f radiologic features of, 586 treatment and prognosis for, 587 Hemangioma cavernous, 583–585 clinical manifestations, 583 demographics of, 583–585 differential diagnosis of, 584, 585t with focal nodular hyperplasia, 584, 585f gross pathology of, 584, 584f with hemangioma-like vessels, 584 incidence of, 583–585 microscopic pathology of, 584, 584f radiologic features of, 583–584 treatment and prognosis for, 585 differential diagnosis of, 62t–63t imaging of, 56f, 57–58, 60f infantile, differential diagnosis of, 585t sclerosed, 583 differential diagnosis of, 587t Hemangioma-like vessels, 584 Hematopoietic cell transplantation, loss of intrahepatic bile ducts after, 434t due to graft-versus-host disease, 439–440 acute, 439, 439t–440t chronic, 439–440 microscopic pathology of, 440, 441f–442f Hemochromatosis, 151–166 ancillary diagnostic studies for, 162 hepatic iron concentration as, 162 hepatic iron index as, 162 in cirrhosis, 160 due to alcoholic liver disease, 160 due to spur cell anemia, 160 genetic/hereditary cause of, 160 related to advanced fibrosis, 160, 160f due to African iron overload, 158 due to alcoholic liver disease, 155t, 159 due to chronic viral hepatitis, 159–160 due to dyserythropoietic syndromes, 155t, 157 due to dysmetabolic iron overload syndrome, 155t, 158–159 due to hemodialysis, 155t due to hemolysis, 155t due to hereditary aceruloplasminemia, 157 due to iron overload, with alpha-1antitrypsin deficiency, 157–158 due to nonalcoholic fatty liver disease, 155t, 159, 159f due to porphyria cutanea tarda, 155t, 158 due to sickle cell disease, 155t

Hemochromatosis (Continued) due to transfusion, 155t due to viral hepatitis, 155t hepatocellular carcinoma and, 530 hereditary with cirrhosis, 160 classification of, 152t ferroportin in due to gain-of-function mutations, 157 due to loss-of-function mutations, 158 hepcidin and, 152–153 and iron homeostasis, 152–153 hemojuvelin gene in, 152t, 153–154 hepcidin deficiency/hepcidin resistance in, 152t, 153–154 hepcidin in, 152t, 153f HFE gene in, hepcidin and, 152–153, 152t iron homeostasis and, 152–154 liver biopsy, role of, 160–162 SLC40A1 gene in, 152t transferrin receptor 2 (TFR2) gene in, 152t type 4 ferroportin gain-of-function mutations, 157 ferroportin loss-of-function mutations, 158 types 1, 2A, 2B, and 3, 155–156 iron overload pattern in, 152t microscopic pathology of, 156–157 histologic effects of chelation therapy for, 162 on fibrosis, 162 on stainable iron, 162, 162f juvenile, 155t liver biopsy, role of, 160–162 for differential diagnosis, 160–161 for histologic grading of iron deposition, 161–162, 162t iron-free foci in, 161, 161f microscopic pathology of, 154–155 iron deposition, patterns of, 154–155, 154f–155f, 155t mesenchymal, 155, 156f mixed, 155, 156f parenchymal, 154–155, 156f iron pigment in, 154 neonatal, 76–77, 79f “low-GGT” intrahepatic cholestasis due to, 460 perinatal, 122–123 clinical manifestations, 122–123 pathology and diagnosis of, 122–123, 122f Hemojuvelin gene, in hereditary hemochromatosis, 152t, 153–154 Hemolysis, Elevated Liver Enzymes and Low Platelets (HELLP) syndrome, 468b, 475 Hemolysis, hemochromatosis due to, 155t, 158 Hemolytic disorders, genetic, 121–122, 121f Hemophagocytic lymphohistiocytosis, 468f with HIV infection, 249–250, 251f Hemophagocytosis, with HIV infection, 249–250, 251f

Index Hemorrhagic fevers, acute hepatitis due to, 203–206 Hemosiderin in hepatocytes, 14–15, 17f in hereditary hemochromatosis Type 4, 154f–156f, 158 for HIV, 250 in neonatal (giant cell) hepatitis, 77, 79f pigment, in acute viral hepatitis, 195f Hemosiderosis primary, 154 secondary, 154 Hepatectomy, for transplant recipient, 619, 620f Hepatic adenomas, and loss of intrahepatic bile ducts, 434, 435f Hepatic angiosarcoma, due to thorotrast, 364f Hepatic arteries anatomy of, 9–11, 13f disease of, 479, 480f and intrahepatic bile ducts, 434, 434f “isolated” or “unpaired”, 11 thrombosis, in liver transplantation, 655–656, 656f–657f Hepatic copper accumulation, disorders of, 130 Hepatic encephalopathy due to acute liver failure, 34 due to cirrhosis, 41, 41t grades of, 41, 41t treatment for, 41 types of, 41 Hepatic fibrosis, imaging of, 60–63 contrast-enhanced sonography for, 62 magnetic resonance elastography for, 63 transient elastography for, 62–63 Hepatic foregut cyst, ciliated, 546 clinical manifestations of, 546 differential diagnosis of, 546, 546t pathology of, 546, 546f Hepatic hydrothorax, 40 Hepatic iron concentration (HIC), 162 and African iron overload, 158 biochemical measurements of, 161 threshold of, 157 Hepatic iron index (HII), 162 Hepatic metastases differential diagnosis of, 63t imaging of, 59, 63f hypervascular, 59, 63f PET/CT, 59f Hepatic microcirculatory subunit, 4–5 Hepatic outflow obstruction, after liver transplantation, 621 Hepatic parenchymal changes, in primary biliary cirrhosis, 412–414, 413f with cholate stasis, 412–414, 414f, 415t with cholestasis, 414, 414f with copper deposition, 414, 414f, 415t with encroachment of limiting plate, 412, 413f with fibrosis, 414, 414f–415f with keratin7 expression, 414 Hepatic plates, 6, 7f, 12 Hepatic repair complex, 674–676 Hepatic siderosis, 152 Hepatic stellate cells (HSCs), 671–672

Hepatic vein transit time (HVTT), in hepatic fibrosis and cirrhosis, 62 Hepatic veins, anatomy of, 7f, 11–12, 16f Hepatic venoocclusive lesions, in alcoholic liver disease, 379, 379f Hepatic venous pressure gradient, 682 Hepatic venules, anatomy of, 11–12, 16f Hepatic wedged venous pressure, 682 Hepatitis acute viral, 189–210, 192f clinicopathologic course related to special patterns of hepatic necrosis and regeneration in, 193–197, 196f–197f due to adenovirus, 202–203 diagnosis of, 203 pathology of, 202–203 transmission of, 202 due to arenaviruses, 207 due to cytomegalovirus, 200–202 with acquired immunodeficiency syndrome (AIDS), 201 diagnosis of, 201–202 pathology of, 200–201, 201f transmission of, 200 due to dengue fever, 205–206 diagnosis of, 206 pathology of, 206, 206f due to Ebola and Marburg viruses, 206–207 due to Epstein-Barr virus, 199–200 diagnosis of, 200 pathology of, 200, 200f transmission of, 199 due to hantavirus, 207 due to hepatitis A virus, 197 due to hepatitis B virus, 198 due to hepatitis C virus, 198 due to hepatitis D (delta) virus, 198 clinical manifestations and natural history of, 198 pathology of, 198, 199f due to hepatitis E virus, 197–198 due to hepatotropic viruses, 191, 192f due to herpes simplex virus types 1 and 2, 202 pathology of, 202 transmission of, 202 due to herpes zoster, 202 due to herpesviruses, 198–202 due to human herpesvirus 6, 202 due to nonhepatotropic viruses, 191, 192f due to parvovirus, 203 due to yellow fever, 204–205 diagnosis of, 204 pathology of, 204, 205f vaccination and viscerotropic disease in, 204–205 epidemiology of, 34 gross pathology of, 192, 193f histologic patterns of injury in, 192–198, 192t with HIV infection, 249t, 259–260 “lobular”, 192–197 microscopic pathology of, 193 apoptosis in, 193, 195f cholestasis in, 193, 195f

Hepatitis (Continued) hemosiderin pigment in, 195f lymphocytes in, 193, 195f lytic (spotty) necrosis in, 193, 194f portal inflammatory infiltrate in, 193, 195f swollen/ballooned hepatocytes in, 193, 194f regeneration in, 196, 196f alcohol, clinical presentation, 34 cholestatic with HIV infection, 249t, 259–260 liver tests for, 44 chronic active, 233 differential diagnosis, 218–219 other chronic liver diseases, 219 vs. other chronic hepatitides, 219 grading and staging of, 233–246 aggressiveness (necroinflammation, activity) in, 233 best, 238 general principles of, 234 grading and staging system, 234–238, 235t histologic activity index, 235, 235t limitations of liver biopsy in, 238–240 limitations of semiquantitative scoring for, 240–241 need for, 233–234 noninvasive nonbiopsy-based, 242–243 semiquantitative scoring for vs. morphometric analysis, 241–242 systems for, 234–238 with HIV infection, 251–252, 253f, 259–260 interface, in chronic hepatitis C, 225–226, 225f laboratory investigation of, 48 lobular, 233 persistent, 233 vs. autoimmune hepatitis, 219 congenital alloimmune, 77, 79f drug-induced, vs. chronic hepatitis B, 219 due to cytomegalovirus, with HIV infection, 254, 254f due to herpesvirus, with HIV infection, 254–255, 254f due to toxoplasmosis, with HIV infection, 254f, 255 granulomatous, 332t–333t with HIV infection acute, 249t, 259–260 cholestatic, 249t, 259–260 chronic, 251–252, 259–260 due to cytomegalovirus, 254 due to hepatitis B virus, 252, 253f fibrosis in, 257–258 due to hepatitis C virus, 251–252 fibrosis in, 257–258 steatosis in, 251, 252f due to herpesvirus, 254–255, 254f due to toxoplasmosis, 254f, 255 interface in chronic hepatitis B, 213 701

Index Hepatitis (Continued) in chronic hepatitis C, 226f in grading of chronic hepatitis, 233 in Ishak system, 236, 238f–239f METAVIR, 238, 242f Scheuer, 235, 236f–237f neonatal (giant cell), 76–77, 76f, 78f clinical manifestations of, 76–77 differential diagnosis of, 74, 75t, 77 etiology of, 77 pathology of, 77 canalicular cholestasis with biliary rosettes in, 77, 78f focal areas of necrosis in, 77, 77f giant cells in, 76–77, 77f–78f hemosiderin deposition in, 77, 79f post-infantile, 76 treatment and prognosis for, 77 nonspecific reactive, 266 sinusoidal lining cells, 16, 19f viral, differential diagnosis of, primary biliary cirrhosis versus, 416–417, 418f Hepatitis A, liver transplantation for, 609 Hepatitis A virus (HAV) acute, 197 infection, laboratory investigation of, 46 Hepatitis B, 211–222, 647–648, 648f acute liver biopsy for, 213 natural history and clinical manifestations of, 212–213 chronic, 212–213 clinical manifestations of, 212 extrahepatic, 212–213 differential diagnosis of, 218–219 vs. cytologic changes mimicking groundglass cells, 219 epidemiology of, 211 and hepatocellular carcinoma, 213 liver biopsy for practical approach to evaluating, 219–220, 220b lobular inflammation, apoptosis, and necrosis as, 213–214, 215f microscopic pathology of, 213–218, 213b architectural distortion as, 217 fibrosis as, 217, 217f–218f ground-glass cells and sanded nuclei as, 214–215, 216f immunohistochemical stains for viral antigens as, 218, 219f large cell and small cell changes as, 216–217, 216f portal changes and interface hepatitis as, 213, 214f serologic and molecular markers for, 212b and hepatocellular carcinoma, 213 incidence and demographics of, 211 in liver allograft donor, 617 liver biopsy for, 213 role of, 213 liver transplantation for, 609 molecular virology of, 211–212 natural history and clinical manifestations of, 212–213 transmission of, 211 treatment of, 213 702

Hepatitis B core antigen (HBcAg), 212b, 215 Hepatitis B e antigen (HBeAg), 211–212 Hepatitis B surface antigen (HBsAg), 212, 219f Hepatitis B virus (HBV) acute, 198 hepatocellular carcinoma and, 530 with HIV infection, 252, 253f fibrosis in, 257–258 infection, laboratory investigation of, 46 Hepatitis C, 223–232 acute, 224 chronic, 224 differential diagnosis of, 225–230, 225b, 230b vs. chronic biliary diseases, 230 vs. chronic hepatitides, 230 vs. chronic hepatitis B, 218–219 vs. hereditary metabolic disorders, 230 vs. malignant lymphoma, 230 vs. steatohepatitis, 230 liver biopsy practical approach in evaluating, 230–231, 230b role of, 224 microscopic pathology of, 225–230, 225b fibrosis as, 228–230 lobular inflammation, apoptosis, and necrosis as, 226, 227f portal changes and interface hepatitis as, 225–226, 225f steatosis and other cytoplasmic changes of hepatocytes as, 226–227, 227f persistent, 225–226 treatment of, 224 vs. chronic hepatitis B, 218–219 in donor biopsies, 631–632, 631f granulomas and, 296–297, 296f and hepatocellular carcinoma, 224 incidence and demographics of, 223 in liver allograft donor, 617 liver biopsy of, 224 liver transplantation for, 607–609 molecular virology of, 223–224 natural history and clinical manifestations of, 224 primary biliary cirrhosis and, 435–436, 436f recurrent, 643–647 clinical considerations in, 643–644 differential diagnosis of, 646–647 microscopic pathology of, 645, 646f–647f Hepatitis C virus (HCV) acute, 198 hepatocellular carcinoma and, 530 with HIV infection, 251–252 fibrosis in, 257–258 steatosis in, 251, 252f infection, 181–182, 181f laboratory investigation of, 46 Hepatitis C-associated granuloma, differential diagnoses of, 304t Hepatitis D virus (HDV), 198 clinical manifestations and natural history of, 198

Hepatitis D virus (HDV) (Continued) laboratory investigation of, 46 pathology of, 198, 199f Hepatitis E virus (HEV), acute, 197–198 Hepatitis-like changes, in sarcoidosis, 302–303 Hepatobiliary cystadenoma, 548–549 clinical manifestations of, 548 differential diagnosis of, 548–549 pathology of, 548, 549f–550f radiologic features of, 548, 549f Hepatobiliary iminodiacetic acid (HIDA) scan, in biliary atresia, 71–72, 72f Hepatobiliary tuberculosis, 293 Hepatoblastoma, 556–570 cholangioblastic, 557t, 561–564, 565f classification of, 556b clinical manifestations of, 556 current classification of, 556–557 ductal plate tumor of, 556t, 564 embryonal, 557t, 558 fetal-type, 557–558 genetics and molecular pathology of, 565–568, 569f gross pathology of, 557 incidence and demographics of, 556 macrotrabecular, 558, 560f microscopic pathology of, 557–560, 558f–561f mixed epithelial and mesenchymal, 560, 562f multilineage tumors, 565, 568f nested stromal epithelial tumor of the liver as, 564–565, 567f–568f papillary type, 565, 568f pathology of treated, 560–561, 562f–563f pediatric hepatic stromal tumors, 564, 566f radiologic features of, 557, 557f staging of, 560f, 561, 564f, 564t treatment and prognosis of, 568–570, 570t undifferentiated, 558–560, 561f variants of, 561–565 Hepatocellular adenoma (HCA), 332t–333t absence of portal tracts, 6, 10f, 10t with β−catenin-activated, 511–512, 517t genetics of, 526 immunohistochemistry, 520 inflammatory features, 520 clinical manifestations, 508–509 definitions and synonyms, 508, 508t differential diagnosis of, 63t, 511–512 vs. angiomyolipoma, 591t vs. focal fatty change, 591t vs. focal nodular hyperplasia, 511–512, 525t in drug-induced liver injury, 334t–347t genetics of, 526 genotype-phenotype classification of, 515–520, 517t with gp130 gene mutation, 520, 526 gross pathology, 512, 517f histologic variants, 522 with HNF1a gene mutations, 515–518 genetics, 526 pathology of, 517t, 518f radiologic appearance of, 510–511, 512f

Index Hepatocellular adenoma (HCA) (Continued) imaging of, 58, 61f immunohistochemistry, 520 incidence and demographics of, 508 inflammatory, 517t, 518–520 genetics, 526 pathology, 517t, 519f, 521f–522f radiologic appearance of, 511, 513f malignant transformation of, 525 microscopic pathology, 515, 517f mixed focal nodular hyperplasia and, 508 multiple, 520, 525 not otherwise specified, 517t, 520 radiologic features of, 510–511, 512f–515f steatotic, 512, 522 with telangiectatic features, 508 treatment of, 526 Hepatocellular carcinoma (HCC), 332t–333t, 529–544, 572–573 after liver transplantation, 621–622 in alcoholic liver disease, 382–383 cholangiocarcinoma and, 553, 553t cirrhosis and, imaging of, 55, 56f, 63t clear cell, 537 clinical manifestations of, 531, 572 differential diagnosis of, 538–539, 538b, 573, 591t in cirrhotic liver, 58–59, 62t, 65f in noncirrhotic liver, 63t vs. angiomyolipoma, 591t vs. focal fatty change, 591t in drug-induced liver injury, 334t–347t early, 491, 491t, 492f–493f elementary morphologic features and diagnostic tools in, 495t nodule-in-nodule growth in, 498 role of imaging in, 494 stromal invasion in, 495–497 epidemiology of, 530 fibrolamellar, 535 differential diagnosis of, 61f, 63t gross examination on, 535, 536f histologic features of, 535, 536f–537f prognosis of, 535 genetics and molecular pathology of, 573 grading and other prognostic factors of, 538 gross pathology of, 531 hepatocholangiocarcinoma and, 665–666 histologic variants of, 535–538 imaging of, 56f, 58–59 immunohistochemistry of, 533–535 incidence and demographics of, 572 liver transplantation for, 540, 610, 610t microscopic pathology of, 532–533, 573, 574f absence of portal tracts, 6 growth patterns in, 533 tumor cells in, 532, 532f–533f molecular genetics of, 539–540 natural history of, 540 progressed, 491, 491t, 492f–493f nodule-in-nodule growth in, 498 radiologic features and gross pathology of, 572–573, 573f risk factors of, 530 hepatitis B virus as, 213 hepatitis C virus as, 224

Hepatocellular carcinoma (HCC) (Continued) sarcomatoid, 537, 537f sclerosing, 537–538 small, 491 nomenclature and comparative features of, 491t steatohepatitic, 537, 537f treatment of, 540 and prognosis, 573 Hepatocellular damage, in primary biliary cirrhosis, 412, 415t Hepatocellular injury, liver tests for, 44 Hepatocholangiocarcinoma, 663–670 cholangiolocellular subtype of, 665–666, 667f epidemiology of, 666–667 immunohistochemistry of, 665–666 intermediate-cell subtype of, 665–666, 667f microscopic pathology of, 665–666, 666f–668f pathologic classification of, 666 prognosis of, 666–667 stem cell features of, 665–666, 668f–669f typical subtype of, 665–666, 667f Hepatocyte ballooning, in alcoholic liver disease, 374t–375t, 377 Hepatocyte necrosis, perivenular, 643 Hepatocyte nuclear factor 1 alpha (HNF1α) gene mutations, in hepatocellular adenoma, 515–518 genetics, 526 pathology of, 517t, 518f radiologic appearance of, 510–511, 512f Hepatocyte paraffin 1 (HepPar-1), in hepatocellular carcinoma, 534 Hepatocytes, 12–15 ballooned, in nonalcoholic fatty liver disease, 172–173, 173f bile in, 14–15, 17f blushing, in primary biliary cirrhosis, 435–436, 437f copper in, 14–15, 17f cytoplasm of, 7f, 14, 16f electron microscopy, 14f, 20, 21f glycogen in, 7f, 14, 16f glycogenated nuclei, 12–14, 14f hemosiderin in, 14–15, 17f lipofuscin in, 7f, 14, 16f in lobular parenchyma, 7f, 12–15, 16f membrane domains of, 20, 21f nuclear pleomorphism, 16f oncocytic in hepatitis B, 219t in hepatitis C, 226–227 organelles of, 20, 21f swollen/ballooned, in acute viral hepatitis, 193, 194f Hepatoid tumors, differential diagnosis of, 591t Hepatolithiasis, vs. primary sclerosing cholangitis (PSC), 429 Hepatomegaly, in chronic liver disease, 36, 36f Hepatoportal sclerosis, 332t–333t in schistosomiasis, 281 Hepatopulmonary syndrome (HPS) due to cirrhosis, 38f, 41, 41f liver transplantation with, 613

Hepatorenal ciliopathies, 394t Hepatorenal syndrome (HRS) continuous venovenous hemofiltration for, 35 due to cirrhosis, 40–41 liver transplantation with, 613 Hepatosplenic lymphoma, 592 Hepatosplenic (sinusoidal) T-cell lymphoma, 592t–593t, 594–595 clinical manifestations of, 594 differential diagnosis, 595 incidence and demographics of, 594–595 microscopic pathology of, 594–595, 595f treatment and prognosis for, 595 Hepatotoxicity, 328t confirmed, 328 direct, 330 drug metabolism and, 324 drugs with recently reported, 328b drugs withdrawn due to, 328t due to HAART, 248, 248t idiosyncratic, 324, 330t immunologic, 330, 330t index of drugs and herbals associated with, 334t–347t indirect, 330t intrinsic, 324, 330, 330t metabolic, 330, 330t mixed, 332t–333t Hepatotropic viruses, hepatocellular carcinoma and, 530 Hepcidin excess, ferroportin deficiency, 154 in hereditary hemochromatosis, 153–154 in iron homeostasis, 152–153, 153f Herbal-associated hepatotoxicity, 351f Hereditary aceruloplasminemia, 157 Hereditary fructose intolerance, 111, 111f Hereditary hemochromatosis (HH), 151 with cirrhosis, 160 classification of, 152t ferroportin in due to gain-of-function mutations, 157 due to loss-of-function mutations, 158 and iron homeostasis, 152–153 hemojuvelin gene in, 153–154 hepcidin deficiency/hepcidin resistance in, 153–154 hepcidin in, 152t, 153f HFE gene in, hepcidin and, 152–153, 152t iron homeostasis and, 152–154 laboratory investigation of, 47–48 liver biopsy, role of, 160–162 SLC40A1 gene in, 152t transferrin receptor 2 (TFR2) gene in, 152t type 4 ferroportin gain-of-function mutations, 157 ferroportin loss-of-function mutations, 158 types 1, 2A, 2B, and 3, 155–156 iron overload pattern in, 152t microscopic pathology of, 156–157 Hereditary hemorrhagic telangiectasia (HHT), differential diagnosis of, 585t 703

Index Hereditary tyrosinemia, 120 clinical manifestations, 120 diagnosis of, 120 pathology, 120, 121f Hernia, umbilical, due to ascites, 37f, 40 Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), acute hepatitis due to, 202 pathology of, 202 transmission of, 202 Herpes zoster, acute hepatitis due to, 202 Herpesvirus hepatitis, with HIV infection, 254–255, 254f Herpesviruses, hepatitis due to acute, 198–202 Hexagonal lobule, in parenchymal architecture, 3, 6f HFE gene mutations, 152, 152t hepcidin and, 152–153 iron deposition, pattern of, 154–155, 154f–155f, 155t HH. see Hereditary hemochromatosis (HH). HIC. see Hepatic iron concentration (HIC). HIDA. see Hepatobiliary iminodiacetic acid (HIDA) scan. “High-GGT” intrahepatic cholestasis, 460 High-grade dysplastic nodule (HGDN), 488–490, 496f architectural changes in, 496f stromal invasion in, 495–497 Highly active antiretroviral therapy (HAART) for HIV, 247 mitochondriopathies with, 259, 260f High-performance liquid chromatography (HPLC), 97 HII. see Hepatic iron index (HII). Hilar bile ducts, in primary sclerosing cholangitis (PSC), 425–426 bile duct ulceration as, 425–426, 425f bile extravasation from, 425–426, 425f inflammatory myofibroblastic tumor in, 425–426, 426f onion-skin appearance in, 425–426, 426f scar formation in, 426f stones in, 425–426, 426f xanthogranuloma of, 425–426, 425f Hilar nerve, with amyloid, 630f Histidine-tryptophan-ketoglutarate (HTK) solution, for organ preservation, 619 Histiocytosis, Langerhans cell, sclerosing cholangitis due to, 83–85, 84f Histochemical stains, for liver biopsy specimens, 8t lipofuscin, 14, 16f reticulin, 6, 7f, 9f trichrome, 6, 7f Histologic activity index (HAI), for grading and staging of chronic hepatitis, 235, 235t Histoplasma capsulatum, granulomas due to, with HIV infection, 255–256, 257f Histoplasmosis, granulomas and, 295 due to, with HIV infection, 255–256, 257f pathology of, 295 Hodgkin disease, with HIV infection, 261 Hodgkin lymphoma, liver tests for, 51 Horizontal transmission, of hepatitis B, 211 HSCs. see Hepatic stellate cells (HSCs). 704

Human herpesvirus 6 (HHV-6) acute hepatitis due to, 202 in liver transplantation, 657 Human herpesvirus 8 (HHV-8), and Kaposi sarcoma, 260, 261f Human immunodeficiency virus (HIV) infection, 247–264 bacterial infections with abscess formation in, 249t, 256–257, 257f basic reactivity pattern, 248–249, 250f cholangiopathy in, 249t, 250–251 effects on organ system of, 248 fibrosis in, 249t, 257–258, 258f with granulomatous inflammation, 249t, 255–256 due to mycobacteria, 255, 256f due to mycoses, 255–256, 257f HAART for, 247 hemophagocytic lymphohistiocytosis with, 249–250, 251f hepatotoxicity of, 248, 248t hepatitis with acute, 249t, 259–260 cholestatic, 249t, 259–260 chronic, 251–252, 259–260 due to cytomegalovirus, 254, 254f due to hepatitis B virus, 252, 253f fibrosis in, 257–258 due to hepatitis C virus, 251–252 fibrosis in, 257–258 steatosis in, 251, 252f due to herpesvirus, 254–255, 254f due to toxoplasmosis, 254f, 255 with multifocal parenchymal necrosis, 249t, 254–255, 254f histologic pattern, 248–250, 249t acute and cholestatic hepatitis as, 249t, 259–260 bacterial infection pattern as, 249t, 256–257 cholangiopathy pattern as, 249t, 250–251 chronic hepatitis pattern as, 249t, 251–252 granulomatous inflammation pattern as, 249t, 255–256 hepatitis pattern with multifocal parenchymal necrosis as, 249t, 254–255, 254f mitochondriopathy pattern as, 249t, 259, 260f pattern of reactivity of the reticuloendothelial system, 248–250, 249t pericellular, perisinusoidal, portal, periportal fibrogenic pattern as, 249t, 252f, 257–258, 258f steatosis pattern as, 249t, 251 vascular lesions as, 249t, 258–259, 259f mitochondriopathy, 249t, 259, 260f neoplasia associated with, 260–262 Kaposi sarcoma, 260–261, 261f lymphomas as, 261–262 reticuloendothelial system, reactivity in, 248–250, 249t steatosis in, 249t, 251 vascular lesions in, 249t, 258–259, 259f

Human immunodeficiency virus (HIV) infection (Continued) bacillary angiomatosis, 258, 259f nodular regenerative hyperplasia, 258–259 peliosis, 258, 259f visceral leishmaniasis with, 249, 251f, 274, 274f Human leukocyte antigen (HLA) associated with drug injury, 367t in primary sclerosing cholangitis, 424 Humoral rejection, 635 Hunter syndrome, common findings with, 92t–93t Hurler syndrome common findings with, 92t–93t pathology of, 113f–114f HVTT. see Hepatic vein transit time (HVTT). Hy law, 46–47 Hy rule, 46–47 Hycanthone, hepatotoxicity of, 334t–347t Hydatid cyst, 283–284 clinical manifestations of, 283 diagnosis of, 284 life cycle in relation to liver disease, 283 pathology of, 283–284, 283f primary sclerosing cholangitis due to rupture of, 430 solitary bile duct cysts and, 546, 546t Hydralazine, hepatotoxicity of, 334t–347t Hydrochlorothiazide, hepatotoxicity of, 334t–347t Hydrops fetalis, 121 Hydrothorax, hepatic, 40 Hydroxyprogesterone, hepatotoxicity of, 334t–347t Hydroxyurea, hepatotoxicity of, 334t–347t Hyperacute rejection, 635–636, 636f Hyperbilirubinemia conjugated, 455 unconjugated, 461 Hypercholanemia, familial, 459 Hyperemesis gravidarum, laboratory investigation of, 49 Hypersensitivity granulomas, 289 Hypertension, portopulmonary, due to cirrhosis, 41 Hypertrophic osteoarthropathy, in chronic liver disease, 38 Hypervascular lesions, differential diagnosis of, 62t–63t Hypervascular metastases, differential diagnosis of, 63t Hypoglycemia, in acute liver failure, 34–35 Hypovascular lesions, differential diagnosis of, 62t–63t Hypovascular metastases, differential diagnosis of, 63t I Ibufenac, hepatotoxicity of, 334t–347t Ibuprofen, hepatotoxicity of, 334t–347t ICP. see Intrahepatic cholestasis of pregnancy (ICP). Icteric hemorrhagic fevers, acute hepatitis due to, 203–206 Idiopathic adulthood ductopenia, 443

Index Idiopathic chronic hepatitis de novo, 654, 654f in late cellular rejection, 638, 638f Idiopathic fibrosis, in liver transplantation, 659 Idiopathic noncirrhotic portal hypertension, 477 Idoxuridine, hepatotoxicity of, 334t–347t IL6ST gene, in hepatocellular adenomas, 520 Image analysis systems, 673–674 Imaging of diffuse liver disease, 59–63 hepatic fibrosis and cirrhosis as, 60–63 contrast-enhanced sonography for, 62 CT for, 62 differential diagnosis of dominant liver nodules in, 58–59, 62t–63t magnetic resonance elastography for, 63, 64f–65f transient elastography, 62–63 hepatic steatosis as, 59–60, 64f of liver tumors, 57–59 cholangiocarcinoma as, 57f, 59, 63t with cirrhosis, 58–59 focal nodular hyperplasia as, 58, 61f differential diagnosis of, 63t hemangioma as, 56f, 57–58, 60f differential diagnosis of, 62t–63t hepatocellular adenoma as, 58, 61f, 63t hepatocellular carcinoma as, 56f, 58–59 with cirrhosis, 55, 56f, 63t differential diagnosis of, 61f, 62t–63t metastases as, 59, 59f, 63f, 63t modalities for, commonly used, 55–66 CT as, 55 of alcoholic cirrhosis, 56f of cholangiocarcinoma, 57f delayed phase, 55, 56f dual phase, 55 of focal nodular hyperplasia, 58 of hemangioma, 57–58 of hepatic metastases, 59, 59f, 63f of hepatic steatosis, 59–60 of hepatocellular carcinoma, 56f, 58–59 with PET, 55–57, 59f phases of, 55, 57t MRI as, 55–57 chemical shift, 60, 64f contrast agents, 58t of focal nodular hyperplasia, 58, 61f of hemangioma, 57–58, 60f of hepatic metastases, 59 of hepatic steatosis, 59–60, 64f of hepatocellular adenoma, 58, 61f of hepatocellular carcinoma, 58–59, 61f phases of, 57t PET as, 55–57, 59f sonography as, 55 contrast-enhanced, 55, 56f of focal nodular hyperplasia, 58 of hemangioma, 56f, 57–58 of hepatic fibrosis and cirrhosis, 60–63 of hepatic steatosis, 59–60

Imatinib, hepatotoxicity of, 334t–347t Imipramine, hepatotoxicity of, 334t–347t Immune granulomas, 289 Immune-mediated disorder, primary sclerosing cholangitis as, 424 Immunodeficiency, primary sclerosing cholangitis due to rupture with, 430 Immunoglobulin G4 (IgG4)-related sclerosing cholangitis, 429 Immunoglobulins, in primary biliary cirrhosis, 410 Immunohistochemical stains, 14f for hepatitis B virus, 218, 219f for K7, 6, 10f for viral antigens as, 218, 219f Immunologic mechanisms, loss of intrahepatic bile ducts due to, 433–434 Immunosuppressed patients, CMV hepatitis in, 201 Immunosuppression, posttransplant, 622–625 immunosuppression agents, 622–624, 623t induction therapy, 623t, 624–625 prophylactics with, 623t, 625 Immunosuppression agents, for posttransplant immunosuppression, 622–624, 623t azathioprine as, 624 cyclosporine as, 622–623 mycophenolate mofetil as, 624 prednisone as, 624 sirolimus/everolimus, 624 tacrolimus as, 623–624 Immunosuppressive therapy, for autoimmune hepatitis, 314 Imuran (azathioprine), for posttransplant immunosuppression, 624 Inborn errors of metabolism acid lipase deficiency as, 112, 115f bile acid synthetic defects as, 116–119, 118t, 119f citrin deficiency as, 110, 110f clinical findings that suggest, 102, 102b clinical manifestations of, 111 cystinosis as, 115 diagnosis of, biochemistry and medical genetics in clinical approach to, 91–93, 92t–93t, 94f collection, storage, and transportation of biologic specimens for, 96t common findings from, 92t–93t methodologies involved in, 94–97, 95t fatty acid oxidation (FAO) defects as, 105–106 clinical manifestations of, 105–106, 106f diagnosis of, 106 pathology of, 106 galactosemia, 110–111, 111f genetic counseling for, 98 genetic hemolytic disorders as, 121–122, 121f genetic metabolic diseases of unknown etiology, 123 hereditary fructose intolerance as, 111, 111f

Inborn errors of metabolism (Continued) hereditary tyrosinemia as, 120 clinical manifestations, 120 diagnosis of, 120 pathology, 120, 121f histologic patterns of, 101–124 bile ductules versus ducts in, 104–105, 104f inflammatory, 102–103, 103t normal, 102, 102b prominent lobular cholestasis as, 103–104, 103f, 103t steatotic, 104–105, 104b, 105f liver biopsy specimens for analysis and reporting of, 102 handling of, 102 lysosomal storage disorders as, 111–115 enzyme replacement therapy for, 111–112 pathology of, 112, 113f–114f phenotype-genotype correlation in, 111 mitochondriopathies as, 106–108 clinical manifestations of, 106–108 diagnosis of, 108 pathology of, 107–108, 107f–108f Niemann-Pick disease, type C as, 112–115, 115f–116f nonlysosomal glycogenosis and polyglucosan storage disorders as, 115–116 diagnosis of, 116 pathology of, 115–116, 117f–118f organ involvement in, 101, 102t perinatal hemochromatosis as, 122–123 clinical manifestations, 122–123 pathology and diagnosis of, 122–123, 122f peroxisomal diseases as, 119–120 clinical manifestations of, 120 diagnosis of, 120 pathology of, 120, 120f Reye syndrome as, 108, 109f treatment and management of, 98 tyrosinemia, pathology of, 103f urea cycle defects as, 108–110 clinical manifestations, 109–110 diagnosis of, 110 pathology of, 109–110, 110f Incomplete septal cirrhosis (ISC), in chronic hepatitis C, 229, 229f Indian childhood cirrhosis, 130 Indicine, hepatotoxicity of, 334t–347t Indinavir, hepatotoxicity of, 334t–347t Indirect assays, for staging of chronic hepatitis, 242–243 Indomethacin, hepatotoxicity of, 334t–347t “Induced” hepatocytes, 219t Induction therapy, for posttransplant immunosuppression, 623t, 624–625 Infantile hemangioma, differential diagnosis of, 585t Infections ascites due to, 40, 40t bacterial, 266–271 actinomycosis, 268 brucellosis, 267–268 chlamydial, 271 legionellosis, 268 705

Index Infections (Continued) leptospirosis, 268–270, 270f pyogenic hepatic abscess due to, 266, 267f rickettsial, 270–271 Q fever, 271 Rocky mountain spotted fever, 271, 271f salmonellosis as, 266–267 sepsis as, 266, 266f syphilis as, 268, 269f bacterial, with HIV infection, 249t, 256–257, 257f chlamydial, 271 fungal, 271 granulomas due to, with HIV infection, 255–256, 257f in liver transplantation, 656–658 adenovirus as, 658 cytomegalovirus as, 657, 657f–658f Epstein-Barr virus as, 658, 658f human herpesvirus 6 as, 657 mycobacterial, 271 nonviral, 265–286 parasitic, 275–284 ascariasis, 275–276 capillariasis, 277 clonorchiasis and opisthorchiasis, 282–283 fascioliasis, 281–282 hydatid cyst, 283–284 pentastomiasis, 281 schistosomiasis, 278–281 strongyloidiasis, 277–278 visceral larva migrans/toxocariasis, 276–277 posttransplant, 621 with CMV, 621 prophylaxis and treatment of, 623t, 625 protozoal, 271–275 amebiasis, 271–272 malaria, 274–275 visceral leishmaniasis (Kala-azar), 272–274, 273f rickettsial, 270–271 visceral leishmaniasis, with HIV infection, 249, 251f Infectious complications, of acute liver failure, 34 Infectious diseases, liver tests for, 51 Infectious mononucleosis, 199 Infiltrative (massive) pattern, of hepatocellular carcinoma, 531, 532f Inflammation, terminology for, 22–23 Inflammatory bowel disease (IBD) liver tests for, 52 with primary sclerosing cholangitis, 424 Inflammatory hepatocellular adenoma, 517t, 518–520 genetics, 526 pathology, 517t, 519f, 521f–522f radiologic appearance of, 511, 513f Inflammatory (myofibroblastic) pseudotumor, 595–596 clinical manifestations of, 596 differential diagnosis for, 596 gross pathology of, 596 incidence and demographics for, 596 706

Inflammatory (myofibroblastic) pseudotumor (Continued) microscopic pathology of, 596, 596f radiologic features of, 596 treatment and prognosis for, 596 Inflammatory myofibroblastic tumor, in primary sclerosing cholangitis (PSC), 425–426, 426f Inflammatory pattern, metabolic diseases with, 102–103, 103t Infliximab, hepatotoxicity of, 334t–347t Injury category, in drug-induced liver injury, 331t Integrase inhibitor, for HIV infection, 247–248 Interface hepatitis, 23, 24f in autoimmune hepatitis, 310–311, 310f in chronic hepatitis B, 213, 214f in chronic hepatitis C, 225–226, 225f in grading of chronic hepatitis, 233 in Ishak system, 236, 238f–239f METAVIR, 238, 242f Scheuer, 235, 236f–237f Interferon alpha, hepatotoxicity of, 334t–347t Interferon beta, hepatotoxicity of, 334t–347t Interleukin-2, hepatotoxicity of, 334t–347t Interleukin-6, hepatotoxicity of, 334t–347t Interlobular bile ducts, 8–9 primary sclerosing cholangitis (PSC) of, 427 direct involvement of, 427, 427f periductal fibrosis in, 427, 427f Intermediate cell undifferentiated hepatoblastoma (ICUD-HB), 558–560 Intermediate metabolizers, 320–321 Intermediate-cell subtype, of hepatocholangiocarcinoma, 665–666, 667f International Bone Marrow Transplant Registry (IBMTR), for grading, of graftversus-host disease, 439, 440t International normalized ratio (INR), liver tests of, 45 International sensitivity index (ISI), liver tests of, 45 Interobserver variability, in grading and staging of chronic hepatitis, 240–241 Intraductal papillary neoplasm of the bile duct (IPNB), 550–551 clinical manifestations of, 550 cystic variant of, 546t, 549 differential diagnosis of, 550–551 incidence and demographics of, 550 pathology of, 550, 551f radiologic features of, 550 Intrahepatic bile ducts development of, 394, 394f hepatic artery and, 434, 434f loss of, in adults, 433–444 paucity of, 433 portal veins and, 434, 434f Intrahepatic cholangiocarcinoma, differential diagnosis of, 587t Intrahepatic cholestasis, 70–71 “benign” recurrent, 460–461 clinical manifestations of, 460

Intrahepatic cholestasis (Continued) etiopathogenesis of, 460 microscopic findings of, 461, 461f bile acids, 449–450 functions of, 450, 450f ileal transport of, 451 signaling, 450 cholangiocyte modification of, 451 enterohepatic circulation of, 450–451 formation and secretion diseases of, 453–464 molecular physiology of, 445–464.e1 bilirubin metabolism, disorders of, 461–462 Crigler-Najjar syndrome, 461–462 Dubin-Johnson syndrome, 462, 462f Gilbert syndrome, 461–462 Rotor syndrome, 462 differential diagnosis of, 460 due to hyperbilirubinemia conjugated, 455 unconjugated, 461 “high-GGT”, 460 “low-GGT”, 459–460 overview of, 445, 453 of pregnancy, 461 clinical manifestations of, 461 etiopathogenesis of, 461 microscopic pathology of, 461 treatment of, 461 progressive familial, 454–459 clinical manifestations of, 455, 455t electron microscopy of, 459, 459f etiopathogenesis of, 454–455, 454t immunohistochemistry of, 457f–458f, 458–459 incidence and demographics of, 455 laboratory findings of, 455 microscopic findings of, 456–457 PFIC-1 or ATP8B1 disease as, 456, 456f–457f clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t PFIC-2 or ABCB11 disease as, 456, 457f–458f clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t PFIC-3 or ABCB4 disease as, 457, 458f clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t treatment of, 455t, 459 transporter proteins for, 445–449, 446f–447f apical (canalicular) membrane transporters and, 447–449 basolateral (sinusoidal) membrane transporters and, 446–447, 448t–449t

Index Intrahepatic cholestasis (Continued) electroneutral anion exchanger and, 449 hepatic basolateral ATC-transporter proteins and, 449 hepatocyte transporters and, 449 treatment of, 461 Intrahepatic cholestasis of pregnancy (ICP), 461 clinical manifestations of, 461 etiopathogenesis of, 461 microscopic pathology of, 461 treatment of, 461 Intrahepatic strictures, posttransplant, 621 Intralobular biliary channels, 15–16, 18f Intralobular necroinflammatory activity in chronic hepatitis B, 213–214, 215f in chronic hepatitis C, 226 Intrinsic hepatotoxicity, 330, 330t Investigative imaging, of liver, 55–66. see also Imaging. Iodipamide meglumine, hepatotoxicity of, 334t–347t Iodoform, hepatotoxicity of, 334t–347t Ion exchange chromatography, 97 Ipilimumab, hepatotoxicity of, 334t–347t IPNB. see Intraductal papillary neoplasm of the bile duct (IPNB). Iprindole, hepatotoxicity of, 334t–347t Iproclozide, hepatotoxicity of, 334t–347t Iproniazid, hepatotoxicity of, 334t–347t Irbesartan, hepatotoxicity of, 334t–347t Irinotecan, hepatotoxicity of, 334t–347t Iron deposits, in acute viral hepatitis, 193, 195f hepatic stores of, in chronic hepatitis C, 226–227 homeostasis, and hereditary hemochromatosis, 152–154 pigment, in hereditary hemochromatosis, 153f–154f, 154 Iron deposition, patterns of in hemochromatosis, 154–155, 154f–155f, 155t mesenchymal, 155, 156f mixed, 155, 156f parenchymal, 154–155, 156f histologic grading of, in hemochromatosis, 161–162, 162t in reticuloendothelial system, 156–157 Iron overload. see also Hemochromatosis. in alcoholic liver disease, 381, 381f Iron storage disorders, vs. Wilson disease, 130t Iron-free foci, 161, 161f Ischemic cholangiopathy, loss of intrahepatic bile ducts due to, 440–442, 442f microscopic pathology of, 441–442, 443f Ischemic cholangitis in liver transplantation, 655–656, 657f loss of intrahepatic bile ducts due to, 440–441, 442f microscopic pathology of, 441–442, 443f Ischemic damage, loss of intrahepatic bile ducts due to, 433–434 Ischemic hepatitis, 468b, 479–480, 480f

Ishak system, in chronic hepatitis, 236–238, 241f comparison of, 234t for grading, 236, 238f–239f comparison of, 234t vs. Knodell score, 235t for staging, 236–238, 241f–243f comparison of, 234t Isoflurane, hepatotoxicity of, 334t–347t Isolated central perivenulitis (ICP), 642, 642f–643f in acute cellular rejection, 637 Isolated thick collagen fibers, cirrhosis and, 674, 676f Isoniazid, 324 hepatotoxicity of, 334t–347t Isoniazid hepatitis, 350f Itraconazole, hepatotoxicity of, 334t–347t J Jaundice breast milk, 69–70 cholestatic, 69–70 diagnosis of, 70–71, 70t differential diagnosis of, 70–71, 70t incidence and demographics of, 70 management of, 70–71 in chronic liver disease, 36, 36f in neonates, 69–70 new-onset, etiology of, 46–47, 47t physiologic, 69–70 Jin bu huan, hepatotoxicity of, 334t–347t K K7, immunohistochemical stains for, 6, 10f Kala-azar, 272–274, 273f in AIDS, 274, 274f diagnosis of, 274 life cycle in relation to liver disease, 272 pathology of, 272–274 Kaposi sarcoma AIDS-associated, 260–261, 261f differential diagnosis of, 589t Kasai portoenterostomy, for biliary atresia, 74–76 liver, removed after successful, 72f, 74, 75f Kava, hepatotoxicity of, 334t–347t Kayser-Fleischer rings, in Wilson disease, 126 Keratin7 expression, in primary biliary cirrhosis, 414, 415t Ketoconazole, hepatotoxicity of, 334t–347t Ketoprofen, hepatotoxicity of, 334t–347t King’s College Criteria for Liver Transplantation in Acute Liver Failure, 35, 35t Knodell score, for chronic hepatitis, 235, 235t Kupffer cells, 22 anatomy of, 16–19, 19f electron microscopy of, 14f, 20 in hepatic sinusoid, 16–19 in HIV infection, 249, 251f L Labetalol, hepatotoxicity of, 334t–347t Laboratory tests, in liver disease, 43–54

Laboratory tests, in liver disease (Continued) for acute liver injury, 46–47, 47f, 47t approach to evaluation of, 45–49, 46t of “biliary” enzymes, 44–45 for cardiac diseases, 51 for connective tissue diseases, 50–51 for disease of other organs, 49–52 for endocrine disorders, 51 for gastrointestinal diseases, 51–52 for infectious diseases, 51 of measures of coagulation, 45 for neoplastic diseases, 51 in pregnancy, 48–49 for systemic diseases, 49–52, 50b of transaminases, 44 Labrea hepatitis, 198 Laennec system, for substaging of cirrhosis, 683, 683f Lamivudine (Epivir), for posttransplant prophylaxis, 623t, 625 Lamotrigine, 351f hepatotoxicity of, 334t–347t, 351f Landsteiner, Karl, 606, 606b Langerhans cell histiocytosis (LCH), 595, 595f sclerosing cholangitis due to, 83–85, 84f Lapatinib, hepatotoxicity of, 334t–347t Large bile duct disease, in cystic fibrosis, 148, 149f Large cell changes (LCCs) in chronic hepatitis B, 216–217, 216f in chronic hepatitis C, 227–228, 228f Large cell dysplasia, 490 Large cell lymphoma anaplastic, 592t–593t diffuse, 592t–593t Large cell undifferentiated hepatoblastoma (LCUD-HB), 556t Large (hilar/parahilar) bile ducts, in primary sclerosing cholangitis (PSC), 425–426 bile duct ulceration as, 425–426, 425f bile extravasation from, 425–426, 425f inflammatory myofibroblastic tumor in, 425–426, 426f onion-skin appearance of, 425–426, 426f scar formation in, 426f stones in, 425–426, 426f xanthogranuloma as, 425–426, 425f Late cellular rejection, 638, 638f–639f Lateral domain, of hepatocytes, 20, 21f LCH. see Langerhans cell histiocytosis (LCH). Left hepatic vein, anatomy of, 11 Legionella pneumophila, 268 Legionellosis, 268 Legionnaire disease, 268 Leiomyoma, 597t Leiomyosarcoma, 598t Leishmania donovani, 272 Leishmaniasis, visceral, 272–274, 273f in AIDS, 274, 274f diagnosis of, 274 with HIV infection, 249, 251f life cycle in relation to liver disease, 272 pathology of, 272–274 Leptospirosis, 268–270, 270f clinical manifestations of, 269 pathogenesis, 269–270 pathology of, 270 707

Index Lergotrile, hepatotoxicity of, 334t–347t LIBD. see Loss of intrahepatic bile ducts (LIBDs). Limiting plate, 22 encroachment of, in primary biliary cirrhosis, 412, 413f Linezolid, hepatotoxicity of, 334t–347t Linguatula serrata, 281 Lipid metabolism, abnormalities of, NAFLD and, 180–181 Lipodystrophies, 181 Lipofuscin in hepatocytes, 7f, 14, 16f as histochemical stain, 14, 16f in HIV infection, 249 Lipogranulomas, 23, 25f, 291, 293f in alcoholic liver disease, 376, 376f in chronic hepatitis C, 226f differential diagnoses of, 304t Lipogranulomatosis, Farber, 112, 113f–114f Lipoma, 591t, 597t Lipomatous lesions of, differential diagnosis of, 591t Lipopeliosis, 634 Lipopolysaccharide, in sepsis, 266 Liposarcoma, 598t Lisinopril, hepatotoxicity of, 334t–347t Livedo reticularis, in chronic liver disease, 38, 38f Liver age-related changes, 16b cells and structures, 22 eight independent segments, 22f electron microscopy, 20–22 Disse space, 20–22 hepatocytes, 14f, 20, 21f in routine diagnostic practice, 22, 22b sinusoidal lining cells, 14f, 20 elemental lesions of, 22–28 biliary, 26–27 inflammation, cell damage and necrosis, 22–23 intracellular, 23–26 sinusoidal, 27–28 injury due to drugs and herbal agents, 327–370 investigative imaging of, 55–66. see also Imaging. lipomatous lesions of, differential diagnosis of, 591t microscopic anatomy of hepatic veins in, 7f, 11–12, 16f lobular parenchyma in, 12–20 Disse space, 8, 19–20, 19f hepatocytes, 7f, 12–15, 16f intralobular biliary channels, 15–16, 18f sinusoids, 4, 7f, 16–19, 19f parenchymal architecture and tissue organization, 3–6, 5f–6f acinar concept in, 4, 5f assessment in biopsy, 6–8 bland appearance on lower power of, 3, 4f fibrous septa, 3, 6f hepatic microcirculatory subunit, 4–5 708

Liver (Continued) hexagonal lobule, 3, 6f portal venule, 4, 5f zones in, 4, 5f portal tracts, 8–11 absence of, 6 bile ducts, 8–9, 14f–15f hepatic arteries, 9–11, 13f lymphatics in, 8, 14f portal veins, 11, 13f size and shape of, 8, 13f terms for cells and structures in, 22 vascular disorders of, 465–484 Liver allograft allocation of, 617–618 algorithm for, 614–615, 615t biopsy of, indications for, 630b evaluation of, 614–617, 614b extended criteria donors, 614–617, 614b medical history, 616–617 physiologic, 615–616 with partial liver allografts, 617, 618f implantation of, 619–620 living donor, 617, 618f loss of intrahepatic bile ducts in due to allograft rejection, 435f, 438–439 acute, 438, 438f chronic, 438, 438f due to recurrent primary biliary cirrhosis and primary sclerosing cholangitis, 439 partial, 617, 618f pathologic processes occurring, 630b preparation of, 619 primary nonfunction of, 620 recurrent primary biliary cirrhosis in, 419–420 rejection of, 621, 634–642 acute in children, 622 loss of intrahepatic bile ducts due to, 438, 438f acute antibody-mediated, microscopic pathology of, 636, 636f cellular, 636–639 acute, 636–637, 637f, 637t–638t differential diagnosis of, 638–639, 639f late, 638, 638f–639f chronic, 639–641, 640f–641f antibody-mediated, 641, 642b differential diagnosis of, 641 early and late features of, 641t loss of intrahepatic bile ducts due to, 438, 438f treatment of, 642 clinical manifestations of, 635 common pathways of, 635f differential diagnosis of, 636 ductopenic, 639–640, 640f humoral, 635 hyperacute, 635–636, 636f loss of intrahepatic bile ducts due to, 435f, 438–439 acute, 438, 438f chronic, 438, 438f terminology in, 634–642 split, 617

Liver biochemistry tests, 44 Liver biopsy in alcoholic liver disease, 382 allograft of, indications for, 630b assessment of parenchymal architecture, 10t absence of portal tracts, 6, 10f, 10t fragmentation in, 6–8, 11f–12f hepatic plates, 6, 7f, 12 histochemical stains for, 8t lipofuscin, 14, 16f reticulin, 6, 7f, 9f trichrome, 6, 7f subcapsular parenchyma in, 8, 12f donor for, evaluation of, 630–633 with chronic hepatitis C, 631–632, 631f evaluation of, 630–633 freezing artifact in, 631, 631f indications for, 631t reporting, standard form for, 631–632, 632f steatosis in, 631–632 for grading and staging of chronic hepatitis, limitations of, 238–240 for hepatitis B practical approach in evaluating, 219–220, 220b role of, 213 for hepatitis C, role of, 224 for HIV infection, 248 indications for, 6b for premalignant and early malignant hepatocellular lesions, 499–504, 502f diagnostic criteria in, 499–503, 502f–503f nodule management in, 503–504 for primary biliary cirrhosis, 415, 415t–416t role of, for hemochromatosis, 160–162 for differential diagnosis, 160–161 for histologic grading of iron deposition, 161–162, 162t iron-free foci in, 161, 161f specimens, for metabolic liver disease analysis and reporting of, 102 handling of, 102 Liver carcinoma, primary, biphenotypic, 663–670 Liver cell death, in alcoholic liver disease, 378, 378f Liver diseases alcoholic liver disease interactions with other, 384 alcohol-induced, 371–390 Liver enzymes for donor liver, 616 in primary biliary cirrhosis, 410 Liver failure, acute, 123 Liver fatty acid binding protein (LFABP), in hepatocellular adenomas, 518, 518f, 520 Liver function tests, 44 Liver Imaging Reporting and Data System (LI-RADS), in small nodules, 494 Liver injury, laboratory investigation of acute, 46–47, 47f, 47t chronic, 47–48, 49f

Index Liver nodules in cirrhotic liver, 62t regenerating, 58–59, 62f, 62t Liver phosphorylase deficiency, 118t Liver plates, 6, 7f, 12 Liver regeneration, in acute viral hepatitis, 196, 196f Liver segments, 22 anatomy of, 22f Liver tests, 43–54 for acute liver injury, 46–47, 47f, 47t approach to evaluation of, 45–49, 46t of “biliary” enzymes, 44–45 for cardiac diseases, 51 for connective tissue diseases, 50–51 for disease of other organs, 49–52 for endocrine disorders, 51 for gastrointestinal diseases, 51–52 for infectious diseases, 51 of measures of coagulation, 45 for neoplastic diseases, 51 in pregnancy, 48–49 for systemic diseases, 49–52, 50b of transaminases, 44 Liver transplantation, 603–628, 642f allograft allocation for, 617–618 for autoimmune hepatitis, 315 central perivenulitis in, 642–643, 642f–644f diagnosis of, 644f grading of, 642, 643t isolated, 637, 642, 642f–643f complications after infections as, 621 with CMV, 621 prophylaxis and treatment of, 623t, 625 long-term renal failure as, 621 malignancy as, 621–622 in pediatric recipients, 622 posttransplant lymphoproliferative disorder (PTLD) as, 622 in children, 622 surgical, 620–621 biliary complications as, 621 hepatic outflow obstruction as, 621 primary nonfunction as, 620 complications after, posttransplant lymphoproliferative disorders as, 592t–593t de novo diseases in, 653–655 idiopathic chronic hepatitis as, 654, 654f malignancy as, 654–655, 655f plasma cell hepatitis as, 653–654, 653f viral hepatitis as, 654 donor and allograft evaluation for, 614–617, 614b extended criteria donors, 614–617, 614b medical history, 616–617 physiologic, 615–616 with partial liver allografts, 617, 618f donor and recipient operation for, 618–620 anesthesia for, 620 closure of abdomen in, 620 implantation of allograft in, 619–620

Liver transplantation (Continued) organ procurement from deceased donors in, 618–619 preparation of allograft in, 619 recipient hepatectomy in, 619, 620f donors of, biopsy in with chronic hepatitis C, 631–632, 631f evaluation of, 630–633 freezing artifact in, 631, 631f indications for, 631t reporting, standard form for, 631–632, 632f steatosis in, 631–632 for hepatocellular carcinoma, 540 history of, 606–607, 606b current trends in, 607, 607f, 608t legislative mandates in, 607 immunosuppression after, 622–625 immunosuppression agents, 622–624, 623t induction therapy, 623t, 624–625 prophylactics with, 623t, 625 indications for, 35, 35t, 630t acute liver failure as, 610–611 in adults, 607–611, 608b alcoholic liver disease as, 609 autoimmune hepatitis as, 609 in children, 611, 611b cholestatic liver disease as, 609–610 hepatitis B and hepatitis A as, 609 hepatitis C as, 607–609 hepatocellular carcinoma as, 610, 610t nonalcoholic fatty liver disease as, 609 noncholestatic liver disease as, 607–609 primary biliary cirrhosis as, 609–610 primary sclerosing cholangitis as, 610 infections in, 656–658 adenovirus, 658 cytomegalovirus as, 657, 657f–658f Epstein-Barr virus as, 658, 658f human herpesvirus 6 as, 657 late protocol biopsies in, changes in, 658–659, 659b idiopathic fibrosis, 659 nodular regenerative hyperplasia, 659, 659f loss of intrahepatic bile ducts after, 434t due to allograft rejection, 435f acute, 438, 438f chronic, 438, 438f due to recurrent primary biliary cirrhosis and primary sclerosing cholangitis, 439 organ matching for, 618 pathology of, 629–662 patient evaluation for, 611–614 comorbidities in, 613 contraindications to, 612b elderly in, 612 obesity in, 612 pediatric patients in, 613–614 retransplantation in, 613 substance abuse in, 612–613 pediatric allograft allocation for, 617, 618b complications of, 622 current trends in, 607, 607f, 608t donor and allograft evaluation for, 617

Liver transplantation (Continued) indications for, 611, 611b patient evaluation for, 613–614 posttransplant lymphoproliferative disease in, 655 preservation-reperfusion injury in, 633–634 clinical manifestations of, 633–634 differential diagnosis in, 634, 634f microscopic pathology in, 633–634, 633f–634f recurrent diseases in, 643–653, 645t alcohol related liver disease, 652–653, 652f autoimmune hepatitis as, 648–649, 649f, 649b hepatitis B as, 647–648, 648f hepatitis C as, 643–647, 646f–647f nonalcoholic steatohepatitis as, 651–652, 652f primary biliary cholangitis as, 649–650, 650f primary sclerosing cholangitis as, 650–651, 650b, 651f surgical complications in, 655–656 biliary strictures as, 655, 656f hepatic artery thrombosis as, 655–656, 656f–657f ischemic cholangitis as, 655–656, 657f survival rates after, 629–630 Liver tumors, imaging of, 57–59 cholangiocarcinoma as, 57f, 59, 63t with cirrhosis, 58–59 focal nodular hyperplasia as, 58, 61f differential diagnosis of, 63t hemangioma as, 56f, 57–58, 60f differential diagnosis of, 62t–63t hepatocellular adenoma as, 58, 61f, 63t hepatocellular carcinoma as, 56f, 58–59 with cirrhosis, 55, 56f, 63t differential diagnosis of, 61f, 62t–63t metastases as, 59, 59f, 63f, 63t Living donor graft, 617, 618f Lobular activity, in grading of chronic hepatitis in Batts and Ludwig system, 235–236 in Ishak system, 236, 238f in METAVIR algorithm, 236, 240f in Scheuer system, 235, 236f Lobular cholestasis, metabolic diseases with, 103–104, 103f, 103t Lobular granuloma, drug-induced, 298f Lobular hepatitis acute, 192–197 chronic, 233 in drug-induced liver injury, 334t–347t Lobular inflammation in alcoholic liver disease, 374t–375t, 377–378 in autoimmune hepatitis, 311–312, 311f in chronic hepatitis B, 213–214 in chronic hepatitis C, 226, 227f metabolic diseases with, 102–103, 103t Lobular parenchyma, 12–20 Disse space, 8, 19–20, 19f hepatocytes, 7f, 12–15, 16f intralobular biliary channels, 15–16, 18f sinusoids, 4, 7f, 16–19, 19f 709

Index Long-chain 3-hydroxyacyl Co A dehydrogenase (LCHAD) deficiency, common findings with, 92t–93t Long-chain acyl-CoA dehydrogenase deficiency, 105–106, 106f Losartan, hepatotoxicity of, 334t–347t Loss of intrahepatic bile ducts (LIBDs), 433–444 after hematopoietic cell transplantation, 434t, 439t due to graft-versus-host disease, 439–440 acute, 439, 439t–440t chronic, 439–440 microscopic pathology of, 440, 441f–442f after liver transplantation, 434t due to allograft rejection, 435f acute, 438, 438f chronic, 438, 438f due to recurrent primary biliary cirrhosis and primary sclerosing cholangitis, 439 diseases frequently associated with, 434b drug-induced, 442–443 due to ischemic cholangiopathy, 440–442, 442f microscopic pathology of, 441–442, 443f due to primary biliary cirrhosis, 435–436 microscopic pathology of, 435–436, 436f hepatitis C and, 435–436, 436f due to primary sclerosing cholangitis, 436–437 microscopic pathology of, 437, 437f due to sarcoidosis, 437–438 due to secondary sclerosing cholangitis, 437 microscopic pathology of, 434, 434f pathogenetic pathway of, 433–434 immunologic mechanisms in, 433–434 ischemic damage in, 433–434 pitfalls in microscopic diagnosis of, 434–435, 435f Lovastatin, hepatotoxicity of, 334t–347t “Low-GGT” intrahepatic cholestasis, 459–460 Low-grade dysplastic nodule (LGDN), 488–490 liver biopsy in, 499–503 Ludwig system, for staging of primary biliary cirrhosis, 415, 416t Lymphangioma, 589–590 clinical manifestations of, 589 differential diagnosis of, 585t, 589 gross pathology of, 589 incidence and demographics of, 589–590 microscopic pathology of, 589, 589f radiologic features of, 589 treatment and prognosis of, 589–590 Lymphatics, portal, 8, 14f Lymphocytes, in acute viral hepatitis, 193, 195f Lymphocytic cholangitis, in primary biliary cirrhosis, 410, 411f Lymphocytic infiltrate, in Epstein-Barr virus hepatitis, 200f 710

Lymphocytic piecemeal necrosis, in primary biliary cirrhosis, 415t Lymphohistiocytosis, hemophagocytic, with HIV infection, 249–250, 251f Lymphoid aggregate, in primary biliary cirrhosis, 413f Lymphoid follicles in chronic hepatitis B, 213, 214f in chronic hepatitis C, 225 Lymphoma(s), 592–594 AID-associated, 261–262 B-cell extranodal marginal zone, 592t–593t T-cell-rich, 592t–593t clinical manifestations of, 593 differential diagnosis of, 593 follicular, 592t–593t Hodgkin disease, with HIV infection, 261 incidence and demographics of, 592–594 large cell anaplastic, 592t–593t diffuse, 592t–593t lymphoplasmacytoid, 592t–593t mantle cell, 592t–593t microscopic pathology of, 593, 594f non-Hodgkin, with HIV infection, 261 radiologic features of, 593 subtypes, 592t–593t T-cell, hepatosplenic (sinusoidal) T-cell, 592t–593t, 594–595 clinical manifestations of, 594 differential diagnosis, 595 incidence and demographics of, 594–595 microscopic pathology of, 594–595, 595f treatment and prognosis for, 595 treatment and prognosis of, 593–594 Lymphoplasmacytic inflammation, in primary biliary cirrhosis, 413f Lymphoplasmacytoid lymphoma, 592t–593t Lymphoproliferative disorder, posttransplant, 592t–593t, 622 in children, 622 Lysinuric protein intolerance, common findings with, 92t–93t Lysosomal hydrolase testing, collection, storage, and shipping of specimens for, 96t Lysosomal storage disorders, 111–115 clinical manifestations of, 111 common findings with, 92t–93t enzyme replacement therapy for, 111–112 pathology of, 112, 114f phenotype-genotype correlation in, 111 tests, methods, and required biologic samples for, 95t Lysosomes primary, 20, 21f secondary, 20 Lytic necrosis, 22, 23f Lytic (spotty) necrosis, in acute viral hepatitis, 193, 194f M Ma Huang, hepatotoxicity of, 334t–347t Macronodular cirrhosis, 680, 680f

Macrotrabecular hepatoblastoma (MT-HB), 558, 560f Macrovesicular steatosis, 23, 25f in alcoholic liver disease, 374t–375t, 375 in nonalcoholic fatty liver disease, 170–171, 171f Magnetic resonance cholangiopancreatography (MRCP) for primary biliary cirrhosis, 410 for primary sclerosing cholangitis, 424, 424f Magnetic resonance elastography (MRE), of hepatic fibrosis and cirrhosis, 63, 65f Magnetic resonance imaging (MRI), 55–57 chemical shift, 60, 64f contrast agents, 58t of focal nodular hyperplasia, 58, 61f of hemangioma, 57–58, 60f of hepatic metastases, 59 of hepatic steatosis, 59–60, 64f of hepatocellular adenoma, 58, 61f of hepatocellular carcinoma, 58–59, 61f phases of, 57t of regenerating nodules, 62f Magnetic resonance spectroscopy (MRS), of hepatic steatosis, 60, 64f Malaria, 274–275 clinical manifestations of, 274 diagnosis of, 275 life cycle and pathogenesis, 274 pathology of, 274–275, 274f MALDI. see Matrix-assisted laser desorption/ionization (MALDI). Malignancy after liver transplantation, 621–622 de novo, 654–655, 655f Malignant primary tumors, miscellaneous, 597, 597f, 598t Malignant schwannoma, 598t Malignant transformation, of hepatocellular adenomas, 525 Malignant tumors, of bile ducts, 551–553 cholangiocarcinoma, 551–553 clinical manifestations of, 551 differential diagnosis of, 552–553, 553t pathology of, 552, 552f–553f radiologic features of, 552, 552f Mallory bodies, in Wilson disease, 128, 128f, 130 Mallory hyaline, 26, 26f Mallory-Denk bodies (MDB) in alcoholic liver disease, 374t–375t, 377, 377f in hepatocellular carcinoma, 533f in nonalcoholic fatty liver disease, 173, 173f Mantle cell lymphoma, 592t–593t Maple syrup urine disease, common findings with, 92t–93t Marginal zone B-cell lymphoma, extranodal, 592t–593t Margosa oil, hepatotoxicity of, 334t–347t Maroteaux-Lamy syndrome, common findings with, 92t–93t Mass spectrometry, 94–96 gas chromatography-, 97 tandem, 96–97

Index Massive (fulminant) necrosis, in drug-induced liver injury, 331t Massive necrosis, in acute viral hepatitis, 193–194 Masson trichrome stain, 6, 7f, 8t Mate tea, hepatotoxicity of, 334t–347t Matrix-assisted laser desorption/ionization (MALDI), 94–96 Matrix-degrading enzymes metalloproteinases (MMPs), 672 Mebendazole, hepatotoxicity of, 334t–347t Mechanical large bile duct obstruction, primary biliary cirrhosis versus, 415 Mechanism-based inhibitors, 320 Medawar, Peter, 606, 606b Medical history extended criteria donors, 616–617 “Mediovesicular steatosis”, 375 Medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) deficiency, 105–106, 106f common findings with, 92t–93t Medium-droplet fat, 23, 25f Medroxyprogesterone, hepatotoxicity of, 334t–347t Mefloquine, hepatotoxicity of, 334t–347t Megamitochondria, in nonalcoholic fatty liver disease, 173–174, 173f Meglumine antimoniate, hepatotoxicity of, 334t–347t Melanoma, 598t Meloxicam, hepatotoxicity of, 334t–347t Membrane, domains of hepatocytes, 20, 21f Membrane permeability transition, in Reye syndrome, 108 Mercaptopurine, hepatotoxicity of, 334t–347t Mesalamine (Mesalazine), hepatotoxicity of, 334t–347t Mesenchymal hamartoma, 574 clinical manifestations of, 574 differential diagnosis of, 575 genetics and molecular pathology of, 575 incidence and demographics of, 574 microscopic pathology of, 575, 576f radiologic features and gross pathology of, 575, 576f treatment and prognosis of, 575 Mesenchymal hepatoblastoma, 574–579 hepatobiliary rhabdomyosarcoma as, 575–578 clinical manifestations of, 577 differential diagnosis of, 577–578 histopathology of, 577, 578f incidence and demographics of, 575 radiologic features and gross pathology of, 577 treatment and prognosis of, 578 malignant extrarenal rhabdoid tumor as, 578–579 clinical manifestations of, 578 differential diagnosis of, 579 genetics and molecular pathology of, 579 incidence and demographics of, 578 microscopic pathology of, 578–579, 579f radiologic features and gross pathology of, 578

Mesenchymal hepatoblastoma (Continued) treatment and prognosis of, 579 mesenchymal hamartoma as, 574 undifferentiated (embryonal) sarcoma, 575, 577f Mesenchymal iron overload, 158 Mestranol, hepatotoxicity of, 334t–347t Metabolic disease, hereditary, autoimmune hepatitis and, 314 Metabolic fatty liver disease, 383 Metabolic liver disease acid lipase deficiency as, 112, 115f bile acid synthetic defects as, 116–119, 118t, 119f citrin deficiency as, 110, 110f clinical findings that suggest, 102, 102b cystinosis as, 115 diagnosis of, biochemistry and medical genetics in clinical approach to, 91–93, 92t–93t, 94f collection, storage, and transportation of biologic specimens for, 96t common findings from, 92t–93t methodologies involved in, 94–97, 95t fatty acid oxidation (FAO) defects as, 105–106 clinical manifestations of, 105–106, 106f diagnosis of, 106 pathology of, 106 galactosemia as, 110–111, 111f genetic counseling for, 98 genetic hemolytic disorders as, 121–122, 121f genetic metabolic diseases of unknown etiology, 123 hereditary fructose intolerance as, 111, 111f hereditary tyrosinemia, 120 clinical manifestations, 120 diagnosis of, 120 pathology, 120, 121f histologic patterns of, 101–124 bile ductules versus ducts in, 104–105, 104f inflammatory, 102–103, 103t normal, 102, 102b prominent lobular cholestasis as, 103–104, 103f, 103t steatotic, 104–105, 104b, 105f liver biopsy specimens for analysis and reporting of, 102 handling of, 102 lysosomal storage disorders as, 111–115 clinical manifestations of, 111 enzyme replacement therapy for, 111–112 pathology of, 112, 114f phenotype-genotype correlation in, 111 mitochondriopathies as, 106–108 clinical manifestations of, 106–108 diagnosis of, 108 pathology of, 107–108, 107f–108f Niemann-Pick disease, type C as, 112–115, 115f–116f nonlysosomal glycogenosis and polyglucosan storage disorders as, 115–116

Metabolic liver disease (Continued) diagnosis of, 116 pathology of, 115–116, 117f–118f organ involvement in, 101, 102t perinatal hemochromatosis as, 122–123 clinical manifestations, 122–123 pathology and diagnosis of, 122–123, 122f peroxisomal diseases as, 119–120 clinical manifestations of, 120 diagnosis of, 120 pathology of, 120, 120f Reye syndrome as, 108, 109f treatment and management of, 98 tyrosinemia, pathology of, 103f urea cycle defects as, 108–110 clinical manifestations, 109–110 diagnosis of, 110 pathology of, 109–110, 110f Metabolic syndrome, hepatocellular carcinoma and, 530 Metastases, hepatic, imaging of, 59 hypervascular, 59, 63f PET/CT, 59f Metastatic adenocarcinoma, cholangiocarcinoma and, 553, 553t Metastatic tumors, common, 597, 598t, 599f METAVIR system, in chronic hepatitis for grading, 236, 242f comparison of, 234t for staging, 238, 242f–243f comparison of, 234t Metformin, hepatotoxicity of, 334t–347t Methandrostenolone, hepatotoxicity of, 334t–347t Methimazole, hepatotoxicity of, 334t–347t Methotrexate hepatotoxicity of, 334t–347t staging related injury, 364t therapy, steatosis and fibrosis related to, 359f Methoxyflurane, hepatotoxicity of, 334t–347t Methyl salicylate, hepatotoxicity of, 334t–347t Methylation, in drug metabolism, 324 Methyldopa, hepatotoxicity of, 334t–347t Methylmalonic aciduria, common findings with, 92t–93t Methyltestosterone, hepatotoxicity of, 334t–347t Methylthiouracil, hepatotoxicity of, 334t–347t Methyltransferases, in drug metabolism, 324 Microabscesses, with HIV infection, 256–257 Microgranulomas, 291, 292f in CMV hepatitis, 201, 201f Microhamartoma, 395, 396f biliary, 546–547 clinical manifestations of, 546–547 differential diagnosis of, 547 pathology of, 547, 547f prognosis of, 547 radiologic features of, 547 Micronodular cirrhosis, 680, 680f Microscopic anatomy of liver hepatic veins in, 7f, 11–12, 16f lobular parenchyma in, 12–20 711

Index Microscopic anatomy of liver (Continued) Disse space, 8, 19–20, 19f hepatocytes, 7f, 12–15, 16f intralobular biliary channels, 15–16, 18f sinusoids, 4, 7f, 16–19, 19f parenchymal architecture and tissue organization, 3–6, 5f–6f acinar concept in, 4, 5f assessment in biopsy, 6–8 bland appearance on lower power of, 3, 4f fibrous septa, 3, 6f hepatic microcirculatory subunit, 4–5 hexagonal lobule, 3, 6f portal venule, 4, 5f zones in, 4, 5f portal tracts, 8–11 absence of, 6 bile ducts, 8–9, 14f–15f hepatic arteries, 9–11, 13f lymphatics in, 8, 14f portal veins, 11, 13f size and shape of, 8, 13f terms for cells and structures in, 22 Microvesicular steatosis, 23, 25f, 358–359, 359f in alcoholic liver disease, 374t–375t, 375 in drug-induced liver injury, 334t–347t in nonalcoholic fatty liver disease, 170–171, 171b Microvillus inclusion disease (MIVD), 459–460 Middle hepatic vein, anatomy of, 11 Miliary tuberculosis, 293 Mineral oil, hepatotoxicity of, 334t–347t Minocycline, hepatotoxicity of, 334t–347t Minute regenerative nodules (“buds’’), 675 Mirtazapine, hepatotoxicity of, 334t–347t Miscellaneous hepatorenal ciliopathies, 394t Mithramycin, hepatotoxicity of, 334t–347t Mitochondria giant, in alcoholic liver disease, 374t–375t, 377, 377f of hepatocytes, 20, 21f Mitochondrial disease common findings with, 92t–93t diagnosis of, genetic testing for, 97 tests, methods, and required biologic samples for, 95t treatment of, 98 Mitochondrial DNA (mtDNA) testing, collection, storage, and shipping of specimens for, 96t Mitochondriopathies, 106–108 clinical manifestations of, 106–108 diagnosis of, 108 with HIV infection, 249t, 259, 260f pathology of, 107–108, 107f–108f Mitomycin C, hepatotoxicity of, 334t–347t MIVD. see Microvillus inclusion disease (MIVD). Mixed adenoma-focal nodular hyperplasia, 508 Mixed cholestasis- hepatitis, in drug-induced liver injury, 334t–347t Mixed epithelial and mesenchymal hepatoblastoma (MEM-HB), 560, 562f Mixed injury, liver tests for, 44 712

Mixed parenchymal-mesenchymal iron overload, 158–160 Mixed-cholestatic, in drug-induced liver injury, 334t–347t MMPs. see Matrix-degrading enzymes metalloproteinases (MMPs). Model for end-stage liver disease (MELD), 36t score for liver allograft allocation, 617, 618b for liver cirrhosis, 682 Mononuclear inflammatory cells, 249, 250f Mononucleosis, infectious, 199 Mononucleosis-like hepatitis, 332t–333t Morphometric image analysis, in grading and staging of chronic hepatitis, vs. semiquantitative scoring, 241 Morphometry, fibrosis and, 673–674 Morquio syndrome, common findings with, 92t–93t Morula cells, in hepatitis D, 198, 199f Moxifloxacin, hepatotoxicity of, 334t–347t MPV17 defect, 106–107 MRE. see Magnetic resonance elastography (MRE). MRI. see Magnetic resonance imaging (MRI). MRS. see Magnetic resonance spectroscopy (MRS). MS/MS (tandem mass spectrometry), 96–97 MT-HB. see Macrotrabecular hepatoblastoma (MT-HB). Mucinous cystic neoplasm, 548–549 clinical manifestations of, 548 differential diagnosis of, 546t, 548–549 pathology of, 548, 549f–550f radiologic features of, 548, 549f Mucopolysaccharidoses (MPSs), 112, 113f–114f common findings with, 92t–93t tests, methods, and required biologic samples for, 95t Mucoviscidosis, 143 Multidrug resistance 1 (ABCB1), 447 Multidrug resistance 2 (ABCC2), 449 Multidrug resistance 3 phospholipid transporter (ABCB4), 447 Multidrug resistance-associated protein 2 (MRP2), in Dubin-Johnson syndrome, 462 Multilineage tumors, pediatric, 565 Multilobular cirrhosis, in cystic fibrosis, 146–148, 148f Multinucleated giant cells, in sarcoidosis, 302, 304f Multinucleation, of hepatocytes, 16f Multiple FNH syndrome, 508 Mutation analysis, collection, storage, and shipping of specimens for, 96t Mycobacteria, granulomas, due to, with HIV infection, 255, 256f Mycobacterium avium complex (MAC), granulomas due to, with HIV infection, 255, 256f Mycobacterium avium-intracellulare, 294 granulomas due to, with HIV infection, 256f

Mycobacterium leprae, granulomas due to, with HIV infection, 255 Mycophenolate mofetil (Cellcept), for posttransplant immunosuppression, 623t, 624 Mycoses, granulomas due to, with HIV infection, 255–256, 257f Myelodysplastic syndrome, hemochromatosis due to, 155f, 157, 157f MYO5B, in microvillus inclusion disease, 459–460 N N-acetyl transferase (NAT), 323t, 324 N-acetylcysteine, for acute liver failure, 35 N-acetyl-p-benzo-quinone imine (NAPQI), 324–325 NAFLD. see Nonalcoholic fatty liver disease (NAFLD). NAFLD activity score (NAS), 176–178, 177t Nail changes, in chronic liver disease, 38 Naproxen, hepatotoxicity of, 334t–347t NASH. see Nonalcoholic steatohepatitis (NASH). National Organ Transplant Act (NOTA), 606b, 607 Navajo neurohepatopathy, 106–107 NCPH. see Noncirrhotic portal hypertension (NCPH). Necroinflammatory patterns, 234 Necrosis bridging, in acute viral hepatitis, 193, 196f in chronic hepatitis B, 213–214 in chronic hepatitis C, 226, 227f confluent in acute viral hepatitis, 193, 196f in chronic hepatitis, 235t in chronic hepatitis B, 214, 215f in chronic hepatitis C, 227f focal, in grading of chronic hepatitis, 235t, 237f in grading of chronic hepatitis in Batts and Ludwig system, 235–236 in Ishak system, 236, 238f in METAVIR algorithm, 240f in Scheuer system, 236f lytic (spotty), in acute viral hepatitis, 193, 194f massive, 193–194 piecemeal in Batts and Ludwig System, 235–236 in chronic hepatitis B, 213 in chronic hepatitis C, 225–226 in Ishak system, 235t, 238f in METAVIR algorithm, 236, 240f in primary biliary cirrhosis, 415t in Scheuer system, 235, 237f punched-out, due to HSV hepatitis, 202 punctate, due to HSV hepatitis, 202 submassive, in acute viral hepatitis, 193–194, 197f submassive to massive, 332t–333t terminology for, 22–23 Necrotizing eosinophilic granuloma, 295, 296f Nefazodone, hepatotoxicity of, 334t–347t

Index Neonatal cholestasis, 69–71 in cystic fibrosis, 145–146, 145f–146f diagnosis of, 70–71, 70t differential diagnosis of, 70–71, 70t biliary atresia versus, 75f due to Alagille syndrome, 76 due to neonatal hepatitis, 76 incidence and demographics of, 70 liver biopsy in, role of, 70–71 management of, 70–71 Neonatal (giant cell) hepatitis, 76–77 clinical manifestations of, 76–77 differential diagnosis of, 74, 75t, 77 etiology of, 77 pathology of, 77 canalicular cholestasis with biliary rosettes in, 77, 78f focal areas of necrosis in, 77, 77f giant cells in, 76–77, 77f–78f hemosiderin deposition in, 77, 79f treatment and prognosis for, 77 Neonatal hemochromatosis, 76–77, 79f “low-GGT” intrahepatic cholestasis due to, 460 Neonatal sclerosing cholangitis, 85 “high-GGT” intrahepatic cholestasis due to, 460 Neoplasia, HIV-associated, 260–262 Kaposi sarcoma, 260–261, 261f lymphomas as, 261–262 Neoplasms, 332t–333t Neoplastic diseases, liver tests in, 51 Neoral (cyclosporine), for posttransplant immunosuppression, 622–623 Nested stromal epithelial tumor of the liver, 564–565, 567f–568f Neuroendocrine tumor carcinoid/large cell, 591t, 598t large cell/well-differentiated, vs. angiomyolipoma, 591t Neurofibroma, 597t Neurohepatopathy, Navajo, 106–107 Nevirapine, hepatotoxicity of, 334t–347t Newborn screening, diseases related to, treatment and management of, 98 Niacin, hepatotoxicity of, 334t–347t Niemann-Pick disease type A, 112–115 type B, 111, 113f–114f type C, 112–115, 115f–116f Nifedipine, hepatotoxicity of, 334t–347t Nimesulide, hepatotoxicity of, 334t–347t Nitrofurantoin advanced liver disease due to, 350f hepatotoxicity of, 334t–347t toxicity, 348f–349f N-methylation, 324 Nodular pattern, of hepatocellular carcinoma, 531, 531f–532f Nodular regenerative hyperplasia (NRH), 50, 258–259, 332t–333t, 362–363, 479 in drug-induced liver injury, 334t–347t due to chemotherapy, 362f in liver transplantation, 659, 659f in primary biliary cirrhosis, 415t, 420 Nodule, large regenerative, absence of portal tracts, 6, 10f

Nodule-in-nodule growth, in premalignant and early malignant hepatocellular lesions, 498, 501f Nomifensine, hepatotoxicity of, 334t–347t Nonalcoholic fatty liver disease (NAFLD), 167–188, 357–358, 371 alcoholic liver disease and, 179, 179t ancillary diagnostic tests in, 182 causes of, 168t chronic liver diseases and, 181–182 clinical manifestations of, 169 with concurrent liver disease, 179 definitions and synonyms in, 168 differential diagnosis of, 179 genetics of, 182–183 grading and staging of, 176–179, 177t–178t, 382 gross pathology of, 170, 170f hemochromatosis due to, 155t, 159, 159f histologic features of, 384b incidence and demographics of, 168–169, 168t liver transplantation for, 609 metabolic syndrome and, 179–182 microscopic pathology of, 170–176, 170f apoptotic cells, 174, 174f ballooned hepatocytes, 172–173, 173f fibrosis, 175–176, 175f glycogenated nuclei, 174, 174f inflammation, 173, 173f iron stores, 174–175, 174f macrovesicular steatosis, 170–171, 171f microvesicular steatosis, 170–171, 171b mixed steatosis, 171f other features, 173–175 special stains, 176, 177f steatohepatitis, 172–173 steatosis, 170–172, 171f–172f nutritional causes of, 181 primary, 383 radiology in, 169–170 treatment and prognosis of, 183 variations in children, 176 Nonalcoholic steatohepatitis (NASH), 168. see also Nonalcoholic fatty liver disease (NAFLD). hemochromatosis due to, 155t, 159 histologic features of, 172b recurrent, 651–652, 652f Noncholestatic liver disease, liver transplantation for, 607–609 Noncirrhotic portal fibrosis, in schistosomiasis, 281 Noncirrhotic portal hypertension (NCPH), 50 Non-Hodgkin lymphoma, with HIV infection, 261 Nonlysosomal glycogenosis, 115–116 Nonlysososmal glycogenosis diagnosis of, 116 pathology of, 115–116, 117f–118f Nonnucleoside reverse transcriptase inhibitors (NNRTIs), for HIV infection, 247–248 Nonparenchymal changes, in premalignant and early malignant hepatocellular nodules, 495, 497f Nonspecific reactive hepatitis, 266

Nonsuppurative cholangitis, in primary biliary cirrhosis, 410 Nonsynonymous single nucleotide polymorphisms, 320 Norethindrone, hepatotoxicity of, 334t–347t Norfloxacin, hepatotoxicity of, 334t–347t NOTA. see National Organ Transplant Act (NOTA). Novobiocin, hepatotoxicity of, 334t–347t Nuclear pleomorphism, in hepatocytes, 16f Nuclear testing, collection, storage, and shipping of specimens for, 96t Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), for HIV infection, 247–248 “Nutmeg” liver, 471f O Obesity, liver transplantation in, 612 Obliterative portal venopathy, 477–478, 478f in schistosomiasis, 281 Ofloxacin, hepatotoxicity of, 334t–347t Oil of cloves, hepatotoxicity of, 334t–347t Oil red O, 8t Olanzapine, hepatotoxicity of, 334t–347t Older donor livers, 616 O-methylation, 324 Oncocytic hepatocytes, in alcoholic liver disease, 216f, 219t Onion skinning, 26–27 Onion-skin appearance, in primary sclerosing cholangitis (PSC), 425–426, 426f Opisthorchiasis, 282–283 clinical manifestations of, 282 diagnosis of, 283 life cycle in relation to liver disease, 282 pathology of, 282–283 Opisthorchis felineus, 282 Opisthorchis viverrini, 282 OPTN. see Organ Procurement and Transplantation Network (OPTN). Orcein, 8t Organ matching, for liver transplantation, 618 Organ procurement, from deceased donors, 618–619 Organ Procurement and Transplantation Network (OPTN), 606b, 607 Organic acid, methodologies for, 97 Organic aciduria common findings with, 92t–93t newborn screening for, 98 Ornithine transcarbamylase deficiency, 110f common findings with, 92t–93t Osler-Weber-Rendu disease, differential diagnosis of, 585t Osteosarcoma, 598t Overlap syndrome autoimmune hepatitis, with primary sclerosing cholangitis, 424 autoimmune hepatitis-primary biliary cirrhosis, 413f, 419 autoimmune hepatitis-primary sclerosing cholangitis (AIH-PSC) clinical manifestations of, 81 microscopic pathology of, 82, 82f 713

Index “Owl’s eye” inclusions, in CMV hepatitis, with HIV infection, 254, 254f Oxacillin, hepatotoxicity of, 334t–347t Oxaprozin, hepatotoxicity of, 334t–347t Oxcarbazepine, hepatotoxicity of, 334t–347t Oxymetholone, hepatotoxicity of, 334t–347t Oxyphenbutazone, hepatotoxicity of, 334t–347t Oxyphenisatin, hepatotoxicity of, 334t–347t P Pale bodies, in fibrolamellar hepatocellular carcinoma, 571, 572f Palmar erythema, in chronic liver disease, 37, 37f Pancreatic involvement, with primary sclerosing cholangitis, 424 Pancreatobiliary adenocarcinoma, 598t Papaverine, hepatotoxicity of, 334t–347t Papillary-type hepatoblastoma, 565, 568f Para-aminosalicylic acid, hepatotoxicity of, 334t–347t Paracoccidioides brasiliensis, granulomas due to, with HIV infection, 256 Parahilar bile duct, in primary sclerosing cholangitis (PSC), 425–426 bile duct ulceration as, 425–426, 425f bile extravasation as, 425–426, 425f inflammatory myofibroblastic tumor in, 425–426, 426f onion-skin appearance in, 425–426, 426f scar formation in, 426f stones in, 425–426, 426f xanthogranuloma as, 425–426, 425f Parasitic infections, 275–284 ascariasis, 275–276 pathology of, 276f capillariasis, 277 clonorchiasis and opisthorchiasis, 282–283 fascioliasis, 281–282 granulomas and, 295 hydatid cyst, 283–284 pentastomiasis, 281 schistosomiasis, 278–281 strongyloidiasis, 277–278 visceral larva migrans/toxocariasis, 276–277 Parenchymal architecture and tissue organization, 3–6, 5f–6f acinar concept in, 4, 5f assessment in biopsy, 6–8 bland appearance on lower power of, 3, 4f fibrous septa, 3, 6f hepatic microcirculatory subunit, 4–5 hexagonal lobule, 3, 6f portal venule, 4, 5f zones in, 4, 5f Parenchymal changes, in premalignant and early malignant hepatocellular lesions, 494–495, 495t, 496f Parenchymal fibrosis, fragmentation of biopsy material due to, 6–8, 11f–12f Parenchymal iron overload, 155–158 Parenteral nutrition-associated liver disease (PNALD), liver tests for, 52 Paroxetine, hepatotoxicity of, 334t–347t 714

Partial external biliary diversion (PEBD), for progressive familial intrahepatic cholestasis, 459 Partial liver allografts, 617, 618f Parvovirus, acute hepatitis due to, 203 Pazopanib, hepatotoxicity of, 334t–347t PBC. see Primary biliary cholangitis (PBC). PBC-like cholangiodestructive, 332t–333t Pediatric hepatic stromal tumors (PHSTs), 564, 566f Pediatric liver transplantation allograft allocation for, 617, 618b complications of, 622 current trends in, 607, 607f, 608t donor and allograft evaluation for, 617 indications for, 611, 611b patient evaluation for, 613–614 Pediatric liver tumor(s), 555–582 epithelial, 556–574, 556b cholangiocarcinoma as, 574 fibrolamellar hepatocellular carcinoma as, 570–572 clinical manifestations of, 571 differential diagnosis of, 571 genetics and molecular pathology of, 571–572 incidence and demographics of, 570–571 microscopic pathology of, 571, 572f radiologic features and gross pathology of, 571, 572f treatment and prognosis of, 572 focal nodular hyperplasia, 574 hepatoblastoma as, 556–570 cholangioblastic, 557t, 561–564, 565f classification of, 556b clinical manifestations of, 556 current classification of, 556–557 ductal plate tumor of, 556t, 564 embryonal, 557t, 558 fetal-type, 557–558 genetics and molecular pathology of, 565–568, 569f gross pathology of, 557 incidence and demographics of, 556 macrotrabecular, 558, 560f microscopic pathology of, 557–560, 558f–561f mixed epithelial and mesenchymal, 560, 562f multilineage tumors, 565, 568f nested stromal epithelial tumor of the liver as, 564–565, 567f–568f papillary type, 565, 568f pathology of treated, 560–561, 562f–563f pediatric hepatic stromal tumors, 564, 566f radiologic features of, 557, 557f staging of, 560f, 561, 564f, 564t treatment and prognosis of, 568–570, 570t undifferentiated, 558–560, 561f variants of, 561–565 hepatocellular carcinoma, 572–573 clinical manifestations of, 572 differential diagnosis of, 573

Pediatric liver tumor(s) (Continued) genetics and molecular pathology of, 573 incidence and demographics of, 572 microscopic pathology of, 573, 574f radiologic features and gross pathology of, 572–573, 573f treatment and prognosis of, 573 liver cell adenoma, 573–574 transitional liver cell, 570 clinical manifestations of, 570 differential diagnosis of, 570 microscopic pathology of, 570, 571f radiologic features and gross pathology of, 570 treatment and prognosis of, 570 mesenchymal, 574–579 hepatobiliary rhabdomyosarcoma as, 575–578 clinical manifestations of, 577 differential diagnosis of, 577–578 histopathology of, 577, 578f incidence and demographics of, 575 radiologic features and gross pathology of, 577 treatment and prognosis of, 578 malignant extrarenal rhabdoid tumor as, 578–579 clinical manifestations of, 578 differential diagnosis of, 579 genetics and molecular pathology of, 579 incidence and demographics of, 578 microscopic pathology of, 578–579, 579f radiologic features and gross pathology of, 578 treatment and prognosis of, 579 mesenchymal hamartoma as, 574 clinical manifestations of, 574 differential diagnosis of, 575 genetics and molecular pathology of, 575 incidence and demographics of, 574 microscopic pathology of, 575, 576f radiologic features and gross pathology of, 575, 576f treatment and prognosis of, 575 undifferentiated (embryonal) sarcoma, 575, 577f clinical manifestations of, 575 differential diagnosis of, 575 genetics and molecular pathology of, 575 incidence and demographics of, 575 microscopic pathology of, 575 radiologic features and gross pathology of, 575 treatment and prognosis of, 575 study groups, 555–556 vascular, 579–581 epithelioid hemangioendothelioma as, 580 infantile hemangioendothelioma as, 579–580 clinical manifestations of, 579 differential diagnosis of, 580 histopathology of, 579–580, 580f

Index Pediatric liver tumor(s) (Continued) incidence and demographics as, 579 radiologic features and gross pathology of, 579 treatment and prognosis of, 580 pediatric angiosarcoma, 580–581 clinical manifestations of, 581 incidence and demographics of, 581 microscopic pathology of, 581 radiologic features and gross pathology of, 581 treatment and prognosis of, 581 of perivascular epithelioid cell, 581 Pediatric version of the MELD score (PELD), for liver allograft allocation, 617, 618b Peliosis, in drug-induced liver injury, 334t–347t Peliosis hepatis differential diagnosis of, 585t with HIV infection, 258, 259f Pemoline, hepatotoxicity of, 334t–347t Penicillamine, hepatotoxicity of, 334t–347t Penicillin, hepatotoxicity of, 334t–347t Pennyroyal oil, hepatotoxicity of, 334t–347t Pentamidine, hepatotoxicity of, 334t–347t Pentanoic acid, hepatotoxicity of, 334t–347t Pentastomiasis, 281 diagnosis of, 281 life cycle in relation to liver disease, 281 pathology of, 281 Perforated delicate septa, cirrhosis and, 674, 676f Perhexiline maleate, hepatotoxicity of, 334t–347t Peribiliary gland hamartoma, 547–548 clinical manifestations of, 547 differential diagnosis of, 548, 553t pathology of, 547–548, 548f radiologic features of, 547 Pericellular fibrosis, 28, 257, 258f in alcoholic liver disease, 374t–375t, 379, 379f Periductal fibrosis, in primary sclerosing cholangitis (PSC), 427, 427f Periductulitis, in metabolic liver disease, 104f Perinatal hemochromatosis (PH), 122–123 clinical manifestations, 122–123 pathology and diagnosis of, 122–123, 122f Perinuclear antineutrophil cytoplasmic antibody (pANCA), in primary sclerosing cholangitis, 424 Periodic acid -Schiff, 8t Peripheral antineutrophil nuclear antibody (pANNA), in primary sclerosing cholangitis, 424 Peripheral portal tracts, primary sclerosing cholangitis (PSC) of, 427 cholate stasis in, 427, 428f copper-associated protein in, 427, 428f early indirect portal changes in, 427, 428f florid ductular reaction in, 427, 428f Periportal activity, 23 Periportal areas, 22 anatomy of, 4, 5f Periportal fibrosis, 257 in alcoholic liver disease, 374t–375t in primary biliary cirrhosis, 414

Periportal fibrosis (Continued) in staging of chronic hepatitis in Ishak system, 238 in Scheuer system, 236, 241f Periportal inflammation in chronic hepatitis B, 214f in chronic hepatitis C, 225f Perisinusoidal fibrosis, 28, 28f, 257 in alcoholic liver disease, 374t–375t, 379 Peritonitis, spontaneous bacterial, due to cirrhosis, 40 Periventricular areas, anatomy of, 4, 5f Perivenular area, 22 Perivenular cell dropout, in chronic rejection, 640f Perivenular fibrosis, 28 in alcoholic liver disease, 374t–375t, 379 Perivenular hepatocyte necrosis, 643 Perivenulitis, central, 642–643, 642f–644f diagnosis of, 644f grading of, 642, 643t isolated, 637, 642, 642f–643f Perls iron, 8t Peroxisomal biogenesis disorders, 119 Peroxisomal diseases, 119–120 clinical manifestations of, 120 common findings with, 92t–93t diagnosis of, 120 pathology of, 120, 120f tests, methods, and required biologic samples for, 95t Peroxisomal enzyme deficiency disorders, 119 Peroxisomal enzymes, 20 Peroxisomes, of hepatocytes, 20, 21f PET. see Positron emission tomography (PET). PEX family of genes, in peroxisomal disorders, 119 Pharmacodynamics, 320 Pharmacogenetics, 320 Pharmacokinetics, 320 Phase I enzymes, 319 Phase II enzymes, 319 Phase III enzymes, 319, 324 Phenazone, hepatotoxicity of, 334t–347t Phenazopyridine, hepatotoxicity of, 334t–347t Phenelzine, hepatotoxicity of, 334t–347t Phenindione, hepatotoxicity of, 334t–347t Phenobarbital, hepatotoxicity of, 334t–347t Phenprocoumon, hepatotoxicity of, 334t–347t Phenylbutazone, hepatotoxicity of, 334t–347t Phenylketonuria, common findings with, 92t–93t Phenytoin, hepatotoxicity of, 334t–347t Phlebosclerosis, in alcoholic liver disease, 379 Phosphorylase kinase activator deficiency, 118t Phosphorylase kinase deficiency, 118t Physical examination, for inborn errors of metabolism, 91 Physiologic extended criteria donors, 615–616 Physiologic jaundice, 69–70

Pi (protease inhibitor) gene, in alpha-1 antitrypsin deficiency, 133 Pichlmayr, Rudolf, 606b Piecemeal necrosis, 23 in autoimmune hepatitis, 310–311, 311f in Batts and Ludwig System, 235–236 in chronic hepatitis B, 213 in chronic hepatitis C, 225–226 in Ishak system, 235t, 238f lymphocytic, in primary biliary cirrhosis, 415t in METAVIR algorithm, 236, 240f in Scheuer system, 235, 237f Piggyback technique, for liver transplantation, 619, 620f PiM, in alpha-1 antitrypsin deficiency, 133 PiMS, alpha-1 antitrypsin deficiency with incidence and demographics of, 134 microscopic pathology of, intracytoplasmic globules in, 137 PiMZ, alpha-1 antitrypsin deficiency with clinical manifestations and natural history of liver disease in, 134t, 135 incidence and demographics of, 134 pathology of, 138 Pioglitazone, hepatotoxicity of, 334t–347t Piroxicam, hepatotoxicity of, 334t–347t Pirprofen, hepatotoxicity of, 334t–347t PiS, alpha-1 antitrypsin deficiency with incidence and demographics of, 134 microscopic pathology of, intracytoplasmic globules in, 137 PiSS, alpha-1 antitrypsin deficiency with clinical presentation of, 134t incidence and demographics of, 134 microscopic pathology of, intracytoplasmic globules in, 137 PiSZ, alpha-1 antitrypsin deficiency with clinical presentation of, 134t incidence and demographics of, 134 microscopic pathology of, intracytoplasmic globules in, 136 Pit cells, 22 PiZ, alpha-1 antitrypsin deficiency with incidence and demographics of, 134 microscopic pathology of, intracytoplasmic globules in, 137 Pizotifen, hepatotoxicity of, 334t–347t PiZZ, alpha-1 antitrypsin deficiency with clinical manifestations and natural history of liver disease in, 134–135, 134t incidence and demographics of, 134 pathology of, 137–138, 137f–138f Plasma cell hepatitis, 653–654 in central perivenulitis, 643 diagnosis of, 653f in late cellular rejection, 638, 639f Plasma cells, in primary biliary cirrhosis, 412, 415t Plasmalogens collection, storage, and transportation of biologic specimens for, 96t tests, methods, and required biologic samples for, 95t Plasmodium falciparum, 274 Plasmodium malariae, 274 Plasmodium ovale, 274 Plasmodium vivax, 274 715

Index Platelet count, 45 Pneumocystis carinii, after liver transplantation, 625 Polycystic liver, 396–397 autosomal dominant, 396 clinical manifestations of, 396, 397f macroscopic pathology of, 397, 397f microscopic pathology of, 397, 398f treatment of, 397 autosomal recessive, 397–399 clinical manifestations of, 398–399 macroscopic pathology of, 399, 400f microscopic pathology of, 399, 401f treatment of, 399 Polyglucosan storage disorders, 115–116 Polygonal tumor cells, in hepatocellular carcinoma, 532, 532f Polymorphisms, enzyme, drug bioavailability and, 320–321 Polyvinylpyrrolidone, hepatotoxicity of, 334t–347t Pompe disease, 113f Poor metabolizers, 320–321 Popper, Hans, 327 Porocephalus armillatus, 281 Porphyria, congenital erythropoietic, 122, 122f Porphyria cutanea tarda, hemochromatosis due to, 155t, 158 Porta hepatis, in biliary atresia, 73 Portal changes in autoimmune hepatitis, 310–311, 310f in chronic hepatitis B, 213 in chronic hepatitis C, 225–226 Portal dyad, 434 Portal fibrosis, 257 in sarcoidosis, 302 in schistosomiasis, 279 in staging of chronic hepatitis, 234 in Ishak system, 238 in Scheuer system, 236 Portal granuloma, in schistosomiasis, 296f Portal hepatitis, in drug-induced liver injury, 334t–347t Portal hyperperfusion syndrome, 636 Portal hypertensive gastropathy, due to cirrhosis, 39, 39f Portal inflammation in alcoholic liver disease, 374t–375t, 380, 380f in chronic hepatitis, 235t, 237f in chronic hepatitis B, 214f metabolic diseases with, 102–103, 103t in primary biliary cirrhosis, 411f, 412 Portal inflammatory infiltrate, in acute viral hepatitis, 193, 195f Portal lobule, 3–4 Portal lymphatics, 8, 14f Portal tract inflammation, in HIV infection, 248–249, 250f Portal tract remnants, 676 Portal tracts absence of, 6 anatomy of, 8–11 bile ducts, 8–9, 14f–15f branching, 10t, 13f hepatic arteries, 9–11, 13f in hexagonal lobule, 5f 716

Portal tracts (Continued) large, 10t, 13f longitudinal cut, 10t, 13f on low power, 4f lymphatics in, 8, 14f portal veins, 11, 13f size and shape of, 8, 13f fibrous, 13f Portal triad, 8, 434 Portal vein, and intrahepatic bile ducts, 434, 434f Portal vein thrombosis, 468b, 475–477 clinical manifestations of, 476 etiopathogenesis of, 475–477 gross pathology of, 476 incidence and demographics of, 475 laboratory findings in, 476 microscopic pathology of, 476, 476f–477f radiologic features of, 476 treatment and prognosis of, 477 Portal veins, anatomy of, 11, 13f Portal venule, 4, 5f Portal-based fibrosis, 680, 681f Portal-periportal activity, in grading of chronic hepatitis in Ishak system, 238, 238f in Scheuer system, 236, 236f–237f Portal-to-central bridging necrosis, in grading of chronic hepatitis, in Ishak system, 236, 238f Portopulmonary hypertension (POPH), due to cirrhosis, 41 Positron emission tomography (PET), 55–57, 59f Postinfantile giant cell hepatitis, 76, 311–312, 312f Posttransplant lymphoproliferative disease (PTLD), 592t–593t, 622 in children, 622 in liver transplantation, 655, 655f Practolol, hepatotoxicity of, 334t–347t Prajmalium, hepatotoxicity of, 334t–347t Pravastatin, hepatotoxicity of, 334t–347t Prednisone, for posttransplant immunosuppression, 623t, 624 Preeclampsia, 468b, 474–475 Pregnancy intrahepatic cholestasis of, 461 clinical manifestations of, 461 etiopathogenesis of, 461 microscopic pathology of, 461 treatment of, 461 liver tests in, 48–49 Premalignant hepatocellular lesions, in chronic hepatitis/cirrhosis, 485–506 basic histopathologic features of, 494–495, 495t biomarkers for, 497–498, 499f–500f classification of, clinical relevance of, 488b clinical setting of, 488 dysplastic foci as, 490, 490b, 491f dysplastic nodules as, 489f–490f, 490–491, 490b, 493t, 494 in daily clinical practice, 494 key diagnostic points for, 495–498 liver biopsy for, 499–504, 502f

Premalignant hepatocellular lesions, in chronic hepatitis/cirrhosis (Continued) diagnostic criteria in, 499–503, 502f–503f nodule management in, 503–504 natural history of, 493, 493t nodule in nodule, 498, 501f nomenclature of, 488–491 nonparenchymal changes in, 495, 497f parenchymal changes in, 494–495, 496f prevalence of according to size, 488, 488t ultrasonography detected, 488, 488t small hepatocellular carcinoma as, 491, 491t, 492f–493f stromal invasion in, 495–497, 498f target population of, 488 Preservation-reperfusion injury, 633–634 clinical manifestations of, 633–634 differential diagnosis in, 634, 634f microscopic pathology in, 633–634, 633f–634f Pretreatment extent of disease (PRETEXT) system, for hepatoblastoma, 561, 564f, 564t Primary biliary cholangitis (PBC) laboratory investigation of, 48 recurrent, 649–650 clinical considerations of, 649–650 diagnosis of, 650b differential diagnosis of, 650 microscopic pathology of, 650, 650f Primary biliary cirrhosis, 409–422 clinical manifestations of, 410 diagnosis of, 415 differential diagnosis of, 415–418 adverse drug reaction versus, 416 autoimmune hepatitis versus, 416, 417t granulomatous inflammation versus, 418, 418f mechanical large bile duct obstruction versus, 415 primary sclerosing cholangitis versus, 415, 417f, 417t viral hepatitis versus, 416–417, 418f vs. primary sclerosing cholangitis (PSC), 427–429 vs. Wilson disease, 130t gross pathology of, 410 hepatitis C and, 435–436, 436f incidence and demographics of, 409–410 laboratory findings of, 410 for autoantibodies, 410 antimitochondrial, 410 antinuclear, 410 other, 410 for liver enzymes and immunoglobulins, 410 liver biopsy for, 415, 415t–416t liver transplantation for, 609–610 loss of intrahepatic bile ducts due to, 435–436 blushing hepatocytes in, 435–436, 437f microscopic pathology of, 435–436, 436f microscopic pathology of, 410–414

Index Primary biliary cirrhosis (Continued) bile duct injury, 410–412, 415t with bile duct epithelial damage, 410, 411f with bile duct loss and ductopenia, 410–412, 412f–413f with ductular reaction, 410, 412f with florid duct lesion, 410, 411f–412f, 415t with granulomas, 410 with lymphocytic cholangitis, 410, 411f nonsuppurative cholangitis due to, 410 hepatic parenchymal changes in, 412–414, 413f portal inflammation in, 411f, 412 microscopic pathology of, with loss of intrahepatic bile ducts, 435–436 hepatitis C and, 435–436, 436f overlap syndrome with autoimmune hepatitis, 413f radiologic features of, 410 staging of, 415, 416t treatment and prognosis for, 418–419 variants and special diagnostic considerations with, 419–420 antimitochondrial antibody-negative, 419 asymptomatic patients with positive antimitochondrial antibody, 419 autoimmune hepatitis overlap syndrome with, 413f, 419 nodular regenerative hyperplasia, 415t, 420 Primary biliary cirrhosis-autoimmune hepatitis overlap syndrome, 413f, 419 Primary sclerosing cholangitis (PSC), 423–432 as autoimmune disease, 424 in children, 81–83 clinical manifestations of, 81 diagnosis of, 82 incidence and demographics, 81 microscopic pathology of, 82, 82f–83f radiologic findings in, 82 treatment and prognosis for, 82–83 clinical manifestations of, 81, 424 conditions associated with, 424 diagnosis of, 82 differential diagnosis of, 427–429, 428f primary biliary cirrhosis versus, 415, 417f, 417t vs. autoimmune hepatitis, 429 vs. dominant stricture, 429 vs. hepatolithiasis and recurrent pyogenic cholangitis, 429 vs. IgG4-related sclerosing cholangitis, 429 vs. other chronic liver diseases, 429 vs. primary biliary cirrhosis, 427–429 vs. Wilson disease, 130t genetics of, 429 grading of, 427 gross pathology of, 424–425, 425f incidence and demographics of, 424 laboratory findings in, 424 large bile duct, 425–426, 425f–426f

Primary sclerosing cholangitis (PSC) (Continued) liver transplantation for, 610 loss of intrahepatic bile ducts due to, 436–437 microscopic pathology of, 437, 437f microscopic pathology of, 425–427, 425f fibrous obliterative lesion in, 437 gall bladder and, 427 of large hilar/parahilar bile ducts, 425–426 bile duct ulceration as, 425–426, 425f bile extravasation as, 425–426, 425f inflammatory myofibroblastic tumor in, 425–426, 426f onion-skin appearance in, 425–426, 426f scar formation in, 426f stones in, 425–426, 426f xanthogranuloma as, 425–426, 425f loss of intrahepatic bile ducts in, 437, 437f parenchymal changes in, 427 of small peripheral portal tracts, 427 cholate stasis in, 427, 428f copper-associated protein in, 427, 428f early indirect portal changes in, 427, 428f florid ductular reaction in, 427, 428f of small septal/interlobular bile ducts, 427 direct involvement of, 427, 427f periductal fibrosis in, 427, 427f microscopic pathology of, in children, 82, 82f–83f overlap with autoimmune hepatitis (AIH) of clinical manifestations of, 81 microscopic pathology of, 82, 82f radiologic features of, 424, 424f radiologic findings in, 82 recurrent, 650–651, 651f secondary (acquired), 430, 430b secondary vs, 429 small duct, 423 peripheral portal tracts, 427, 428f septal/interlobular bile, 427, 427f treatment and prognosis for, 82–83, 430 Primary sclerosing cholangitis-autoimmune hepatitis (PSC-AIH) overlap syndrome. see Autoimmune hepatitis-primary sclerosing cholangitis (AIH-PSC) overlap syndrome. Procainamide, hepatotoxicity of, 334t–347t Prochlorperazine, hepatotoxicity of, 334t–347t Prograf (tacrolimus), for posttransplant immunosuppression, 623–624 Progressed hepatocellular carcinoma (pHCC), 491, 491t, 492f–493f nodule-in-nodule growth in, 498 Progressive familial intrahepatic cholestasis (PFIC), 454–459 clinical manifestations of, 455, 455t electron microscopy of, 459, 459f etiopathogenesis of, 454–455, 454t

Progressive familial intrahepatic cholestasis (PFIC) (Continued) immunohistochemistry of, 457f–458f, 458–459 incidence and demographics of, 455 laboratory findings of, 455 lobular cholestasis in, 103f microscopic findings of, 456–457 PFIC-1 or ATP8B1 disease as, 456, 456f–457f clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t PFIC-2 or ABCB11 disease as, 456, 457f–458f clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t PFIC-3 or ABCB4 disease as, 457, 458f clinical manifestations of, 455t laboratory findings in, 455t molecular characteristics of, 454t, 457f–458f therapeutic approaches in, 455t treatment of, 455t, 459 Propafenone, hepatotoxicity of, 334t–347t Prophylaxis, after liver transplantation, 623t, 625 acyclovir as, 625 aspirin as, 625 fluconazole as, 625 ganciclovir as, 625 lamivudine as, 625 trimethoprim/sulfamethoxazole as, 625 valganciclovir as, 625 Propionic aciduria, common findings with, 92t–93t Propylthiouracil, hepatotoxicity of, 334t–347t Prostata, hepatotoxicity of, 334t–347t Protease inhibitor gene, in alpha-1 antitrypsin deficiency, 133 Protease inhibitors allelic mutations of, laboratory investigation of, 48 for HIV infection, 247–248 Protein deficiency, steatosis due to, 105 Proteins, methodologies for, 97 Prothrombin time (PT), liver tests of, 45 Proton density fat fraction (PDFF), 169–170 Protozoal infections, 271–275 amebiasis, 271–272 malaria, 274–275 clinical manifestations of, 274 diagnosis of, 275 life cycle and pathogenesis, 274 pathology of, 274–275, 274f visceral leishmaniasis, with HIV infection, 249, 251f visceral leishmaniasis (Kala-azar), 272–274, 273f in AIDS, 274, 274f diagnosis of, 274 717

Index Protozoal infections (Continued) life cycle in relation to liver disease, 272 pathology of, 272–274 PSC. see Primary sclerosing cholangitis (PSC). Pseudoabscess, due to amebiasis, 271 Pseudoacinar change, 26, 27f Pseudoacinar groups, in acute viral hepatitis, 196, 197f Pseudolipoma, differential diagnosis of, 591t Pseudomonas aeruginosa, sepsis due to, 266 Pulmonary adenocarcinoma, 598t Punched-out necrosis, 23 due to HSV hepatitis, 202 Punctate necrosis, due to HSV hepatitis, 202 Pyogenic abscess, 266, 267f with HIV infection, 256–257 Pyogenic cholangitis, recurrent, 429 Pyrazinamide, hepatotoxicity of, 334t–347t Pyrrolizidine alkaloids, hepatotoxicity of, 334t–347t Pyruvate carboxylase deficiency, common findings with, 92t–93t Q Q-fever, 271, 294 in fibrin-ring granulomas, 292 Quadrupole analyzers, 96 Quantitative amino acids, collection, storage, and shipping of specimens for, 96t Quasispecies, of hepatitis C virus, 223–224 Quetiapine, hepatotoxicity of, 334t–347t Quinethazone, hepatotoxicity of, 334t–347t Quinidine, hepatotoxicity of, 334t–347t Quinine, hepatotoxicity of, 334t–347t R R ratio, 45–46, 46t Rabbit antithymocyte globulin (rATG), for posttransplant immunosuppression, 623t, 624–625 Raloxifene, hepatotoxicity of, 334t–347t Ramipril, hepatotoxicity of, 334t–347t Ranitidine, hepatotoxicity of, 334t–347t Rapamycin (sirolimus), for posttransplant immunosuppression, 624 Reactive hepatitis, nonspecific, 266 Recurrent diseases, in liver transplantation, 643–653, 645t alcohol related liver disease as, 652–653, 652f autoimmune hepatitis as, 648–649, 649f, 649b hepatitis B as, 647–648, 648f hepatitis C as, 643–647, 646f–647f nonalcoholic steatohepatitis as, 651–652, 652f primary biliary cholangitis as, 649–650, 650f primary sclerosing cholangitis as, 650–651, 650b, 651f Recurrent pyogenic cholangitis, 429 Red blood cells, for genetic and biochemical tests, collection, storage, and shipping of specimens for, 96t Regeneration, in acute viral hepatitis, 196, 196f 718

Regenerative hyperplasia, nodular, in liver transplantation, 659, 659f Regenerative nodule, absence of portal tracts, 6, 10f Regression, of cirrhosis, 683–684, 684f, 684b “Regression spheres”, in treated hepatoblastoma, 560–561, 562f–563f Rejection of liver allograft, 621 acute in children, 622 loss of intrahepatic bile ducts due to, 438, 438f chronic, loss of intrahepatic bile ducts due to, 438, 438f loss of intrahepatic bile ducts due to, 435f acute, 438, 438f chronic, 438, 438f Rejection, of allograft, 634–642 acute antibody-mediated, microscopic pathology of, 636, 636f cellular, 636–639 acute, 636–637, 637f, 637t–638t differential diagnosis of, 638–639, 639f late, 638, 638f–639f chronic, 639–641, 640f–641f antibody-mediated, 641, 642b differential diagnosis of, 641 early and late features of, 641t treatment of, 642 clinical manifestations of, 635 common pathways of, 635f differential diagnosis of, 636 ductopenic, 639–640, 640f humoral, 635 hyperacute, 635–636, 636f terminology in, 634–642 Rejection activity index (RAI), 638, 638t Renal (clear) cell carcinoma, 598t vs. angiomyolipoma, 591t Renal failure acute, with acute liver failure, 34–35 long-term, after liver transplantation, 621 Repaglinide, hepatotoxicity of, 334t–347t Reperfusion injury, 633–634 clinical manifestations of, 633–634 differential diagnosis in, 634, 634f microscopic pathology in, 633–634, 633f–634f Reticulin, as histochemical stain, 6, 7f, 8t, 9f Reticulin fibers in hepatocellular carcinoma, 534f in sarcoidosis, 302, 303f Reticuloendothelial system (RES) iron deposition patterns in, 156–157 reactivity, with HIV infection, 248–250, 249t Reticulogenesis, in acute viral hepatitis, 196f Retransplantation, 613 Reye syndrome, 108, 109f Rheumatoid factor, in primary biliary cirrhosis, 410 Rhodamine, 8t Rickettsia rickettsii, 271 Rickettsial infection, 270–271 Q fever, 271 Rocky mountain spotted fever, 271, 271f

Rifampin, hepatotoxicity of, 334t–347t Right hepatic vein, anatomy of, 11 Riluzole, hepatotoxicity of, 334t–347t Risperidone hepatotoxicity of, 334t–347t steatosis associated with, 360f Ritonavir, hepatotoxicity of, 334t–347t Rituximab, for posttransplant immunosuppression, 623t Rocky mountain spotted fever, 271, 271f Rofecoxib, hepatotoxicity of, 334t–347t Rogers cirrhosis, 272, 273f Rosiglitazone, hepatotoxicity of, 334t–347t Rosuvastatin, hepatotoxicity of, 334t–347t Rotor syndrome, 462 Rough endoplasmic reticulum, of hepatocytes, 20, 21f Roussel Uclaf Causality Assessment Method (RUCAM), 328 Roxithromycin, hepatotoxicity of, 334t–347t S “S” allele, alpha-1 antitrypsin deficiency with clinical manifestations and natural history of liver disease in, 134t, 135–136 incidence and demographics of, 134 SAF score, in NAFLD, 178, 178t Salicylate, in Reye syndrome, 108 Salmonella paratyphi, 266 Salmonella typhi, 266 Salmonellosis, 266–267 Sampling error, for grading and staging of chronic hepatitis, limitations of, 238–240 Sanded nuclei, in chronic hepatitis B, 214–215, 216f Sandimmune (cyclosporine), for posttransplant immunosuppression, 622–623 Sanfilippo disease, 114f common findings with, 92t–93t Santa Marta hepatitis, 198 Sarcoidosis, 301–306 chronic cholestasis of, 418, 418f clinical manifestations of, 301–302 differential diagnosis of, 304, 304t, 305f granulomas in, 297 pathology of, 297, 297f incidence and demographics of, 301 loss of intrahepatic bile ducts due to, 437–438 microscopic pathology of, 302–304, 302f–304f radiologic feature of, 302 treatment and prognosis of, 304 Sarcomatoid hepatocellular carcinoma, 537, 537f Satellitosis, in alcoholic liver disease, 377–378, 378f Scar formation, in primary sclerosing cholangitis (PSC), 426f Scheuer system in chronic hepatitis for grading, 235, 236f–237f comparison of, 234t for staging, 236, 240f–242f comparison of, 234t

Index Scheuer system (Continued) for histologic grading of iron deposition, 161 for staging of primary biliary cirrhosis, 415, 416t Schistosoma haematobium, 278 Schistosoma intercalatum, 278 Schistosoma japonicum, 278 Schistosoma mansoni, 278, 280f Schistosomiasis, 278–281 clinical manifestations of, 279 diagnosis of, 279–281 differential diagnoses of, 304t granulomas and, 295, 296f life cycle in relation to liver disease, 279 pathology of, 279, 280f Schwannoma, 597t malignant, 598t Scientific Registry of Transplant Recipients (SRTR), 607 Scirrhous growth pattern, of hepatocellular carcinoma, 533, 534f Sclerosed hemangioma, 583 differential diagnosis of, 587t Sclerosing cholangitis autoimmune clinical manifestations of, 81 microscopic pathology of, 82, 82f causes of, 430b differential diagnosis of, 9, 15f due to Langerhans cell histiocytosis, 83–85, 84f IgG4-related, 429 neonatal, 85 “high-GGT” intrahepatic cholestasis due to, 460 primary. see Primary sclerosing cholangitis (PSC). secondary or acquired, 430 loss of intrahepatic bile ducts due to, 437 Sclerosing hepatocellular carcinoma, 537–538 Searle method, for histologic grading of iron deposition, 162t Secondary sclerosing cholangitis (SSC), 430 causes of, 430b loss of intrahepatic bile ducts due to, 437 primary vs., 429 Segmental anatomy of liver, 22, 22f Semiquantitative scoring, in grading and staging of chronic hepatitis limitations of, 240–241 vs. morphometric analysis, 241–242 Senna, hepatotoxicity of, 334t–347t Sepsis, 266, 266f pathology of, 266 Septal bile ducts, 8–9 in primary sclerosing cholangitis (PSC), 427 direct involvement of, 427, 427f periductal fibrosis in, 427, 427f Septal cirrhosis, incomplete, in chronic hepatitis C, 229, 229f Septal fibrosis, in staging of chronic hepatitis, 234 in Scheuer system, 241f

Septra (trimethoprim/sulfamethoxazole), for posttransplant prophylaxis, 625 Serpin peptidase inhibitor, in alpha-1 antitrypsin deficiency, 133–134 Sertraline, hepatotoxicity of, 334t–347t Serum amyloid protein A, in hepatocellular adenomas, 518–520, 521f–522f Serum glutamic-oxaloacetic transaminase (SGOT), liver tests of, 44 Serum glutamic-pyruvic transaminase (SGPT), liver tests of, 44 Serum-ascites albumin gradient (SAAG), 40 Sevoflurane, hepatotoxicity of, 334t–347t Shiga-like toxin (SLT), in drug metabolism, 323 Sibutramine, hepatotoxicity of, 334t–347t Sickle cell disease, 468b, 473–474, 474f hemochromatosis due to, 155t Siderosis in alcoholic liver disease, 381, 381f hepatic, 152 Siderotic nodules, in hereditary hemochromatosis, 156–157 Silver stain, 8t. see also Reticulin. Simvastatin, hepatotoxicity of, 334t–347t Single-nucleotide polymorphisms (SNPs), 320 Sinusoidal capillarizations, 19, 19f Sinusoidal congestion, differential diagnosis of, 467–468, 468f, 468b Sinusoidal dilation/peliosis, 332t–333t in drug-induced liver injury, 334t–347t Sinusoidal domain, of hepatocytes, 20, 21f Sinusoidal inflammatory cells, 250f Sinusoidal lesions, terminology for, 27–28 Sinusoidal lining cells anatomy of, 16–19 electron microscopy, 14f, 20 in hepatitis, 16, 19f Sinusoidal lymphocytosis, 27, 28f Sinusoidal membrane, 14f, 20, 21f Sinusoidal obstruction syndrome/venoocclusive disease, 332t–333t, 361f, 468b, 472–473, 472f–473f, 472b Sinusoidal T-cell lymphoma, 592t–593t Sinusoid(s), anatomy of, 4, 16–19 capillarizations of, 19, 19f megakaryocytes in, 16, 19f SIOPEL, on hepatoblastoma classification of, 556b staging of, 561, 564f, 564t Sirius red, 8t Sirolimus (Rapamycin) hepatotoxicity of, 334t–347t for posttransplant immunosuppression, 623t, 624 Skin fibroblasts, for genetic and biochemical tests, 94 collection, storage, and shipping of specimens for, 96t Skullcap, hepatotoxicity of, 334t–347t SLC40A1 gene, in hereditary hemochromatosis, 152t Small cell changes in chronic hepatitis B, 216–217, 216f in chronic hepatitis C, 227–228 Small cell dysplasia, 490

Small cell undifferentiated hepatoblastoma (SCUD-HB), 556t, 561f Small hepatocellular carcinoma, 491 nomenclature and comparative features of, 491t Small peripheral portal tracts, primary sclerosing cholangitis (PSC) of, 427 cholate stasis in, 427, 428f copper-associated protein in, 427, 428f early indirect portal changes in, 427, 428f florid ductular reaction in, 427, 428f Small septal/interlobular bile ducts, in primary sclerosing cholangitis (PSC) direct involvement of, 427, 427f periductal fibrosis in, 427, 427f Small-droplet fat, 23, 25f Small-for-size syndrome, 636 S-methylation, 324 Smooth endoplasmic reticulum, of hepatocytes, 20, 21f Smooth muscle antibodies, in primary biliary cirrhosis, 410 Solitary bile duct cyst, 545–546 clinical manifestations of, 545 differential diagnosis of, 546, 546t pathology of, 545, 546f Solitary fibrous tumor, 597t Solute carrier (SLC), hepatic drug transporters of, 323t, 324 Sonography, 55 contrast-enhanced, 55, 56f of focal nodular hyperplasia, 58 of hemangioma, 56f, 57–58 of hepatic fibrosis and cirrhosis, 60–63 of hepatic steatosis, 59–60 Sorafenib, hepatotoxicity of, 334t–347t Southern blotting, collection, storage, and shipping of specimens for, 96t Specimens, for genetic and biochemical tests, 96t Spectroscopy, magnetic resonance, of hepatic steatosis, 60, 64f Spider angiomas, in chronic liver disease, 37, 37f Spider cells, in hepatitis D, 198, 199f Spillover, 23 Spinal fluid, for genetic and biochemical tests, collection, storage, and shipping of specimens for, 96t Spindle cell tumors, vascular, differential diagnosis of, 589t Spironolactone, hepatotoxicity of, 334t–347t Splenomegaly in chronic liver disease, 36 tropical, 275 Split liver graft, 617 Spontaneous bacterial peritonitis (SBP), due to cirrhosis, 40 Spotty necrosis, 22, 23f in acute viral hepatitis, 193, 194f Spur cell anemia, in cirrhosis, 160 Staging, of chronic hepatitis, 233–246 Staphylococcus aureus, sepsis due to, 266 Starvation, NAFLD and, 181 Starzl, Thomas, 606, 606b Stauffer syndrome, 51 Stavudine, hepatotoxicity of, 334t–347t 719

Index Steatohepatitic hepatocellular carcinoma, 537, 537f Steatohepatitis, 332t–333t alcohol, clinical presentation, 34 alcoholic, 372, 376–379, 376f borderline, zone 1, 380 differential diagnosis of, vs. Wilson disease, 130t in drug metabolism, 321, 322f in drug-induced liver injury, 334t–347t Steatonecrosis, alcoholic, 376 Steatosis in alcoholic fatty liver, 375, 375f in chronic hepatitis C, 227f in cystic fibrosis, 145, 145f in donor biopsies, 631–632 in donor liver, 616 with HIV infection, 249t, 251 imaging of, 59–60, 64f in nonalcoholic fatty liver disease, 170–172, 171f–172f simple, 104–105, 105f, 375, 375f Steatotic drug-induced liver injury, 332t–333t Steatotic hepatocellular adenoma, 512, 522 Steatotic pattern in drug-induced liver injury, 357–359 metabolic diseases with, 104–105, 104b, 105f Steatotic tumor cells, in hepatocellular carcinoma, 533f Stellate cells, 22 anatomy of, 19–20, 19f electron microscopy of, 14f, 20–22 Stellate scar, in focal nodular hyperplasia, 516f, 520, 524f Stem cell, features of, in hepatocholangiocarcinoma, 665–666, 668f–669f Steroid-induced glycogenosis, 363f Stones, in primary sclerosing cholangitis (PSC), 425–426, 426f Straight-chain acyl-CoA oxidase deficiency, 119 Streptozotocin, hepatotoxicity of, 334t–347t Stricture dominant vs. primary sclerosing cholangitis (PSC), 429 posttransplant biliary, anastomotic, 621 Stromal invasion, in premalignant and early malignant hepatocellular lesions, 495–497, 498f Stromal tumors gastrointestinal, 598t pediatric hepatic, 564, 566f Strongyloidiasis, 277–278 clinical manifestations of, 278 diagnosis of, 278 life cycle in relation to liver disease, 278 pathology of, 278, 278f Subacute liver failure, 33, 35 etiology of, 35, 35b Subcapsular parenchyma in, 8, 12f Sublobular veins, anatomy of, 11–12, 16f Submassive necrosis, in acute viral hepatitis, 193–194, 197f Substance abuse, liver transplantation and, 612–613 720

Succinylacetone, in hereditary tyrosinemia, 120 Suicide inhibitors, 320 Sulfadiazine, hepatotoxicity of, 334t–347t Sulfadimethoxine, hepatotoxicity of, 334t–347t Sulfadoxine-pyrimethamine, hepatotoxicity of, 334t–347t Sulfamethizole, hepatotoxicity of, 334t–347t Sulfamethoxazole, hepatotoxicity of, 334t–347t Sulfasalazine, hepatotoxicity of, 334t–347t Sulfonamides (class), hepatotoxicity of, 334t–347t Sulfonation, in drug metabolism, 323 Sulindac, hepatotoxicity of, 334t–347t Suloctidil, hepatotoxicity of, 334t–347t Sulpiride, hepatotoxicity of, 334t–347t SULT1, in drug metabolism, 323t Suppurative granulomas, 291 Suppurative necrosis, in epithelioid granulomas, 290–291 Surgical hepatitis, 23, 25f Sustained virologic response (SVR), in hepatitis C, 224 Swollen hepatocytes, in acute viral hepatitis, 193, 194f Synonymous single nucleotide polymorphisms, 320 Syo-saiko-to, hepatotoxicity of, 334t–347t Syphilis, 268, 269f Syphilitic gumma, 268 Systemic diseases, liver tests in, 49–52, 50b Systemic mastocytosis, 595 Systemic mycoses, granulomas and, 294 T Tacrine, hepatotoxicity of, 334t–347t Tacrolimus (Prograf) hepatotoxicity of, 334t–347t for posttransplant immunosuppression, 623–624, 623t Tamoxifen, hepatotoxicity of, 334t–347t Tandem mass spectrometry (MS/MS), 96–97 Tannic acid, hepatotoxicity of, 334t–347t T-cell lymphoma, hepatosplenic (sinusoidal), 592t–593t, 594–595 clinical manifestations of, 594 differential diagnosis, 595 incidence and demographics of, 594–595 microscopic pathology of, 594–595, 595f treatment and prognosis for, 595 T-cell-rich B-cell lymphoma, 592t–593t Telangiectasia, hereditary hemorrhagic, differential diagnosis of, 585t Telangiectatic features, hepatocellular adenoma, 508 Telangiectatic focal nodular hyperplasia, 518–520 Telomerase reverse transcriptase (TERT), mutations of, 497 Temozolomide, hepatotoxicity of, 334t–347t Temporal eligibility, 365–366 Teratoid features, mixed epithelial and mesenchymal hepatoblastoma, 560, 562f Terbinafine, hepatotoxicity of, 334t–347t

Terfenadine, hepatotoxicity of, 334t–347t Testicular atrophy, in chronic liver disease, 38 Testosterone, hepatotoxicity of, 334t–347t Tetracycline, hepatotoxicity of, 334t–347t Thalidomide, hepatotoxicity of, 334t–347t Thiabendazole, hepatotoxicity of, 334t–347t Thioguanine, hepatotoxicity of, 334t–347t Thiopurine S-methyltransferase (TPMT), in drug metabolism, 323t, 324 Thioridazine, hepatotoxicity of, 334t–347t Thiotepa, hepatotoxicity of, 334t–347t Thorotrast hepatic angiosarcoma due to, 364f hepatotoxicity of, 334t–347t pigment, 332t–333t Ticarcillin-Clavulanate, hepatotoxicity of, 334t–347t Ticlopidine, hepatotoxicity of, 334t–347t Ticrynafen, hepatotoxicity of, 334t–347t Tight junction protein 2 (TIP2), in familial hypercholanemia, 459 Tight junctions, electron microscopy of, 20, 21f Time of flight (TOF) method, 96 TIMPs. see Tissue inhibitors of metalloproteinases (TIMPs). Tiopronin, hepatotoxicity of, 334t–347t Tissue biopsy specimens, for genetic and biochemical tests, 96t Tissue inhibitors of metalloproteinases (TIMPs), 672 Tissue organization, 3–6 Tocainide, hepatotoxicity of, 334t–347t Tocilizumab, hepatotoxicity of, 334t–347t Tolazamide, hepatotoxicity of, 334t–347t Tolbutamide, hepatotoxicity of, 334t–347t Tolcapone, hepatotoxicity of, 334t–347t Tolmetin, hepatotoxicity of, 334t–347t Toloxatone, hepatotoxicity of, 334t–347t Total iron-binding capacity (TIBC), 47–48 Total parenteral nutrition (TPN) biliary atresia and, 73f hepatotoxicity of, 334t–347t liver tests for, 52 NAFLD and, 181 Toxocara canis, 276, 295 Toxocara cati, 276 Toxocariasis, 276–277, 277f clinical manifestations of, 276 diagnosis of, 277 life cycle in relation to liver disease, 276 pathology of, 276–277 Toxoplasmosis hepatitis, with HIV infection, 254f, 255 TPN. see Total parenteral nutrition (TPN). Trabecular growth pattern, of hepatocellular carcinoma, 533, 534f Transaminases, liver tests of, 44 Transferrin receptor 2 (TFR2) gene, in hereditary hemochromatosis, 152t Transfusion, hemochromatosis due to, 155t Transient elastography, for hepatic fibrosis and cirrhosis, 62–63 Transitional liver cell tumor (TLCT), 570 clinical manifestations of, 570 differential diagnosis of, 570 microscopic pathology of, 570, 571f

Index Transitional liver cell tumor (TLCT) (Continued) radiologic features and gross pathology of, 570 treatment and prognosis of, 570 Transjugular intrahepatic portosystemic shunt (TIPS) for esophageal varices, 39, 41 for hepatopulmonary syndrome, 41 Transmission, of hepatitis B, 211 Tranylcypromine, hepatotoxicity of, 334t–347t Trastuzumab, hepatotoxicity of, 334t–347t Trazodone, hepatotoxicity of, 334t–347t Triangular cord sign, in biliary atresia, 71, 71f Triazolam, hepatotoxicity of, 334t–347t Trichlormethiazide, hepatotoxicity of, 334t–347t Trichrome, 6, 7f, 8t Trifluoperazine, hepatotoxicity of, 334t–347t Trimethoprim, hepatotoxicity of, 334t–347t Trimethoprim-sulfamethoxazole hepatotoxicity of, 334t–347t for posttransplant prophylaxis, 623t, 625 Trimethoprim-sulfamethoxazole-related injury, 357f Tripelennamine, hepatotoxicity of, 334t–347t Troglitazone, hepatotoxicity of, 334t–347t Troleandomycin, hepatotoxicity of, 334t–347t Tropical splenomegaly syndrome, 275 Trovafloxacin, hepatotoxicity of, 334t–347t Tuberculosis, 292–293 diagnosis of, 293 differential diagnoses of, 304t hepatobiliary, 293 with HIV infection, 255 miliary, 293 pathology of, 293 Tuberculous hepatitis, 293 Tumor cells, in hepatocellular carcinoma, 532, 532f–533f Tumors, of bile ducts, 545–554 Type 1 (insulin-dependent) diabetes, liver tests of, 51 Typical subtype, of hepatocholangiocarcinoma, 665–666, 667f Tyrolean cirrhosis, endemic, 130 Tyrosinemia, hereditary, 120 clinical manifestations, 120 diagnosis of, 120 pathology of, 103f, 120, 121f Tyrosinemia I, common findings with, 92t–93t U UGT1A1, in unconjugated hyperbilirubinemia, 461 Ulcerative colitis, with primary sclerosing cholangitis, 424 Ultrarapid metabolizers, 320–321 Ultrasound, portal vein thrombosis and, 476

Ultrasound elastography, 63 contrast-enhanced, 55, 56f of focal nodular hyperplasia, 58 of hemangioma, 56f, 57–58 of hepatic fibrosis and cirrhosis, 60–63 of hepatic steatosis, 59–60 Ultrastructural pathology, of alpha-1 antitrypsin deficiency, 138–139, 138f Umbilical, hernia, due to ascites, 37f, 40 Unconjugated hyperbilirubinemia, 461 “Underfill” theory, 613 Undifferentiated (embryonal) sarcoma, 575, 577f clinical manifestations of, 575 differential diagnosis of, 575 genetics and molecular pathology of, 575 incidence and demographics of, 575 microscopic pathology of, 575 radiologic features and gross pathology of, 575 treatment and prognosis of, 575 Undifferentiated hepatoblastoma, 558–560, 561f Uniform Determination of Death Act (UDDA), 606b, 607 United Network for Organ Sharing (UNOS), 607 University of Wisconsin (UW) solution, for organ preservation, 619 Urea cycle defects, 108–110 clinical manifestations, 109–110 diagnosis of, 110 pathology of, 109–110, 110f Urea cycle disorders, common findings with, 92t–93t Urethane, hepatotoxicity of, 334t–347t Uridine diphosphate glucuronosyltransferase (UDPGT) in drug metabolism, 322–323, 323t in unconjugated hyperbilirubinemia, 453–454, 461 Urine, for genetic and biochemical tests, collection, storage, and shipping of specimens for, 96t Ursodeoxycholic acid (UDCA) for primary biliary cirrhosis, 419 for primary sclerosing cholangitis, 430 for progressive familial intrahepatic cholestasis, 459 Usnic acid, hepatotoxicity of, 334t–347t V Vaccination, for yellow fever, and viscerotropic disease, 204–205 Valcyte (valganciclovir), for posttransplant prophylaxis, 625 Valganciclovir (Valcyte), for posttransplant prophylaxis, 623t, 625 Valproate-associated liver failure, Alpers disease with, 108f Valproic acid hepatotoxicity of, 334t–347t in mitochondriopathy, 107 Vanishing bile duct syndrome, 332t–333t, 433 Variceal bleeding, due to cirrhosis, 38–39, 39f Vascular changes, in sarcoidosis, 303–304

Vascular disorders, of liver, 465–484 amyloidosis, 480–481, 481f Budd-Chiari syndrome, 468–469, 468b, 469f–470f congestive hepatopathy, 468b, 470–471, 471f, 471t Hemolysis, Elevated Liver Enzymes and Low Platelets (HELLP) syndrome, 468b, 475 hepatic artery, disease of, 479, 480f idiopathic noncirrhotic portal hypertension, 477 ischemic hepatitis, 468b, 479–480, 480f nodular regenerative hyperplasia, 479 obliterative portal venopathy, 477–478, 478f portal vein thrombosis, 468b, 475–477, 476f–477f preeclampsia, 468b, 474–475 sickle cell disease, 468b, 473–474, 474f sinusoidal congestion, differential diagnosis of, 467–468, 468f, 468b sinusoidal obstruction syndrome/venoocclusive disease, 468b, 472–473, 472f–473f, 472b Vascular injury, in drug-induced liver injury, 331t Vascular lesions, with HIV infection, 249t, 258–259, 259f bacillary angiomatosis, 258, 259f nodular regenerative hyperplasia, 258–259 peliosis, 258, 259f Vascular septum, anatomy of, 4, 5f, 11 Vascular shunt, differential diagnosis of, 62t Vascular spindle cell tumors, differential diagnosis of, 589t Venlafaxine, hepatotoxicity of, 334t–347t Veno-occlusive disease (VOD), 332t–333t, 361f Verapamil, hepatotoxicity of, 334t–347t Vertical transmission, of hepatitis B, 211 Very long chain acyl-CoA dehydrogenase (VLCAD) deficiency, common findings with, 92t–93t methodologies for, 97 Victoria blue, 8t Vincristine, hepatotoxicity of, 334t–347t Viral hepatitis, 191. see also Hepatitis; acute viral. de novo, 654 differential diagnosis of primary biliary cirrhosis versus, 416–417, 418f vs. Wilson disease, 130t laboratory investigation of, 47–48 Visceral larva migrans, 276–277, 277f clinical manifestations of, 276 diagnosis of, 277 granulomas due to, 295 life cycle in relation to liver disease, 276 pathology of, 276–277 Visceral leishmaniasis (VL), 272–274, 273f in AIDS, 274, 274f diagnosis of, 274 with HIV infection, 249, 251f life cycle in relation to liver disease, 272 pathology of, 272–274

721

Index Viscerotropic disease, vaccination for yellow fever and, 204–205 Vitamin A, hepatotoxicity of, 334t–347t von Meyenburg complexes, 395, 396f, 546–547 clinical manifestations of, 546–547 differential diagnosis of, 547, 553t pathology of, 547, 547f prognosis of, 547 radiologic features of, 547 VPS33B, in arthrogryposis-renal dysfunction cholestasis syndrome, 459 W Warfarin, hepatotoxicity of, 334t–347t Weber-Christian disease, 180 Welch, Stuart, 606b White blood cells, for genetic and biochemical tests, collection, storage, and shipping of specimens for, 96t “Wild-type allele,” 320 Wilson disease (WD), 125–132, 182 ancillary diagnostic studies for, 129, 129f clinical manifestations of, 126, 126t diagnosis of, 126 differential diagnosis of, 129–130, 130t genetics of, 126t, 130 grading and staging of, 129 gross pathology of, 126–127, 127f incidence and demographics of, 125–126 laboratory investigation of, key findings in, 126t

722

Wilson disease (WD) (Continued) microscopic features of, 127–128, 127f apoptotic bodies as, 127–128 copper granules as, 127–128, 128f droplet fat as, 127f glycogenated nuclei as, 128, 128f interface hepatitis as, 127, 127f lipofuscin as, 127 macrovesicular steatosis as, 127, 127f massive hepatic necrosis, 128, 129f mild nonspecific hepatocellular damage as, 127, 127f nuclear variability as, 128, 128f portal inflammation as, 127, 127f pathology of, 126–129, 127b radiologic features of, 126 treatment and prognosis of, 130–131 Wolman disease, 112 X X protein, in hepatitis B, 211–212 Xanthogranuloma, as primary sclerosing cholangitis (PSC), 425–426, 425f Xenobiotics, drug metabolism and, 317–326 Xenylamine, hepatotoxicity of, 334t–347t Ximelagatran, hepatotoxicity of, 334t–347t X-linked adrenal leukodystrophy, common findings with, 92t–93t Y Yamaoka, Yoshio, 606b Yellow fever (YF), acute hepatitis due to, 204–205

Yellow fever (YF), acute hepatitis due to (Continued) diagnosis of, 204 pathology of, 204, 205f vaccination and viscerotropic disease in, 204–205 YMDD mutants, of hepatitis B virus, 212 Yolk sac tumor, 598t Z “Z” allele, alpha-1 antitrypsin deficiency with incidence and demographics of, 134 Zafirlukast, hepatotoxicity of, 334t–347t Zellweger spectrum, common findings with, 92t–93t Zellweger syndrome clinical manifestations of, 120 pathology of, 120, 120f Zenapax (daclizumab), for posttransplant immunosuppression, 625 Zidovudine, hepatotoxicity of, 334t–347t Zimelidine, hepatotoxicity of, 334t–347t Zimmerman, Hyman, 324 Zonal coagulative necrosis, 332t–333t Zonal necrosis, 23, 24f in drug-induced liver injury, 331t, 334t–347t due to acetaminophen, 352f Zones, in parenchymal architecture, 4, 5f, 22 Zonisamide, hepatotoxicity of, 334t–347t Zovirax (acyclovir), for posttransplant prophylaxis, 625 Zoxazolamine, hepatotoxicity of, 334t–347t