03: Basic Principles of Liver Pathology

Question 1

What are the causes of acute hepatitis?

Answer 1

• Hepatitis viruses (HAV, HBV, HCV, HDV, HEV)
• Other viruses (CMV, HSV)
• Predictable drug hepatitis (more you take, more damage you get: CCl4, acetaminophen)
• Unpredictable drug hepatitis (only some patients have a reaction; INH, aldomet)

Question 2

What is the pathogenesis of viral hepatitis?

Answer 2

1. Expression of viral Ag’s at cell surface recruits CD8 T-cells (lymphocytes)
2. CD8 T-cell’s FAS-ligand binds with FAS on hepatocyte to induce death pathway

Question 3

What is the pathogenesis of drug hepatitis?

Answer 3

1. Idiosyncratic/unpredictable hepatotoxin produces hapten that is covalently bound to hepatocyte surface
2. CD8 T-cell and eosinophil (responds to drugs, allergies, parasites) infiltrate tissue and clear cells

Question 4

What does this slide show?

Answer 4

• Acute hepatitis
  
  • Diffuse inflammation
  • Lobular disarray
  • Hepatocyte ballooning/apoptosis

Question 5

What does this slide show?

Answer 5

• Massive hepatic necrosis (seen in fulminant hepatitis)
  
  • Loss of virtually all hepatocellular parenchyma
  • Periportal progenitor/stem cell activation –> bile ductular structures
  • Gross anatomy:
    
    • Liver 800g (nl = 1500g)
    • Wrinkled capsule due to massive parenchymal loss underneath
    • Submassive necrosis
    • Hemorrhages in necrotic parenchyma

Question 6

What is chronic hepatitis?

Answer 6

Inflammation of liver continuing without improvement for >6mos

Question 7

What is the grading of chronic hepatitis?

Answer 7

• Degree of necroinflammation
• Scored from 0-4:
  
  • 0 = none
  • 1 = minimal
  • 2 = mild
  • 3 = moderate
  • 4 = marked

Question 8

What is the staging of chronic hepatitis?

Answer 8

• Degree of fibrosis/cirrhosis
  
  • Scored from 0-4:
    
    • 0 = none
    • 1 = minimal
    • 2 = mild
    • 3 = moderate
    • 4 = marked (cirrhosis)