1. Most likely diagnosis and contributing factors

• Persistent chronic HBV infection with ongoing immune-mediated hepatocyte injury and fibrosis.
• Alcohol intake, which aggravates hepatocyte injury and promotes fibrosis/steatosis.
• Long duration of disease, 15 years.
• Possible active viral replication, which increases likelihood of progression to cirrhosis.

2. How chronic HBV causes cirrhosis and portal hypertension

1. HBV infects hepatocytes, but much of the liver damage is not directly caused by the virus. It is mainly due to the host immune response.
2. Cytotoxic CD8+ T lymphocytes recognize HBV antigens on infected hepatocytes and destroy them by apoptosis and necrosis. Repeated episodes produce chronic hepatitis.
3. Persistent hepatocyte injury causes inflammation in portal tracts and at the limiting plate, called interface hepatitis. Severe continuing injury can cause bridging necrosis between portal tracts and central veins.
4. Cytokines released during chronic inflammation, especially TGF-beta, activate hepatic stellate cells in the space of Disse. These cells transform into myofibroblasts and deposit collagen, producing progressive fibrosis.
5. Fibrous septa bridge portal tracts and central veins. Surviving hepatocytes proliferate and form regenerative nodules. Thus, cirrhosis consists of diffuse fibrosis, regenerative nodules, and architectural distortion.
6. Fibrous septa and nodules compress/distort hepatic sinusoids and branches of portal veins, causing increased resistance to portal blood flow. This produces portal hypertension.
7. Portal hypertension leads to:
   • Splenomegaly and hypersplenism
   • Ascites
   • Portosystemic collateral formation, such as esophageal varices
   • Caput medusae and hemorrhoids in advanced disease

3. Microscopic findings

• Distortion of normal lobular architecture due to diffuse fibrosis.
• Broad fibrous septa bridging portal tract to portal tract and portal tract to central vein.
• Regenerative hepatocyte nodules surrounded by fibrous bands. Nodules lack normal lobular organization.
• Chronic inflammatory infiltrate, mainly lymphocytes, in portal tracts.
• Interface hepatitis: lymphocytic destruction of hepatocytes at the limiting plate.
• Variable hepatocyte necrosis/apoptosis, including spotty or bridging necrosis.
• In HBV infection, hepatocytes may show ground-glass cytoplasm because of accumulation of hepatitis B surface antigen, HBsAg.
• If alcohol is an important additional factor: steatosis, ballooning degeneration, neutrophilic inflammation, and sometimes Mallory-Denk bodies may also be found.