Differential diagnosis of biliary stricture
| Histological feature | Biliary stricture | Preservation injury | Acute rejection |
| Portal inflammation | Predominantly neutrophilic | Mild non-specific inflammation | Lymphocytes, plasma cells, and eosinophils (which may predominate when patients are treated with corticosteroid-sparing immunosuppressive regimens) |
| Bile duct epithelium | Relatively normal nucleus-to-cytoplasm ratio | ± | Reactive changes; increased nucleus-to-cytoplasm ratio |
| Perivenular mononuclear inflammation | Absent | Absent | Present |
| Ductular reaction | Usually present | May be prominent if biliary sludge syndrome present | Usually absent |
| Periductal oedema | Usually present | Absent | |
| Neutrophils and bile ducts | Intraepithelial and intraluminal neutrophils may be present in interlobular ducts | Neutrophilic pericholangitis (if severe) | No; duct injury by lymphocytes seen infiltrating biliary epithelium |
| Periportal architectural collapse | Absent | May be present in severe injury | Usually absent |
| Parenchyma | Centrilobular cholestasis in hepatocytes and canaliculi; small clusters of neutrophils in lobules may be seen | Zonal confluent necrosis early. Hepatocellular, swelling, rounding up, centrilobular cholestasis in hepatocytes and canaliculi |