Table 1.

Liver biopsy findings suggestive of biliary strictures and differential diagnosis (BANFF[18])

Histopathological features	PSC/BS	Chronic rejection	Primary biliary cirrhosis
Distribution, severity and composition of portal inflammation	Usually patchy to diffuse; mild neutrophilic, eosinophilic, or occasionally mononuclear predominant	Patchy; usually minimal or mild lymphoplasmacytic	Noticeably patchy and variable intensity; predominantly mononuclear; nodular aggregates and granulomas
Presence and type of interface activity	Prominent and defining feature: ductular type with portal and periportal edema	Minimal to absent	Important feature later in disease development: ductular and necroinflammatory-type with copper deposition
Bile duct inflammation and damage	Periductal lamellar edema "fibrous cholangitis"; acute cholangitis; multiple intra-portal ductal profiles	Focal ongoing lymphocytic bile duct damage; inflammation wanes with duct loss	Granulomatous or focally severe lymphocytic cholangitis is diagnostic in proper setting
Biliary epithelial senescence changes and small bile duct loss	Small bile duct loss associated with ductular reaction	Senescence/atrophy/atypia involve a majority of remaining ducts	Small bile duct loss associated with ductular reaction
Perivenular mononuclear inflammation and/or hepatocyte dropout	Absent	Usually present but variable	Variable but generally mild; if present, involves a minority of perivenular regions
Lobular findings and necroinflammatory activity	Disarray unusual; neutrophil clusters; ± cholestasis	Variable; if present, concentrated in perivenular regions	Mild disarray; parenchymal granulomas; periportal copper deposition and cholestasis are late features
Pattern of fibrosis during progression towards cirrhosis	Biliary pattern	Uncommon; if present usually a venocentric pattern; may evolve to biliary pattern	Biliary pattern

PSC: Primary sclerosing cholangitis; BS: Biliary strictures.