Table 1

Histological staging of PBC on liver biopsy (after Scheuer9)

Stage Key histological features
I: The florid duct lesionExpansion of some, but often not all, portal tracts around septal and interlobular bile ducts by aggregates of lymhocytes and  plasma cells. Formation of often poorly defined granulomas within or close to affected tracts
Irregularities or rupture of biliary epithelium, often with relative preservation of remaining portal architecture
Histological evidence of cholestasis usually absent
II: Ductular proliferationChanges in all portal tracts. Expansion of portal tracts by immature connective tissue, mononuclear and neutrophil aggregates  and, to a lesser extent than in stage I, by lymphocyte aggregates
Bile ducts scanty with proliferation of biliary ductules. Occasional biliary plugging
Mild piecemeal necrosis at limiting plate
III: Septal stageInflammation less severe, although the sites of bile ducts may be marked by lymphocyte collections
Formation of dense fibrous tissue extending from portal tracts, but the absence of regeneration nodules
Cholestasis frequent
IV: CirrhosisFormation of regenrative nodules and a “true” cirrhosis
Gross reduction in number of bile ducts