Surgical pathology of the syndrome of primary sclerosing cholangitis.

The diagnosis of primary sclerosing cholangitis (PSC) is based on the characteristic cholangiographic manifestations of the condition. Surgical biopsy specimens from extrahepatic bile ducts are not diagnostic. They should be obtained only if the presence of bile duct carcinoma must be ruled out. If liver transplantation is anticipated, even that procedure may be contraindicated. Gallbladder disease in PSC is common but again, histologic findings are not diagnostic. Intrahepatic cholangiectases in combination with bile duct obliteration are characteristic for PSC, but tissue samples with these lesions usually are unavailable during work-up of patients. Histologic changes in routine needle or wedge biopsy specimens from the liver may strongly support the diagnosis of PSC. The most important histologic abnormality is the absence of interlobular bile ducts in some portal tracts (ductopenia), which often coexists with evidence of ductal proliferation in other portal tracts. Portal edema and ductular proliferation frequently accompany these changes. Liver biopsy study in PSC is recommended not only for diagnostic purposes but also because the procedure allows staging of the liver disease and thus helps to determine the prognosis of patients, contributes to the decision-making process for liver transplantation, and facilitates therapeutic trials.