Diagnosis of primary sclerosing cholangitis.

Primary sclerosing cholangitis is a progressive chronic hepatobiliary disorder of unknown aetiology for which no effective medical therapy currently exists. This syndrome occurs most commonly in young men and is frequently associated with ulcerative colitis. Primary sclerosing cholangitis should be considered in the differential diagnosis of all patients presenting with chronic cholestasis. The diagnosis is based on a combination of the clinical features and cholestatic biochemical profile accompanied by typical cholangiographic abnormalities and is supported by liver histology findings. The major diagnostic criterion is the finding at cholangiography of irregularly distributed multifocal strictures within both the intrahepatic and extrahepatic bile ducts. The most characteristic histological feature of primary sclerosing cholangitis is periductal concentric obliterative fibrosis of small interlobular bile ducts with or without proliferation of bile ducts in portal tracts, but liver biopsy findings alone are infrequently diagnostic. Nevertheless, liver histology remains important to exclude other causes of chronic cholestasis and in staging the disease.