The spectrum of bile duct lesions in end-stage primary sclerosing cholangitis.

Tissue from 15 livers with primary sclerosing cholangitis, obtained at transplantation, was examined histologically with respect to: small and medium sized bile duct lesions; large bile duct lesions; fibrosis/cirrhosis; and parenchymal changes. Lesions affecting small and medium-sized bile ducts were quantified by determining the percentage of 20 portal tracts involved. The two characteristic bile duct lesions of primary sclerosing cholangitis, periductal fibrosis and fibro-obliterative scars, were largely confined to medium-sized portal areas. Although present in each case, the number of such lesions varied considerably. Loss of bile ducts was the most conspicuous feature in small portal tracts where the diagnostic duct lesions of primary sclerosing cholangitis were rarely observed. Inflammation, ulceration and cholangiectases of large intrahepatic ducts were common, and appear to be useful additional diagnostic features.