Thorotrast-associated cholangiocarcinoma: an epidemiologic and clinicopathologic study.

Six cases of Thorotrast-associated cholangiocarcinoma (TACC) are studied and compared with eight previously reported cases as well as with cases of non-TACC. TACC shares some epidemiologic features both with non-TACC as well as Thorotrast-associated angiosarcoma (TAAS) but appears to occur in younger patients than non-TACC. There is an apparent increased prevalence of both benign and malignant thyroid disease in the current group of patients with TACC; previous epidemiologic studies have not identified this phenomenon. Thorotrast-associated hepatic fibrosis was present in all 14 TACC cases; otherwise, both non-TACC and TACC are clinically and morphologically similar. Bile duct dysplasia and/or transition to adenocarcinoma, which occurred in all the AFIP cases, are seldom described in case reports of either TACC or non-TACC; in the current study they served to validate the intrahepatic origin of the tumors.