[Pathomorphological study of thorotrast-related intrahepatic cholangiocarcinoma--a comparison with non-thorotrast cases].

Thirty-five autopsy cases of Thorotrast (TH)-related intrahepatic cholangiocarcinoma were morphologically studied with a comparison to 45 non-TH cases. Latent periods ranged from 25 to 48 years, with a mean of 34.1 +/- 6.6 years. As to tumor location, the peripheral-middle type, in which the main tumor was located in the periphery to middle portion of the liver, was the most common (89.2%) in the TH-related cases, and the hilar type, in which the main tumor was located in the hepatic hilum, was the most common (78.8%) in the non-TH cases. However, there was no close relationship between the distribution of TH deposits and tumor location by soft-X ray examination of the liver slices. Grossly, the massive type with an infiltrative growth was the most common both in the TH- and non-TH cases. Histologically, there were no remarkable differences between the two groups, and tubular adenocarcinoma with varying degrees of fibrous stroma was the most common. In noncancerous areas, proliferation of the bile ducts with slight to moderate atypism and ductular proliferation around Glisson's capsule were found in 30%, and 10%, respectively, of the TH-related cases. However, such changes were also found in the non-TH cases at almost the same incidence.