CT appearance of Thorotrast-related and non-Thorotrast-related peripheral cholangiocarcinoma

To assess the differences in CT findings among patients with peripheral cholangiocarcinoma with and without a history of Thorotrast administration, CT studies from 13 Thorotrast patients and eight non-Thorotrast patients were reviewed. Diagnostic and prognostic differences were evaluated between the two groups. Despite periodic imaging surveillance, eight of the 13 (62%) lesions discovered by CT were larger than 6 cm. The prognosis for Thorotrast patients was unfavorable due to difficulties in early detection and complications from associated hepatic fibrosis. The main problem with early detection was that a background of uneven Thorotrast deposits visualized in the liver disguised the tumor as Thorotrast granulations. Although non-Thorotrast patients were not monitored regularly, they had a better chance of undergoing curative resection for the following three reasons: 1) it was easy to detect the tumor (detection rate, 100%); 2) this group rarely had associated liver cirrhosis in noncancerous areas, and 3) non-Thorotrast patients were younger than Thorotrast patients. Early detection of cancer by CA19-9 assay and imaging in asymptomatic subjects without any history of liver disease could be important steps toward the early and radical resection of cancer to achieve a better prognosis. (author)