Peripheral cholangiocarcinoma with extensive tumor thrombi in the portal venous system: case report.

Peripheral cholangiocarcinoma is a primary liver tumor, with some features that distinguish it from hepatocellular carcinoma, especially the low incidence of vascular involvement relative to mass size. Radiologically, tumor thrombus seen as an expanding central filling defect is a rare finding of cholangiocarcinoma on computed tomography, even though microscopic invasion or vascular encasement has been reported in a few studies. We report a case of a peripheral cholangiocarcinoma with tumor thrombus expanding and spreading from the portal vein to the superior mesenteric vein.