Intrahepatic cholangiocarcinoma: radiologic-pathologic correlation.

Seventeen proved cases of intrahepatic cholangiocarcinoma (ICAC) were reviewed to establish a radiologic-pathologic correlation. The most common appearance of ICAC at computed tomography (CT) is that of a single, homogeneous low-attenuation mass. Multiple low-attenuation lesions were present in four cases. Calcification was depicted by CT in three cases. At angiography, ICAC has a variable appearance with avascular, hypovascular, and hypervascular patterns possible. Portal obstruction was seen in only one case. The most common appearance of ICAC at sonography is that of a homogeneously hyperechoic mass, either single or multiple. In only one case was ICAC hypoechoic. Plain abdominal radiography demonstrated calcification in three patients and evidence of Thorotrast (thorium dioxide) deposition in one. Upper gastrointestinal series demonstrated abnormal gastric folds in two cases, corresponding to gastric invasion by ICAC. There were no characteristic radiographic findings, but the following features may be helpful in differentiating ICAC from other primary intrahepatic tumors, particularly typical hepatocellular carcinoma: a homogeneously echogenic or high-attenuation appearance on images that reflects the uniform nature observed at pathologic examination, the presence of calcification, and the uncommon invasion of portal or hepatic veins. Conversely, the presence of satellite lesions may blur the the distinction between ICAC and metastatic liver disease.