IMAGING OF INTRAHEPATIC CHOLANGIOCARCINOMA .1. PERIPHERAL CHOLANGIOCARCINOMA

Cholangiocarcinoma is the second most common primary hepatic malignant tumor after hepatocellular carcinoma, accounting for 5-30% of all pri mary hepatic malignant tumors [1]. Intrahepatic cholangiocarcinomas ca n be classified as peripheral cholangiocarcinoma, which originates fro m an interlobular biliary duct, or as hilar cholangiocarcinoma, which originates from a main hepatic duct or from the bifurcation of the com mon hepatic duct. Intrahepatic cholangiocarcinomas account for only ab out half of cholangiocarcinomas, and this pictorial essay focuses only on the peripheral form of the disease. Clinically, therapeutically, a nd radiologically, these two types of cholangiocarcinomas differ. Feat ures suggestive of the diagnosis of peripheral cholangiocarcinoma can be shown by sonography, CT, and MR imaging, Cholangiography and angiog raphy have a limited role in evaluating this neoplasm that manifests a s a focal mass. This essay reviews the appearances of peripheral chola ngiocarcinoma and discusses the various imaging techniques that can be used to evaluate this unusual tumor that is often resectable and pote ntially curable.