Intrahepatic peripheral cholangiocarcinoma: CT features in 18 pathologically proven cases

To determine the morphological features of 18 pathologically proven intrahepatic peripheral cholangiocarcinoma (IHPCC) cases in computerized tomography (CT) image. All 18 patients had CT, using Picker I.Q.T/C and taking pre-contrast continuous 10-mm sections throughout the liver and post-contrast continuous 10-mm sections throughout the focuses. The disease was characterized in CT image by the following: all focuses were found in the periphery of the liver and shown as a lobulated or fused hypodense space-occupying mass; there were one or more divergent or confluent, circular or irregular cystic areas with much lower density, in the majority. All focuses could be enhanced slightly and most revealed a dim edge. Dilated bile ducts around the focus were found frequently; the dilated bile ducts especially seemed to encircle the focus (33.3%, 6/18). This phenomenon were referred to as "encysted sign of dilated bile ducts". CT scanning should be one of the most important investigative methods for IHPCC due to the disease characteristics identified in CT image, especially "encysted sign of dilated bile ducts" which possesses specificity in diagnosing the disease.