Mass Forming Intrahepatic Cholangiocarcinoma- An Imaging Mimicker Of Hepato-Cellular Carcinoma And Abscess

Cholangiocarcinoma (CCA) is the second most common primary malignancy of liver. Intrahepatic mass-forming (IMCC) is one of the three patterns of cholangio carcinoma. On imaging IMCC usually presents as irregularly outlined homogenous mass with low attenuation and minimal peripheral enhancement, mild intrahepatic biliary dilatation (IHBD). Sometimes, biliary dilatation, capsular retraction and satellite nodules are other features helping in diagnosis of IMCC. Out of 56 cases we evaluated for liver neoplasms on MDCT, the most common lesions encountered are Hepatocellular carcinoma (n=47, 83.9%) followed by Cholangiocarcinoma. All the 5 cases of IMCC are larger tumors with homogenously hypodense on NECT. On contrast there was rim enhancement in most of these cases. One case had delayed wash out mimicking HCC. Capsular retraction indicated the diagnosis of IMCC. The 5TH case was confused with abscess but absence of double rim sign indicated alternate diagnosis. Hence absence of double rim and washout in delayed images differentiate IMCC from liver abscess and HCC.