Contrast enhanced CT-scan to diagnose intrahepatic cholangiocarcinoma in patients with cirrhosis

Background & Aims: Contrast enhanced computed tomography (CT-scan) is a standard of care for the radiological diagnosis of hepatocellular carcinoma (HCC) in patients with cirrhosis. This technique, however, is not validated to exclude intrahepatic cholangiocarcinoma (ICC) which may develop in patients with cirrhosis, as well. Methods: To assess the features of contrast CT-scan in the diagnosis of ICC, we reviewed all CT-scan films obtained in cirrhotic patients with a histologically documented ICC, taking in consideration the pattern and dynamics of the arterial, portal venous and delayed phases of contrast uptake. Results: Thirty-two patients had 40 nodules of ICC (22 male; median age 62 years; 13 hepatitis C) that were identified either during surveillance with abdominal ultrasound (21 patients, 66%) or incidentally (11 patients, 34%). ICC was either multifocal or ≥30 mm in 11 of the former and 10 of the latter group (52% vs. 91%, p <0.05). Two nodules (5%) escaped detection by CT-scan, while the remaining 38 showed a heterogeneous contrast enhancement pattern, being the arterial peripheral-rim enhancement present in 19 (50%) cases and a progressive homogeneous contrast uptake in 16 (42%) cases during the three vascular phases, with no relation to tumor size. Importantly, all nodules lacked the radiological hallmark of HCC, the only ICC nodule showing a homogeneous wash-in during the arterial phase followed by a wash-out in the delayed venous phase, however showing a homogeneous wash-in during the portal phase too. Conclusions: ICC in cirrhotic patients displays distinct vascular patterns at CT-scan that allow for differentiation from HCC.