Intrahepatic peripheral cholangiocarcinoma: CT evaluation

Background: The purpose of our study was to evaluate the imaging features a nd patterns of contrast enhancement in peripheral cholangiocarcinomas with computed tomography (CT) and correlate these features with histologic findi ngs when available. Methods: We reviewed the CT scans of 24 patients with 25 peripheral cholang iocarcinomas proved by orthotopic liver transplantation (n = 1), liver rese ction (n = 7), percutaneous needle biopsy (n = 10), and fine needle aspirat ion biopsy (n = 6). Incremental dynamic nonhelical CT was performed in four cases and helical CT in 21 cases. Portal venous phase images were obtained in all 25 cases. Fourteen patients underwent helical CT during arterial an d portal phases. Delayed images were obtained in 20 patients. Results, The size of the tumors ranged from 1.2 to 17 cm. Bile duct dilatat ion was present in 13 patients (52%), and regional lymph node enlargement w as observed in six patients (24%). Retraction of the Liver capsule was pres ent in nine patients (36%). In eight patients (32%), satellite nodules were also detected. All tumors were globally hypodense during the portal phase. In 14 patients (70%), delayed images disclosed hyperattenuating tumors. Ri mlike contrast enhancement was the most frequent pattern observed in either arterial (57% of patients) or portal (60% of patients) phase imaging. Port al venous encasement was seen in 10 patients (40%). Conclusion: In the proper clinical setting, detection elf a hypodense hepat ic lesion with peripheral enhancement, biliary dilatation, and contrast enh ancement on delayed images are highly suggestive of peripheral intrahepatic cholangiocarcinoma.