The CT Findings of Mass-forming Type Intrahepatic Cholangiocarcinoma without Peripheral Bile Duct Dilatation

Objective: To investigate CT findings and pathological features of the mass-forming type(MF type) intrahepatic cholangiocarcinoma(ICC) without peripheral bile duct dilatation. Methods: This study involved 22 patients with ICC diagnosed by pathological data. All CT data were retrospectively analyzed and no peripheral bile duct dilatation found on CT imagings. Results: 22 cases were adenocarcima, 3 cases was mixed cholangiocarcinoma and hepatocellular carcinoma. 16 cases were well or medium differentiated staging on pathology. The macroscopic type of 22 cases were MF type, which had general features of MF type cholangiocarcinoma, such as: irregular mass 14 cases(with shallow lobulated edge), like-round mass 8 cases; a large number of fibers or mucus in the center of the lesion(15case were with a large number of fibers, 3 case were with a large number of mucus); calcification(3/22); the capsular retraction sign(10/22); 19 cases with delayed enhancement feature. However, there were some features different from the typical mass forming cholangiocarcinoma, included no peripheral bile duct dilatation, there were no relative satellite lesions and lymph metastasis. Conclusion: The ICC without peripheral bile duct dilatation mostly was well or medium differentiated carcinoma and showed MF type features without feature of peripheral bile duct dilatation on MR imagines, easily misdiagnosed as atypical hepatocellular carcinoma or infectious disease.