Comparison of the Clinicopathological Features in Small Bile Duct and Bile Ductular Type Intrahepatic Cholangiocarcinoma

Background: The classification of intrahepatic cholangiocarcinomas (ICCs) has been reported in several studies, however, it remains controversial. Materials and Methods: Between January 2003 and December 2015, 94 patients underwent hepatectomy for ICC. The ICCs of 63 of these patients were classified as predominantly small bile duct type or bile ductular type ICC and were included in this analysis. Results: Thirty-seven patients (58.7%) were classified into the small bile duct ICC group, and 26 (41.3%) into the bile ductular ICC group. A multivariate analysis identified intrahepatic metastasis [hazard ratio (HR)=2.53, p=0.011], small bile duct ICC (HR=2.05, p=0.046) and portal vein invasion (HR 2.05, p=0.047) as independent prognostic factors for poorer survival. Conclusion: It is important to correctly distinguish between small bile duct and bile ductular ICC types because these two types clearly have different clinicopathological and prognostic features.