Periductal infiltrating type of intrahepatic cholangiocarcinoma: a rare macroscopic type without any apparent mass

Abstract

This study was undertaken to elucidate the clinicopathological characteristics and surgical outcome of the periductal infiltrating (PI) type of intrahepatic cholangiocarcinoma (ICC), which is a distinct macroscopic type of ICC arising from the second-order of the intrahepatic bile ducts without apparent invasion of the surrounding liver parenchyma. All patients with the PI type of ICC were identified from a database of patients with intrahepatic cholangiocellular carcinoma that underwent surgical resection between 1983 and 2009. The clinicopathological data of these patients were analyzed retrospectively. Sixteen of 203 patients (7.9%) had the PI type of ICC. The median survival was 7.7 years with 5-year survival rate of 62.1%. The PI type of ICC showed a significantly better survival than the mass-forming (MF) type (P = 0.0293) or MF plus PI type of ICC (P = 0.0001). Microscopic examinations showed intrahepatic metastasis to be absent in all the patients with PI type ICC. The incidence of intrahepatic metastases in patients with PI type was significantly lower in comparison to that of patients with MF type (P = 0.0030) and MF plus PI type (P = 0.0533), respectively. Surgery could therefore provide a favorable outcome in patients with the PI type of ICC, probably due to its lower incidence of intrahepatic metastases.