This study is intended to investigate the clinicopathological features of the intraductal papillary neoplasms of the intrahepatic bile duct (IPNB), especially focused on malignant changes.

From the institutional database of liver resection cases (Asan Medical Center, University of Ulsan College of Medicine), 18 patients who met the definition of IPNB were selected. They had undergone liver resection between February 2002 and October 2006; thus, the follow-up period was more than 5 years.

Of the 18 patients, 11 patients were male. Their mean age was 61.3±6.7 years. There were no differences between the non-malignant and malignant lesions, in the comparison of the CEA levels (5.6±2.7 vs.12.6±31.1 ng/ml, p=0.439) and the CA19-9 levels (29.2±34.7 vs.31.9±30.2 ng/ml, p=0.871). The common radiologic findings were: intraductal growing mass in 10; bile duct dilatation in 6; and saccular duct dilatation in 2. Left and right hepatectomies were performed in 15 and 3, respectively. Five patients showed benign lesions of IPNB, and 13 patients revealed malignant lesions of intraductal papillary adnocarcinoma or cholangiocarcinoma. All 4 patients with benign lesions survived for a mean period of 53 months without recurrence. In 13 patients with the malignant lesions, 1-year, 3-year, and 5-year survival rates were 100%, 84.6%, and 59.2%, respectively.

We concluded that intrahepatic IPNB is a rare type of biliary neoplasm which includes a histological spectrum, ranging from benign disease to invasive malignancy. The long-term survival was anticipated after complete curative resection.