Clinicopathological Features and Long-Term Outcomes of Intraductal Papillary Neoplasms of the Intrahepatic Bile Duct.

We intended to investigate the clinicopathological features of intrahepatic intraductal papillary neoplasms of the bile duct (IPNB), especially their malignant features and post-resection prognosis. Forty-three patients who met the definition of IPNB and who underwent liver resection between January 2002 and June 2015 were selected from our institutional database of liver resection cases. The mean age was 63.3 ± 6.9 years and 24 were male. Hepatolithiasis was present in addition in 10 of the patients. Left- and right-sided hepatectomies and concurrent bile duct resection (BDR) were performed in 28, 15, and 10 patients, respectively; R0 resection was performed in 37 patients. The mean tumor diameter was 4.1 ± 2.2 cm. Histological tumor grade was low in 4 cases, intermediate in 6, and malignant in 33. There was no cancer-related recurrence or death in the 10 patients with low-grade or intermediate lesions. In the 33 patients with malignant lesions, rates of tumor recurrence and overall survival were 12.5 and 96.2 % at 1 year, 36.4 and 91.3 % at 3 years, and 47.0 and 68.8 % at 5 years, respectively. Multivariate analysis showed that R1 resection was the only prognostic factor for tumor recurrence and patient survival. BDR was performed in only 2 of 6 patients undergoing R1 resection. Intrahepatic IPNB is a rare type of biliary neoplasm that encompasses a histological spectrum ranging from benign disease to invasive malignancy. Long-term survival was anticipated after curative resection. R1 resection reduced survival outcomes; therefore, we suggest that concurrent BDR should be performed if the resection margin of the bile duct is not reliably free of neoplastic involvement.