Intraductal papillary neoplasm of the bile duct extending superficially from the intrahepatic to extrahepatic bile duct

Abstract

Intraductal papillary neoplasm of the bile duct (IPNB) or liver is a recently noted rare disease, and its pathogenesis remains unclear. Here we present a case of IPNB with an interesting morphology, which was treated by resection of the right hemiliver and extrahepatic bile duct. A 79-year-old woman was found to have a high alkaline phosphatase level and slight dilatation of the right intrahepatic bile duct on imaging studies. The right intrahepatic bile duct became dilated over a 2-year period; however, no solid mass could be detected, and tumor markers were not elevated. Hepatic resection was scheduled because a mucin-producing bile duct carcinoma of the liver was suspected. A right hemihepatectomy was conducted, and the extrahepatic bile duct was also resected after malignant cells were found in the surgical stump of the right bile duct and in the bile itself. Macroscopically, diffuse dilatation of the intrahepatic bile duct was noted, but no solid component or mucin within the duct was found. Histopathological findings revealed carcinoma in situ, IPNB, in the majority of intrahepatic bile ducts, with no lymph node metastasis, and it extended continuously to the epithelium of the common bile duct. No tumor recurrence or biliary dilatation was observed at follow-up 2 years after surgery. It is important to consider malignancy in the presence of a dilated bile duct and in the absence of any cause of occlusion. Complete resection of IPNB results in a good prognosis and no recurrence.

Clinicopathological Aspects and Diagnostic Problems in Patients with Intraductal Papillary Neoplasm of the Bile Duct

“…Both IPNB and PAC exhibited morphology of papillary growth, and one case of IPNB had specific characteristics, which we previously reported as a case report (24), in which no mass components were found, but only diffuse dilatation of the bile duct in evenly resected specimens. In this case, histological examination showed that the low papillary structure of adenoma was dominant and glandular cells of carcinoma in situ were partially observed.…”

“…However, consistency of histological definition has not been observed, and the controversy of diagnosis is still referred to by clinical physicians and pathologists (11,21,23) Therefore, the clinical aspect of preoperative histological diagnosis and surgical indication has not yet been fully clarified. Our previous reports identified the various tumor morphologies of IPNB, good prognosis, and difficulty in comparison with similar biliary tumors (19,(24)(25)(26). The significance of protruding bile duct carcinoma accompanied by widely superficial extension was also reported as characteristics in common with IPNB (27).…”

“…In the IPNB group, asymptomatic patients with mild liver dysfunction tended to be predominant because biliary obstruction is rare at this stage. To find IPNB or early-stage biliary carcinomas, it is important to find by imaging examination those patients who have chronic hepato-biliary dysfunction, and we also previously emphasized the importance of an increased level of alkaline phosphatase (24,31). One woman with IPNB had worked in the printing industry for many years, and she had metachronous triple cancer.…”

Intraductal papillary growth of liver metastasis originating from colon carcinoma in the bile duct: Report of a case

“…We have previously treated cases of IPNB similar to the present case, and several of these cases showed in situ carcinomas with or without adenoma that superficially extended along the biliary epithelium. 13,14 Compared with the usual histological findings of cholangiocarcinoma, the histological characteristics of IPNB were papillary growth different from the common cholangiocarcinoma, with deep ductal infiltration. Only HE staining cannot show the differential diagnosis between this type of cholangiocarcinoma and liver metastasis.…”

A Case of Intraductal Papillary Neoplasm of the Bile Duct with Stromal Invasion

“…We have experienced 7 patients of IPNB including the present case [16]; 4 presented abdominal pain or discomfort due to biliary obstruction. However, another 3 patients had onset of liver dysfunction.…”