Intraductal papillary neoplasm of the bile ducts: A case report and literature review.

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare bile duct neoplasm mostly found in far eastern nations where hepatolithiasis and clonorchiasis infections are endemic. In western countries, it is very rare and the etiology is unknown. In this article, we report the first IPNB patient we encountered in our clinic and a literature review. The patient is a 38-year-old female with a history of choledocholithiasis who presented with obstructive jaundice. She was found to have a papillary mass at the junction of the right hepatic duct and common hepatic duct with six masses in the liver parenchyma. The immunophenotypic and histologic features of the tumor are consistent with IPNB, gastric subtype. The patient had a partial hepatectomy and has been receiving palliative chemotherapy. In a search of PubMed database, we collected 354 IPNB patients reported in 22 articles. In these patients, 52.8% were from Japan and 27.7% were from western countries including the United States (11.0%). The age of the patients ranged from 35 to 80 years old with an average of 64.6. Male/female ratio was 1.5. Macroscopically, 57.5% of the tumors were in the left lobe and 29.5% were in the right lobe. The average size of the tumor were 4.2 cm at the time of diagnosis. Histologically, pancreato-biliary subtype accounted for 41.8%, intestinal 28.0%, gastric 13.5% and oncocytic 16%. An invasive component is most often present in the pancreato-biliary and gastric subtypes. Despite recent advanced technologies, diagnosis of IPNB is still challenging, especially in western countries due to its rarity. Defined clinico-pathologic features are in demand for the accurate diagnosis and proper treatment.