Pol. Lt. Col. Akkaraphorn Deeprasertvit, M.D., FRCST

Isolated Extrahepatic Intraductal Papillary Neoplasm of the Bile Duct: A Rare Type of Bile Duct Tumour

Intraductal papillary neoplasm of the bile duct (IPNB) is a relatively raretype of bile duct tumor. The neoplasm features an intraductal papillary growth of neoplastic biliary epithelia with a fibrovascular stalk.1Its nomenclature was given regarding the tumor characters, for example, biliary papillomatosis2, mucin-secreting bile duct adenoma3, mucin-producing bile duct tumor4, or mucin-producing cholangiocarcinoma.5,6 Term “intraductal papillary neoplasm of the bile duct” is a recent terminology.7 According to the latest classification of bile duct tumors, benign IPNB is classified as a pre-malignant lesion of intraductal-growth and papillary type of cholangiocarcinoma.8The development of IPNB follows an adenoma-carcinoma sequence that correlates with the stepwise activation of common oncogenic pathways.9 IPNB usually progresses slowly bearing a better prognosis compared to the conventional cholangiocarcinoma.