[Intraductal papillary neoplasms of the bile duct (IPNB). Diagnostic criteria, carcinogenesis and differential diagnostics].

Intraductal papillary neoplasms of the bile duct (IPNB) are rare precursor lesions of intrahepatic and extrahepatic cholangiocarcinoma that follow an adenoma-carcinoma sequence. According to the histomorphology and the distinct immunohistochemical mucin pattern, four different subtypes are recognized: pancreatobiliary, intestinal, gastric and oncocytic. Differential diagnoses include micropapillary lesions (biliary intraepithelial neoplasms), papillary cystic lesions (intraductal tubulopapillary neoplasms) and cystic lesions (mucinous cystic neoplasms).