[Malignant biliary papillomatosis: analysis of p53 expression].

Biliary papillomatosis is a papillary adenomatosis of the biliary mucosa of the extra- and the intrahepatic biliary tree. It is a rare neoplasm difficult to manage, characterized by extensive lesions and a great potential for malignant transformation. We report a case of a 75 year-old man, who presented with malignant papillomatosis of the common bile duct without involvement of the intrahepatic biliary ducts. Duodenopancreatectomy enabled the diagnosis of papillomatosis lined 5.5 cm of the common bile duct which displayed an invasive 1.5 cm papillary carcinoma located in the distal portion of the choledocus. Immunohistochemistry showed strong expression of p53 in the distally located invasive carcinoma and in distant dysplastic lesions. MUC5AC was exclusively detected in both malignant and dysplastic lesions without detection of MUC1 or MUC2. Detection of p53 expression on biliary brush samples could be interesting for the follow-up and the prediction of malignant progression in multifocal biliary papillomatosis.