The diagnosis of cystadenoma is rare, even more so when located in the extrahepatic bile duct.Unspeciflc clinical signs may lead this pathology to be misdiagnosed.The need for pathological anatomy in order to distinguish cystadenomas from simple biliary cysts is crucial.The most usual treatment nowadays is resection of the bile duct, together with cholecystectomy and Roux-en-Y reconstruction. The diagnosis of cystadenoma is rare, even more so when located in the extrahepatic bile duct. Unpeciflc clinical signs may lead this pathology to be misdiagnosed. Need for pathological anatomy in order to distinguish cystadenomas from simple biliary cysts is crucial. The most usual treatment nowadays is resection of the bile duct, together with cholecystectomy and Roux-en-Y reconstruction.