Biliary mucinous cystic neoplasm: a case report and review of the literature.

Hepatobiliary cystadenomas (HBC) is a rare neoplasm which comprising less than one percent of liver cystic neoplasms. Although it's known as a benign tumor, but they have a potential for neoplastic transformation. Making a proper diagnosis and ruling out of other differential diagnosis is important because of different treatment. In the present study, we described a case of HBC manifested as idiopathic dominant biliary stricture in common hepatic duct (CHD), on the basis of spiral CT scan and MRI, and elevated CA19-9. With a probable diagnosis of malignant biliary stricture, she underwent ERCP and cholangioscopy that were non-diagnostic and final diagnosis was made surgically. HBCs usually found incicentally as a cystic lesion and biliary stricture without visible cyst in imaging like that seen in cholangiocarcinoma is very unlikely. In truth, this patient is an unusual manifestation of one rare disease.