A special growth manner of intrahepatic biliary cystadenoma.

We report a case of a 56-year-old woman with intrahepatic biliary cystadenoma (IBC) accompanying a tumor embolus in the extrahepatic bile duct, who was admitted to our department on October 13, 2008. Imaging showed an asymmetry dilation of the biliary tree, different bile signals in the biliary tree, a multiloculated lesion and an extrahepatic bile duct lesion with internal septation. A regular left hemihepatectomy en bloc was performed with resection of the entire tumor, during which a tumor embolus protruding into the extrahepatic bile duct and originating from biliary duct of segment 4 was revealed. Microscopically, the multiloculated tumor was confirmed to be a biliary cystadenoma with an epithelial lining composed of biliary-type cuboidal cells and surrounded by an ovarian-like stroma. An aggressive en bloc resection was recommended for the multiloculated lesion. Imaging workup, clinicians and surgeons need to be aware of this different presentation.