EXTRAHEPATIC BILIARY CYSTADENOCARCINOMA ARISING FROM THE LEFT HEPATICDUCT

A 54-year-old man, who had no clinical symptoms, underwent a routine h ealth checkup at our hospital. Abdominal ultrasonography disclosed a w ell demarcated tumor containing a solid portion occupying the dilated left hepatic duct and a cystic portion expanding into the parenchyma o f the left hepatic lobe, with mild dilatation of the intrahepatic bile ducts. These findings were later confirmed by computed tomography (GT ) and magnetic resonance imaging. Endoscopic retrograde cholangiograph y revealed a complete defect at the level of the left hepatic duct, wh ile drip infusion cholangiographic-CT (DIC-GT) disclosed a defect of t he left hepatic duct only, with the distal portions of the left intrah epatic ducts being visualized on the image. Hepatic angiography reveal ed light stains in the solid portion in the parenchymal phase. At left lobectomy, a multiloculated polyp-like tumor was found arising from t he left hepatic duct and expanding into the parenchyma of the left hep atic lobe. Microscopically, all the lining cells in the cysts and the tumor cells in the solid portion showed the features of papillary aden ocarcinoma. In this patient with extrahepatic biliary cystadenocarcino ma, DIG-CT was useful in identifying the site of origin of the tumor, and hepatic angiography was also useful in differentiating this rare m alignant tumor from benign cystadenoma.