Poorly Differentiated Gastric Adenocarcinoma Can Mimic Hilar Cholangiocarcinoma

This report describes two cases with obstructive jaundice caused by poorly differentiated gastric adenocarcinoma. Computed tomography scans showed circumferential stenosis in the hilar bile ducts. Endoscopic retrograde cholangiopancreatography showed dilatation of the bilateral hepatic ducts and stenosis of the common hepatic ducts from the bifurcation of the bilateral hepatic ducts. The first diagnoses were hilar cholangiocarcinoma and biliary drainage decreased serum bilirubin; however, both patients died of cancer within a short period of time. Autopsies revealed lymphatic vessel invasion and possible subepithelial invasion by gastric adenocarcinoma into the hilar bile ducts. A differential diagnosis should thus be required in suspected cases of hilar cholangiocarcinoma.