A case of bile duct cancer associated with pancreatobiliary maljunction without bile duct dilatation

Abstract

A 71-year-old woman was admitted to our hospital with abdominal pain and jaundice. Abdominal CT revealed an enhancing mass measuring 20 mm in diameter in the middle portion of the common bile duct. MRCP showed stenosis of the middle portion of the bile duct, with a maximal diameter of the distal bile duct of 7 mm. ERCP showed pancreaticobiliary maljunction (PBM) with a long common channel (14 mm) , obstruction in the middle portion of the bile duct and mild stenosis in the right hepatic duct. Peroral transpapillary cholangioscopy revealed a papillary mass in the middle bile duct and reddish and irregular mucosa in the hilar bile duct. Histological examination of biopsies from the two lesions led to the suspicion of adenocarcinoma.
Reflux of pancreatic juice into the biliary tract in PBM is probably the reason for the higher incidence of biliary tract cancer in these patients. Although both gallbladder and bile duct cancers occur in cases of congenital biliary dilatation, most biliary cancers associated with PBM without bile duct dilatation are gallbladder cancers. This is a rare case of PBM without bile duct dilatation associated with two bile duct cancers.