Primary sclerosing cholangitis in which differential diagnosis from gallbladder carcinoma was difficult

We report a case of localized primary sclerosing cholangitis (PSC) which was difficult to distinguish from gallbladder carcinoma. A 75-year-old woman with elevated serum bilirubin was hospitalized and underwent endoscopic nasobiliary drainage (ENBD). There was no history of diseases such as gallbladder stone, pancreatitis, or ulcerative colitis. Cholangiography through the ENBD tube showed localized stenosis of the common bile duct; the gallbladder could not be seen. Angiography showed no encasement of the hepatic artery. Ultrasonography showed a tumor in the cystic duct, and the tumor had invaded the gallbladder and common bile duct. We diagnosed gallbladder carcinoma on radioimaging, and performed an S4aS5 subsegmentectomy of the liver and resection of the extrahepatic biliary tree. Pathologically, no malignant cells were detected, and fibrosis around bile ducts and infiltration of inflammatory cells into hepatic tissue were found. It is well known that PSC is sometimes difficult to differentially diagnose from cholangiocarcinoma. Our case is of high interest because ultrasonography showed findings suggestive of gallbladder carcinoma. It is therefore necessary to keep the possibility of PSC in mind for the diagnosis and treatment of such localized biliary stenosis.