Heterotopic chondroid tissue of the main bile duct mimicking Klatskin tumor: case report and review of the literature.

Heterotopic tissue in the bile duct is a very rare condition. There are a few case reports of heterotopic tissue including gastric and pancreatic cells. However, we could not find any data regarding heterotopic chondroid tissue obstructing the common bile duct in the literature. A 56-year-old woman was admitted to our hospital with complaints of progressive jaundice and pruritus. Laboratory test results were within the normal limits except bilirubin and alkaline phosphatase which were 10.8 mg/dL and 256 IU/L, respectively. Endoscopic retrograde cholangiography (ERCP) and computed tomography (CT) revealed a biliary stricture confined to the upper part of the common bile duct. The patient was operated as soon as the bilirubin level dropped below 5 mg/dL by percutaneous transhepatic cholangiography. Despite the lack of a precise confirmation, the patient was prepared for operation considering the possibility of a malignant biliary tumor since the radiographic mass findings together with hyperbilirubinemia were highly suggestive of malignancy. The patient underwent total extrahepatic bile duct resection and Roux-en-Y hepaticojejunostomy, and was discharged without any postoperative complications. Histologic examination of the bile duct and the nodule revealed the presence of a well-demarcated chondroid tissue within the subepithelial connective tissue. Herein, we presented the first case, to our knowledge, of heterotopic chondroid tissue of the common bile duct in the literature. It is a benign condition that should be considered in the differential diagnosis of stricture and mass-forming lesions of the bile duct.