Granular cell tumour of the bile duct mimicking distal cholangiocarcinoma: one case report and review of the literature.

Granular cell tumours (Gcts) are rare and most commonly located in the oral cavity, skin or subcutaneous tissue. The occurrence of this tumour in the biliary tract is rare. A 26 year old African man presented with abdominal pain and obstructive jaundice was found to have a localised distal bile stricture suggestive of cholangiocarcinoma which was resected by pylorus preserving partial pancreaticoduodenectomy. Histology revealed a gct of the intrapancreatic portion of the distal bile duct. GCT of the biliary tract are important as they are benign and can mimic bile duct cancers. A review of the 77 reported cases of Gcts of the biliary tract showed that the common bile duct is the most common site of occurrence (n=35). Only 2 cases in literature have been reported to be diagnosed preoperatively. Since there are no characteristic radiological features, the GCTs are difficult to differentiate from cholangiocarcinoma, sclerosing cholangitis or other benign tumors.