[Granular cell tumor of the common bile duct. Contribution of endoscopic ultrasonography in 2 cases].

We report two cases of granular cell tumors involving the common bile duct in patients presenting with obstructive jaundice. Pre-operative endoscopic ultrasonography showed short asymmetric stricture with small well delimited hypoechoic mass in the distal common bile duct wall and proximal dilatation. These tumors were misdiagnosed as a bile duct carcinoma in one case and biliary metastasis of a melanoma in the other. Histological examination of the resected specimen showed granular cell tumors. A review of the previously reported cases shows that preoperative diagnosis is uncommon. It should be considered when endoscopic ultrasonography performed for biliary obstruction in a young woman shows a small and well limited hypoechoic mass.