Granular cell myoblastoma of the extrahepatic biliary system.

We have reported our experience with two cases of granular cell myoblastoma, bringing the total number of cases to 29. Granular cell myoblastoma of the extrahepatic biliary system is a rare benign tumor that affects black women predominantly. Both black men in this study had multiple lesions involving the skin and biliary system. Surgery is necessary for tissue diagnosis and curative resection. Tumors involving the common bile duct or common hepatic duct require wide local excision and bilioenteric anastomosis. The cause is uncertain, but present data indicate a neuroectoderm origin.