Granular cell myoblastoma of the cystic duct. A case associated with hydrops of the gallbladder.

The first known case of true hydrops of the gallbladder that resulted from granular cell myoblastoma is reported. Granular cell tumors are benign multicentric tumors that should be treated by total excision so that free margins are assured. These tumors are rarely found in the biliary tract; however, they may cause complications of biliary tract obstruction.