Granular cell tumor of the extrahepatic biliary tract.

Granular cell tumors (GCTs) are usually benign lesions that most commonly arise in the skin, subcutaneous tissue, tongue, and oral cavity. GCT of the biliary tract is rare, but most commonly occurs in young African-American females. We report the 58th case of GCT involving the extrahepatic biliary system, and review the world literature on this tumor in this location.