Granular cell tumor of the biliary system: a report of 2 cases with cytologic diagnosis on endoscopic brushing

BACKGROUND: Granular cell tumors (GCTs) of biliary system are rare. GCTs show a striking preponderance for young, black females, who generally present with obstructive jaundice. To our knowledge, these are the first 2 reports of GCT of biliary system identifed on endoscopic brushing cytology. CASES: In case 1, a 24-year-old, black woman presented with a 5-month history of pruritus. Radiographic studies demonstrated a mass in the distal common bile duct. Endoscopic biopsy and bile duct brushing were diagnosed as GCT. A Whipple procedure was confirmatory of GCT. In case 2, a 38-year-old, black female presented with a 7-month history of pruritus and jaundice. Radiographic studies showed a stricture of the common hepatic duct at the hilum. Endoscopic brushing cytology of the stricture yielded only a few sheets of granular cells that were missed on initial screening. Suspicion of cholangiocarcinoma prompted surgery, and final histopathology showed GCT. Both patients were well 1 1/2 and 6 years after presentation. CONCLUSION: GCT of the bile duct can be diagnosed on endoscopic brushing and should be considered in the cytologic differential diagnosis in the appropriate clinical settings.