title: Granular cell tumor at the hepatic duct confluence mimicking Klatskin tumor. A report of two cases and a review of the literature.
abstract: BACKGROUND
  Granular cell tumors are rare tumors most often located in the oral cavity, skin or subcutaneous tissue. The occurrence of this tumor in the biliary tree is extremely rare.
  
  
  METHODS
  Two patients are described presenting with biliary obstruction due to a tumor at the hepatic duct confluence. One patient is a 38-year-old white male with concomitant cutaneous granular cell tumors, and the other a 50-year-old white female.
  
  
  RESULTS
  Hilar excision was performed in both patients. Histopathology of the tumors revealed a proliferation of cells with granular cytoplasm, diagnosed as granular cell tumor.
  
  
  CONCLUSIONS
  At preoperative examination, hilar granular cell tumors are difficult to differentiate from cholangiocarcinoma, sclerosing cholangitis or more common benign biliary tumors. Treatment consists of surgical excision after which prognosis is favorable.
authors.affiliation: Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: D S
authors.initials: DS
authors.lastname: te Boekhorst
authors.forename: M F
authors.initials: MF
authors.lastname: Gerhards
authors.forename: T M
authors.initials: TM
authors.lastname: van Gulik
authors.forename: D J
authors.initials: DJ
authors.lastname: Gouma
mesh_terms: D000328:Adult; D001650:Bile Duct Neoplasms / Q000175:diagnosis*; D002760:Cholangiopancreatography, Endoscopic Retrograde; D003251:Constriction, Pathologic; D005260:Female; D016586:Granular Cell Tumor / Q000175:diagnosis*; D006500:Hepatic Duct, Common / Q000473:pathology; D006801:Humans; D018285:Klatskin Tumor / Q000175:diagnosis*; D008297:Male