title: Asymptomatic pancreatic perivascular epithelial cell tumor (PEComa) in a male patient: report and literature review.
abstract: BACKGROUND
  Perivascular epithelial cell tumors (PEComas) are a family of rare mesenchymal neoplasms which share cellular, immunohistochemical and ultrastructural characteristics but are found in different visceral and soft tissue sites. PEComas of the pancreas are extremely rare neoplasms.
  
  
  METHODS
  We describe a 49-year-old male who was incidentally diagnosed with a pancreatic mass. Endoscopic ultrasound-guided biopsy suggested a PEComa. An uneventful pylorus-preserving pancreaticoduodenectomy was thus performed. The tumor was a solid well-circumscribed mass in the pancreatic head with dilatation of the main pancreatic duct. Histopathology revealed a well-circumscribed and vascularized neoplasm, measuring 32x27x30 mm, composed of epithelioid smooth muscle cells with clear cytoplasm rich in glycogen. The tumor exhibited immunoreactivity to alpha-smooth muscle actin and to melanoma-associated antigen HMB-45.
  
  
  CONCLUSIONS
  Although rare, pancreatic PEComas should be included in the differential diagnosis of a pancreatic mass. Currently, the paucity of cases published makes it impossible to predict the behavior and prognosis of these tumors or to advocate an optimal therapy.
authors.affiliation: Department of Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus and Ein Kerem, Hadassah-Hebrew University Medical School, Jerusalem, Israel.
authors.forename: Roni
authors.initials: R
authors.lastname: Zemet
authors.forename: Haggi
authors.initials: H
authors.lastname: Mazeh
authors.forename: Tzahi
authors.initials: T
authors.lastname: Neuman
authors.forename: Herbert R
authors.initials: HR
authors.lastname: Freund
authors.forename: Ahmed
authors.initials: A
authors.lastname: Eid
mesh_terms: D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D016577:Pancreaticoduodenectomy; D054973:Perivascular Epithelioid Cell Neoplasms / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome