title: Malignant insulinoma arising from intrasplenic heterotopic pancreas.
abstract: BACKGROUND
  Heterotopic pancreas is defined as ectopic pancreatic tissue without vascular or anatomic continuity with the normal pancreas. The spleen is a rare site of origin. This case report describes a patient with a malignant insulinoma which originated from an intrasplenic heterotopic pancreas.
  
  
  METHODS
  A 46-year-old man with three previous episodes of neuroglucopenic and adrenergic symptoms was referred to our hospital. A fasting test was performed and discontinued due to hypoglycemic symptoms. Preoperative studies failed to demonstrate any pancreatic lesions. However, a heterogeneous encapsulated tumor in the spleen was found on MRI. During surgery, only the splenic tumor was found, with neither vascular nor anatomical connections to the normal pancreas. Pathology reported a malignant insulinoma. Insulin and proinsulin were documented by immunohistochemistry. After one year of follow up, the patient is free of symptoms and no recurrent disease has been documented.
  
  
  CONCLUSIONS
  Only seven cases of splenic heterotopic pancreas have been reported, six with cystic mucinous neoplasms. In addition, only one case of a malignant insulinoma arising from heterotopic pancreas has previously been described. This is the second case reported of an insulinoma arising from heterotopic pancreas and the first to originate from intrasplenic heterotopia.
authors.affiliation: Department of Surgery, National Institute of Medical Sciences and Nutrition Salvador Zubirán, Tlalpan, México DF, Mexico.
authors.forename: Carmen M Hernández
authors.initials: CM
authors.lastname: Cárdenas
authors.forename: Ismael
authors.initials: I
authors.lastname: Domínguez
authors.forename: Manuel
authors.initials: M
authors.lastname: Campuzano
authors.forename: Paulina
authors.initials: P
authors.lastname: Bezaury
authors.forename: María
authors.initials: M
authors.lastname: Iñiguez-Rodríguez
authors.forename: Armando
authors.initials: A
authors.lastname: Gamboa-Domínguez
authors.forename: Luis F
authors.initials: LF
authors.lastname: Uscanga
mesh_terms: D002828:Choristoma / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007340:Insulinoma / Q000473:pathology* / Q000601:surgery; D007515:Islets of Langerhans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000601:surgery; D013158:Splenic Diseases / Q000473:pathology* / Q000601:surgery