title: Pheochromocytoma and gastrointestinal stromal tumors in patients with neurofibromatosis type I.
abstract: BACKGROUND
  Neurofibromatosis I may rarely predispose to pheochromocytoma and gastrointestinal stromal tumors.
  
  
  METHODS
  A 59-year-old woman with neurofibromatosis I presented with pheochromocytoma of the left adrenal gland. During surgery, 3 gastrointestinal stromal tumors adjacent to the stomach and small intestine were removed. Despite appropriate thrombosis prophylaxis, the patient died of a pulmonary embolus 2 days postoperatively. The second patient, a 55-year-old man with neurofibromatosis I and bilateral pheochromocytomas, had several small gastrointestinal stromal tumors adjacent to the jejunum during surgery. A review of the literature was conducted to identify patients with neurofibromatosis I with concurrence of pheochromocytoma and gastrointestinal stromal tumors and to define the specific clinical features of these patients.
  
  
  RESULTS
  In addition to our 2 patients, 12 other cases of neurofibromatosis I with concomitant occurrence of pheochromocytomas and gastrointestinal stromal tumors have been reported. Pheochromocytomas had adrenal locations in all patients. Two of the 14 patients had a mixed pheochromocytoma/ganglioneuroma. In 4 of the 14 patients, gastrointestinal stromal tumors were located along the stomach. The gastrointestinal stromal tumors in our 2 patients showed no somatic mutations in KIT and PDGFRA genes. A pulmonary embolism was diagnosed in 4 patients.
  
  
  CONCLUSIONS
  The simultaneous occurrence of pheochromocytoma and gastrointestinal stromal tumor should be considered in all patients with neurofibromatosis I presenting with an abdominal mass with symptoms suggestive of pheochromocytoma. Therefore, a pheochromocytoma should be excluded before a patient with neurofibromatosis I undergoes surgery for a gastrointestinal stromal tumor because an undiagnosed pheochromocytoma carries a high risk of life-threatening cardiovascular complications during surgery. Finally, this combination may be associated with an increased risk for thromboembolic events, but more studies are necessary to confirm this.
authors: Department of Medical Oncology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors: Myrella
authors: M
authors: Vlenterie
authors: Uta
authors: U
authors: Flucke
authors: Lorenz C
authors: LC
authors: Hofbauer
authors: Henri J L M
authors: HJ
authors: Timmers
authors: Joerg
authors: J
authors: Gastmeier
authors: Daniela E
authors: DE
authors: Aust
authors: Winette T A
authors: WT
authors: van der Graaf
authors: Pieter
authors: P
authors: Wesseling
authors: Graeme
authors: G
authors: Eisenhofer
authors: Jacques W M
authors: JW
authors: Lenders
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000150:complications*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000150:complications*; D046152:Gastrointestinal Stromal Tumors / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009456:Neurofibromatosis 1 / Q000150:complications*; D010673:Pheochromocytoma / Q000150:complications*