title: Extra-gastrointestinal stromal tumor presenting as hemorrhagic pancreatic cyst diagnosed by EUS-FNA.
abstract: BACKGROUND
  Pancreatic gastrointestinal stromal tumors (GIST) are rare mesenchymal tumor with only 6 cases reported to date. We report a case of pancreatic GIST presenting as hemorrhagic cyst.
  
  
  METHODS
  A 63-year-old female with past medical history of hypertension and pancreatic mass presented with fatigue. She was found to have anemia requiring blood transfusion. An abdominal CT scan revealed an 11x16 cm cystic mass at the pancreatic body that had increased in size compared with previous CT scan. Endoscopic ultrasound confirmed a large complex pancreatic mass and fine needle aspiration demonstrated gross bloody fluid. Cytology revealed a spindle cell lesion. Immunohistochemistry from cyst wall biopsy was strongly positive for CD34 and CD117 confirming the diagnosis of pancreatic GIST.
  
  
  CONCLUSIONS
  We report a case of pancreatic GIST which presented as hemorrhagic cyst. Endoscopic ultrasound guided fine needle aspiration plays an important role in the diagnosis. Although it is an uncommon tumor, pancreatic GIST should be in differential diagnosis of hemorrhagic pancreatic cystic lesions as well as a rare cause of solid pancreatic lesions.
authors.affiliation: Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Tasma
authors.initials: T
authors.lastname: Harindhanavudhi
authors.forename: Tanyanan
authors.initials: T
authors.lastname: Tanawuttiwat
authors.forename: Joseph
authors.initials: J
authors.lastname: Pyle
authors.forename: Rogelio
authors.initials: R
authors.lastname: Silva
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D006470:Hemorrhage / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D010181:Pancreatic Cyst / Q000175:diagnosis* / Q000209:etiology; D010190:Pancreatic Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis
chemical_list: D018952:Antigens, CD34; D019009:Proto-Oncogene Proteins c-kit