title: Duodenal somatostatinoma of the ampulla of vater diagnosed by endoscopic fine needle aspiration biopsy: a case report.
abstract: BACKGROUND
  Duodenal somatostatinoma is a rare neuroendocrine neoplasm. A better prognosis can be obtained if these tumors are resected at an early clinical stage. Endoscopic punch biopsy has been the method most commonly used for the preoperative diagnosis of neuroendocrine duodenal tumors. To the best of our knowledge, endoscopic fine needle aspiration biopsy (FNAB) of duodenal somatostatinoma has not been reported before.
  
  
  METHODS
  A 41-year-old, black female presented with upper gastrointestinal bleeding as well as elevated bilirubin, liver enzymes and glucose. Computed tomography, esophagogastroduodenoscopy and endoscopic retrograde cholangiopancreatography (ERCP) detected a mass at the region of the ampulla of Vater partially obstructing the pancreatic duct. The initial punch biopsy yielded only intestinal mucosa. Subsequent endoscopic FNAB suggested the diagnosis of a neuroendocrine neoplasm, as confirmed by additional punch biopsies. Immunohistochemical and electron microscopic studies disclosed somatostatin production by the tumor, which was resected through a modified Whipple procedure. The patient recovered fully.
  
  
  CONCLUSIONS
  This case demonstrates the usefulness of endoscopic FNAB in diagnosing submucosal gastrointestinal neuroendocrine tumors.
authors.affiliation: Department of Pathology, University of Mississippi Medical Center, Jackson 39216-4505, USA.
authors.forename: M
authors.initials: M
authors.lastname: Guo
authors.forename: L B
authors.initials: LB
authors.lastname: Lemos
authors.forename: S
authors.initials: S
authors.lastname: Bigler
authors.forename: M
authors.initials: M
authors.lastname: Baliga
mesh_terms: D000328:Adult; D014670:Ampulla of Vater / Q000473:pathology; D001707:Biopsy, Needle; D003138:Common Bile Duct Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D004379:Duodenal Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D004384:Duodenoscopy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D013005:Somatostatinoma / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology