Duodenal somatostatinoma of the ampulla of vater diagnosed by endoscopic fine needle aspiration biopsy - A case report

BACKGROUND: Duodenal somatostatinoma is a rare neuroendocrine neoplasm. A b etter prognosis can be obtained if these tumors are resected at an early cl inical stage. Endoscopic punch biopsy has been the method most commonly use d for the preoperative diagnosis of neuroendocrine duodenal tumors. To the best of our knowledge, endoscopic fine needle aspiration biopsy (FNAB) of d uodenal somatostatinoma has not been reported before. CASE: A 41-year-old, black female presented with upper gastrointestinal ble eding as well as elevated bilirubin, liver enzymes and glucose. Computed to mography, esophagogastrodudenoscopy and endoscopic retrograde cholangiopanc reatography (ERCP) detected a mass at the region of the ampulla of Water pa rtially obstructing the pancreatic duct. The initial punch biopsy yielded o nly intestinal mucosa. Subsequent endoscopic FNAB suggested the diagnosis o f a neuroendocrine neoplasm, as confirmed by additional punch biopsies. Imm unohistochemical and electron microscopic studies disclosed sotochemical an d electron microscopic studies disclosed somatostatin production by the tum or, which was resected through a modified Whipple procedure. The patient re covered fully. CONCLUSION: This case demonstrates the usefulness of endoscopic FNAB in dia gnosing submucosal gastrointestinal neuroendocrine tumors.