S6006 Rare Case of Duodenal Bulb Neuroendocrine Tumor Presenting as Refractory Peptic Ulcer Disease

Introduction: Gastrinoma, a rare neuroendocrine tumor (NET), is associated with excessive gastrin release, causing upper gastrointestinal (UGI) inflammation and ulceration, resulting in abdominal pain, vomiting and diarrhea. We present a case of gastrinoma in the duodenal bulb causing significant UGI pathology with complete remission following surgical resection. Case Description/Methods: A 65-year-old woman with history of diabetes mellitus presented with 6-month history of epigastric pain, nonbilious non-bloody vomiting, and diarrhea. She’d had several long hospitalizations for similar symptoms, with multiple UGI endoscopies revealing erosive esophagitis and diffuse stomach, duodenal and jejunal ulcerations, not associated with infection. Trials of maximum dose proton pump inhibitors did not produce a significant response. Comprehensive rheumatological workup was negative. Cholecystectomy for possible gallstone-related upper abdominal symptoms did not improve her symptoms. Fasting gastrin level obtained (off proton pump inhibitors) was 577 pg/mL. Positron emission tomography/computed tomography Netspot scan revealed focal uptake in the duodenum and pancreaticoduodenal groove. Subsequently, repeat esophagogastroduodenoscopy demonstrated a 7 mm subepithelial duodenal bulb nodule, biopsies of which showed submucosal nests of gastrin positive well differentiated grade 1 NET/gastrinoma. No pancreatic abnormality was seen on endoscopic ultrasound. Patient underwent duodenal tumor resection with partial gastrectomy and retroduodenal/portal lymphadenectomy. Her gastrin level post-surgery (on pantoprazole) fell to 16 pg/mL. She had complete remission of symptoms and was able to return to her activities of daily living. Discussion: Gastrinoma, a rare NET, often arises in the gastrinoma triangle between the biliary tracts, the second/third portions of duodenum and the pancreas. It can be associated with Zollinger Ellison syndrome (ZES) causing refractory peptic ulcer disease in the distal duodenum/jejunum and fasting gastrin levels >10 times normal range. Our patient had a rare presentation of duodenal bulb gastrinoma causing diffuse stomach and proximal duodenal ulcerations, and given her localized disease, she underwent successful surgical resection, which carries a >90% 5-year survival rate. ZES caused by gastrinoma can be debilitating for patients and pose diagnostic challenges. A multidisciplinary treatment approach should be promptly instituted for appropriate management.