1332 Diarrhea, Heartburn, and Recurrent Pancreatitis: An Interesting Presentation of Zollinger-Ellison Syndrome

Abstract

INTRODUCTION: Zollinger-Ellison syndrome (ZES) is a condition characterized by severe diarrhea and peptic ulcer disease caused by the secretion of gastrin by a neuroendocrine tumor located in the duodenum or pancreas. The most common presenting finding is peptic ulcer disease, followed by heartburn, diarrhea, and weight loss. CASE DESCRIPTION/METHODS: A 40-year-old man presented with watery diarrhea and heartburn for 2 years. In addition, he endorsed history of recurrent pancreatitis beginning 15 years prior to presentation. Esophagogastroduodenoscopy (EGD) revealed reflux esophagitis and enlarged gastric folds with erythematous duodenopathy, mucosal biopsies were negative for malignancy. Patient was started on oral proton pump inhibitor with only mild improvement in heartburn and diarrhea. Upper endoscopic ultrasound revealed a 4 × 6 cm mass in the region of the pancreatic head and biopsies were consistent with neuroendocrine tumor. Abdominal computed tomography with intravenous contrast revealed an uncinate process mass. Gastrin level at the time of evaluation was significantly elevated 971 pg/mL (normal <100) and glucagon level was normal. Gallium-68 dotatate positron emission tomography (PET) scan was performed to fully stage the tumor and was notable for a large mass in the uncinate process as well as nodal metastases localizing around the right kidney in the portocaval region. Patient was referred to surgery and underwent Whipple procedure with excision of infrarenal lymph nodes without complication. Stools returned to normal in the month after surgery and proton pump inhibitor was tapered without recurrence of symptoms. DISCUSSION: In patients with the constellation of refractory peptic ulcers, diarrhea, heartburn, or abdominal pain, ZES should be suspected. Only approximately 25 percent of gastrinomas arise in the pancreas, with the majority being found in the first portion of the duodenum. Elevated level of gastrin (especially in the absence of PPI therapy) in the presence of low gastric pH is suggestive of ZES. Initial steps in localizing the tumor involve upper endoscopy and abdominal imaging. Gallium-68 dotatate PET imaging (PET/CT or PET/MRI) is increasingly preferred over other imaging modalities for identifying somatostatin receptor-positive neuroendocrine tumors due to high sensitivity in identifying these tumors. Conventional imaging was unable to capture the extent of disease in this patient, but advanced imaging was able to localize portocaval nodal metastasis.