S3559 Diagnostic Challenges in Zollinger-Ellison Syndrome: A Case Report

Abstract

INTRODUCTION: Zollinger Ellison syndrome is a rare disorder characterized by gastric acid over production from increased gastrin by neuroendocrine tumors generally located in the duodenum or pancreas. Typically, patients present with abdominal pain, nausea and vomiting. If left untreated, it can lead to refractory PUD, severe GERD, and diarrhea. CASE DESCRIPTION/METHODS: Patient is 82-year-old male with CAD, DM, GERD initially evaluated 14 years prior for anemia with EGD showing gastritis and duodenitis. 8 years later, EGD for melena showed a duodenal ulcer and gastritis without H pylori. Patient most recently was hospitalized with several weeks of epigastric pain, diarrhea and vomiting. His symptoms were initially suspected to be from gastroenteritis. The patient was subsequently hospitalized several more times with similar complaints. Despite extensive testing including c. diff and stool culture, Abdominal US and CT, a clear etiology could not be determined. Of note, he described transient relief of his symptoms while hospitalized on PPI however symptoms returned following discharge from the hospital, where he was noncompliant with PPI therapy. With continued symptoms, additional evaluation included cortisol, urine metanephrines, prolactin, VIP and gastrin levels. Notably gastrin level was 12,676 pg/mL. Octreotide scan then showed a somatostatin-bearing receptor tumor localized between the 1st and 2nd portions of the duodenum. EGD then showed severe esophagitis, duodenitis and a 10 mm subepithelial nodule in the 2nd part of the duodenum proximal to the ampulla with a single cratered ulcer in the 2nd part of duodenum distal to the ampulla. EUS revealed 12 × 19 mm hypoechoic duodenal bulb mass and two hypoechoic masses in pancreatic head measuring 43 × 23 mm and 10 × 2.5 mm with FNA revealing well-differentiated neuroendocrine neoplasms of the lesions indicating Zollinger Ellison Syndrome. Patient was deemed high risk for surgery and was simply continued on PPI therapy with improvement in symptoms. DISCUSSION: Diagnosis of ZES is suspected in patients with multiple gastric and duodenal ulcerations, particularly distally, and those with persistent dyspepsia refractory to PPI or who have a relapse of symptoms immediately after PPI is stopped. It is important to develop suspicion in the patients with chronic GI complaints to avoid delay in diagnosis. As in this case, despite nonadherence to medication therapy for PUD, it is still important to maintain a high index of suspicion of this disorder.