RESUMO
INTRODUCTION: Zollinger-Ellison syndrome (ZES) is due to a gastrin-producing neuroendocrine tumor (gastrinoma) with subsequent gastric acid hypersecretion, gastroesophageal reflux disease (GERD), peptic ulcers, and chronic diarrhea. CASE PRESENTATION: A 40-year old patient presented with epigastric pain associated with diarrhea evolving for 10 years, he has been treated by acid-suppressive medications without substantial clinical improvement. Gastro-duodenal endoscopy was performed with gastric biopsies that showed peptic ulcerations, a serum gastrin assay that showed high levels exceeding 10 times the upper limit of the normal range. The abdominal contrast-enhanced computed tomography scan (CT-Scan) showed a solid-cystic mass with contrast enhancement in the right colon mesentery. The histopathological analysis of the resected mass showed a well-differentiated neuroendocrine tumor, and the diagnosis of a sporadic Zollinger-Ellison syndrome (ZES) was disclosed. Eighteen months after the surgical treatment the patient has no symptoms of the disease. CLINICAL DISCUSSION: Patients with ZES present often with long-standing clinical symptoms with delayed diagnosis. The surgical resection of the causative gastrinoma remains the most effective therapeutic treatment. CONCLUSION: Patients with refractory chronic diarrhea and epigastric pain should be suspected of having ZES in order to benefit from adequate clinical management.