Zollinger Ellison Syndrome

Zollinger Ellison syndrome (ZES) is classically characterized by the presence of hypergastrinemia secondary to a gastrinsecreting tumor otherwise known as a gastrinoma. ZES occurs sporadically in 75% of the cases and is associated with multiple endocrine neoplasia-1 (MEN-1) in 25% of cases identified. ZES usually occurs after the onset of hyperparathyroidism in MEN-1 and occurs 50% of the time. Rare causes of hypergastrinemia with acid hypersecretion include retained gastric antrum syndrome, chronic gastric outlet obstruction, chronic renal failure, massive small bowel resection, and gastric G-cell hyperplasia. A careful history and physical, along with other ancillary tests, will help discern these causes from ZES.