Gastrinoma (Zollinger-Ellison Syndrome; Z-E Syndrome) By Minhhuyen Nguyen, MD, Fox Chase Cancer Center, Temple University Reviewed / Revised Mar 2021 | Modified Sep 2022 View Patient Education Symptoms and Signs Diagnosis Prognosis Treatment Key Points Topic Resources Somatostatin Receptor Scintigraph... A gastrinoma is a gastrin-producing tumor usually located in the pancreas or the duodenal wall.