Images of interest. Gastrointestinal: multiple endocrine neoplasia type I and duodenal gastrinomas.

Abstract

Multiple endocrine neoplasia type I (MEN I) syndrome is an autosomal dominant disorder characterized by tumors in the pituitary gland, parathyroid glands and upper gastrointestinal tract. While almost all patients have pituitary and parathyroid tumors, only approximately 60% develop islet cells tumors that secrete gastrin (gastrinomas). The presence of gastrinomas causes the Zollinger–Ellison syndrome, a syndrome characterized by hypersecretion of gastric acid and aggressive peptic ulceration. However, only a minority of patients with the Zollinger–Ellison syndrome have MEN I; the majority (70%) have ‘sporadic’ tumors without MEN I. Most gastrinomas occur in the ‘gastrinoma triangle’ that includes the first, second and third parts of the duodenum and the head of the pancreas. However, tumors can occur elsewhere in the pancreas, in peripancreatic lymph nodes and, rarely, in distant sites such as the ovary. Whether tumors in peripancreatic lymph nodes are primary tumors or a site of local spread from a tiny focus in the pancreas remains unclear. Typical gastrinomas occur with similar frequency in the duodenum and pancreas. However, in contrast to ‘sporadic’ gastrinomas, gastrinomas associated with MEN I are more likely to be located in the duodenum, more likely to be small and multiple and more likely to be associated with gastric carcinoid tumors. In addition, gastrinomas associated with MEN I have a lower metastatic potential and a greater longer-term survival (90% at 20 years). Because of the multifocal nature of gastrinomas in MEN I, cure by surgery is less frequent and the majority of patients are managed medically with proton pump inhibitor drugs. Figures 1 and 2 show the endoscopic appearances of multiple polypoid gastrinomas in a patient with MEN I. The diagnosis was confirmed by endoscopic biopsies.