Gastric Carcinoids and Polyps

Abstract

Gastric polyps are commonly found on upper endoscopy. With the increasing use of proton pump inhibitors and decreasing incidence of Helicobacter pylori infection, fundic gland polyps are now the most common gastric polyps in Western countries. Most of the other polyps, such as hyperplastic polyps, gastric adenomas, and gastric neuroendocrine tumors (NETs), are strongly associated with the presence of chronic atrophic gastritis, commonly due to either H. pylori infection or autoimmune gastritis. Gastric NETs, previously termed carcinoids, are rare neoplasms that often present as polypoid lesions and can be subcategorized into three subtypes. The most common subtype, type 1, is associated with chronic atrophic gastritis and generally thought to have low malignant potential. Type 2 NETs behave similarly to type I NETs but are specifically associated with the Zollinger-Ellison syndrome. Type 3 NETs are sporadic and highly malignant. All gastric polypoid lesions require histopathologic examination for diagnosis. The key aspect to the management of gastric NETs and other gastric polyps is to determine the malignant potential of the lesion in question. This then informs whether the patient needs removal of additional polyps if multiple, whether the patient needs further endoscopic surveillance, or whether surgery is indicated. This review contains 5 figures, 5 tables, and 50 references. Key Words: atrophic gastritis, fundic gland polyp, gastric adenoma, gastric carcinoid, gastric neuroendocrine tumor, gastric polyp, hyperplastic polyp, intestinal metaplasia