Gastric polyps usually originate in the gastric mucosa; In about 6% of cases found during upper GI endoscopy, gastric polyps are a heterogeneous group of epithelial and subepithelial lesions. Most have no risk of cancer, but there are a small number of polyps that are potentially malignant, requiring further endoscopic treatment or periodic monitoring.

Epithelial polyps are the most common type of gastric polyp. They include fundic gland polyps (FGPs), hyperplastic polyps, and adenomatous polyps. Other less common epithelial lesions that may appear as polyps include neuroendocrine tumors (formerly called carcinoids), ectopic pancreatic tissue, and pyloric adenomas.