Introduction
Gastric neoplasm is a very common digestive disease, and different types of tumors are treated differently.[1] Ectopic duodenal mucosa with adenomatous hyperplasia in the stomach has not been reported previously. We encountered a case of intragastric tumor in September 2022, which was confirmed by pathology as ectopic duodenal mucosa with adenomatous hyperplasia in the stomach. According to our experience, a case of diagnosis and treatment of this disease reported with the literature review.