Foveolar‐Type Gastric Adenoma With a Raspberry‐Like Appearance That Underwent Dramatic Morphological Changes Within Eight Months

Background Foveolar‐type gastric adenomas with a raspberry‐like appearance in the stomach have recently been identified. However, their etiology and mechanisms of development and growth remain unknown. Case Presentation We observed a foveolar‐type gastric adenoma with a raspberry‐like appearance that underwent rapid morphological changes. The first esophagogastroduodenoscopy revealed multiple reddish polyps on the cardia and fundus of the stomach, without Helicobacter pylori infection. The second‐largest polyp on the fundus had a red glove appearance and measured 5 mm in diameter. We diagnosed all of them as hyperplastic polyps on the basis of their shape. Given that the patient had received 10 mg of vonoprazan for a long time to treat reflux esophagitis, 20 mg of famotidine was prescribed instead. Eight months later, the largest polyp on the cardia had disappeared. However, a reddish raspberry‐like lesion was observed at the site of a previously identified polyp on the fundus and was diagnosed as foveolar‐type gastric adenoma by forceps biopsy. The pathological diagnosis was foveolar‐type gastric adenoma with high‐grade dysplasia as determined by tissue resection with endoscopic mucosal resection (EMR). Conclusion This is a valuable case report of a lesion evolving from a hyperplastic‐like polyp morphology to a raspberry‐like lesion within eight months.