Revealing autoimmune gastritis: Polypoid nodule scar development after endoscopic submucosal dissection for early gastric cancer

• DOI: 10.1002/deo2.70094
• Publication Date: 2025-03-11T12:21:00Z
• Authors: Naoya Masuda; Kenji Yamazaki; Yasuhiko Maruyama; Ryoji Kushima; Nae Hasebe; Noritaka Ozawa; Shogo Shimizu; Masahito Shimizu
• Keywords: Autoimmune Gastritis; Endoscopic mucosal resection; Atrophic gastritis; Submucosa

Abstract Endoscopic submucosal dissection (ESD), the standard treatment for early gastric cancer, typically results in homogeneous flat scars. However, some cases, polypoid nodule scars (PNS) may develop, complicating cancer recurrence assessment. This case report describes a 60‐year‐old man with history of Helicobacter pylori infection who underwent two ESD procedures: first antral and then body adenoma. Subsequently, an erythematous protruding lesion developed at scar site. Lesion biopsy revealed regenerative hyperplastic tissue growth, consistent PNS. Despite H. eradication therapy discontinuation potassium‐competitive acid blockers H 2 ‐receptor antagonists, continued to enlarge. PNS growth be caused by excessive mucosal regeneration enhanced peristalsis, suggesting that hypergastrinemia, which enhance these effects, underlying cause. Further, elevated serum gastrin levels, decreased pepsinogen presence antiparietal cell antibodies, pathological findings confirmed autoimmune gastritis (AIG). highlights diagnostic challenges AIG, especially cases active or previous because typical endoscopic features obscured. Persistent after warrants consideration AIG as potential cause its association hypergastrinemia. To our knowledge, this is describing link between