Gastric inflammatory fibroid polyp morphologically changed by Helicobacter pylori eradication.

A 60-year-old male presented to our hospital for further investigation of abnormal findings on an upper gastrointestinal series. Esophagogastroduodenoscopy demonstrated atrophic gastritis and a submucosal tumor (SMT) at the anterior wall of the antrum. The patient was positive for serum anti-Helicobacter pylori (H. pylori) antibody and H. pylori eradication therapy was performed. Five months later, the SMT showed a remarkable morphological change in that an ulcer had developed on its apex, and partial gastrectomy was performed. Pathological examination suggested an inflammatory fibroid polyp (IFP), and genetic analysis revealed no mutation in the platelet-derived growth factor receptor alpha gene. This case suggests that H. pylori infection plays an important role in the etiology of IFPs.