Rapid Development of a Hemorrhagic Hyperplastic Polyp in a Patient with Evolving Autoimmune Gastritis after <i>Helicobacter pylori</i> Eradication

In 2020, a 56-year-old woman with a history of Helicobacter pylori (H. pylori) eradication 9 years previously presented with a hemorrhagic hyperplastic polyp. Endoscopic and histological findings led to the diagnosis of advanced-stage autoimmune gastritis (AIG). A review of endoscopic findings from 2014 was available, and narrow-band imaging showed swelling of the gastric areas, characteristic of early-stage AIG. Together with the rapid growth of a hyperplastic polyp, these findings suggest a case of AIG that rapidly exacerbated after eradication. To our knowledge, this is the first case report of a rapidly developing hemorrhagic hyperplastic polyp associated with AIG after H. pylori eradication.