Helicobacter heilmannii Infection With Concurrent Gastric Cancer: A Case Report

<i>Helicobacter heilmannii</i> (<i>H. heilmannii</i>), a zoonotic pathogen, is increasingly recognized as a cause of gastritis and a potential risk factor for gastric cancer, despite its rarity. Here, we report a case of multiple synchronous early gastric cancers in a female patient in her 40s with <i>H. heilmannii</i>-associated gastritis. She underwent an esophagogastroduodenoscopy (EGD) for the evaluation of gastric discomfort. Endoscopy revealed cobblestone-like gastritis. Histological examination confirmed a signet ring cell carcinoma. <i>Helicobacter pylori</i> (<i>H. pylori</i>) antibody test was negative, and spiral-shaped bacteria were detected by Giemsa staining and real-time polymerase chain reaction (PCR), confirming <i>H. heilmannii</i> infection. Endoscopic submucosal dissection achieved curative resection without recurrence. <i>Helicobacter heilmannii</i>-induced gastritis presents distinct features, including a cobblestone-like appearance and lymphocyte-dominant infiltration, differing from <i>H. pylori</i>-associated gastritis. Chronic inflammation and immune modulation caused by <i>H. heilmannii</i> infection may contribute to carcinogenesis. Considering the diagnostic challenges and zoonotic transmission risks, enhanced awareness of <i>H. heilmannii</i>-associated gastric cancer is essential. This case highlights the importance of identifying <i>H. heilmannii</i> in <i>H. pylori</i>-negative gastritis and its potential role in gastric carcinogenesis. Further research is required to elucidate the pathogenic mechanisms and establish effective management protocols.