A case of Helicobacter heilmannii-associated primary gastric mucosa-associated lymphoid tissue lymphoma achieving complete remission after eradication.

A 46-year-old man underwent gastrointestinal endoscopy while visiting the hospital for a general physical check-up. Coarse mucosa in the antrum with superficial erosions was found by endoscopic gastrointestinal examination, but no atrophic changes were seen in the corpus. Histopathological examination of gastric biopsy specimens revealed mucosa-associated lymphoid tissue (MALT) lymphoma. Although Helicobacter pylori was not detected in our patient, H. heilmannii was identified histologically and by polymerase chain reaction analysis, resulting in the diagnosis of H. heilmannii-associated gastric MALT lymphoma. We successfully eradicated H. heilmannii and achieved complete remission of gastric MALT lymphoma by antibiotic therapy. H. heilmannii usually causes milder gastritis than H. pylori, but it has been more closely associated with MALT lymphoma. As such, when H. pylori infection is excluded in patients with gastric MALT lymphoma, physicians should next consider the possibility of H. heilmannii. Furthermore, our research suggests that eradication therapy is effective for treatment of localized H. heilmannii-associated gastric MALT lymphoma.