[Regression of MALT lymphoma of the rectum after Helicobacter pylori eradication therapy in a patient negative for Helicobacter pylori].

A 53-year-old woman was referred to our hospital for further examination of a rectal polypoid lesion. Colonoscopy revealed a submucosal tumor in the rectum (Ra) and a diagnosis of MALT lymphoma was made on the histological examination of the biopsy specimens and Southern blot analysis of the immunoglobulin heavy chain gene rearrangement. Although the patient was negative for Helicobacter pylori, H. pylori eradication therapy was performed. Colonoscopy 3 months after the eradication therapy showed disappearance of the rectal tumor. H. pylori eradication appears to be a useful treatment for not only H. pylori-positive colonic MALT lymphoma but H. pylori-negative colonic MALT lymphoma.