Mucosa-associated lymphoid tissue lymphoma of the duodenum: report of a case resistant to Helicobacter pylori eradication.

We present a case of mucosa-associated lymphoid tissue (MALT) lymphoma of the duodenum treated with surgical resection. A 64-year-old woman underwent upper gastrointestinal endoscopy because of melena. Examinations revealed an ulcer-forming lesion at the second portion of the duodenum that was diagnosed histologically as low-grade MALT lymphoma. We attempted Helicobacter pylori eradication therapy, although all the tests revealed negative results for its infection. No sign of remission was observed and we performed surgical resection. The patient has shown no sign of recurrence at present, 39 months after the operation. Duodenal MALT lymphoma is a rare entity. Only 17 cases have been reported in the English literature. We summarized the characteristics of the disease and tried to figure out differences in comparison with those in the stomach, including the involvement of the Helicobacter pylori infection.