Gastric MALT lymphoma refractory to Helicobacter pylori antibiotic therapy.

Gastric mucosa-associated lymphoid tissue lymphoma is a rare clonal B-cell neoplasm that is usually associated with Helicobacter pylori infection. The presence of H. pylori should be confirmed via special stains and/or immunohistochemistry of gastric biopsies from multiple anatomic sites of the stomach. Mucosa-associated lymphoid tissue lymphoma is diagnosed with histopathologic examination and positive immunohistochemical staining for certain B-cell markers. Ancillary testing should be performed to determine any genetic abnormalities in H. pylori that increases its virulence. We report the case of a 49-year-old woman with recurrent epigastric pain and vomiting found to have chronic H. pylori gastritis despite appropriate rounds of treatment with first-line therapy. She was diagnosed with mucosa-associated lymphoid tissue lymphoma via histopathologic examination. She ultimately required oncological treatment due to H. pylori infection refractory to antibiotic treatment.