Extranodal marginal zone (MALT) lymphoma in common variable immunodeficiency.

We describe two patients with common variable immunodeficiency (CVID) who developed extranodal marginal zone lymphoma (formerly described as mucosa-associated lymphoid tissue lymphoma or MALT lymphoma). One patient, with documented pernicious anaemia and chronic atrophic gastritis with metaplasia, developed a Helicobacter pylori-positive extranodal marginal zone lymphoma in the stomach. Three triple regimens of antibiotics were necessary to eliminate the H. pylori, after which the lymphoma completely regressed. Patient B had an H. pylori-negative extranodal marginal zone lymphoma of the parotid gland, which remarkably regressed after treatment with clarithromycin. Reviewing the literature, we found eight cases of extranodal marginal zone lymphoma complicating CVID, but probably many more cases labelled as non-Hodgkin's lymphoma are hidden in the literature. Until more data are available on the predictive value of noninvasive screening for pathology of the stomach, we recommend endoscopy to assess the gastric status in CVID patients in order to detect these malignancies at an early stage. Elimination of H. pylori infection is the treatment of choice in Helicobacter-positive extranodal marginal zone lymphoma. The possibility of elimination failure, most probably due to frequent and prolonged exposure to antibiotics in this patient group, should be taken into account. Treatment with antibiotics in Helicobacter-negative extranodal marginal zone lymphoma must be considered.