Concomitant occurrence of MALT lymphoma and multiple myeloma.

The association between multiple myeloma and secondary malignancies is already well established. We report here on the concomitant occurrence of mucosa-associated lymphoid tissue (MALT) lymphoma and multiple myeloma. Despite the fact that both malignancies are mature B-cell neoplasms, the clinical approach to these two types of tumor is completely different. This paper describes the diagnostic approach to this particular case and presents immunophenotypic and molecular cytogenetic data suggesting that the two B-cell malignancies were clonally unrelated.