Multiple myeloma and systemic lupus erythematosus in a young woman.

Although systemic lupus erythematosus (SLE) is associated with lymphoid malignancies, concurrent multiple myeloma and SLE are rare. We report a 28-year-old black woman with SLE who developed smoldering IgA kappa multiple myeloma. The coexistence of these conditions in this age and race has not been previously reported. A literature search was conducted and all 12 previously reported cases of concurrent SLE and multiple myeloma were reviewed. The demographic and clinical features of multiple myeloma in SLE are summarized. Possible mechanisms underlying this association are also discussed. In the appropriate clinical context, multiple myeloma should be considered in SLE patients irrespective of young age, race, SLE disease activity, or duration.