[Multiple myeloma in systemic lupus erythematosus. Report of two cases].

There is an increased incidence of hematological malignancies, particularly non-Hodgkin lymphoma (NHL) in systemic lupus erythematosus (SLE). In contrast, the concurrence with Multiple Myeloma (MM) is very rare, and the possible pathogenetic mechanisms underlying this association remain unclear. We report two patients who developed MM 15 and four years after being diagnosed as having SLE.