Chronic pure red cell aplasia developed in a patient with multiple myeloma treated with lenalidomide

An 84-year-old man with symptomatic immunoglobulins G (IgG)-lambda-type multiple myeloma (MM) suddenly developed shortness of breath on day 30 of lenalidomide plus dexamethasone therapy. Rapidly progressive anemia with marked decrease in reticulocyte count and severe depletion of erythroid precursor cells in the bone marrow indicated the diagnosis of pure red cell aplasia (PRCA). Although oral cyclosporine relieved anemia, he is still dependent on immunosuppressant for longer than 18 months. While controversial reports are seen, lenalidomide appears to be a potential trigger of PRCA. Accumulation of clinical data on this rare complication might help in the differential diagnosis of anemia seen in MM.