Plasma cell leukemia: response to conventional myeloma therapy

A 76-year-old man with plasma cell leukemia was treated with L-phenylalanine mustard and prednisone (CLGB 7461). There was good partial remission of the plasma cell disease characterized by disappearance of the plasma cells in the peripheral blood, reduction of plasma cells in the marrow aspirates to less than 5% of the nucleated hematopoietic cells, a reduction in the serum monoclonal IgG from 7.6 to 2 gms/100 ml, and the disappearance of urinary monoclonal IgG, Bence-Jones protein and a complex of gamma-chain fragment and beta2-microglobulins. There was also a marked improvement in the renal function and a decrease in the proteinuria from 4+ to 1+. The patient relapsed after more than 8 months of response and failed to respond to subsequent treatment with cytoxan and cytosine arabinoside. However, the efficacy of standard myeloma therapy was clearly apparent in this case of plasma cell leukemia.