Coexistent myelodysplasia and plasma cell neoplasia.

The oncogenic effect of alkylating agents, particularly that of melphalan, has been postulated as the most likely cause of myelodysplastic syndrome (MDS) and acute leukaemia in patients with plasma cell neoplasia. Five patients aged between 69 and 79 years were found to have features of MDS at the time of diagnosis of multiple myeloma. In three of these cases MDS transformed into acute leukaemia. These patients had not received any chemotherapy prior to their presentation. The possible importance of these features is discussed.