Therapy-related acute nonlymphoblastic leukemia following mitoxantrone therapy in a patient with multiple sclerosis.

A 58-year-old male with migraine headaches, complex partial epilepsy, and secondary progressive multiple sclerosis treated with mitoxantrone was admitted to our facility in August 2005 with febrile neutropenia, worsening ataxia, aphasia, cough, and declining mental status. Bone marrow aspirate was consistent with acute nonlymphoblastic leukemia. Review of the literature reveals ten reported cases of nonlymphoblastic leukemias following treatment with mitoxantrone. Although de novo leukemia cannot be fully excluded, the likelihood of de novo disease is low given the patient's medical history. This case continues the important discussion of efficacy versus toxicity when selecting mitoxantrone as a therapeutic option for patients with multiple sclerosis. Although leukemia is rarely seen, the potential for this outcome warrants careful consideration before initiating this therapy.