-Mitoxantrone (MX) is an immunosupressant drug used in secondarily progressive multiple sclerosis (SPMS) and in relapsing-remitting multiple sclerosis (RRMS). It has a leukemogenesis potential induced by cytogenetic abnormalities, though with a low incidence. Promyelocitic leukaemia (type M3) and other forms of acute myeloblastic leukaemias (M4 and M5) have been described in a few MS patients who received MX during their treatment. We describe a white female patient, 47 year-old, with SPMS (EDSS = 4) with 14 years of disease. She received MX during her disease and developed acute promyelocytic leukaemia (M3), with severe thrombocytopenia 30 months later. She ultimately died due to intracerebral hemorrhage. Other cases of treatment related to AML are reviewed and discussed.KEY WORDS: multiple sclerosis, mitoxantrone, acute myeloblastic leukemia. Leucemia mielóide aguda induzida por mitoxantrone: relato de casoRESUMO -Mitoxantrone (MX) é uma agente imunossupressor utilizado nas formas progressivas secundárias de esclerose múltipla (EM) ou formas surto-remissão sem resposta com outras formas de tratamento (p.ex. beta-interferon, acetato de glatirâmer). Com o uso desta medicação, ocorre uma incidência maior, embora pequena, de desenvolvimento de leucemia mielóide aguda induzida por quimioterápicos. Descrevemos o caso de uma paciente com forma progressiva secundária de EM, submetida a uma dose única de MX de 15mg e que 30 meses após desenvolveu quadro fulminante de leucemia promieloblástica aguda (M3), com trombocitopenia grave. A paciente faleceu por hemorragia intracerebral maciça. É feita revisão de outros casos relatados na literatura e os possíveis mecanismos de desenvolvimento desta complicação grave secundária ao uso do MX. PALAVRAS-CHAVE: esclerose múltipla, mitoxantrone, leucemia mielóide aguda.Mitoxantrone (MX) is a DNA-topoisomerase II inhibitor widely used in cancer therapy. In addition, mitoxantrone induces immunodepletion. It is the first immunosuppressant approved for worsening relapsing and secondary progressive multiple sclerosis (MS) 1,2 . The incidence of acute myeloblastic leukemia (AML) in the population of MS patients treated with mitoxantrone is higher than the estimated incidence proportion of de novo AML in the global population 3 .We report a case of fatal AML in a woman with MS who developed AML after use of MX. This is the first case of AML in a series of 25 patients with MS treated with MX in our Service. CASEA 47-year-old woman had a diagnosis of definite MS picture for 14 years. During the first months of 2001 she entered the secondarily progressive phase with progressive right spastic hemiparesis, neurogenic bladder, and

Mitoxantrone hydrochloride (Novantrone®) is an anthracenedione that has been used as one of the latest in a long line of general immunosuppresive agents studied in multiple sclerosis (MS). We reviewed the clinical, laboratory, neuroimaging and echocardiography data of 18 patients from February 2001 to March 2004 out of a total number of 100 patients with definite MS. Fourteen patients were women (77.7%) and four were men. The mean age of the patients was 41.6±10 years old (confidence intervals 95%: 36.4-46.7 years old). The mean duration of disease was 10.5±6.3 years. Fourteen patients had the secondarily progressive form of MS, and four had the relapsing-remitting form. Mitoxantrone is an useful and clinically effective drug in MS and its major limitation is the potencial cardiotoxicity due to cumulative dose (140 mg).