Myelodysplasia and acute myeloid leukemia fifteen years after high-dose cyclophosphamide in a child with severe aplastic anemia

Aplastic anemia (AA) is a rare disorder characterized by suppression of bone marrow function. It can develop as the result of congenital marrow disease and chemical exposure; however, most cases are idiopathic.1 Treatment with immunosuppressive therapy (IST) for patients who do not have an human leukocyte antigen (HLA)-compatible donor relies on the evidence that a deregulated immune system drives T lymphocytes to cytokine-mediated destruction of their own hematopoietic stem cells.1 The majority of these patients respond well to up-front administration of IST, including antithymocyte globulin (ATG) and cyclosporine (CsA), which is successful in around 80%.2 Unfortunately, ATG and CsA can lead to clonal disorders, in particular myelodysplastic syndrome (MDS) and paroxysmal nocturnal hemoglobinuria.3 On the other hand, high doses of cyclophosphamide (HDCY) have been administered as a sole immunosuppressive agent in severe aplastic anemia (SAA), principally in adults, with no