Malignant myeloid transformation in a child with severe congenital neutropenia (Kostmann's syndrome).

We report a case of a child with severe congenital neutropenia (Kostmann's syndrome) who was treated with daily prophylactic subcutaneous granulocyte colony-stimulating factor (G-CSF) from the age of eight to sixteen years before being discontinued for poor haematological and clinical response. She did not have a HLA-matched sibling to enable bone marrow transplantation. She subsequently developed acute megakaryoblastic leukemia at the age of 17 years and succumbed during induction chemotherapy. The role of G-CSF in the pathogenesis of her malignant transformation to AML is complicated as this disorder has a propensity for myelodysplasia or AML as part of its natural history.