RESUMEN
BACKGROUND: Infant acute myeloid leukemia is a rare but aggressive form of leukemia. OBSERVATION: We report 2 children who presented with hyperleukocytosis, subsequently diagnosed with infant acute myeloid leukemia, and both developed isolated central nervous system relapse while on chemotherapy. Both infants underwent successful bone marrow transplantation with myeloablative conditioning (thiotepa, busulfan, and cyclophosphamide) without radiation, followed by 12 empiric post-transplant lumbar punctures with intrathecal cytarabine. Both patients tolerated these therapies well, and are without infections, chronic graft-versus-host disease, or any post-transplant sequelae. CONCLUSION: Nonradiation-based conditioning followed by empiric central nervous system-directed intrathecal chemotherapy may be considered for high-risk infants with leukemia.