Neonatal Acute Megakaryoblastic Leukemia Presenting with Leukemia Cutis and Multiple Intracranial Lesions Successfully Treated with Unrelated Cord Blood Transplantation.

Neonatal acute megakaryoblastic leukemia (AMKL) without Down syndrome (DS) is an extremely rare disorder. We report of a one-day-old male infant without DS who developed AMKL with leukemia cutis and right facial nerve palsy. Magnetic resonance imaging of the patient's brain revealed multiple intracranial tumors. A biopsy specimen of the skin lesion was suggestive of AMKL, but the bone marrow leukemic cells were less than 5% of the marrow nucleated cells. The skin and intracranial lesions had spontaneously regressed within one and a half months, but the patient's anemia and thrombocytopenia gradually worsened and the leukemic cells in the bone marrow gradually increased to more than 20% of the nucleated cells. In addition, multiple intracranial lesions reappeared at 72 days of life. We diagnosed the patient with AMKL, and chemotherapy followed by unrelated cord blood transplantation after a reduced-intensity conditioning regimen resulted in sustained complete remission. At present, the patient is well, and he has demonstrated normal development for five years.