Donor cell leukemia in umbilical cord blood transplant patients: a case study and literature review highlighting the importance of molecular engraftment analysis.

Donor cell neoplasms are rare complications of treatment regimens that involve stem cell transplantation for hematological malignancies, myelodysplastic processes, or certain genetic or metabolic disorders. We report a case of donor cell leukemia in a pediatric patient with a history of acute myeloid leukemia that manifested as recurrent AML FAB type M5 fourteen months after umbilical cord blood transplantation. Although there was some immunophenotypic drift from the patient's original AML and their posttransplant presentation, the initial pathological impression was of recurrent disease.