Purpose: Myelodysplastic syndromes in children commonly evolve into acute leukemia, usually acute myelogenous leukemia (AML) and rarely acute lymphoblastic leukemia (ALL). The lineage of the leukemia can be predicted based on characteristic morphologic and cytogenetic findings of the marrow and peripheral blood.
Patient and methods: A 3-year-old boy had refractory anemia with excess blasts and abnormalities suggestive of pre-AML with highly unusual cytogenetic changes. ALL of pre-B phenotype developed.
Results: Leukoerythroblastic anemia, pseudo Pelger-Huet neutrophils, and dysmyelopoietic hyperplasia of the marrow suggested likely early progression to AML. Complex cytogenetic abnormalities (monosomy 17 and 20, ring chromosome 11 with deletion of bands q23, and a derivative dicentric chromosome 12) were present in both the myelodysplastic marrow and the subsequent ALL.
Conclusion: This case presents cytogenetic evidence of common early progenitor cell ontogeny of both malignancies (refractory anemia with excess blasts and ALL).