Myelodysplastic syndrome with translocation (8;21): a distinct myelodysplastic syndrome entity or M2-acute myeloid leukemia with extensive myeloid maturation?

We report a case of refractory anemia with excess of blasts in transformation with the translocation (8;21), which is frequent in acute myeloid leukemia (AML) but not in myelodysplastic syndromes (MDS). Bone marrow blasts were 1.6% and an extensive myeloid differentiation was noted. Fluorescence in situ hybridization analysis revealed the presence of 21q22 translocations in mature neutrophils, indicating that clonogenic blast progenitors could actively undergo terminal differentiation to mature end cells in vivo. We consider that t(8;21)+ MDS may represent a rare clinical manifestation of M2-AML, in which blast progenitors have an extensive differentiation potential to mature neutrophils without maturation arrests.