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 transfo rmation with the translocation (8;21), which is frequent in acute myel oid leukemia (AML) but not in myelodysplastic syndromes (MDS). Bone ma rrow blasts were 1.6% and an extensive myeloid differentiation was not ed. Fluorescence in situ hybridization analysis revealed the presence of 21q22 translocations in mature neutrophils, indicating that clonoge nic blast progenitors could actively undergo terminal differentiation to mature end cells in vivo. We consider that t(8;21)+ MDS may represe nt a rare clinical manifestation of M2-AML, in which blast progenitors have an extensive differentiation potential to mature neutrophils wit hout maturation arrests.