“…32 The present data, that is, 97% of the cases expressed CD34 and 58% of the cases were MPO Ϫ , indicate that the phenotype of MDS blasts is more immature compared with de novo AML blasts, in which 35% to 60% of cases are CD34 ϩ and 5% to 10% of cases are MPO Ϫ . 20,[33][34][35][36] As shown in Table 5, 47% of our de novo AML cases were CD34 ϩ . Although blasts of minimally differentiated de novo AML (AML-M0) show, by definition, a negative cytochemical reaction for MPO in all cases and are CD34 ϩ in nearly 90% to 100% of cases, [35][36][37] MDS EBCs are CD34 ϩ in most cases, irrespective of the MPO status.…”