[Megakaryocytic dysplasia in acute nonlymphoblastic leukemias]

Megakaryocytic dysplasia, platelet and megakaryocytic counts were measured in 87 ANLL patients. High megakaryocytic levels were registered in 16.1%, normal in 17.2%, low or negligible in the rest of the examinees. Half of the patients had dysplasia. Thrombocytopenia present in 93% of cases attested to ineffective proliferation of megakaryocytes. Increased number of megakaryocytes with signs of dysplasia occurred more commonly in M0- and M4- variants of ANLL universally in anomalies of chromosome 3 long arm with involvement of q21 and/or q26 segments and occasionally in combination with other chromosome disorders. Megakaryocytosis developed less frequently in patients with ANLL variant M2 with t (8;21) and did not correlate with granulocyte and erythroid cell dysplasia. Pronounced megakaryocytosis in combination with thrombocytosis emerged in 4 patients: 2 of them had typical anomalies of chromosome 3--inv3(q21q26) and dup (3q21q26), 1 had monosomy 7 and 1 normal karyotype. Potential mechanisms responsible for dysplasia of megakaryocytes in ANLL are considered.