Defective differentiation of megakaryocytes in acute myeloid leukemia

In a patient with acute myeloid leukemia chromosome analysis, using banding technique, revealed an isochromosome 17 in granulopoietic and erythropoietic precursors as well as in polyploid cells, probably megakaryocytes. An abundant number of megakaryocytes in the bone marrow permitted characterization of the ploidy levels of these cells. It is demonstrated that most megakaryocytes were diploid and that polyploidy was not normally developed. The results indicate a defective differentiation of the megakaryocytes and/or their precursors analogous to what has previously been demonstrated in the myeloblasts of acute leukemia.