Two subpopulations of progenitors of leukemic lineages in human myeloid leukemias exhibit different heterochromatin condensation state in central and peripheral nuclear regions (A morphological note with additional original observations)

The computer assisted optical image densitometry indicated that myeloid leukemias were characterized by two subpopulations of progenitor cells classified according to the heterochromatin condensation state (HChCS). The first subpopulation of these cells was characterized by a larger HChCS in the nuclear central regions than in the nuclear periphery. Such progenitors seemed to possess the potential for further differentiation and were predominantly present in patients suffering from the chronic phase of chronic myelocytic and acute monoblastic leukemias. The second subpopulation of progenitors was characterized by a marked similarity of HChCS in both central and peripheral nuclear regions. That similarity was also noted in terminally differentiated granulocytes and monocytes. Thus, these progenitors were in the state of premature terminal differentiation and reflected the altered differentiation process. The large dominant incidence of such progenitors was noted in acute myeloblastic, acute promyelocytic and acute myelomonocytic leukemias with a known alteration of the further differentiation process.