Acute leukemias are clonal malignant neoplastic diseases which do not originate from the transformation of totipotent hematopoietic stem cells but of progenitors committed to the myeloid, T-lymphatic or B-lymphatic differentiation lineage. The transforming event seems to be associated with a nonrandom aberrant DNA rearrangement. Although a leukemic population is clonal, originating from a single cell, it exhibits phenotypic, and sometimes even karyotypic, heterogeneity. Leukemic cells are allocated to a particular differentiation cell lineage on the basis of a positive finding of the lineage specific differentiation marker (LSDM) in the presented classification of acute leukemias. Criteria for common types of acute myeloid leukemias are described and the possible existence of several other types is discussed.

Institute of Hematology and Blood Transfusion Prague Czechoslovakia

To the intranucleolar translocation of AgNORs in leukemic early granulocytic and plasmacytic precursors