Features of individual forms of non-lymphoblastic leukemia
Acute myeloblastic( M1, M2) and myelomonoblast( M4) leukemia have almost the same morphological features and do not differ in the clinical picture of the disease. They account for 62-73% of all onLL.At the same time, acute myelomonoblastic leukemia can be represented by blast cells belonging to myeloblasts and monoblasts, but more often blasts in this form of leukemia have cytochemical signs of both monocytic and granulocyte numbers. The frequency of remission in acute myelogenous and myelomonoblastic leukemia under conditions of modern therapy is 60-80% [Vladimirskaya E.B.et al., 1998].The duration of remission is 12-24 months, and the life expectancy of patients may exceed 3 years. In 10% of cases, recovery is noted. Acute promyelocytic leukemia( M3).Cellular substrates of this form of leukemia are blasts, characterized by abundant azurophilic granularity and reminiscent of promyelocytes. Blasts are large( 15-20 nm) and a large eccentrically located nucleus of irregular shape, sometimes dicotyledonous, of a delicate chromatin structure. Nucleol in the nucleus is not always clearly delimited. The number of blast cells containing azurophilic granularity is at least 50%.It is believed that if granularity is found in 30-40% of blasts and more - it is promyelocytic leukemia, if less than 20% - myeloblastic. Possible cytoplasmic outgrowths, which are devoid of granules. Basophilia of the cytoplasm is expressed in varying degrees. The red bone marrow is marked by total infiltration with promyelocytes. The number of blasts in the blood is 40-85% [Morozova VT, 1977].Erythropoiesis and megakaryo-cytopoiesis are sharply depressed. Acute promyelocytic leukemia is observed in 5-10% of cases of ONL.The clinical picture of the disease is characterized by severe hemorrhagic syndrome, which appears against a background of moderate thrombocytopenia( 20-100x109 / L).The development of hemorrhagic
syndrome is due to ICE, as well as the release of heparin-like substances from leukemia cells.
Acute erythromyelosis( Di Guglielmo disease, M6) is a rare form of leukemia( 5% of all cases).Changes in the punctate of the bone marrow do not differ from M2.The picture of blood at the beginning of the disease may be aleukemic, but as the disease develops, leukemia occurs: erythrocaryocytes and / or blasts enter the bloodstream. Anemia is usually mildly hyperchromic, normoblasts are detected in the blood, reticulocytes are less than 1%.Leukopenia and thrombocytopenia are often developed at the very beginning of the disease.