Acute leukoses - Practical hematology of children's age

Acute leukosis — a malignant tumor which pathological substrate is provided by young people, or blast, cells.
At children's age the acute leukosis in most cases meets. Many decades establishment of the diagnosis of an acute leukosis meant the unfavourable forecast. Rough increase of clinical signs, development of anemia, a hemorrhagic syndrome, necrotic changes, infectious complications within several months led to a lethal outcome. Modern development of science, development of means of polychemotherapy allow to approach treatment of this pathology more optimistically. Also the fact that the best results of treatment of an acute leukosis are achieved at children is pleasant. At an acute lymphoblastoid leukosis the percent of remissions at patients comes nearer to 100. According to the domestic and foreign children's hematologic centers, at a half of children 5 years' remissions are received. About 5% of children have superlong (7 — 10 years) remissions that allows to carry this contingent to recovering from an acute leukosis.
Search of objective criteria of classification of acute leukoses is conducted constantly. Experience demonstrates that morphological features cannot serve as objective criterion of differentiation. At modern therapy of leukoses, considerable extension of life of patients morphological forms of leukemic cells change. The stablest sign are cytochemical properties of blast cells which reflect features of an exchange and are individual at each look. Cytochemical criteria also are the basis for classification of acute leukoses. Different authors offer several options of classifications, however they have no basic character. Allocation of such forms of acute leukoses as lymphoblastoid, miyeloblastny, monoblast, miyelomonoblastny, promiyelotsitarny, an erythremic myelosis and a nondifferentiable form does not raise doubts. The cytochemical characteristic of these forms is provided to tab. 6.

Table 6. Cytochemical characteristic of various options of an acute leukosis (E. N. Mosyagina, N. A. Torubarov, E. B. Vladimirskaya, 1981).

Note: N-----reaction positive, ± — slabopolozhitelny,----------------negative.

For practical purposes it should be noted importance of allocation and differentiation of a lymphoblastoid form and group of the miyelomonoblastny nature. Tactics of treatment of the acute lymphoblastoid leukosis which is the most frequent form at children is other than that at other forms of an acute leukosis whereas acute miyeloblastny, monoblast and miyelomonoblastny leukoses are treated according to similar programs. Also the acute promiyelotsitarny leukosis having features of therapeutic tactics is subject to allocation. In classification of acute leukoses such forms as an erythroleukosis, an eosinophilic leukosis, a basphilic leukosis, plazmoblastny option, megakarioblastny option, a low-percentage form of an acute leukosis meet. However allocation of some forms remains diskutabelny, other forms in pediatric practice do not meet.
The clinical course of an acute leukosis at children under the influence of modern methods of therapy underwent qualitative changes. From quickly progressing acute process the leukosis passed into the category of diseases with a long wavy current. Allocate the next periods of a disease: initial, period of a full course of a disease, remission, aggravation and terminal. Now the period of remission is considered obligatory, especially at children with an acute lymphoblastoid leukosis. Long remission (more than 5 years) allows to speak about recovery. Return to kliniko-hematologic displays of an illness is treated as
to pass the recurrence of an acute leukosis able into an end-stage. At an acute lymphoblastoid leukosis at children recurrence of a disease can be stopped and transferred to a remission phase, however, already in smaller percent of cases again, than during the first attack. Allocation of the periods of leukemic process has practical value as in many respects defines the forecast of a disease and therapeutic tactics.