Diagnosis of acute leukemia – classification
Diagnosis of acute leukemia includes the study of peripheral blood, bone marrow, in some cases – trepanobiopsy. All leukemias are divided into two large groups: acute non-lymphoblastic (ONLL), or myeloid (AML), and acute lymphoblastic (ALL) leukemia.
Anemia, thrombocytopenia and neutropenia are characteristic signs that are found in the majority of patients at diagnosis. T
rombocytopenia is determined in the vast majority of patients. The lowest rates of platelets (10-15 • 109 / l and below) are characteristic of acute promyelocytic leukemia. In 1-2% of cases of ONLL, thrombocytosis is noted in peripheral blood (more than 400 × 109 / L), sometimes combined with an increase in the number and dysplasia of megakaryocytes. A similar pattern is specific for patients with ONLL with chromosome 3 abnormality.
The number of leukocytes in the peripheral blood of patients with acute leukemia can vary within very wide limits – from 0.8 • 109 / l to 200 • 109 / l. In the hemogram, in most cases, blast cells are detected, their number is very variable (1-95%). It should be borne in mind that in some cases at the time of diagnosis, blasts in the blood may not be detected. As a rule, when calculating a blood formula, pronounced neutropenia draws attention.
Punctate of the bone marrow usually contains a sufficient number of myelokaryocytes (30-400 x 10 9 / L), low cellularity is noted in rare cases. Hypocellular bone marrow in combination with leukopenia is observed more often with promyelocytic leukemia.
A characteristic symptom of acute leukemia is blast metaplasia: the number of blast cells exceeds 20%. Normal hemopoiesis sprouts in the bone marrow are narrowed. In some cases, an increase in the number of pathological forms of normoblasts (erythromyelosis) or megakaryocytes (with anomalies of chromosome 3) is observed.