Acute myeloid leukemias – diagnosis

The initial CNS lesion in acute myeloid leukemia is rare and is also most often associated with myelomonoblastic and monoblastic AML variants and during hyperleukocytosis.

In the debut of the disease in the blood are determined by very diverse changes. Power cells are found in 85-90% of patients, and their percentage ranges from 2-3 to 90-95. Neutropenia, anemia, and thrombocytopenia of varying severity are common at the time of diagnosis. In more than half of the patients, the number of leukocytes is increased, but the number of leukocytes more than 100 • 109 / l is determined in less than 20% of patients.

Hyperleukocytosis in acute myeloid leukemia, in contrast to ALL, often has clinical manifestations: leukostasis occurs in brain vessels, causing neurological symptoms (headache, workload, inability to concentrate), in vessels of the lungs, which manifests as respiratory failure, in kidney vessels, etc. e. As a prognostic criterion, the most frequently used leukocyte count is 30 • 109 / l; if at the time of diagnosis their content is more, patients are considered to be at high risk.

In certain forms of acute myeloid leukemia, most often in acute promyelocytic leukemia, a prominent clinical sign is DIC and activated fibrinolysis syndrome, which are manifested by severe bleeding or, less commonly, thrombotic complications. This is due to the release of procoagulants from azurophilic granules of leukemic cells and is often aggravated during cytostatic therapy due to their destruction.

In half of the patients with acute myeloid leukemia, hyperuricemia is observed, especially during the beginning of chemotherapy and tumor cell lysis. With monoblastic and myelomonoblastic acute leukemia, serum levels of lysozyme are possible. The increased content of lysozyme aggravates damage to the renal tubules, causes deep hypokalemia, not associated with diuretics and antibiotics. In a number of patients, an increase in the serum LDH content is noted. This indicator serves as a prognostic criterion: its 2-fold increase in relation to the norm indicates an unfavorable prognosis.

In the bone marrow is found from 20 to 99% of blast cells. The bone marrow is in most cases hypercellular, adipose tissue is completely replaced by tumor cells, the number of megakaryocytes is usually reduced, they are dystrophic. As noted, in 30% of patients with primary AML, one or other signs of hematopoiesis are noted. In this regard, it is unclear why in the modern classification of leukemias with this characteristic, belonging to different morphological and cytochemical variants, belong to a separate category.

Both dizeritroez, and / or dysgranulocytopoiesis, and / or dizegakaryocytopoiesis, or combinations thereof are detected. Dyserythropoiesis is characterized by hyperplasia of the red sprout or its substantial decrease, a disproportionate increase in the number of immature forms, megaloblastoidity, nuclear splitting, multi-core, vacuolization and cytoplasmic outgrowths, ring sideroblasts. Dizgranomonocytopoez is characterized by hyper- or hypoplasia of the cells of the man-made creatures, monitored by the pseudo-Egerger, the pseudopergerian anomaly, the dissociation between the degree of maturity of the nucleus and the cytoplasm, the hypersegmentation of the nucleus, the ring nuclei, microflora of the granulocyte, myelocyte, and the cell culture, the hypersegmentation of the nucleus, the ring nuclei, the microform of the granulocyte, the myelocyte, and the cell culture;

Dimegakaryocytopoiesis includes the following features: hyper- or hypoplasia of the germ, an increase in the number of microforms, single-binuclear megakaryocytes, vacuolization of the cytoplasm.

Trilinear dysplasia occurs on average in 5–7% of patients (with age, the probability of detecting this morphological phenomenon increases by 2–3 times). It was believed that patients in whom, at the time of diagnosis of OL, three-linear hemopoiesis dysplasia is determined, regardless of the ONLL variant, should be included in the group of poor prognosis for long-term survival. However, as emphasized, modern works refute this position.

The diagnostic signs and features of acute myeloid leukemia considered are the result of routine research. No less significant at present for the differential diagnosis and assessment of prognostic factors are those signs that are established during immunophenotyping of power cells, with their cytogenetic and molecular-biological studies.
Source: MedUniver

Leave a Reply

Your email address will not be published. Required fields are marked *