All leukemias (leukemia) are divided into two types – acute and chronic. This division is due to the different ability of leukemias to grow and develop proliferating cells.
With acute leukemia, the development of cells is practically absent, a large number of immature cells accumulate in the blood at an early stage of development. This leads to the inhibition of normal hematopoiesis of all sprouts. Such signs are detected in the blood in more than 80% of cases.
Chronic leukemia produces a population of granulocyte cells that are growing, which gradually replace normal peripheral blood cells.
It should be noted that acute leukemia will never go to chronic and vice versa.
All leukocytes in the human body are divided into 2 types – granulocyte and agranulocyte (granular and non-granular), these two groups, in turn, are divided into eosinophils, basophils, neutrophils (granulocyte), and lymphocytes (B- and T-type) and monocytes (agranulocyte). In the process of maturation and development (differentiation), all cells undergo several stages, the first of which is the blast stage (lymphoblasts). Because of the bone marrow involvement by the tumor, the lymphocytes do not have enough time to develop in order to fully perform their protective functions. For the most part, in acute lymphoblastic leukemia, B-lymphocytes (approximately 85% of cases) are responsible for the formation of antibodies in the body. There are two types of acute lymphoblastic leukemia (ALL): B-linear and T-linear, depending on the type of cells – lymphoid progenitors.
Clinical symptoms of acute lymphoblastic leukemia
Syndrome of intoxication – weakness, fever, malaise, weight loss. Fever may also be associated with the presence of a bacterial, viral, fungal or protozoal (less common) infection, especially in children with neutropenia (less than 1500 neutrophils per 1 μl).
Hyperplastic syndrome – an increase in all groups of peripheral lymph nodes. Infiltration of the liver and spleen leads to their increase, which can be manifested by pain in the abdomen. There may be pain and aches in the bones due to leukemia infiltration of the periosteum and articular capsule and a tumor increase in the volume of the bone marrow. At the same time, on radiographs, it is possible to detect changes characteristic of leukemia infiltration, especially in tubular bones, near large joints.
Anemic syndrome – pallor, weakness, tachycardia, hemorrhage of the oral mucosa, hemorrhagic syndrome on the skin, pallor. Weakness occurs as a result of anemia and intoxication.
Hemorrhagic syndrome is associated with both thrombocytopenia and intravascular thrombosis (especially with hyperleukocytosis) and leads to the appearance of petechiae, ecchymoses on the skin and mucous membranes, hemorrhages, melena, vomiting with blood.
In boys, an initial increase in the testicles (5-30% of cases of primary ALL) can be detected. These are painless, dense, one- or two-sided infiltrates. Especially often it happens with hyperleukocytosis and T-cell variant of ALL.
Respiratory disorders associated with enlarged lymph nodes of the mediastinum, which can lead to respiratory failure. This feature is characteristic of the T-linear ALL.
There may appear hemorrhages in the retina of the eye, edema of the optic nerve. At an ophthalmoscopy leukemic plaques on an eyeground can be found out.
Because of the greatly reduced immunity, any skin damage is the focus of infection, paronychia, panaritium, infected insect bites and injection marks may appear.
Quite rare complications can be kidney damage as a result of infiltration (clinical manifestations may be absent) and exudate pericarditis due to impaired lymph flow between the endocardium and the epicardium.
Acute leukemia is a form of cancer that develops very quickly and during which the altered leukocytes accumulate in the blood and bone marrow. Acute leukemia can be of several types: lymphoblastic leukemia, which occurs most often in children, and granulocytic leukemia, which can be found most often in adults.
In the first case of leukemia, the changed leukocytes are collected in the bone marrow or lymph nodes, and in the case of granulocyte leukemia, leukocytes accumulate in the bone marrow.
The causes of leukemia
The causes of leukemia are still unknown. There is an opinion according to which there are some factors that make the risk of leukemia higher. These are genetic disorders, problems with the immune system, the effects of radiation and some chemicals that suppress hematopoiesis.
Symptomatic of acute leukemia
When an acute leukemia occurs, a person experiences high fever, weakness in the body, and other symptoms that are similar to the symptoms of influenza. Lymph nodes, as well as the liver and spleen, are increasing. There is a pain in the bones. Blood is poorly drained, bruises appear from a weak touch. Bleeding provokes the appearance of red or purple spots on the skin. There are frequent infections, weakness is progressing.
Chronic lymphocytic leukemia is an oncological disease of the lymphatic tissue, in which tumor lymphocytes accumulate in the peripheral blood, bone marrow and lymph nodes. Unlike acute leukemia, the tumor grows slowly enough, as a result of which hematopoiesis disorders develop only in the late stages of the disease.
Symptoms of chronic lymphocytic leukemia
- Enlargement of lymph nodes
- Heaviness in the abdomen (in the left hypochondrium)
- Inclination to infections
- Weight loss
Most often, the first symptom of chronic lymphocytic leukemia is an increase in the size of the lymph nodes. Due to the enlargement of the spleen, there may be a sensation of heaviness in the abdomen. Often, patients experience significant general weakness, lose weight, they have an increased incidence of infectious diseases. Symptoms develop gradually, for a long time. Approximately in 25% of cases, the disease is detected by accident when analyzing blood prescribed for another reason (medical examination, examination for non-hematological disease).
In order to diagnose chronic lymphocytic leukemia, the following studies should be carried out:
Clinical blood count with counting of leukocyte formula
The examination of the bone marrow makes it possible to reveal a picture of the lesion characteristic of this disease.
Immunophenotyping of bone marrow cells and peripheral blood reveals specific immunological markers characteristic of tumor cells in chronic lymphocytic leukemia.
Biopsy of the affected lymph node with its morphological and immunological examination.
Determining the level of β 2-microglobulin helps predict the course of the disease.
Cytogenetic analysis allows obtaining data on the characteristics of tumor cells, which in some cases have prognostic significance.
Determination of the level of immunoglobulins allows to determine how great the risk of development of infectious complications in this patient.
There are several approaches to determining the stages of chronic lymphocytic leukemia – the Rai, Binet system and the International Working Group on Chronic Lymphocytic Leukemia. All of them take into account the fact that the life expectancy of patients with chronic lymphocytic leukemia depends on the extent of the tumor (the number of affected groups of lymph nodes) and the degree of hemopoiesis in the bone marrow. Disturbance of bone marrow hematopoiesis, caused by tumor growth in the bone marrow, leads to the development of anemia (a decrease in the number of erythrocytes in the blood) and thrombocytopenia (decrease in the number of platelets). Determination of the stage of chronic lymphocytic leukemia allows to make a decision about the need to start treatment and choose the most suitable regimen for this patient.
Acute myeloblastic leukemia (acute granulocytic leukemia, acute myelocytic leukemia) often occurs in adults, the subtype depends on the level of cell differentiation. In most cases, the myeloblastic clone of cells is derived from stem hemopoietic cells capable of multiple differentiation into colony-forming units of granulocytes, erythrocytes, macrophages or megakaryocytes; therefore, in most patients malignant clones do not show signs of lymphoid or erythroid sprouts AML are observed most often; has four variants (M0 – M3) mo and M1 – acute without cell differentiation
M2 – acute with differentiation of M3 cells – promyeloblast leukemia, characterized by the presence of abnormal promyelocytes with giant granules; often combined with ICE, due to the thromboplasty effect of granules, which casts doubt on the usefulness of heparin in therapy. The prognosis for M: is more favorable than for M0-M, myelomonoblast and monoblast leukemia (M4 and M5, respectively) are characterized by the predominance of non-erythroid cells like monoblast. M <and M5 constitute 5-10% of all cases of acute myeloblastic leukemia. A frequent sign is the formation of extraostestinal foci of hematopoiesis in the liver, spleen, gingiva and skin, hyperleukocytosis exceeding 50-100×109 / l. Sensitivity to therapy and survival is lower than in other variants of acute myeloblastic leukemias Erythromycosis (Mv). The variant of acute myeloblastic leukemia, accompanied by increased proliferation of erythroid progenitors; characterized by the presence of abnormal blast nucleus-containing red blood cells. Efficacy of treatment of erythroleukemia is similar to the results of therapy of other subtypes, or somewhat lower. Megacaryoblastic leukemia (M7) is a rare variant associated with bone marrow fibrosis (acute myelosclerosis). Poorly gives in to therapy. The outlook is unfavorable.
Acute promyelocytic leukemia (APL, AML M3, OPML) is a variant of acute myeloid leukemia, which is characterized by abnormal accumulation of one of myeloid cells – promyelocytes. In turn, promyelocytes (see the article “Hemopoiesis”) are the precursor cells of granulocytes arising at one of the stages of their maturation (myeloblasts – promyelocytes – myelocytes – granulocytes).
Frequency of occurrence
APL is about 10% of all cases of acute myeloid leukemia. Unlike many other variants of acute myelogenous leukemia, APL is often found not in the elderly, but in young adults: the average age of patients at the time of diagnosis is about 40 years. However, APL can occur at any age, including children.
Signs and Symptoms
Like other types of acute leukemia, APL is usually characterized by manifestations of anemia (fatigue, weakness, dyspnea) and thrombocytopenia, that is, a lack of platelets (increased bleeding, bruising and bruising). Lack of normal leukocytes leads to infections. In addition, with PAL, bleeding may be observed in addition to the syndrome of disseminated intravascular coagulation (ICD). This is the most formidable symptom of PLA.
As a rule, APL is characterized by a very rapid appearance and increase in symptoms.
APL is diagnosed on the basis of morphological and cytochemical analysis of a bone marrow sample. Diagnostics necessarily involves the detection of a characteristic chromosomal translocation of t (15; 17) (sometimes other, much rarer translocations) during a standard cytogenetic or molecular-genetic (polymerase chain reaction) assay.
Acute myeloid (myelocytic, myelogenous, myeloblastic, myelomonocytic) leukemia is a life-threatening disease in which myelocytes (cells from which granulocytes normally develop) become malignant and quickly displace normal cells in the bone marrow. This type of leukemia occurs in people of all ages, but mainly in adults.
The first symptoms are usually due to the fact that the bone marrow is unable to produce a sufficient number of normal blood cells. There are weakness, shortness of breath, fever and bleeding, infections often develop. Other possible symptoms are headaches, vomiting, irritability, pain in the bones and joints.
The likelihood of developing acute myeloid leukemia increases in the event of exposure to large doses of radiation and the use of certain chemotherapy agents for malignant tumors.
Leukemia cells accumulate in the bone marrow, destroying and replacing healthy cells from which normal blood cells should be produced. Malignant cells enter the bloodstream and enter other organs, where they continue to grow and divide. They can form small tumors (chloromas) under the skin; penetration into other organs may be accompanied by the development of meningitis, anemia, hepatic and renal insufficiency and damage to other organs.