In the article we will consider the classification, forms and types of leukemia.
Leukemia (leukemia, leukemia) is a clonal disease of the hematopoietic system. This name unites a whole group of pathologies. The development of this disease is due to the transformation and mutation of cells that are in the bone marrow and are responsible for the process of hematopoiesis. There are several types of leukemia, and among other oncological diseases, these ailments are not the most common. The most common pathology occurs in children aged three to four years, as well as in the elderly (60-70 years).
Types of leukemia are detailed below.
Etymology and pathogenesis
At the moment, medicine does not know the exact cause of leukemia. Nevertheless, scientists have established factors that are considered fundamental in the development of this disease:
- Genetic. It is generally accepted that the presence of leukemia in a blooda relative by 3-4 times increases the likelihood of developing pathology in the next generations. It is the genetic factor that causes the manifestation of leukemia in children.
- Carcinogenic, chemical. This factor involves the use of certain drugs intended for the treatment of various pathological conditions. First of all, they include penicillin antibiotics. This factor also includes prolonged and systematic contact with various kinds of polymer paints, varnishes, detergents.
- Viral and infectious diseases suffered by the patient during his life. Scientists suggest that a virus that enters the human body interacts with he althy cells and thereby causes the process of their pathological degeneration and irreversible mutation. This factor is considered provoking, contributing to the emergence and development of malignant tumors.
- Radiation. When exposed to radioactive rays on the body, the risk of developing this pathology increases significantly.
Stages
Regardless of the type of leukemia, each of them goes through the following stages in its development:
- Initiation stage. Under the influence of any factor, a tumor degeneration of hematopoietic stem cells begins. This is due to damage to prooncogenes that turn into oncogenes, as well as damage to antioncogenes.
- Promotion stage. Uncontrolled growth and reproduction of transformed cells in the bone marrow begins. Parallelleukemic clones are formed. This stage can last for several years, and it is not clinically manifested.
- Progression stage. A monoclonal tumor begins to turn into a polyclonal one.
- Metastasis stage. At this stage, pathological hematopoiesis exits the bone marrow. It spreads to other tissues and organs (liver, lymph nodes). This process is due to the proliferation of diseased cells. As a result, the organs increase, their dysfunction is observed.
Types of leukemia
During the development of pathology, certain types of blood cells are converted into malignant ones. In this regard, there is a classification of leukemia based on the type of lesion.
According to this, there are two types of leukemia: lymphocytic leukemia and myeloid leukemia. Each of them, in turn, can be acute or chronic.
It should be noted that the classification into chronic or acute forms is not based on the nature of the course of the disease. The specificity of the classification lies in the fact that these two forms are not interconnected and cannot flow into each other. Only in rare cases can a chronic illness be complicated by an acute course.
Types, causes and symptoms of acute leukemia are of interest to many.
In the development of the disease, a latent period and a period of symptom expression are distinguished. The first period is characterized by the absence of clinical symptoms. There is a proliferation of cells, but their number is not at a critical level. The duration of the latent period ranges from several months toseveral years. The period of symptom expression is characterized by a decrease in the functionality of the hematopoietic system as a result of a critical level of the number of tumor cells.
Syndromes
All clinical manifestations of leukemia are divided into 4 groups of syndromes:
- Hyperplastic syndromes. The characteristic signs of hyperplastic syndromes are enlargement and soreness of the lymph nodes, enlargement of the spleen and liver, the appearance of pain and aches in the joints, the appearance of reddish-bluish plaques on the skin, lesions of the oral mucosa, tonsils, the development of necrotic stomatitis, gum hyperplasia. Syndromes are caused by leukemic infiltration of the spleen, liver, articular capsule and periosteum, as well as a tumor increase in bone marrow volume.
- Hemorrhagic syndromes. Manifested by the occurrence of bleeding and hemorrhage (gingival, nasal, internal). Very often causeless bruises appear, even a minor injury can cause almost unstoppable bleeding, wounds heal over a long period. Syndromes are caused by a violation of blood clotting against the background of damage to platelets.
- Anemic syndromes. There is weight loss, increased heart rate, hair loss, general malaise, pale skin, memory impairment and loss of concentration. Syndromes are caused by a decrease in hemoglobin levels, as there are not enough red blood cells in the blood.
- Immunodeficiency and intoxication syndromes. Manifestthey are in the form of weakness, fever, excessive sweating, headache, nausea and vomiting, lack of appetite, significant weight loss, the development of various infectious and inflammatory processes that are very difficult.
Each type of leukemia has its own specific symptoms. They also differ in the course of pathology.
So what are the main types of leukemia?
Acute lymphoblastic leukemia
This type of disease most often affects children and people at a young age.
The disease is characterized by a rapid increase in the number of blasts - immature cells, precursors of lymphocytes. They accumulate in the lymph nodes, spleen, creating an obstacle to the formation and functioning of normal blood components.
Patients often complain of fatigue, intermittent joint pain. Some of them note an increase in the cervical, inguinal and axillary lymph nodes. After some time, pronounced manifestations of the disease begin to be observed.
This type of acute leukemia may be suspected if the following symptoms are present:
- Severe sore throat.
- Anemia, in which the number of leukocytes in the blood increases sharply, while the number of platelets decreases.
- The spleen is enlarged.
- The temperature is rising. It can be slightly elevated or consistently high.
- Increased bleeding gums, frequent nosebleeds, tendency to bruise from minor injuries.
- The defeat of the ribs, clavicles and bones of the skullinfiltrate.
This type - acute lymphoblastic leukemia - most often manifests itself in children aged 3-6 years. Symptoms are as follows:
- The spleen and liver are enlarged, against the background of which the size of the child's abdomen increases significantly.
- Lymph nodes increase. Enlargement of the thoracic lymph nodes is accompanied by the appearance of shortness of breath and painful dry cough.
- This type of leukemia in children causes pain in the abdomen and legs.
- The child has pale skin, gets tired quickly.
- When infected with ARVI, pronounced manifestations are observed.
- Child often falls, loses balance.
What other types of acute leukemia are there?
Acute Myeloid Leukemia
This type of leukemia often affects adult and elderly patients. It is very difficult to recognize it, it is characterized by uncontrolled growth and accumulation of cells that have a hematopoietic nature. Localized acute myeloid leukemia in the bone marrow and peripheral blood.
This type of leukemia has no characteristic symptoms. Most often, patients report the appearance of pain in the bones, fever, fatigue, pallor and cyanosis of the skin, shortness of breath and loss of appetite.
Reduced platelet levels cause excessive blood loss when injured or injured. As a result of a decrease in the level of full-fledged leukocytes, immunity is suppressed, infectious diseases occur more often, chronic ones become aggravated andbecome resistant to therapy. In acute myeloid leukemia, swelling on the gums may appear, and lesions of the mucous membranes of the gastrointestinal tract and mouth are not excluded.
Let's also consider types of leukemia in adults.
Chronic lymphoblastic leukemia
This disease affects people over the age of 50 years. Has a long course. Characterized by the accumulation of tumor lymphocytes in the peripheral blood, spleen, liver, lymph nodes, bone marrow.
The main difference from acute lymphoblastic leukemia is the slow growth of the tumor. Only in the later stages of the disease are hematopoietic disorders observed.
The first and main symptom of chronic lymphoblastic leukemia is an enlarged spleen and lymph nodes. The patient feels pain in the hypochondrium on the left. In addition, the disease is accompanied by symptoms characteristic of other types of leukemia, but they develop over a long period.
Approximately a quarter of cases are discovered as a result of a laboratory blood test ordered for another ailment. The analysis shows a greatly increased number of lymphocytes (up to 95%). There is a significantly reduced level of erythrocytes and, as a result, hemoglobin. The chronic course of this type of leukemia in adults can last 3-7 years.
Chronic myeloid leukemia
This type of disease is the most common. Most often it affects adults. Doctors believe that the predisposition to this pathologydue to heredity and has a relationship with a defect in the chromosomes.
The initial stages of the disease have no pronounced manifestations, almost never detected during diagnosis. Leukemia can be detected by chance during a laboratory blood test. It detects an inexplicable increased number of leukocytes, an increase in the number of eosinophils and basophils with varying degrees of maturity. No signs of anemia.
The most common form of leukemia is chronic, which can last for several years. It is worth noting that this type of leukemia is well controlled with medication.
At this stage, the disease begins to manifest itself in the form of fever, fatigue, weight loss, pain in the left hypochondrium against the background of an increase in the size of the spleen, an increase in the size of the liver.
Bone marrow at this stage contains approximately 5% of blasts. Quite often at this time there is a suspicion of the presence of chronic myeloid leukemia. Treatment involves a course of chemotherapy, which results in a period of remission. Subject to the prescribed treatment, the state of remission can last more than 5 years.
We continue the cytomorphological characterization of various types of leukemia.
Hairy cell lymphocytic and juvenile myelomonocytic leukemia
These forms of leukemia are observed in different age groups.
A special form of leukemia is juvenile myelomonocytic. Thisthe disease affects children of two to four years. This type of leukemia is the rarest of all. More commonly seen in boys. Doctors believe that the reason for its development lies in heredity.
Symptoms of juvenile myelomonocytic leukemia are manifested in the form of signs of anemia: bleeding gums, nosebleeds, physical underdevelopment, which is expressed by a lack of height and weight.
The distinctive feature of this type of leukemia is its sudden onset. If a pathology is detected, immediate intervention of doctors is necessary. However, therapeutic methods are powerless in this case, and the only chance for a cure is allogeneic bone marrow transplantation.
Very rare disease is hairy cell lymphocytic leukemia. The risk group is people over the age of 50. The course of the disease is very long and slow. This type of leukemia can be refractory, progressive, untreated.
The first two are the most common. Symptoms of the disease are often attributed to the age of the patient, as a result, it proceeds hidden. A blood test reveals an increased ten, and sometimes a hundred times, level of leukocytes. Hemoglobin, platelets and red blood cells are reduced to a minimum.
The following are the types of blood leukemia in adults in the table.
| Type of disease | Location of defeat |
| Acute lymphoblastic disease | Lymph nodes, spleen |
| Acute myeloid disease | Peripheral blood, bone marrow |
| Chronic lymphoblastic disease | Peripheral blood, liver, bone marrow, spleen, lymph nodes |
| Chronic myeloid disease | Liver, spleen, bone marrow |
| Juvenile myelomonocytic | Bone marrow |
| Hairy cell lymphocytic | Lymph nodes |
Animal leukemias
Leukemia is also quite common in animals. However, unlike leukemia in humans, the disease in animals is viral in nature.
Hemoblastosis (leukemia, leukemia, leukemia) is a disease of a tumor nature affecting the hematopoietic tissue of animals. The disease is characterized by a violation of the process of hematopoiesis, which is expressed in the uncontrolled reproduction of pathological leukemic cells that have not reached maturity. It can be observed not only in the organs of hematopoiesis, but also in other systems and organs. From farm animals, leukemia is most often found in cows, from birds - in chickens. There are many forms of animal leukemia. Bovine lymphocytic leukemia, as well as various forms of avian leukemia, cause the greatest economic damage to animal husbandry.
The spread of leukemia in certain animal species occurs as a result of exposure to oncornaviruses belonging to the Retraviridae family. Their development largely depends on the immunological state of the animal and the genetic predisposition to the disease.
Direct relationship between leukemiafarm animals and people are absent. It should be noted that animals under the influence of chemical and radiation factors can develop various types and forms of leukemia.
Leukemia runs for quite a long time, which can be up to several years. In most cases, specific clinical signs are not detected. As a result of the growth of tumor-like defective cells, as well as against the background of leukemia infiltration of various organs, general intoxication of the animal's body occurs, the function of the affected systems and organs is disrupted, and general exhaustion is observed.
How is the diagnosis made?
Diagnosis is based on a laboratory blood test showing an increased number of lymphoid and myeloid leukocytes in the blood, as well as an increased percentage of lymphocytes. Also, the disease can be detected by histological or pathoanatomical examination.
Treatment of leukemia in animals is considered irrational. Preventive measures and methods of combating leukemia include protective measures aimed at protecting farms from infection, as well as timely vaccination of livestock.
We looked at the types and signs of leukemia (leukemia).
