Myeloid leukemia is a type of blood or bone marrow cancer that causes a change in the number of blood cells, usually white blood cells (leukocytes), red blood cells, and platelets (platelets).
In a healthy person, the cells that form as white blood cells protect the body from infection.
If a person suffers from AML, the immature blasts do not become white blood cells.
Despite the increased number, the immature white blood cells are unable to protect the body from diseases and disorders.
A leukemia patient’s bone marrow cannot produce a sufficient number of healthy blood cells due to immature blood cells.
In general, the number of red blood cells, platelets and healthy white blood cells is much lower than the number of leukemia cells.
The decreased number of red blood cells and platelets together with the increased number of white blood cells is characteristic of leukemia.
Contents
Type of leukemia
Classification of leukemia by cell proliferation
Acute leukemia
It is a proliferative disease characterized by rapid growth of immature blood cells.
This growth prevents the bone marrow from producing healthy blood cells. The acute forms of dysplastic leukemia can occur in children and adults.
Prompt therapy is important due to the rapid progression and accumulation of malignant cells that spread to other organs via blood flow.
If left untreated, the patient dies within a few months or even weeks.
There is a serious variant of acute leukemia, which is also called fulminant leukemia. In this case, the course is very fast and causes the death of the person concerned in a very short time.
It used to be called acute non-lymphocytic leukemia.
Acute myeloid leukemia (AML) is more common in adults than in children.
Studies show that AML occurs primarily in men and less in women.
Chronic leukemia
Chronic leukemia is characterized by the massive accumulation of relatively mature but still abnormal blood cells.
The course is slow, usually progresses over months or years and the formation of cells compared to normal cells occurs faster with consequently increased levels of red blood cells in the blood.
Chronic leukemia occurs mainly in the elderly.
Sometimes chronic forms are monitored for some time before therapy to achieve maximum effectiveness of therapy.
Classification of leukemia according to type of blood cells affected
Myeloid leukemia
It is also called myeloid leukemia and affects the red blood cells and sometimes the white blood cells or platelets.
The above two groups form the basis of the four main types of leukemia.
These may have additional subcategories, but the most important types are:
Acute lymphocytic leukemia
Also known as acute lymphoblastic or lymphoid leukemia, it is the most common form of leukemia in children. This condition also affects adults, especially those aged 65 years or older.
It is a cancer of lymphocytes characterized by the overproduction and continuous proliferation of malignant immature white blood cells in the bone marrow. It is a blood cancer.
Chronic lymphocytic leukemia (CLL)
It is also called lymphoblastic leukemia and occurs when the B lymphocytes get out of hand and cause leukemia.
Often, chronic lymphocytic leukemia affects adults over 55 years of age.
Sometimes it occurs in adolescents, but does not affect children.
Chronic myeloid leukemia (CML)
It is also called chronic granulocytic or myelogenic leukemia.
CML occurs mainly in adults. Also, a very small number of children develop this disease. This species is characterized by the increased and regulated production of myeloid cells, especially in the bone marrow.
If a person suffers from CML, the organism tends to produce an enormously high number of immature and mature white blood cells. The white blood cells produced are called myelocytes.
Hairy cell leukemia (HCL)
In general, this tumor is a subtype of chronic lymphocytic leukemia.
This disease mainly affects adult men and is incurable.
However, there are treatments that allow control of tumoral proliferation.
Large granular lymphocyte leukemia
Involved are the T-lymphocytes or NK cells, it is a rare type of leukemia
It is not a very aggressive tumor, so treatment works in most cases.
Prolymphocytic leukemia of T cells (T-PLL)
This is a very rare form of aggressive leukemia. It affects adults and involves the mature T-lymphocytes. It is very difficult to treat, the survival rate is low.
Adult T-cell leukemia
The human T-lymphotropic virus (HTLV) can affect the T-lymphocytes CD4+.
This induces abnormal replication and proliferation and leads to adult T-cell leukemia.
Eosinophilic leukemia
Eosinophilic leukemia is characterized by a constant proliferation of eosinophils and their precursors.
What is aleucemic leukemia?
In aleucemic leukemia, the increase in the number of white blood cells is not revealed by a complete blood count. It is a rare leukemia. This type of leukemia can also be lymphocytic, monocytic, or myeloatical.
They are observed in people diagnosed with acute/chronic, lymphocytic/myeloid and prolymphocytic leukemia as well as myeloplastic syndrome.
Infantile leukemia
Similar to adult leukemia, infantile leukemia can be acute or chronic.
The immature white blood cells grow and reproduce much faster in the previous disease than in the latter.
In children, however, leukemia is mainly acute.
Acute infantile leukemia is divided into 3 categories:
- Acute lymphoblastic leukemia (ALL)
- Acute myeloid leukemia (AML)
- Hybrid leukemia
In ALL, the problem begins in the cells that make the lymphocytes, while in AML, the problem begins in the non-lymphocytic cells that make up the white and red blood cells, as well as the platelets.
Hybrid leukemia is a combination of ALL and AML, affecting lymphocytic and non-lymphocytic mother cells.
ALL represents the most common type of infantile leukemia, accounting for 70% of infantile leukemia cases.
The remaining 30% consists of AML and hybrid leukemia.
A rare form, juvenile myelomonocytic leukemia (JMML), occurs in young children under 4 years of age. It can be acute or chronic.
Because an excess of white blood cells leads to an abnormal red blood cell count, it is not uncommon for a child with leukemia to suffer from great fatigue and muscle weakness.
Causes of myeloid leukemia
The exact causes of leukemia are unknown, but it is believed that there are some responsible factors.
These factors cause a mutation of the DNA in the blood cells.
This causes them to grow and divide quickly.
Their lifespan is longer than that of normal cells in the blood.
Symptoms of myeloid leukemia
Chronic myeloid leukemia (CML)
This disease has 3 phases.
The chronic phase, in which there are no signs and symptoms, the acceleration phase (accelerated phase), in which the cells grow very quickly, and the phase of blast crisis, in which severe symptoms can occur.
Possible symptoms of CML:
- Fever
- Bone pain
- Ecchymoses and haemorrhages
- Fatigue and weakness
- Petechiae
- Heavy sweating
- Enlargement of the spleen, which causes pressure below the left-sided thorax
Acute myeloid leukemia (AML)
AML is also known as acute myelocytic or granulocytic leukemia.
It spreads rapidly in blood and bone marrow.
This is a very common type of leukemia in adults, only rarely are children affected.
Symptoms
- Fever
- Weight loss
- Fatigue
- Bone pain with and without sensory disturbances
- Shortness of breath
- Haematoma
- lesions or rashes
- Nosebleeds, bleeding gums, and copious menstrual bleeding
Symptoms in children
According to the number of leukemia cells, the children show different symptoms.
These children appear pale, weak and anemic. In addition, they show other symptoms:
- Fever
- Joint and bone pain
- Formation of painless blood clots on the neck, armpits, groin and stomach
- Weakness
- Tiredness and exhaustion
- Anorexia
- Petechiae (small flat red spots under the skin due to bleeding)
- Mild formation of ecchymosis
- Gum and nosebleeds
- Gasping breath (especially in the final phase)
- Recurrent infections
A decrease in the number of red blood cells also causes skin pallor and lymph node enlargement due to the excessive white blood cells in the blood.
Diagnosis of myeloid leukemia
If the patient’s signs and symptoms indicate leukemia, the doctor must take a sample of the bone marrow cells for the laboratory to confirm the diagnosis.
Examination of the bone marrow
The bone marrow sample is taken using 2 methods performed simultaneously.
- Aspiration of bone marrow
- Biopsy of the bone marrow
The samples are taken from the posterior hip area, but sometimes they are also taken from other bones.
The FAB classification of AML
1970 divided a group of French, American and British experts into acute myeloid leukemia into subspecies from M0 to M7, based on the cell type that developed the leukemia and the degree of maturity of the cells.
| FAB subtype | Designation |
| M | Acute myeloid leukemia with minimal differentiation |
| M | Acute myeloid leukemia without maturation |
| M | Acute myeloid leukemia with maturation |
| M | Acute promyelocyte leukemia (APL) |
| M | Acute myelomonocytic leukemia with eosinophilia |
| M | Acute monocyte leukemia |
| M | Acute erythroleukemia |
| M | Acute megakaryoblast leukemia |
Treatment of myeloid leukemia
Treatment includes:
- Chemotherapy, for example hydroxycarbamide (Syrea®)
- Radiotherapy
- Transplantation of hematopoietic stem cells
How long do you live? Prognosis
From 2003 to 2009, the survival rate after 5 years for children was:
- ALL: 91.7% for children and adolescents under 15 years and 92.6% for children under 5 years
- AML: 64.8% for children and adolescents under 15 years of age
Survival rate statistics have improved significantly over the past five decades.
Most children and adolescents under the age of 20 who have ALL survive at least 5 years or experience complete remission (healing).
In severe cases, the disease is frozen (does not respond to treatment) or recurrence (relapse) occurs after complete remission of symptoms.
Survival rate in adults
Adults are more susceptible to chronic leukemia. The five-year survival rate is approximately 40% after chemotherapy. In adults with acute lymphocytic leukemia, the five-year survival rate is about 35%.
