- Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many immature lymphocytes (a type of white blood cell).
- Family history and being exposed to radiation may affect the risk of developing childhood ALL.
- Possible signs of childhood ALL include fever and bruising.
- Tests that examine the blood and bone marrow are used to detect (find) and diagnose childhood ALL.
- Certain factors affect prognosis (chance of recovery) and treatment options.
Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many immature lymphocytes (a type of white blood cell).
Childhood acute lymphoblastic leukemia (also called acute lymphocytic leukemia or ALL) is a cancer of the blood and bone marrow. This type of cancer usually gets worse quickly if it is not treated.
ALL is the most common type of cancer in children.
In a healthy child, the bone marrow makes blood stem cells (immature cells) that become mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell.
A myeloid stem cell becomes one of three types of mature blood cells:
- Red blood cells that carry oxygen and other substances to all tissues of the body.
- Platelets that form blood clots to stop bleeding.
- White blood cells that fight infection and disease.
A lymphoid stem cell becomes a lymphoblast cell and then one of three types of lymphocytes (white blood cells):
- B lymphocytes that make antibodies to help fight infection.
- T lymphocytes that help B lymphocytes make the antibodies that help fight infection.
- Natural killer cells that attack cancer cells and viruses.
In a child with ALL, too many stem cells become lymphoblasts, B lymphocytes, or T lymphocytes. These cells are cancer (leukemia) cells. The leukemia cells do not work like normal lymphocytes and are not able to fight infection very well. Also, as the number of leukemia cells increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. This may lead to infection, anemia, and easy bleeding.
This summary is about acute lymphoblastic leukemia in children, teenagers, and young adults. See the following PDQ summaries for information about other types of leukemia:
- Childhood Acute Myeloid Leukemia/Other Myeloid Malignancies Treatment
- Adult Acute Lymphoblastic Leukemia Treatment
- Chronic Lymphocytic Leukemia Treatment
- Adult Acute Myeloid Leukemia Treatment
- Chronic Myelogenous Leukemia Treatment
- Hairy Cell Leukemia Treatment
Family history and being exposed to radiation may affect the risk of developing childhood ALL.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk with your child’s doctor if you think your child may be at risk.
Possible risk factors for ALL include the following:
- Being exposed to x-rays before birth.
- Being exposed to radiation.
- Past treatment with chemotherapy.
- Having certain changes in the genes.
- Having certain genetic conditions that include the following:
- Down syndrome.
- Bloom syndrome.
- Shwachman syndrome.
Possible signs of childhood ALL include fever and bruising.
These and other symptoms may be caused by childhood ALL. Other conditions may cause the same symptoms. Check with your child’s doctor if your child has any of the following problems:
- Easy bruising or bleeding.
- Petechiae (flat, pinpoint, dark-red spots under the skin caused by bleeding).
- Bone or joint pain.
- Painless lumps in the neck, underarm, stomach, or groin.
- Pain or feeling of fullness below the ribs.
- Weakness, feeling tired, or looking pale.
- Loss of appetite.
Tests that examine the blood and bone marrow are used to detect (find) and diagnose childhood ALL.
The following tests and procedures may be used:
- Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
- Complete blood count (CBC) with differential : A procedure in which a sample of blood is drawn and checked for the following:
- The number of red blood cells and platelets.
- The number and type of white blood cells.
- The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
- The portion of the sample made up of red blood cells.
Bone marrow aspiration and biopsy : The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for signs of cancer.
Cytogenetic analysis : A laboratory test in which the cells in a sample of blood or bone marrow are viewed under a microscope to look for certain changes in the chromosomes in the lymphocytes. For example, in Philadelphia chromosome-positive ALL, part of one chromosome is moved to another chromosome. This is called the “Philadelphia chromosome.” Other tests, such as fluorescence in situ hybridization (FISH), may also be done to look for certain changes in the chromosomes.
- Immunophenotyping : A test in which the cells in a sample of blood or bone marrow are looked at under a microscope to find out if malignant lymphocytes (cancer) began from the B lymphocytes or the T lymphocytes.
- Blood chemistry studies : A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
- Chest x-ray : An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) depends on:
- Age at diagnosis, gender, and race.
- The number of white blood cells at diagnosis.
- Whether the leukemia cells began from B lymphocytes or T lymphocytes.
- Whether there are certain changes in the chromosomes of lymphocytes.
- Whether the child has Down syndrome.
- Whether the leukemia has spread to the brain, spinal cord, or testicles.
- How quickly and how low the leukemia cell count drops after initial treatment.
The treatment options depend on:
- Whether the leukemia cells began from B lymphocytes or T lymphocytes.
- Whether the child has standard-risk or high-risk ALL.
- The age of the child at diagnosis.
- Whether there are certain changes in the chromosomes of lymphocytes, such as the Philadelphia chromosome.
For leukemia that recurs (comes back) after initial treatment, the prognosis and treatment options depend on:
- How long it is between the end of initial treatment and when the leukemia recurs.
- Whether the leukemia recurs in the bone marrow or outside the bone marrow.
Source: National Cancer Institute