In a child with ALL, too many stem cells become lymphoblasts, B lymphocytes, or T lymphocytes. The cells do not work like normal lymphocytes and are not able to fight infection very well. These cells are cancer (leukemia) cells. 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, adolescents, and young adults. See the following PDQ
summaries for information about other types of leukemia:
Past treatment for cancer and certain genetic conditions affect the risk of having 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:
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 to diagnose
childhood ALL and find out if leukemia cells have spread to other parts of the body such as the brain or testicles
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.
The portion of the sample made up of red blood cells.
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.
The following tests are done on blood or the bone marrow tissue that is removed:
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 of lymphocytes. For example, in Philadelphia chromosome
–positive ALL, part of one chromosome switches places with part of another chromosome. This is called the “Philadelphia chromosome.”
Immunophenotyping: A laboratory test in which the antigens
or markers on the surface of a blood or bone marrow cell are checked to see if they are lymphocytes or myeloid cells. If the cells are malignant
lymphocytes (cancer) they are checked to see if they are B lymphocytes or T lymphocytes.
Lumbar puncture: A procedure used to collect a sample of cerebrospinal fluid
(CSF) from the spinal column. This is done by placing a needle between two bones in the spine
and into the CSF around the spinal cord
and removing a sample of the fluid. The sample of CSF is checked under a microscope
for signs that leukemia cells have spread to the brain and spinal cord. This procedure is also called an LP or spinal tap.
This procedure is done after leukemia is diagnosed to find out if leukemia cells have spread to the brain and spinal cord. Intrathecal chemotherapy
is given after the sample of fluid is removed to treat any leukemia cells that may have spread to the brain and spinal cord.
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. The chest x-ray is done to see if leukemia cells have formed a mass
in the middle of the chest.
Certain factors affect prognosis (chance of recovery) and treatment options.