Cancer Home > Childhood Acute Lymphoblastic Leukemia
There are no screening tests for childhood acute lymphoblastic leukemia. In cancers such as leukemia that appear throughout the body during their earliest stages, screening does not appear to be useful. Instead, children with any possible symptoms of the condition should see their physician, who can examine the child and determine if further testing is needed.
Making a Diagnosis
If a child has symptoms that suggest childhood acute lymphoblastic leukemia, the physician may first order blood tests. A sample of blood is examined to determine:
- The number of normal blood cells
- What the cells look like
- If any leukemia cells are present in the blood.
For a definitive diagnosis of childhood acute lymphoblastic leukemia, a doctor who specializes in leukemia examines a sample of bone marrow under a microscope. The sample is obtained by a procedure called bone marrow aspiration. In this procedure, the doctor will insert a needle into a large bone, usually the hip, and remove a small amount of liquid bone marrow for examination.
If leukemia cells are found in the bone marrow sample, the patient's doctor will then order other tests to find out the extent of the disease. These other tests can include a spinal tap, which is also called a lumbar puncture. The spinal tap will check for leukemia cells in the cerebrospinal fluid -- the fluid that fills the spaces in and around the brain and spinal cord.
Subtypes of Childhood Acute Lymphoblastic Leukemia
Although leukemia cells from different children with ALL often look similar under the microscope, there are actually many distinctive subtypes of childhood acute lymphoblastic leukemia. Most cases of leukemia are associated with changes in genes and chromosomes in the cancerous white blood cells.
The various subtypes of ALL can be identified using special laboratory tests that look for specific changes in genes and chromosomes. It is important for doctors to determine their patients' subtype of ALL because some treatments work better for some subtypes than for others.