ON THIS PAGE: You will find a list of the common tests, procedures, and scans that doctors can use to find the cause of a medical problem. Use the menu to see other pages.
Doctors use many tests to find, or diagnose, leukemia. They also do tests to learn if cancer has spread to another part of the body from where it started. If the cancer has spread, it is called metastasis. Doctors may also do tests to learn which treatments could work best.
How acute lymphoblastic leukemia (ALL) is diagnosed
There are many tests used for diagnosing ALL. Not all tests described here will be used for every person. Your child's doctor may consider these factors when choosing a diagnostic test:
The type of cancer suspected
Your child's signs and symptoms
Your child's age and general health
The results of earlier medical tests
A patient history, physical examination, complete blood cell count (CBC), and bone marrow aspiration (see below) are the main procedures used to diagnose ALL or rule out other conditions.
Blood tests. A CBC provides a count of each type of cell in the blood. The blood count may also show abnormal leukemia cells. The blood count is abnormal, in some way, for nearly all children with ALL when they are diagnosed. A blood chemistry test gives information about the body’s kidney and liver function, as well as other measures, such as salt levels.
Bone marrow aspiration and biopsy. These 2 procedures are similar and often done at the same time to examine the bone marrow. Bone marrow has both a solid and a liquid part. A bone marrow aspiration removes a sample of the fluid with a needle. A bone marrow biopsy is the removal of a small amount of solid tissue using a needle.
A pathologist then analyzes the sample(s). A common site for a bone marrow aspiration and biopsy is the pelvic bone, which is located in the lower back by the hip. Doctors generally give a type of medication called anesthesia beforehand to numb the area. Anesthesia is medication that blocks the awareness of pain. Stronger types of anesthesia can also be used to lessen the pain.
A bone marrow aspiration is recommended if the blood test shows unusual blood counts or immature cells, or if the doctor suspects that a child may have leukemia. From this test, the doctor can find out whether the child has leukemia and, if so, what type of leukemia it is. The doctor or other health care team member will collect more than one sample of bone marrow at the same time for other tests, such as chromosome and molecular genetic tests and immunophenotyping (see Classification). These additional tests are important to plan the most appropriate treatments.
Lumbar puncture (spinal tap). A lumbar puncture can determine if the leukemia has spread to the cerebral spinal fluid (CSF). CSF is the fluid that flows around the brain and the spinal cord. During a lumbar puncture, a needle is used to take a sample of the CSF to look for leukemia cells. Doctors may give an anesthetic to numb the lower back before the procedure and/or use anesthesia to block awareness of the pain. Knowing whether or not there is leukemia in the central nervous system helps doctors choose the most appropriate treatment. All children with ALL receive medicine to treat or prevent leukemia of the central nervous system at the same time as the lumbar puncture at specific times during treatment.
After diagnostic tests are done, your child’s doctor will review the results with you. If the diagnosis is ALL, these results also help the doctor describe the disease. This is called classification.
The next section in this guide is Classification. It explains the system doctors use to describe this type of cancer. Use the menu to choose a different section to read in this guide.