Leukemia - Acute Lymphocytic - ALL: Diagnosis

Approved by the Lineagotica Editorial Board, 05/2017

ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. Use the menu to see other pages.

Doctors use many tests to find, or diagnose, cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If this happens, it is called metastasis. For example, imaging tests can show if the cancer has spread. Imaging tests show pictures of the inside of the body. Doctors may also do tests to learn which treatments could work best.

For most types of cancer, a biopsy is the only sure way for the doctor to know whether an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory.  If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.

This list describes options for diagnosing this type of cancer. Not all tests listed below will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of cancer suspected

  • Your signs and symptoms

  • Your age and medical condition

  • The results of earlier medical tests

The following tests may be used to diagnose ALL:

  • Blood tests. If your doctor suspects that you have ALL based on the symptoms, he or she may do a test called a complete blood count (CBC). This test examines the levels of different types of cells in the blood.

    Low levels of red blood cells and platelets are common in people with ALL, as are high, normal, or low levels of white blood cells. Changes in blood cell levels can also be a sign of another medical problem that is not leukemia. The blood may also be examined to find out if there are lymphoblasts or other abnormal cells.

  • Bone marrow aspiration and biopsy. If the blood test shows abnormalities in the number or appearance of the white blood cells, you may need a 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. If blood tests (see above) indicate ALL, it is better to have the bone marrow aspiration and biopsy at the hospital where treatment will be given so the test does not need to be done again.

    A pathologist analyzes the sample(s) removed during a bone marrow aspiration and biopsy. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. The sample is used to look for leukemia, and molecular testing and immunophenotyping (see below) may also be done.

    A common site for a bone marrow aspiration and biopsy is the pelvic bone, which is located in the lower back by the hip. The skin in that area is usually numbed with medication beforehand. Other types of anesthesia (medication to block the awareness of pain) may also be used.

  • Other testing. Your doctor may recommend running laboratory tests on the leukemia cells to identify specific genes, proteins, and other factors unique to the leukemia.

    Results of these tests will help decide whether your treatment options include a type of treatment called targeted therapy (see Treatment Options).

    • Flow cytometry, also called immunophenotyping, and cytochemistry. These tests use chemicals or dyes on the cancer cells to learn more about the leukemia and its subtype. ALL cells have distinctive markers on their surface called cell surface proteins. The pattern of these markers is called the immunophenotype. These tests are used to distinguish ALL from healthy blood cells and from other types of leukemia, which can also involve lymphocytes. Both tests can be done from a blood sample.

    • Karyotyping, or cytogenetics. This test examines a cell’s chromosomes. Chromosomes are long pieces of DNA that contain genes.

      People with ALL may have specific chromosomal changes, such as the addition or loss of certain chromosomes and translocations. A translocation is when parts of a chromosome have been moved to another chromosome. These changes can be found with special testing, such as a test called fluorescence in-situ hybridization (FISH). Approximately 25% of patients have a normal karyotype when diagnosed with ALL.

      About 20% to 30% of adults with ALL have a specific change in their chromosomes called the Philadelphia chromosome. The Philadelphia chromosome is an example of a small chromosome caused by a translocation. In this instance, it means that genetic material from chromosome 9 breaks off and attaches to chromosome 22 [t(9;22)]. Then, 2 specific genes called BCR and ABL join to make 1 gene called BCR-ABL. Some people may have other types of translocations. For example, many children with ALL have a translocation between chromosomes 12 and 21 [t(12;22)]. These genes are called TEL and AML1.

    • Molecular assays. These tests may be able to find mutations in genes that cannot be seen with a microscope or found with cytogenetic tests. For example, patients with changes in the IKZF1 gene have a poorer long-term prognosis, which is the chance of recovery. Therefore, testing for these changes during diagnosis helps determine a patient’s treatment options.

    • Lumbar puncture (spinal tap). A lumbar puncture is a procedure in which a doctor uses a needle to take a sample of cerebral spinal fluid (CSF) to look at the make up of the fluid and to find out is it contains cancer cells or blood.

      ALL tends to spread to the CSF, which is the fluid that flows around the brain and spinal cord. This means that lumbar punctures are done regularly during ALL treatment. Also, chemotherapy (see Treatment Options) may be given in the CSF.

      Doctors generally give an anesthetic to numb the lower back before the procedure.

  • Imaging tests. The following imaging tests may be used to learn more about the cause of symptoms. They may also help diagnose infections in patients with ALL.

    • Computed tomography (CT or CAT) scan. A CT scan creates a 3-dimensional picture of the inside of the body using x-rays taken from different angles. A computer combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein or given orally (by mouth) to provide better detail.

    • Magnetic resonance imaging (MRI). MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium may be injected into a patient’s vein or given orally (by mouth) to create a clearer picture.

    • Positron emission tomography (PET) or PET-CT scan. A PET scan is usually combined with a CT scan (see above), called a PET-CT scan. However, you may hear your doctor refer to this procedure just as a PET scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body. This substance is absorbed mainly by organs and tissues that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body.

After diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is ALL, results can also help the doctor describe the disease. This is called classification.

The next section in this guide is Subtypes and Classification. It explains the system doctors use to describe the extent of the disease. You may use the menu to choose a different section to read in this guide.