Acute Lymphocytic Leukemia (ALL): Diagnosis
How is acute lymphocytic leukemia (ALL) diagnosed?
If your healthcare provider thinks you might have ALL, you will need certain exams and tests to be sure. Your healthcare provider will ask you about your health history, your symptoms, risk factors, and family history of disease. Your healthcare provider will also give you a physical exam.
What tests might I need?
You may have one or more of the following tests:
Blood tests. Blood is taken from the arm or hand with a needle. The blood is then tested in various ways (see below).
Bone marrow aspiration and biopsy. This procedure is done by taking small amounts of bone marrow. Bone marrow samples are usually taken from the back of the hip (pelvic) bone. For the bone marrow aspiration, the area over the hip is numbed. A thin, hollow needle is inserted into the hip bone. A syringe is used to pull out a small amount of liquid bone marrow. You may have some brief pain when the marrow is removed. A bone marrow biopsy is usually done just after the aspiration. A small piece of bone and marrow is removed with a slightly larger needle that is pushed down into the bone. The biopsy may also cause some brief pain. The bone marrow is then checked for leukemia cells and tested in various ways (see below).
How blood or bone marrow is tested
The tests done on blood or bone marrow samples may include:
Complete blood count (CBC). This test measures the numbers of different types of cells in the blood. People with ALL typically have too many early forms of white blood cells, called blasts.
Immunophenotyping. These tests are done on either blood or bone marrow. The tests measure the types and amounts of certain substances called antigens on the surface of leukemia cells. This can be used to see if you have ALL, and which subtype you have. Results of this test may take several days.
Cytogenetics. For this test, cells are grown in a lab for a week or more. The chromosomes inside the cells are then stained with special dyes and viewed with a microscope. Major problems in the chromosomes can often be seen with this test. But smaller changes may not be visible.
Fluorescence in situ hybridization (FISH). This test is another way to look for changes in chromosomes. The cells in the sample are stained with fluorescent dyes that will only attach to certain parts of chromosomes. The cells are then viewed with a microscope using a special light. This test can find some chromosome changes that can't be seen with standard cytogenetic testing. It is also a quicker test. Many medical centers now use this test.
Polymerase chain reaction (PCR). This is a very sensitive test that can detect very low levels of leukemia cells in a test sample. It works by increasing the amount of genetic material in a sample so that it can be detected. This test can find small levels of chromosome changes that other tests can’t find.
Finding the gene changes for your case of ALL can help decide your treatment. For example, in about 1 out of 4 people with ALL, their leukemia cells have the Philadelphia chromosome. This chromosome contains the abnormal gene BCR-ABL that helps the leukemia cells grow. Those leukemia cells can be treated with medicines that target cells with this gene change.
Getting your test results
When your healthcare provider has the results of your tests, he or she will contact you with the results. Your healthcare provider will talk with you about other tests you may need if ALL is found. Make sure you understand the results and what follow-up you need.