Your doctor will perform the following tests to help confirm the type of leukemia you have and what your prognosis is. A prognosis is a statement about the prospect of surviving and recovering from a disease. Your doctor may also do these tests after treatment to check its success.
A doctor does this test on bones of your hips or your sternum, which is your chest bone. Before making a small cut, the doctor numbs the area with a local anesthetic, which you usually get as an injection. Then the doctor inserts a needle to remove a small amount of liquid marrow from the back of your hipbone or sternum. You may need to have this done on both hips. Next, the doctor uses a larger needle to remove a solid piece of bone and marrow. Even with anesthesia, you may feel uncomfortable as the doctor removes the marrow and bone. But the entire procedure usually doesn't last more than 45 minutes.
After he or she has removed the marrow and bone, your doctor sends the removed samples to a lab where a special doctor, called a pathologist, checks them for leukemia cells. Using these samples, pathologists may also perform these tests.
Immunophenotyping. This test requires a sample of either your blood or your bone marrow. The test not only helps pinpoint which type of white blood cell has become malignant, but can also be used to monitor your progress during treatment. Immunophenotyping measures the types and amounts of antigens on the surface of leukemia cells. Antigens are substances that prompt an immune response. Your doctor uses these facts about your antigens to learn how the leukemia will grow or spread. Results of this test may take several days.
Cytogenetic analysis. This test requires a sample of either your blood or your bone marrow. The cells are then grown in a laboratory. A pathologist uses a microscope to see the cell's chromosomes, which are pieces of DNA that control cell growth. The DNA changes related to leukemia are not inherited but occur after birth when the cells become leukemia cells. With some types of leukemia, chromosomes may exchange DNA. For example, part of chromosome 1 is on part of chromosome 2 and vice versa. This is called translocation. Or there may be the wrong number of total chromosomes. A chromosome can be deleted, or one can be added. This information will affect your treatment plan. You will likely get results from this analysis within a few weeks. A newer type of lab test, known as fluorescence in situ hybridization (FISH), can find chromosome changes using special fluorescent dyes. Because this test is very accurate and typically takes less time than standard cytogenetic testing, many doctors prefer to use it instead.
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