How is chronic myeloid leukemia found?
At this time, there are no special tests that can find chronic myeloid leukemia (CML) early. The best thing to do is report any symptoms to a doctor right away. The doctor will take your medical history and do a physical exam. If symptoms suggest you might have leukemia, you will need certain tests to find out if you have the disease and, if so, what type it is.
Tests to find chronic myeloid leukemia
Testing for CML involves checking blood and samples of bone marrow.
Blood to test for CML is most often taken from a vein in your arm.
Samples of bone marrow are obtained in a procedure called a bone marrow aspiration and biopsy. Samples are most often taken from the back of the hip bone, but sometimes they may be taken from the breastbone or other bones.
In bone marrow aspiration, a hollow needle is used to pull out a small amount of liquid bone marrow. The skin and the surface of the bone are first numbed, but the test can still hurt. During a bone marrow biopsy, a small core of bone and marrow (about ½" long) is removed with a slightly larger needle that is twisted as it is pushed into the bone. The biopsy may also cause some brief pain. Once the biopsy is done, pressure and maybe an ice pack will be put over the site to help prevent bleeding.
Both samples are usually taken at the same time. These samples are sent to a lab, where they are looked at under a microscope. These tests are mostly used to tell how advanced the leukemia is before treatment starts. They can also be done during treatment to tell how well the treatment is working.
Routine blood tests
One or more of these lab tests may be done, either to find CML or to help the doctor figure out how advanced the disease is.
Blood cell counts and blood cell exam: The complete blood count (CBC) is a test that measures the levels of different blood cells such as red blood cells, white blood cells, and platelets. This is often the first test done if your doctor suspects leukemia or another blood problem. Most patients with CML have too many white blood cells and sometimes not enough red blood cells or blood platelets. Even though these findings may suggest leukemia, this diagnosis usually needs to be confirmed with another blood test or a test of the bone marrow.
Blood chemistry tests: These tests measure the amount of certain chemicals in the blood, but they are not used to decide if a person has leukemia. In patients already known to have CML, these tests can help find liver or kidney problems caused by the spread of leukemia cells or by the side effects of certain drugs used for treatment. These tests also help the doctor decide whether treatment is needed to correct low or high blood levels of certain minerals.
Exam under a microscope
The samples of blood and bone marrow are looked at under a microscope by a doctor with special training (a pathologist). The doctor looks at the size and shape of the cells as well as other features to divide the cells into specific types. An important goal of this process is to see whether or not the cells look mature. The most immature cells are called blasts. Blasts do not work the way they should, and they can keep on forming new cells, crowding out normal, mature cells.
Chromosomes are long chains of DNA found in every cell. The leukemia cells of most patients with CML contain an abnormal chromosome called the Philadelphia chromosome. The Philadelphia chromosome contains an abnormal gene called BCR-ABL. Even if the CML cells don’t contain a Philadelphia chromosome, they contain the BCR-ABL gene. Certain tests that look at genes or chromosomes, such as cytogenetics, FISH, and PCR, are used to look for the Philadelphia chromosome or the BCR-ABL gene. These tests can be done on samples of blood and/or bone marrow and are explained in our detailed guide, Leukemia: Chronic Myeloid (Myelogenous).
Imaging tests are ways of taking pictures of the inside of the body. They are not used to find CML, but they may be done to help figure out if it involves certain organs (like the spleen).
CT (computed tomography) scans
The CT scan is a special kind of x-ray in which a beam moves around the body, taking pictures from many angles. CT scans are not usually needed to find CML in the first place, but may be done if your doctor thinks the leukemia is growing in an organ like your spleen.
A CT scanner has been described as a large donut, with a narrow table in the middle opening. You will need to lie still on the table while the scan is being done. CT scans take longer than regular x-rays, and you might feel a bit confined by the ring while the pictures are being taken.
Often before any pictures are taken, you may be asked to drink 1 to 2 pints of a liquid called oral contrast. This helps outline the intestine more clearly.
You may also have an IV (intravenous) line through which you get a different kind of contrast dye. This helps better outline blood vessels and internal organs. The IV dye injection can make you feel flushed or warm in the face or elsewhere. Some people get hives (itchy bumps). A few may have more serious allergic reactions like trouble breathing, feeling dizzy, or passing out. Before the scan, be sure to tell the doctor if you have ever had a reaction to any contrast material used for x-rays
MRI (magnetic resonance imaging)
MRI scans are very helpful in looking at the brain and spinal cord. This test uses powerful magnets and radio waves to make detailed pictures of the inside of the body. They take longer than CT scans, often up to an hour. You may need to lie inside a narrow tube for the test. This can upset people with a fear of enclosed spaces. Special, "open" MRI machines may help with this problem. The MRI machine makes loud thumps and buzzes that some people may find disturbing. Some places give you headphones to block this out.
This test uses sound waves to make pictures of internal organs. Ultrasound can look for enlarged organs in the belly (abdomen). This is a very easy test to have done. For most scans, you lie on a table and a technician moves a kind of wand (transducer) over the part of the body being looked at, which is first smeared with a gel.
This is a plain x-ray of the chest. It isn't used to tell if someone has CML, but to look for lung problems.
Last Medical Review: 02/03/2015
Last Revised: 02/03/2015