How is chronic lymphocytic leukemia found?
At this time, there are no special tests used to look for chronic lymphocytic leukemia (CLL) in people with no symptoms. Still, many people with CLL have no symptoms at the time their cancer is found. In these people, the cancer is found by blood tests done for some other reason.
Just because a person has some of the symptoms of CLL does not mean that they have this disease. The doctor will need to learn more.
Medical history and physical exam
If you have any signs or symptoms that suggest you might have leukemia, your doctor will want to take a complete medical history. The doctor will ask questions about your health, any symptoms you might have, and your family's health.
A physical exam tells the doctor about your general health, possible signs of leukemia, and other health problems. During the physical exam, your doctor will pay close attention to your lymph nodes and other areas that might be affected.
Testing for chronic lymphocytic leukemia
If symptoms or the results of the physical exam suggest you might have leukemia, the doctor will need to check samples of blood and bone marrow to be certain of the diagnosis. Other tissue and cell samples may also be taken to help guide treatment.
Blood samples for tests to check for CLL are most often taken from a vein in the arm.
Complete blood count and blood cell exam
The complete blood count (CBC) is a test that measures the different cells in the blood, such as the red blood cells, the white blood cells, and the platelets. This test is often done along with a test that further looks at the numbers of the different types of white blood cells. People with CLL have too many lymphocytes. Having more than 10,000 lymphocytes/mm³ (per cubic millimeter) of blood makes the diagnosis almost certain, although it may need to be confirmed by more special tests. The patient will often have too few red blood cells and blood platelets as well.
Routine microscopic exams
A sample of blood will be looked at under a microscope by a doctor with special training (called a pathologist). The doctor looks at the size and shape of the cells as well as other features to classify the cells into specific types. An important goal of this process is to see if the cells look mature. The most immature cells are called blasts. These are not normally in the blood.
CLL can be diagnosed with just certain special tests done on the blood. The test used most often is called flow cytometry, but others, like cytochemistry, FISH, immunocytochemistry, cytogenetics, and molecular genetic studies can be useful, too. These tests can also be used to look at bone marrow and lymph nodes. They are explained in Leukemia: Chronic Lymphocytic Detailed Guide.
Blood chemistry tests
People with leukemia will have tests done to measure the amount of certain chemicals in the blood. These tests do not tell if they have leukemia but can help tell how well their kidneys and liver are working. The test results also help the doctor decide whether treatment is needed to correct low or high blood levels of certain minerals.
Bone marrow procedures
The procedures to get bone marrow samples are called bone marrow aspiration and biopsy. Samples are most often taken from the back of the pelvic (hip) bone, but in some cases the aspiration can be taken from the breastbone or other bones.
In bone marrow aspiration, a thin needle is used to draw up a small amount of liquid bone marrow. The skin and the surface of the bone are first numbed, but the test can still cause some brief pain. During a bone marrow biopsy, a small cylinder of bone and marrow (about ½ inch 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 applied to the site to help prevent bleeding.
Both samples are usually taken at the same time. These tests are mostly used to tell how advanced the leukemia is before treatment starts. They are also done during treatment to see how well the treatment is working.
As with samples of blood, bone marrow samples are looked at under a microscope to see what cells are present. Doctors want to see if there are the normal numbers of blood- forming cells or whether leukemia cells have replaced these.
Although bone marrow tests are not often used to diagnose CLL, they can be useful to see how advanced it is.
Imaging studies are ways of taking pictures of the inside of the body. There are many imaging tests that might be used for people with leukemia. They are not done to find leukemia but rather to help find out the extent of the disease and how well treatment is working.
CT (computed tomography) scans
These are special kinds of x-rays in which a beam moves around the body, taking pictures from different angles. Details in soft tissues, such as swollen lymph nodes in the chest or in other parts of the body, show up better on CT scans than on x-rays.
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.
Before the test, you may be asked to drink a contrast liquid or get an intravenous (IV) injection of a contrast dye that helps better outline organs in the body. Some people are allergic and get hives or, rarely, more serious problems like trouble breathing and low blood pressure. Be sure to tell the doctor if you have ever had a reaction to any contrast dye used for x-rays.
Sometimes a CT scan is combined with a PET scan in a test known as a PET/CT scan. For a PET scan, glucose (a form of sugar) that has a radioactive atom is put into the blood. Because cancer cells in the body grow quickly, they absorb large amounts of the radioactive sugar. A special camera can then create a picture of the areas of radioactivity in the body. The PET/CT scan combines both tests in one machine.
MRI (magnetic resonance imaging) scans
MRI scans use strong magnets and radio waves to make detailed pictures of the body. MRI scans are very helpful in looking at the brain and spinal cord. They take longer than CT scans, often up to an hour. A substance (gadolinium) may be put into a vein before the scan to better show details. The substance does not often cause allergic reactions.
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 be a choice for people with a fear of closed spaces. The MRI machine makes loud buzzing and thumping noises that some people may find disturbing. Some places give you headphones to block this out.
This scan uses sound waves – not radiation − to get pictures of internal organs. Ultrasound can be used to look at lymph nodes near the surface of the body or to look for enlarged organs inside your belly. This is a very easy test to have. Most often, you simply lie on a table and a small wand (called a transducer) is moved over the part of the body being looked at.
A plain x-ray of your chest can be done in most outpatient settings. In patients with CLL, it isn't needed to find the cancer, but it may be used to see whether your lungs are normal or if you have an infection.
Last Medical Review: 08/05/2013
Last Revised: 11/01/2013