Diagnosing leukemia

After taking your medical history and completing a physical examination, your doctor may suspect you have leukemia. To confirm the diagnosis, your doctor will arrange special tests. These tests may also be used to classify the leukemia. You may have one or more of the following tests.

Blood tests

Blood is taken and studied to see if the different types of blood cells are normal in number and appearance. The results can also show how well your kidneys, liver and other organs are working. These tests may suggest whether or not you have leukemia.

Imaging studies

Imaging studies allow tissues, organs and bones to be looked at in more detail. Using x-rays, ultrasounds, CT scans or MRIs, your healthcare team can get a picture of where the cancer is and see if it involves your organs, such as the spleen, liver or lymph nodes. These tests are usually painless and do not require an anesthetic.

Biopsy

A biopsy is usually necessary to make a definite diagnosis of leukemia. To diagnose leukemia, cells are removed from the bone marrow, usually from the back of the hip bone. The cells are checked under a microscope. If leukemia cells are found in the bone marrow, they will be studied further to see how fast they are growing. There are two ways to get a bone marrow sample.

• For a bone marrow aspiration, the doctor uses a thin needle to remove samples of bone marrow.
• A bone marrow biopsy uses a thicker needle to remove a sample of bone marrow and a small piece of bone.

Both types of biopsies use a local anesthetic (freezing) to numb the area. It can be painful when cells are pulled into the syringe, but this lasts only a few seconds. Usually, bone marrow aspirations and biopsies are done in a clinic or hospital on an outpatient basis (you will not stay overnight).

If you have enlarged lymph nodes, a lymph node biopsy may be done. Clusters of lymph nodes are found throughout your body. They are part of your lymph or immune system. A lymph node biopsy may remove part or all of a lymph node. If the enlarged lymph node can be easily reached with a needle, a local anesthetic will be used. A general anesthetic (you will be unconscious) may be necessary if the enlarged lymph node is deep in your chest or abdomen.

Lumbar puncture

A lumbar puncture (also called a spinal tap) may be done to see if the leukemia has spread to your nervous system. A needle is inserted between two vertebrae in the backbone and a small amount of cerebrospinal fluid is removed and checked for leukemia cells. Cerebrospinal fluid is the fluid that surrounds the spinal cord and the brain. A local anesthetic is used. A lumbar puncture takes about 30 minutes. You must lie flat for 1 to 2 hours afterward to lessen the chances of getting a headache.

Cytogenetics

Cytogenetic tests (also called chromosome analyses) are done on the bone marrow sample to look for changes in the chromosomes in the cells. Chromosomes are the part of a cell that contains genetic information. In the different types of leukemia, there are often distinct genetic abnormalities that cause changes in the structure of the chromosomes in leukemia cells. These tests help to identify the type of leukemia you may have and therefore which treatment may work best.

Last modified on:  07 January 2009

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