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Chronic Lymphocytic Leukemia

What Is Chronic Lymphocytic Leukemia? | Symptoms | Stages and Treatments | About the Clinical Trials | Greenebaum Cancer Center

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What Is Chronic Lymphocytic Leukemia?

Chronic lymphocytic leukemia is a disease in which too many infection-fighting white blood cells, called lymphocytes, develop in the blood and bone marrow.

Lymphocytes are made by the bone marrow and by other organs of the lymph system. Bone marrow is the spongy tissue inside the large bones in the body. Bone marrow cells are produced by immature immortal stem cells. These cells produce slightly more mature cells called blasts that develop (mature) into the following types of blood cells that have specific jobs to do in the body:

Red blood cells carry oxygen and other materials to all tissues of the body.
White blood cells fight infection.
Platelets make the blood clot.

Lymphocytes are found in the lymph, a colorless, watery fluid in the lymph vessels. The lymph vessels are part of the lymph system, which is made up of thin tubes that branch, like blood vessels, into all parts of the body.

Along this network of vessels are groups of small, bean-shaped organs called lymph nodes. Clusters of lymph nodes are found in the underarm, pelvis, neck, and abdomen. The spleen (an organ in the upper abdomen that makes lymphocytes and filters old blood cells from the blood), the thymus (a small organ beneath the breastbone), and the tonsils (an organ in the throat) are also part of the lymph system.

Lymphocytes fight infection by making antibodies, which attack germs and other harmful bacteria in the body. In chronic lymphocytic leukemia, the developing lymphocytes do not mature correctly and too many are made. The lymphocytes may look normal, but they cannot fight infection as well as they should. These immature lymphocytes are then found in the blood and the bone marrow. They also collect in the lymph tissues and make them swell.

Lymphocytes may crowd out other blood cells in the blood and bone marrow. Anemia may develop if the bone marrow cannot make enough red blood cells to carry oxygen. If the bone marrow cannot make enough platelets to make the blood clot normally, bleeding or bruising may occur easily.

This page was last updated on: October 7, 2009.