Chronic Lymphocytic Leukemia
Chronic lymphocytic leukemia (CLL) is a type of cancer that occurs when bone marrow makes an abundance of lymphocytes. In most cases, CLL progresses slowly. The disease most often develops after middle age; this type of leukemia rarely affects children. Possible signs include swollen lymph nodes and tiredness. Treatment options can include radiation therapy, chemotherapy, and surgery.
Chronic lymphocytic leukemia (also known as CLL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell). Also known as chronic lymphoblastic leukemia, this is the second most common type of leukemia seen in adults, accounting for about 7,000 new cases of leukemia each year. The American Cancer Society estimated that 10,020 Americans (6,280 men and 3,740 women) would be diagnosed with it in 2006. Chronic lymphocytic leukemia often occurs during or after middle age; it rarely occurs in children. CLL usually progresses slowly.
(Click Types of Leukemia to learn more.)
Normally, the body produces bone marrow stem cells (immature cells) that develop into mature blood cells. The three types of mature blood cells include:
- Red blood cells that carry oxygen and other materials to all tissues of the body
- White blood cells that fight infection and disease
- Platelets that help prevent bleeding by causing blood clots to form.
In chronic lymphocytic leukemia, too many stem cells develop into a type of white blood cell called lymphocytes. The three types of lymphocytes include:
- B lymphocytes that make antibodies to help fight infection
- T lymphocytes that help B lymphocytes make antibodies to fight infection
- Natural killer cells that attack cancer cells and viruses.
With chronic lymphocytic leukemia, the lymphocytes are not able to fight infection very well, and as the amount of lymphocytes increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. This may result in infection, anemia, and easy bleeding.