Leukemia Types Cll Lymphocytic

According to the American Cancer Society (2009), there are approximately 15,490 new cases of chronic lymphocytic leukemia (CLL) annually in the United States. Men are more likely to develop CLL as women. In addition, age is another key risk factor: The average age of CLL sufferers is 72 years old.

Chronic lymphocytic leukemia produces abnormal, long-lived white blood cells. Unlike the rapid accumulation of white blood cells associated with acute types of leukemia, scientists believe that this longer life span allows CLL cells to accumulate slowly. These chronic leukemic cells eventually crowd out healthy white blood cells, platelets and red blood cells. Unfortunately, this type of chronic leukemia has no known cure.

Because chronic lymphocytic leukemia progresses so slowly, and given the lack of a cure, treatment doesn’t usually begin until symptoms develop. For this type of chronic leukemia, doctors often recommend watchful waiting or careful monitoring of progression and symptoms.

Diagnosing Chronic Lymphocytic Leukemia

Blood tests that are positive for chronic lymphocytic leukemia reveal high levels of white blood cells — usually accounting for 30 percent or more of bone marrow.

As with other types of leukemia, a bone marrow aspiration is the definitive diagnostic tool for this type of chronic leukemia.

Subtypes of CLL

Chronic lymphocytic leukemia classification depends on whether the abnormal surface markers resemble B or T lymphoid cells. Abnormal B cells account for 98 percent of CLL cases, according to Merck Pharmaceuticals (2008), while the other 2 percent involve T cells.

Chronic lymphocytic leukemia actually encompasses several different types of leukemia. In addition to typical CLL, other types of chronic leukemia include:

  • Hairy cell leukemia (characterized by white blood cells that appear to be covered with tiny hairs when viewed under a microscope)
  • Lymphoma leukemia
  • Prolymphocytic leukemia (a rare form of CLL with a faster progression rate because abnormal lymphocytes don’t fully mature)
  • Sézary syndrome.

Prognosis and Cancer Staging

Two CLL staging methods exist:

  • The Binet method is common in other parts of the world, and stages CLL by measuring the extent of the disease.
  • The Rai method, most commonly employed in the United States, measures hematologic changes (changes in the blood).

Although no cure for CLL exists, the prognosis at the time of diagnosis is not unfavorable for these types of leukemia. The average survival rate is seven to ten years after diagnosis, according to Merck Pharmaceuticals (2008).

Because many people are already 60 or older at the time of diagnosis, chronic lymphocytic leukemia may not necessarily shorten life expectancy. If the cancer has a Rai score between 0 and II, individuals may survive from 5 to 20 years without treatment, whereas those with stage III or IV CLL may survive three to four years without treatment.


American Cancer Society. (2009). What are the key statistics about chronic lymphocytic leukemia? Retrieved March 22, 2010, from http://documents.cancer.org/6893.00/6893.00.pdf.

Mayo Clinic. (2010). Hairy cell leukemia. Retrieved March 22, 2010, from http://www.mayoclinic.com/health/hairy-cell-leukemia/DS00673.

Merck Manuals Online Medical Library. (2008). Chronic lymphocytic leukemia (CLL). Retrieved March 22, 2010, from http://www.merck.com/mmpe/sec11/ch142/ch142c.html?qt=leukemia