Through the Microscope: Blood Cells - Life's Blood

Chronic lymphocytic leukemia (CLL)

Chronic lymphocytic leukemia is the most common type of leukemia and usually occurs in older patients; it is rare in patients less than 40 years of age. The disease is usually discovered when other medical problems are present. Weakness, fatigue, and weight loss are usually seen. The malignant cell in CLL is usually a small, mature-appearing lymphocyte.