Published: Aug. 22, 2011
Updated: Aug. 22, 2011
Chronic lymphocytic leukemia and small lymphocytic lymphoma (SLL) are cancers that affects b-lymphocytes, a type of white blood cell.
White blood cells normally help fight infections. Because both CLL and SLL arise from the same type of cancer cells and have the same prognosis and treatment, we will refer to both diseases as CLL.
CLL is the most common type of leukemia in the United States. No one knows what causes CLL, but sometimes the disease runs in families.
Often a person will be diagnosed with CLL after his or her doctor notices an elevated white blood cell count, and a special test (called flow cytometry) shows the high count is due to the leukemia. In this circumstance, the person may have no symptoms.
Other people with CLL might have enlarged lymph nodes, an enlarged spleen, low red blood cell count and fatigue, or low platelet count and easy bleeding and bruising.
Learn more about leukemias and lymphomas: