Here’s where you’ll find the answers to the most commonly asked questions about Chronic Lymphocytic Leukemia.

Q: What is CLL ?

Chronic Lymphocytic Leukemia is a cancer of the blood and bone marrow that is marked by an abnormal increase in the number of mature lymphocytes and white blood cells. It is characterized by slow onset and a progression of symptoms which include fatigue, and enlargement of the lymph nodes, liver, and spleen. It is most common in older male adults.

Leukemic cells develop because of a change that takes place in the cell’s DNA. Normal cells go through stages of growth, division and death. In cancer cells, changes in the DNA create cells that keep dividing and/or avoid early or usual cell death. Thus, CLL is typically a disease of accumulation of long lived cells in the body.

Q: What’s the difference between CLL and SLL ?

Chronic Lymphocytic Leukemia (CLL) and Small Lymphocytic Lymphoma (SLL) are the same disease with slightly different manifestations. Where the cancerous cells gather determines whether it is called CLL or SLL. When the cancer cells are primarily found in the lymph nodes, it is called SLL. When most of the cancer cells are in the bloodstream and the bone marrow, it is called CLL.

Q: What are lymph nodes ?

The lymphatic system is a circulatory system made up of a series of thin tubes called lymph vessels that branch like blood vessels into all tissues of the body. Lymph vessels carry lymph, a transparent fluid that contains white blood cells called lymphocytes. Within this vast network of vessels are groups of small, bean-shaped organs called lymph nodes. Thousands of lymph nodes are found throughout the body, including the elbows, neck, under the arms and groin.

Lymph flows through lymph nodes and specialized lymph tissues such as the spleen, tonsils, bone marrow and thymus gland. Lymph nodes filter lymph fluid, removing bacteria, viruses and other foreign substances from the body. If a large number of bacteria are filtered through a node or series of nodes, they may swell and become tender to the touch. For example, if a person has a sore throat, the lymph nodes under their jaw and in their neck may swell.

Q: What are white blood cells ?

White blood cells are the cells in the body that fight infections. Neutrophils and lymphocytes are two of the major subtypes of white blood cells. Lymphocytes include the following:

  • T-cell lymphocytes – Help the body fight viral, fungal or tuberculous infections and destroy abnormal (or cancerous cells).
  • B-cell lymphocytes – Make antibodies that can attack the target. Antibodies attach themselves to bacteria and other organisms and alert other immune system cells, such as neutrophils, to their presence in the body.
  • Natural Killer cells (NK-cells) – Kill off virally infected cells and other cancer cells.