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Overview of Lymphoma

By

Peter Martin

, MD, Weill Cornell Medicine;


John P. Leonard

, MD, Weill Cornell Medicine

Last full review/revision Jul 2020| Content last modified Jul 2020
Click here for the Professional Version
Topic Resources

Lymphomas are cancers of lymphocytes, which reside in the lymphatic system and in blood-forming organs.

Lymphomas are cancers of a specific type of white blood cells known as lymphocytes. These cells help fight infections. Lymphomas can develop from either B or T lymphocytes. T lymphocytes are important in regulating the immune system and in fighting viral infections. B lymphocytes produce antibodies, which are essential in fighting off some infections.

Lymphocytes move about to all parts of the body through the bloodstream and through a network of tubular channels called lymphatic vessels. Scattered throughout the network of lymphatic vessels are lymph nodes, which house collections of lymphocytes. Lymphocytes that become cancerous (lymphoma cells) may remain confined to a single lymph node or may spread to the bone marrow, blood, the spleen, or virtually any other organ.

The two major types of lymphoma are

Non-Hodgkin lymphomas are more common than Hodgkin lymphoma. There are many subtypes of non-Hodgkin lymphoma.

Lymphatic System: Helping to Defend Against Infection

The lymphatic system is a vital part of the immune system, along with the thymus, bone marrow, spleen, tonsils, appendix, and Peyer patches in the small intestine.

The lymphatic system is a network of lymph nodes connected by lymphatic vessels. This system transports lymph throughout the body.

Lymph is formed from fluid that seeps through the thin walls of capillaries into the body's tissues. This fluid contains oxygen, proteins, and other nutrients that nourish the tissues. Some of this fluid reenters the capillaries and some of it enters the lymphatic vessels (becoming lymph). Small lymphatic vessels connect to larger ones and eventually form the thoracic duct. The thoracic duct is the largest lymphatic vessel. It joins with the subclavian vein and thus returns lymph to the bloodstream.

Lymph also transports foreign substances (such as bacteria), cancer cells, and dead or damaged cells that may be present in tissues into the lymphatic vessels and to lymph organs for disposal. Lymph contains many white blood cells.

All substances transported by the lymph pass through at least one lymph node, where foreign substances can be filtered out and destroyed before fluid is returned to the bloodstream. In the lymph nodes, white blood cells can collect, interact with each other and with antigens, and generate immune responses to foreign substances. Lymph nodes contain a mesh of tissue that is tightly packed with B cells, T cells, dendritic cells, and macrophages. Harmful microorganisms are filtered through the mesh, then identified and attacked by B cells and T cells.

Lymph nodes are often clustered in areas where the lymphatic vessels branch off, such as the neck, armpits, and groin.

Lymphatic System: Helping to Defend Against Infection

More Information about Lymphoma

The following is an English-language resource that may be useful. Please note THE MANUAL is not responsible for the content of this resource.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
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Chronic Lymphocytic Leukemia (CLL)
Chronic lymphocytic leukemia (CLL) is a generally slow-growing blood disorder. In CLL, lymphocytes (small white blood cells found mostly in the lymph system) become cancerous. Gradually, these cancerous cells replace normal cells. More than three-quarters of people with CLL belong to one age group. Which of the following is that age group?
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