About the lymphatic system

The lymphatic system is made up of thin tubes that branch out to all parts of the body. The lymph system carries lymph, a colorless fluid containing lymphocytes (a type of white blood cell). Lymphocytes are part of our immune system and help fight germs in the body. B-lymphocytes (also called B cells) make antibodies to fight bacteria, and T-lymphocytes (also called T cells) kill viruses and foreign cells and trigger the B cells to make antibodies.

Groups of tiny, bean-shaped organs called lymph nodes are located throughout the body at different sites in the lymphatic system. The largest areas of lymph nodes are found in the abdomen, groin, pelvis, underarms, and neck. Other parts of the lymphatic system include the spleen, which makes lymphocytes and filters the blood; the thymus, an organ under the breastbone; the tonsils, located in the throat; and the bone marrow, the spongy red tissue inside bones that makes white blood cells (cells that fight infection), red blood cells (cells that carry oxygen throughout the body), and platelets (cells that help the blood to clot).

About non-Hodgkin lymphoma

Lymphoma begins when B cells or T cells in the lymphatic system change and grow uncontrollably, which may form a tumor. Hodgkin lymphoma is a specific type of lymphoma that is covered in another section of this website. Non-Hodgkin lymphoma (NHL) is a term that refers to many types of cancer of the lymphatic system, which can have different symptoms and signs, physical findings, and treatments.

Because lymph tissue is found in so many parts of the body, NHL can start almost anywhere and can spread to almost any organ in the body. It most often begins in the lymph nodes, liver, spleen, or bone marrow, but it can also involve the stomach, intestines, skin, thyroid gland, brain, or any other part of the body.

It is very important to know which type and subtype has been diagnosed because the type and subtype help doctors determine the best treatment and a patient’s prognosis (chance of recovery). Specific information can be found in Subtypes of NHL.

This section covers NHL in adults. Learn more about childhood NHL.

Find out more about basic cancer terms used in this section.

Looking for More of an Overview?

If you would like additional introductory information, explore these related items on Cancer.Net:

• ASCO Answers Fact Sheet: Read a one-page fact sheet (available in PDF) that offers an easy-to-print introduction for this type of cancer.
• Cancer.Net Patient Education Video:  View a short video led by an ASCO expert in this type of cancer that provides basic information and areas of research.
• Cancer.Net En Español: Read about NHL in Spanish. Infórmase sobre linfoma no Hodgkin en español.

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