Non-Hodgkin’s lymphoma (NHL) is the name given to a group of lymphomas, or cancers of the lymphoid tissue. Lymphoid tissue is part of the lymphatic system. A major component of the immune system, the lymphatic system consists of organs, lymph nodes and lymph vessels. This system manufactures and transports lymph (fluid made of plasma and white blood cells) from tissues to the bloodstream.

Lymphomas generally develop in the lymph nodes (small, bean-shaped organs located in groups in various areas of the body), or in some situations, in patches of lymphatic tissue in organs such as the stomach or intestines.

The term “non-Hodgkin’s lymphoma” is used to distinguish this group of lymphomas from the other main form of lymphoma, called Hodgkin’s lymphoma or Hodgkin’s disease. NHL is far more common than Hodgkin’s lymphoma, and can usually be distinguished from Hodgkin’s lymphoma when the cells are examined under a microscope. All types of lymphoma that are not diagnosed as Hodgkin’s lymphoma are considered non-Hodgkin’s lymphoma.

Although NHL has been linked to a number of risk factors, most people with the disease have no known risk factors, and the cause of their cancer is unknown. However, researchers have identified genetic defects that can cause normal cells to become lymphoma cells. These mutations may occur from exposure to radiation or cancer-causing chemicals, but many times the mutations occur for no apparent reason. In addition, deficiencies of the immune system appear to play a role in some cases of lymphoma. 

After a diagnosis has been confirmed, the patient typically is seen by an oncologist (a physician who specializes in the treatment of cancer) to stage the cancer. Staging is the process of determining how far the cancer has spread and is necessary for physicians to plan treatment. The main treatment methods for non-Hodgkin’s lymphoma include chemotherapy, radiation therapy and biological therapy.

There are no established prevention methods for non-Hodgkin’s lymphoma. Currently, the best way to prevent developing the disease is to avoid known risk factors, such as human immunodeficiency virus (HIV).

NHL is the fifth most common cancer in women and men in the United States, not counting non-melanoma skin cancers.  The American Cancer Society estimates in 2007 there will be more than 63,000 new cases of NHL. The incidence rates of NHL have nearly doubled in the past 35 years,. Thi increase is partially attributed to AIDS-related lymphomas. In 2007, the disease is expected to cause nearly 19,000 deaths. The overall 5-year survival rate for a patient with NHL is 63 percent. However, survival varies greatly by the cell type and stage of the cancer.