Non-Hodgkin Lymphoma Introduction

People with non-Hodgkin lymphoma now have more treatment choices and more hope for survival than ever before. Doctors keep finding new treatments for non-Hodgkin lymphoma and ways to help people with non-Hodgkin lymphoma have better lives. We are continually learning more about non-Hodgkin lymphoma, its correct diagnosis, and treatment.

What Is Non-Hodgkin Lymphoma

Lymphoma is a kind of cancer that starts in the lymphatic system. The two main types of lymphatic system cancer are Hodgkin disease and non-Hodgkin lymphoma. The information that follows is about non-Hodgkin lymphoma.

Usually, the body makes new cells only when they are needed. Sometimes the body starts making cells when they are not needed. When this happens, a tumor, or mass, may grow. The tumor may be benign (non-cancerous) or malignant (cancerous). In non-Hodgkin lymphoma, cells in the lymphatic system grow out of control, causing the lymph nodes to grow.

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Anatomy of the Lymphatic System

The lymphatic system is part of the immune system. It helps the body fight infections. It has a series of thin tubes, called lymphatic vessels, which collect fluid, called lymph, from different parts of the body. The thin tubes then carry the lymph back to the bloodstream.

Lymph is a colorless, watery fluid that is rich in white blood cells, particularly lymphocytes. Lymphocytes normally play an important role in the immune system by protecting the body against infection and against the growth of tumors. These lymphocytes form lymph nodes in different places in the body. Lymph nodes are about the size of a pea and have large numbers of lymphocytes. Groups of lymph nodes are found throughout the body, and can be felt in the armpit, groin, and neck area. Some of the body's internal organs also make up parts of the lymphatic system. These organs are the bone marrow, spleen, thymus, and tonsils. Other organs such as the digestive tract also contain lymph tissue.

There are two main kinds of lymphocytes: B-lymphocytes (B-cells) and T-lymphocytes (T-cells).

B-cells and T-cells have different functions in the immune system. B-cells fight bacteria by making antibodies. These antibodies attach to the bacteria and attract a cell that eats the bacteria. The antibodies also attract proteins from the blood to help kill bacteria.

Specialized White Blood Cells

T-cells protect the body from fungi, viruses, and some bacteria. T-cells are able to recognize viral proteins in a virus-infected cell and then destroy the infected cell. T-cells also release special proteins called cytokines, which bring other types of white blood cells to the area of the infection. T-cells can kill cancer cells. Unfortunately, T-cells also kill the cells of transplanted organs because they recognize the new organ as foreign to the body. People who have had an organ transplant must take medicine to keep the T-cells from killing, or "rejecting," the new organ.

Normal B- and T-cells can be recognized with certain lab tests. Each type of cell has features that the other does not. B- and T-cells have many stages of growth that can also be seen. Lymphoma can start in either T- or B-cells. Finding out which type of lymphoma a person has is an important step in choosing the best treatment. There are many different types of lymphoma, as well as many different treatments.