AIDS-related lymphoma is a disease in which cancer (malignant) cells are found in the lymph system in patients who have AIDS (acquired immunodeficiency syndrome). AIDS is caused by the human immunodeficiency virus (HIV) which attacks and weakens the immune system. Infections and other diseases can then invade the body, and the immune system cannot fight against them.

The lymph system is made up of thin tubes that branch, like blood vessels, into all parts of the body. Lymph vessels carry lymph, a colorless, watery fluid that contains white blood cells called lymphocytes. Along the network of vessels are groups of small, bean-shaped organs called lymph nodes. Clusters of lymph nodes make and store infection-fighting cells. The spleen (an organ in the upper abdomen that makes lymphocytes and filters old blood cells from the blood), the thymus (a small organ beneath the breastbone), and the tonsils (an organ in the throat) are also part of the lymph system. Because there is lymph tissue in many parts of the body, the cancer can spread to almost any of the body's organs or tissues including the liver, bone marrow (the spongy tissue inside the large bones of the body that makes blood cells), spleen, or brain.

Lymphomas are divided into two general types, Hodgkin's disease and non-Hodgkin's lymphomas, which are classified by the way their cells look under a microscope. This determination is called the histology. Histology is also used to determine the type of non-Hodgkin's lymphoma of which there are ten. They types of non-Hodgkin's lymphomas are classified by how quickly they spread: low-grade, intermediate-grade, or high-grade. The intermediate- or high-grade lymphomas grow and spread faster than the low-grade lymphomas.

Both major types of lymphoma, Hodgkin's disease and non-Hodgkin's lymphoma, may occur in AIDS patients. Also, the intermediate-and high-grade types of non- Hodgkin's lymphoma are more commonly found in AIDS patients. Both types of lymphomas can also occur in adults and in children.

A doctor should be seen if any of the following symptoms persist for longer than 2 weeks: painless swelling in the lymph nodes in the neck, underarm, or groin; fever; night sweats; tiredness; weight loss without dieting; or itchy skin.

If a patient has AIDS and symptoms of lymphoma, a doctor will carefully check for swelling or lumps in the neck, underarms, and groin. If the lymph nodes don't feel normal, the doctor may need to cut out a small piece of tissue and look at it under the microscope to see if there are any cancer cells. This procedure is called a biopsy.

In general, patients with AIDS-related lymphoma respond to treatment differently from patients with lymphoma who do not have AIDS. AIDS-related lymphoma usually grows faster and spreads outside the lymph nodes and to other parts of the body more often than lymphoma that is not related to AIDS. Because therapy can damage weak immune systems even further, patients who have AIDS- related lymphoma are generally treated with lower doses of drugs than patients who do not have AIDS.

How AIDS-related lymphoma is treated:

The treatment of AIDS-related lymphoma is difficult because of the problems caused by HIV infection, which weakens the immune system. The drug doses used are often lower than drug doses given to patients who do not have AIDS. Two types of treatment are used:

• Chemo Therapy (using drugs to kill cancer cells and shrink tumors)

• Radiation Therapy (using high-dose x-rays or other high-energy rays to kill cancer cells and shrink tumors)