General Information About AIDS-Related Lymphoma

AIDS-related lymphoma is a disease in which malignant (cancer) cells form in the lymph system of patients who have acquired immunodeficiency syndrome (AIDS).

AIDS is caused by the human immunodeficiency virus (HIV), which attacks and weakens the body's immune system. A weakened immune system is unable to fight infection and disease. People with HIV disease have an increased risk of infection and lymphoma or other types of cancer. A person with HIV and certain types of infection or cancer, such as lymphoma, is diagnosed as having AIDS. Sometimes, people are diagnosed with AIDS and AIDS-related lymphoma at the same time. For information about AIDS and its treatment, see the AIDSinfo website.

AIDS-related lymphoma is a type of cancer that affects the lymph system. The lymph system is part of the immune system. It helps protect the body from infection and disease.

The lymph system is made up of the following:

• Lymph: Colorless, watery fluid that travels through the lymph vessels and carries T and B lymphocytes. Lymphocytes are a type of white blood cell.
• Lymph vessels: A network of thin tubes that collect lymph from different parts of the body and return it to the bloodstream.
• Lymph nodes: Small, bean-shaped structures that filter lymph and store white blood cells that help fight infection and disease. Lymph nodes are found along a network of lymph vessels throughout the body. Groups of lymph nodes are found in the neck, underarm, mediastinum, abdomen, pelvis, and groin.
• Spleen: An organ that makes lymphocytes, stores red blood cells and lymphocytes, filters the blood, and destroys old blood cells. The spleen is on the left side of the abdomen near the stomach.
• Thymus: An organ in which T lymphocytes mature and multiply. The thymus is in the chest behind the breastbone.
• Tonsils: Two small masses of lymph tissue at the back of the throat. There is one tonsil on each side of the throat.
• Bone marrow: The soft, spongy tissue in the center of certain bones, such as the hip bone and breastbone. White blood cells, red blood cells, and platelets are made in the bone marrow.

Lymph tissue is also found in other parts of the body such as the brain, stomach, thyroid gland, and skin.

Sometimes AIDS-related lymphoma occurs outside the lymph nodes in the bone marrow, liver, meninges (thin membranes that cover the brain) and gastrointestinal tract. Less often, it may occur in the anus, heart, bile duct, gingiva, and muscles.

There are many different types of lymphoma.

Lymphomas are divided into two general types:

• Hodgkin lymphoma.
• Non-Hodgkin lymphoma.

Both non-Hodgkin lymphoma and Hodgkin lymphoma may occur in patients with AIDS, but non-Hodgkin lymphoma is more common. When a person with AIDS has non-Hodgkin lymphoma, it is called AIDS-related lymphoma. When AIDS-related lymphoma occurs in the central nervous system (CNS), it is called AIDS-related primary CNS lymphoma.

Non-Hodgkin lymphomas are grouped by the way their cells look under a microscope. They may be indolent (slow-growing) or aggressive (fast-growing). AIDS-related lymphomas are aggressive. There are two main types of AIDS-related non-Hodgkin lymphoma:

• Diffuse large B-cell lymphoma (including B-cell immunoblastic lymphoma).
• Burkitt or Burkitt-like lymphoma.

For more information about lymphoma or AIDS-related cancers, see the following:

• Adult Non-Hodgkin Lymphoma Treatment
• Childhood Non-Hodgkin Lymphoma Treatment
• Primary CNS Lymphoma Treatment
• Kaposi Sarcoma Treatment

Signs of AIDS-related lymphoma include weight loss, fever, and drenching night sweats.

These and other signs and symptoms may be caused by AIDS-related lymphoma or by other conditions. Check with your doctor if you have any of the following:

• Weight loss or fever for no known reason.
• Drenching night sweats.
• Painless, swollen lymph nodes in the neck, chest, underarm, or groin.
• A feeling of fullness below the ribs.

Tests that examine the lymph system and other parts of the body are used to diagnose AIDS-related lymphoma.

The following tests and procedures may be used:

• Physical exam and health history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health, including fever, drenching night sweats, and weight loss, health habits, and past illnesses and treatments will also be taken.
• Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
  • The number of red blood cells, white blood cells, and platelets.
  • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
  • The portion of the sample made up of red blood cells.
  
• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
• LDH test: A procedure in which a blood sample is checked to measure the amount of lactic dehydrogenase. An increased amount of LDH in the blood may be a sign of tissue damage, lymphoma, or other diseases.
• Hepatitis B and hepatitis C test: A procedure in which a sample of blood is checked to measure the amounts of hepatitis B virus-specific antigens and/or antibodies and the amounts of hepatitis C virus-specific antibodies. These antigens or antibodies are called markers. Different markers or combinations of markers are used to determine whether a patient has a hepatitis B or C infection, has had a prior infection or vaccination, or is susceptible to infection.
• HIV test: A test to measure the level of HIV antibodies in a sample of blood. Antibodies are made by the body when it is invaded by a foreign substance. A high level of HIV antibodies may mean the body has been infected with HIV.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the neck, chest, abdomen, pelvis, and lymph nodes, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.
• Bone marrow aspiration and biopsy: The removal of bone marrow and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow and bone under a microscope to look for signs of cancer.
• Lymph node biopsy: The removal of all or part of a lymph node. A pathologist views the tissue under a microscope to look for cancer cells. One of the following types of biopsies may be done:
  • Excisional biopsy: The removal of an entire lymph node.
  • Incisional biopsy: The removal of part of a lymph node.
  • Core biopsy: The removal of tissue from a lymph node using a wide needle.

  Other areas of the body, such as the liver, lung, bone, bone marrow, and brain, may also have a sample of tissue removed and checked by a pathologist for signs of cancer.

If cancer is found, the following tests may be done to study the cancer cells:

• Immunohistochemistry: A laboratory test that uses antibodies to check for certain antigens (markers) in a sample of a patient’s tissue. The antibodies are usually linked to an enzyme or a fluorescent dye. After the antibodies bind to a specific antigen in the tissue sample, the enzyme or dye is activated, and the antigen can then be seen under a microscope. This type of test is used to help diagnose cancer and to help tell one type of cancer from another type of cancer.
• Cytogenetic analysis: A laboratory test in which the chromosomes of cells in a sample of blood or bone marrow are counted and checked for any changes, such as broken, missing, rearranged, or extra chromosomes. Changes in certain chromosomes may be a sign of cancer. Cytogenetic analysis is used to help diagnose cancer, plan treatment, or find out how well treatment is working.
• FISH (fluorescence in situ hybridization): A laboratory test used to look at and count genes or chromosomes in cells and tissues. Pieces of DNA that contain fluorescent dyes are made in the laboratory and added to a sample of a patient’s cells or tissues. When these dyed pieces of DNA attach to certain genes or areas of chromosomes in the sample, they light up when viewed under a fluorescent microscope. The FISH test is used to help diagnose cancer and help plan treatment.
• Immunophenotyping: A laboratory test that uses antibodies to identify cancer cells based on the types of antigens or markers on the surface of the cells. This test is used to help diagnose specific types of lymphoma.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis and treatment options depend on the following:

• The stage of the cancer.
• The age of the patient.
• The number of CD4 lymphocytes (a type of white blood cell) in the blood.
• The number of places in the body lymphoma is found outside the lymph system.
• Whether the patient has a history of intravenous (IV) drug use.
• The patient's ability to carry out regular daily activities.