Diagnosing AIDS-Related Lymphoma

NYU Langone specialists are experienced in diagnosing AIDS-related lymphoma. This group of cancers may develop in people infected with the human immunodeficiency virus—HIV, the virus that causes AIDS.

In a healthy person, small glands called lymph nodes store lymphocytes—white blood cells that help the body fight infections. Lymphocytes travel throughout the body via a network of vessels called the lymphatic system.

Lymphoma occurs when lymphocytes become malignant, or cancerous. Malignant lymphocytes multiply, forming tumors in the lymph nodes and spreading to other parts of the lymphatic system. For instance, lymphoma often spreads to the spleen—an organ above the left side of the stomach that helps make lymphocytes—and bone marrow, the spongy material inside bone that makes new blood cells.

As lymphoma progresses, it can spread beyond the lymphatic system to organs such as the liver, lungs, or brain.

There are more than 60 types of lymphoma. Doctors classify these cancers according to the type of lymphocyte affected. These include B cells, which make antibodies that attack viruses, bacteria, and other pathogens; T cells, which kill viruses and signal B cells to make antibodies; and NK cells, which help fight cancer cells and viral infections. Most lymphomas begin in B cells.

These cancers are further divided into two large groups: non-Hodgkin lymphoma, the most common type, may affect B cells, T cells, or NK cells. Hodgkin lymphoma begins in a type of B cell called a Reed–Sternberg cell.

HIV Infection and Lymphoma

HIV weakens the immune system by attacking T cells, also called CD4 cells. As a result, people who have HIV are more vulnerable to infections and certain cancers.

When a person who has an HIV infection or AIDS develops lymphoma, it is called AIDS-related lymphoma. Most AIDS-related lymphomas are non-Hodgkin lymphomas, but some are Hodgkin lymphomas. The most common types of lymphomas in people who have HIV or AIDS are diffuse large B cell lymphoma, B cell immunoblastic lymphoma, and Burkitt’s lymphoma.

Lymphomas are usually more aggressive and more likely to spread beyond the lymph nodes in people who have HIV or AIDS. The cancer often spreads to areas outside of the lymph nodes, including the brain and gastrointestinal tract, by the time a person with HIV is diagnosed with lymphoma.

Treatment with a combination of medications to combat HIV infection decreases a person’s risk of developing lymphoma and other serious illnesses. This combination therapy is known as antiretroviral therapy.

Symptoms

AIDS-related lymphoma often causes prolonged swollen glands on either side of the neck above the collarbone, in the armpits, or in the groin. Other symptoms may include fatigue, weight loss, unexplained fevers, itching, and drenching night sweats.

Additional symptoms depend on the location of the lymphoma. For instance, lymphoma in the chest can cause shortness of breath, chest pain, or coughing. Some people with lymphoma have abdominal swelling, due either to an enlarged spleen or swollen lymph nodes in the abdominal cavity. Tumors in the brain or near the spinal cord can cause seizures, difficulty walking, confusion, or partial paralysis.

At NYU Langone, diagnosis of AIDS-related lymphoma begins with a physical exam to identify swollen lymph nodes. Doctors also ask about your symptoms and medical history. If you’re not sure whether you have HIV infection, the doctor orders blood tests.

Additional tests are used to diagnose AIDS-related lymphoma, identify the type of lymphoma present, and determine how fast it is growing. These tests can also indicate whether the condition has spread, how well it may respond to therapy, and whether it’s likely to return.

Blood Tests to Diagnose HIV

Doctors may use several blood tests to diagnose HIV infection and gauge the health of your immune system, especially if you haven’t already been diagnosed with HIV. A basic HIV blood test determines whether you have developed antibodies to HIV. People with AIDS-related lymphoma often have high levels of these antibodies in their blood at the time of diagnosis.

Blood tests also measure viral load, which reveals how many virus cells you have, and the number of CD4 cells. People with AIDS-related lymphoma who have not been taking antiretroviral medication often have an increased viral load and a lowered CD4 count. As the number of CD4 cells decreases, the immune system becomes progressively impaired.

Lymph Node Biopsy

A lymph node biopsy can confirm a diagnosis of AIDS-related lymphoma and identify the type you have. This procedure involves removing tissue from a swollen lymph node and evaluating it under a microscope. The tissue sample also may be used to look for genetic mutations associated with some non-Hodgkin lymphomas. This information can help the doctor select the most effective treatment.

Surgical Biopsy

Surgeons at NYU Langone usually remove an entire lymph node to perform a biopsy. Surgical biopsy is performed in the hospital using local anesthesia. Most people go home the same day.

Needle Biopsy

Sometimes, a surgical biopsy is not possible because a swollen lymph node is difficult to reach without harming blood vessels or other structures. Your doctor may perform a needle biopsy, using fine needle aspiration or core needle biopsy, to obtain a tissue sample.

In fine needle aspiration, the doctor uses a small, thin needle to withdraw fluid and cells from an enlarged lymph node. In a core needle biopsy, the doctor uses a bigger needle to remove a larger portion of tissue. Both types of needle biopsy are performed as outpatient procedures using a local anesthetic.

If the lymph node is located deep within the body, your doctor may use an imaging technique to help guide the needle before inserting it. Depending on the location of the lymph node, the doctor may use a CT scan—a type of X-ray—or an ultrasound, in which sound waves produce images of structures in the body.

Bone Marrow Aspiration and Biopsy

Your doctor may recommend a bone marrow aspiration and biopsy to determine if lymphoma has spread to the bone marrow.

During a bone marrow aspiration, your doctor uses a needle to withdraw liquid and tissue from bone marrow in the back of the pelvis. To perform a biopsy, he or she removes a tiny piece of bone, about half the size of a matchstick, from the same area. New bone quickly regrows, replacing the piece that is removed. Tissue samples are evaluated under a microscope to look for lymphoma cells.

Both of these procedures require a local anesthetic and may be conducted in the doctor’s office or in the hospital as an outpatient procedure.

Lumbar Puncture

Doctors may perform a lumbar puncture, also known as a spinal tap. This test, performed on an outpatient basis in the hospital, can reveal whether lymphoma has spread to the cerebrospinal fluid, a liquid that cushions the spine and brain.

In this test, the doctor injects a local anesthetic into the skin in the lower back. Then, he or she inserts a hollow needle into the spinal canal to remove a small amount of cerebrospinal fluid. Doctors examine the fluid under a microscope to look for the presence of lymphoma cells.

Imaging Tests

Our doctors may also use imaging tests to determine how far the cancer has spread and how quickly it is growing.

CT Scans

A CT scan uses X-rays and a computer to create three-dimensional, cross-sectional images of the body. This test can help your doctor identify the location of a tumor and measure its size.

Before this scan, your doctor may give you contrast material, or dye, by injection or by mouth, as a liquid or a pill. The dye helps to highlight images of the tumor and surrounding blood vessels on the scan. It contains iodine, so it is not recommended for anyone with an allergy to iodine.

PET Scans

Your doctor may use a PET scan to look for smaller AIDS-related non-Hodgkin lymphoma tumors and to determine how active the disease is—that is, how quickly the cells are processing glucose, or sugar.

During a PET scan, the doctor injects a small amount of radioactive glucose into a vein. This substance collects in tumor cells, which are detected by a computer during the scan. The computer then creates three-dimensional images of cancer activity in the body.

Additional Blood Tests

If you’ve been diagnosed with AIDS-related lymphoma, your doctor may order additional blood tests to determine if you have anemia—a reduction in oxygen-carrying red blood cells—or a low number of platelets, which help the blood to clot. Another blood test measures the level of an enzyme called lactate dehydrogenase, which often increases as lymphoma advances.

Blood tests may also be used to look for infection with Epstein–Barr virus. This virus causes mononucleosis, commonly known as “mono,” and increases the risk of developing Hodgkin lymphoma in people who have HIV, as well as those who don’t.