Originally published by Harvard Health.
What is the test?
Lymph nodes are small balls of tissue that are part of the body’s immune system. The nodes produce and harbor infection-fighting white blood cells (lymphocytes) that attack both infectious agents and cancer cells. Cancer, infection, and some other diseases can change the appearance of lymph nodes. For that reason, your doctor may ask a surgeon to remove lymph nodes, to be examined microscopically for evidence of these problems.
Usually, one or more entire lymph nodes are removed and examined under the microscope by a pathologist. On occasion, the doctor does a needle biopsy to remove a portion of a lymph node to see whether a cancer already diagnosed has spread to that point.
How do I prepare for the test?
Tell your doctor if you’re allergic to any medications or if you’re taking aspirin, NSAIDs, vitamin E or any medications that might cause bleeding. Also tell your doctor if you have a condition that bleeds easily such as an ulcer in your stomach or small intestine, or if you’re pregnant.
What happens when the test is performed?
This depends on the location of the lymph nodes to be biopsied. Fortunately many lymph nodes, such as those in your neck, armpits, and groin, are found close to the surface of the skin. These can all be reached through an incision in the skin.
Some lymph nodes are located deeper in your body, such as in the middle of your chest. To reach them, your doctor may insert a tube-like viewing instrument (a scope) through a slit in the skin into the target area to see the lymph nodes, and then remove them with tiny surgical scissors located at the end of the scope. Sometimes removing lymph nodes for microscopic examination requires surgery.
When lymph nodes beneath the skin are biopsied, you lie on an examining table. The doctor cleans the skin at the biopsy site and injects a local anesthetic to numb the area, so that you won’t feel the biopsy. The anesthetic may sting for a few seconds. Next, the doctor makes a small incision in the skin and the tissue just beneath it until he or she can see the lymph node and cut it out. Following such a biopsy, it’s normal to bleed slightly. After applying pressure to the incision site to stop the bleeding, the doctor will cover the area with a bandage. You’ll usually be able to go home within several hours. When a biopsy involves inserting a scope, or surgery, general anesthesia may be required.
What risks are there from the test?
The biopsy site will feel tender for a few days. There’s a slight risk of infection or bleeding. Depending on the location of the lymph node being removed, there is a slight risk of blood vessel or nerve damage.
Must I do anything special after the test is over?
It’s normal for the biopsy site to feel sore afterward, but tell your doctor if it becomes red or hot, or if you develop a fever. These symptoms could be signs of infection.
How long is it before the result of the test is known?
Results will probably be ready in several days.