Sentinel Lymph Node Biopsy

Why It Is Done

A sentinel lymph node biopsy is done to:

• See if a known cancer, such as breast cancer or melanoma, has spread to the lymph nodes.
• Remove a few lymph nodes instead of removing all the lymph nodes in an area. If the sentinel lymph node does not have cancer, this surgery takes less time, is simpler to do, and has a lower chance of long-term problems, such as ongoing swelling of an arm or leg (lymphedema).

How To Prepare

• Follow the instructions exactly about when to stop eating and drinking. If you don't, your test may be canceled. If your doctor told you to take your medicines on the day of the test, take them with only a sip of water.
• Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.
• Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your test. Your doctor will tell you if you should stop taking any of them before the test and how soon to do it.
• If you take a medicine that prevents blood clots, your doctor may tell you to stop taking it before your test. Or your doctor may tell you to keep taking it. (These medicines include aspirin and other blood thinners.) Make sure that you understand exactly what your doctor wants you to do.

How It Is Done

You will need to take off clothing near the biopsy site. You will wear a gown for a covering during the test.

Before a sentinel node biopsy is done, a dye, a tracer, or both are injected into the area. The dye stains the sentinel lymph node or nodes so they can be easily seen. The dye may turn your skin blue for a few days after the biopsy. The tracer travels to the sentinel lymph node where it can be detected.

You will be given anesthesia to make you sleep. Or the anesthesia may just numb the area being worked on. The lymph node or nodes are removed. You will have some stitches and a bandage over the biopsy site. The lymph nodes will be looked at under a microscope for cancer.

You will be watched by a nurse in the recovery room until you are fully awake.

How long the test takes

• The biopsy usually takes 30 to 60 minutes. It may take longer if you have surgery to remove the cancer at the same time.

How It Feels

You will feel only a quick sting from the needle if you have a local anesthesia to numb the biopsy area. If you have a core needle biopsy, you may feel some pressure when the biopsy needle is put in.

You may have general anesthesia if your lymph node biopsy is part of a larger surgery. If so, you won't feel your biopsy at all.

Risks

It is possible to have some problems after a biopsy. Your doctor will give you instructions on what to do if a problem occurs. Risks include:

• Bleeding from the biopsy site. This risk is higher for people who have bleeding problems or who take blood-thinning medicines. If you are at risk for bleeding, you may be given blood clotting factors before the biopsy.
• Skin numbness at the biopsy site.
• Infection at the biopsy site.
• Swelling and fluid buildup (lymphedema). This is less likely after a sentinel node biopsy than if more lymph nodes are taken out (dissection).
• Problems from general anesthesia, if it is used.
• Damage to nerves at the biopsy site. This may cause weakness or pain.

Results

Test results are usually available within a few days.

The lymph node tissue is usually treated with special dyes (stains) that color the cells so problems can be clearly seen.

If the sentinel lymph nodes do not have cancer, no other nodes will need to be taken out.

If the nodes contain cancer cells, more nodes may need to be removed.