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Sentinel Lymph Node Biopsy: About This Test

What is it?

A sentinel lymph node biopsy is a surgery to take out lymph node tissue to look for cancer that has spread into the lymph system.

The lymph system is a network of vessels that carries material between the body tissues and the bloodstream. The sentinel lymph node is the first node in the body where cancer cells may be found if the cancer has spread from the original site.

Why is this test done?

This test is done to see if a cancer has spread from its original site. This information helps stage a cancer. The stage is a way for doctors to describe how far the cancer has spread. Your treatment choices will be based partly on the type and stage of cancer.

How can you prepare for the test?

  • Talk to your doctor about concerns you have regarding the need for the test, its risks, how it will be done, and what the results may mean.
  • Tell your doctor ALL the medicines, vitamins, and natural health products you take.
  • If you take aspirin or some other blood thinner, be sure to talk to your doctor. He or she will tell you if you should stop taking it before your test. Make sure that you understand exactly what your doctor wants you to do.
  • Tell your doctor if you are allergic to any medicines, including any anesthetics or dyes.
  • Tell your doctor if you are or might be pregnant.
  • Follow the instructions exactly about when to stop eating and drinking. If you don't, your test may be cancelled. If your doctor told you to take your medicines on the day of the test, take them with only a sip of water.

What happens before the test?

  • You will take off your clothing near the biopsy site. A paper or cloth gown will cover you during the test.
  • You will be kept comfortable and safe by your anesthesia provider. You will be asleep during the biopsy.

What happens during the test?

  • The doctor injects a dye or tracer into your body near your cancer site. A special camera takes pictures of the lymph nodes. The pictures help the doctor identify the sentinel nodes.
  • The doctor gives you a numbing medicine, then removes the sentinel node and a small amount of tissue around it. The node is tested for cancer cells during the biopsy. The results help the doctor decide whether to remove any more nodes.
  • You will have some stitches and a bandage over the biopsy site.

What else should you know about the test?

  • 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.
  • If you are having surgery to remove the cancer, the sentinel node biopsy may be done during the surgery.

How long does the test take?

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

What happens after the test?

  • The doctor will tell you what to do if you have any bleeding, numbness, or swelling at the biopsy site.
  • You might be able to go home the same day. Be sure to have someone drive you home.
  • Your skin may be blue from the dye for several days after the test. The dye may also turn your urine green for 1 to 2 days.
  • Allow the area to heal. Don't move quickly or lift anything heavy until you are feeling better.
  • During your follow-up visit, your doctor will discuss the results of your biopsy with you and take out any stitches.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse call line if you are having problems. It's also a good idea to keep a list of the medicines you take. Ask your doctor when you can expect to have your test results.

Where can you learn more?

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