Surgical Procedures: Sentinel Lymph Node Biopsy

OncoLink Team
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: November 14, 2013

Also Referred to as: Sentinel node biopsy, SLN biopsy

What is a Sentinel Lymph Node Biopsy?

A surgical procedure to determine if cancer cells are in the lymph nodes under the arm. Only the lymph node(s) that drain fluid from the breast (called sentinel nodes) are removed. The remaining nodes are left alone. This significantly reduces the chance of developing a chronic swelling problem called lymphedema.

In the operating room, under anesthesia, the surgeon injects a blue dye and/or a radioisotope (a nuclear medicine dye) into the breast. Once the dye(s) are injected, they are picked up by the lymphatic fluid in the breast and travel the normal route to the lymph node(s) under the arm. An incision is made under the arm and the surgeon finds the lymph nodes with dye and removes them. It is important to understand that lymph node(s) having dye in them does not mean that they have cancer in them, only that they are the right lymph nodes to check for cancer.

Will I Stay Overnight?

No. This is usually done as an outpatient or "same day" surgery.

Could I Need More Surgery?

If cancer is found in one or more sentinel lymph nodes, you will have a discussion with your surgeon to determine if you should have more lymph nodes removed.

What is Recovery Like?

Your surgeon will discuss specific recovery issues with you. In general, you will be up and moving the day after surgery, with some limitations to your normal schedule and exercise routine in the first week or so. After surgery, you could experience any of the following side effects:

  • Blue urine and greenish colored stool for 24-48 hours after the injection of blue dye as it is excreted from your body. You are NOT radioactive after receiving the radioactive tracer.
  • Pain, numbness and/or sensitivity in the underarm or back of the upper arm.
  • A seroma could develop. A seroma is when lymph fluid collects under the arm instead of draining its normal route. It is not worrisome, but can be uncomfortable. Most go away naturally, over time, but occasionally need to be drained in the office with a needle (an easy, painless procedure).
  • Lymphedema is a chronic swelling in the arm and/or breast, on the side of surgery. There is a low risk of developing lymphedema after this procedure, though this risk is life-long. Learn more about lymphedema and what you can do to minimize your risk of developing lymphedema.

What will I need at Home?

  • 4 x 4 gauze pads and 1-inch paper tape to cover the incision if it is leaking. These can be found at your supermarket or pharmacy.
  • Clean, comfy pillow(s) to put under your arm while sitting or to help with positioning at night.
  • You may experience constipation after surgery due to anesthesia and pain medications. Over-the-counter medications, diet, exercise (as simple as walking) and fluids may ease constipation. Ask your health-care team about over-the-counter medications that may work for you.

Care of the Incision

If you have a post-surgical bandage, remove per your surgeon's instructions (often within 48 hours). Once the bandage is removed, you may shower, but do not scrub the incision. To dry, carefully pat the incision with a clean towel. Avoid lotions, powders or deodorant on or near the incision during the first 1-2 weeks until it is fully closed.

Most surgeons use dissolvable sutures so you won't see any sutures and they don't need to be removed. On the outside, some surgeons use surgical glue over the incision to give added protection, others use paper tape called "steri-strips" while some use nothing at all. Both glue and steri-strips can get wet in the shower.

How Can I Help Myself?

Walking is good. Take rest periods throughout the day as needed. Move your arm on the side of surgery as naturally as possible; do not feel as if you have to guard the area.

Deep breathing and relaxation are important to help with pain, keep lungs healthy after anesthesia and promote good drainage of lymphatic fluid. Try to perform deep breathing and relaxation exercises several times a day in the first week, or whenever you notice you are particularly tense.

  • A simple exercise to do on your own: While sitting, close your eyes and take 5-10 slow deep breaths. Relax your muscles. Slowly roll your head and shoulders.
  • Find more relaxation exercises on OncoLink.

This hand-out provides general information only. Please be sure to discuss the specifics of your surgical plan and recovery with your surgeon.