How does a sentinel node biopsy work?
Before a sentinel lymph node biopsy, a provider will inject a special dye around the cancer site to determine which lymph nodes are the main draining lymph nodes. This means that if the cancer were to spread, it would spread to these lymph nodes first.
During a sentinel node biopsy, a surgeon locates your sentinel nodes, removes them and sends them to a lab for testing. A different provider tests the nodes for cancer cells.
How do I prepare for a sentinel node biopsy?
Follow your healthcare provider’s guidance on how to prepare. You may receive instructions related to:
- Fasting: When (and what foods or drinks) you should stop eating and drinking prior to the surgical procedure.
- Medications: Which medicines, vitamins, herbs or supplements you should stop taking.
Arrange to have someone drive you home on the day of your procedure.
What should I expect during the procedure?
Before or during surgery, you may receive an injection of a safe radioactive substance (tracer) and/or a dye that travels the same path that fluid draining from your tumor would take. The tracer leads your surgeon to your sentinel lymph node(s).
You’ll receive general anesthesia through an IV (a needle in your arm) that will put you to sleep so you don’t feel any pain. Once you’re asleep, your healthcare provider will:
- Locate your sentinel lymph node(s). If you received a tracer, your healthcare provider will use an instrument called a gamma detector to locate the sentinel node. They may inject a blue dye near the tumor site that stains your sentinel nodes blue or a fluorescent dye. Often, providers use both the dye and the tracer.
- Remove the lymph node(s). Providers make an incision (cut) and remove one or more sentinel nodes.
- Close the incision. Your provider will use stitches to close the incision.
Afterward, they’ll send the sentinel nodes to a lab, where a pathologist will test for cancer cells. A pathologist is an expert in diagnosing medical conditions using lab tests.
How many nodes are taken in a sentinel node biopsy?
It depends. Your healthcare provider will remove enough sentinel nodes to accurately detect cancer cells. Most providers remove more than one, but the ideal number is debatable. Some studies show that removing three sentinel nodes is often enough to detect cancer. Other research shows that up to five may need to be removed for an accurate diagnosis.
The numbers vary for every person based on their unique case.
What should I expect after the procedure?
Many people have someone drive them home the same day, but you may need to stay in the hospital overnight. Follow your healthcare provider’s advice on when it’s safe to leave.
As you heal, you can expect the following, which are all normal:
- Soreness or tenderness near your incision site.
- Tingling and numbness. (This is your nerves healing.)
- Blue or green pee (urine) or stool from the dye.
- Bluish color near the incision site from the dye.
- Hardening beneath the tissue where scar tissue is forming.
- Stiffness in your arm (if your provider removed sentinel nodes from your armpit).
Before leaving the medical facility, ensure you know how to care for the incision site and understand what potential complications to look out for. Ask when it’s safe to return to your regular activities. Recovery time for a sentinel node biopsy varies, but most people need to wait several weeks before running, exercising or lifting.
What are the risks of a sentinel node biopsy?
A sentinel node biopsy is a safe procedure. Still, every surgery poses some risks. Potential side effects and complications include:
- Problems at the incision site. Bleeding, bruising, swelling and pain can occur at the incision site. The incision can also become infected. Signs of infection include redness, swelling and fever.
- Allergic reaction. Rarely, some people are allergic to the blue dye providers use to locate the sentinel node.
- Lymphedema. Lymph node removal can cause the fluid that normally flows through your lymph nodes to build up, causing swelling and pain. Lymphedema is a rare complication that occurs most often when providers remove several lymph nodes, not just select sentinel lymph nodes. Typically, providers leave behind enough lymph nodes so that fluid continues to drain normally.
- Axillary web syndrome (AWS). With AWS, or “cording,” you may notice multiple cord-like structures underneath the skin on your inner arm. Although it’s rare, cording may occur if a provider removes lymph nodes from your armpit. The cords may form days, weeks or months after surgery.
Contact your healthcare provider immediately if you notice signs of these complications.
