A sentinel lymph node biopsy is the removal and testing of specific lymph node tissue called sentinel nodes. The sentinel nodes are the lymph nodes to which cancer would spread first.
Reasons for Procedure
This biopsy is done to determine if cancer cells have spread from the tumor to nearby lymph nodes. Cancer often spreads from the tumor to the nearest lymph node or nodes. These lymph nodes are called the sentinel nodes. It is important to understand that the sentinel node will probably be the first one to get cancer if the cancer has spread. For example, the sentinel nodes in breast cancer are often found in the armpit.
This biopsy is often done during cancer-removal surgery or prior to surgery. Sentinel node biopsy is part of the staging process. Staging is an attempt to determine how much the cancer has spread away from the original tumor. The cancerous tissue may have been biopsied already.
Complications are rare. But no procedure is completely free of risk. If you are planning to have this biopsy, your doctor will review a list of possible complications. These may include:
- Bleeding or bruising
- Nerve damage and chronic pain
- Allergy to dye
If the lymph nodes are removed, there is an increased risk of the following:
- Delayed wound healing
- Additional pain
- Lymphedema—a condition in which fluids collect under the skin causing swelling
Some factors that may increase the risk of complications include:
- Recent or long-term illness
- Poor nutrition
- Use of certain medicines
- Bleeding disorders
What to Expect
Prior to Procedure
Your doctor will do a physical exam. Tests may include the following:
- Blood tests
- Urine tests
- Imaging studies may be done to look for cancer spread or the location of the sentinel nodes and may include:
Talk to your doctor about your medicines. You may be asked to stop taking some medicines up to one week before the procedure, such as:
- Aspirin or other anti-inflammatory drugs
- Blood thinners
Prior to the procedure, you should also:
- Eat a light meal the night before. Do not eat or drink anything after midnight.
- Arrange for a ride to and from the hospital.
Depending on the location of the lymph node, you may be given one of the following:
- General anesthesia—You will be asleep.
- Local anesthesia—The area will be numb.
- Regional anesthesia—An area of your body will be numb.
Description of the Procedure
A blue dye, and often a radioactive tracer, will be injected into the area where the tumor is. It may be done several hours before surgery. The dye and tracer will travel from the tumor area to the sentinel nodes. This will also help identify which nodes are the sentinel lymph nodes. A small incision will be made. The sentinel node(s) will be removed. The removed node will be checked for cancer cells. If cancer is found, the rest of the lymph nodes in that area will be removed.
If cancer is not seen in the sentinel node, it is unlikely that the cancer has spread to the other remaining lymph nodes. The other lymph nodes are not removed.
How Long Will It Take?
The biopsy takes about 30-60 minutes. Surgery to remove the entire cancer takes longer.
Will It Hurt?
Anesthesia prevents pain during surgery. Pain medicines are given during recovery.
The result of the sentinel lymph node biopsy determines if additional lymph nodes need to be removed. It can also help determine the severity of your cancer.
Be sure to follow your doctor's instructions. Keep the surgical area clean and dry. Ask your doctor about when it is safe to shower, bathe, or soak in water.
If you develop complications from lymph node surgery, you will need to take some special precautions. Discuss these precautions with your doctor.
Call Your Doctor
After arriving home, contact your doctor if any of the following occur:
- Signs of infection, including fever and chills
- Redness, swelling, increasing pain, excessive bleeding, or discharge from the incision site
- If lymph nodes were removed: redness, warmth, swelling, stiffness, or hardness in the extremity
- Dark or swollen fingers and toes
- Nausea and/or vomiting that you cannot control with the medicines you were given after surgery, or which last for more than two days after discharge from the hospital
- Pain that you cannot control with the medicines you have been given
- Cough, shortness of breath, or chest pain
- New, unexplained symptoms
If you think you have an emergency, call for medical help right away.