HF 7733

Sentinel Lymph Node Excision and/or Biopsy

What is a sentinel lymph node surgery?

This is a surgery to determine if cancer has spread beyond the site of the tumor to any lymph nodes.

What are lymph nodes?

Our bodies have a network of lymph channels and nodes that carry a watery clear fluid called lymph. The lymph fluid carries white blood cells which help us fight infections. This fluid flows throughout our bodies like blood does.

What is a sentinel lymph node?

The first lymph node(s) that the tumor may spread to is called the sentinel lymph nodes. By closely looking at the sentinel nodes, your doctor can decide if the cancer has moved outside the tumor.

Cancer cells can travel in the lymph system. Since the lymph system runs throughout the body, these cancer cells have a chance of spreading to other areas of the body.

Will my lymph nodes be removed?

Almost everyone has some lymph nodes (an average of two) removed. The lymph node(s) that are removed are the ones that cancer would be most likely to spread to first. Many times, the nodes do not contain cancer cells, but the entire node is still removed. A sentinel node cannot be “biopsied.” It must be completely removed so the entire node can be checked for cancer.

A sentinel lymph node mapping and excision (removal) of sentinel node(s) helps to trace the path on which a tumor may drain, and what lymph node (s) it may drain to.

About the Surgery

Before surgery, an injection of a radioactive tracer or dye is given near or at the site of the cancer. This injection and x-rays are done in the nuclear medicine department. There may be some pain with the injection. Pictures will show which lymph node(s) have taken up the radioactive dye.

Sentinel node surgery may take place the same day as the radioactive tracer injection or the following day. In the operating room, the doctor injects a blue dye near the area of the cancer. During the surgery, your doctor looks for lymph nodes that have the blue dye in them.

How do they tell if there is cancer in my lymph nodes?

A pathologist looks at the lymph nodes under a microscope.

What can I expect after surgery?

After your surgery, you may notice that your urine is blue or green in color from the dye. This will go away within 24 hours. Some people get a very faint blue coloring to their skin after surgery as well. This will also go away within 24 hours. You may also notice some temporary numbness in the area of the surgery.

Care of Your Incision

You may have a gauze bandage over your incision which you can remove after 24 hours. If you have drainage from your incision; cover with a new piece of gauze.

Your incision will be covered with Steri-Strips. These strips of tape are usually removed at your clinic visit after surgery. If they fall off before your clinic visit, that is ok.

Look at the site daily for any problems or signs of infection. You may notice a slight redness and swelling along your incision. This is normal.

You may shower 24 hours after your surgery. Let water flow over the incision(s) and pat dry.

Do not soak in a tub or pool until you are seen by your surgeon at your first visit.

Pain Management

The amount of pain may vary. You will be given a prescription for opioid pain medicine. Use it as needed and as directed. Do not drive a vehicle while taking opioid medicine.

  • Eat plenty of fiber (bran, oats, fruits and vegetables).

  • Drink 6-8 glasses of water each day to help prevent constipation.

  • Take stool softeners if needed.

  • If you have nausea, take your pain medicine with food.

Many patients find that taking 1 -2 tablets of Extra-Strength Tylenol every 4-6 hours helps to relieve pain. You may take up to a total of 8 tablets in a 24-hour period. Do not exceed this amount. If you have liver disease, check with your doctor before taking. You may also take ibuprofen as directed by your doctor. Consult your doctor if taking other pain medicine.

You may also use ice from time to time on the incision. Do not use a heating pad. This may burn the skin.

Signs of Seroma (fluid collection)

A seroma is a fluid-filled bulge that forms under the skin at the surgery site.

If you have a fluid collection or seroma that is getting larger and causing pain, contact your doctor. This is not an emergency. You may be asked to return to the clinic to have the fluid drained.

Axillary Web Syndrome (Cording)

Cording can develop as a side effect of removing lymph nodes in up to 20% of patients. Some believe surgery leads to inflammation, scarring, and hardening of lymphatic vessels and other tissues, causing rope-like structures. You will often be able to see and/or feel one or more cords in your underarm area or along the inner part of your arm. Cording can cause pain and tightness in the underarm area or the inner part of the upper arm. It is most noticeable when you raise your arm overhead or out to the side away from your body. Cording usually happens several days to several weeks after surgery. Treatment includes movement and stretches recommended by an experienced therapist.


Lymph vessels can be damaged when lymph nodes are removed. Some of these lymph vessels carry fluid from the arm to the rest of the body. If the remaining vessels cannot remove enough of the fluid in the chest and underarm area, the extra fluid builds up. This causes swelling, or lymphedema. Though the risk of this is low (1-8%) after a sentinel lymph node excision and/or biopsy, notify your doctor if you have these signs and symptoms:

  • achiness,

  • heaviness,

  • fatigue, and/or

  • numbness/tingling of the involved arm.

Reduce Risk of Arm Swelling

Exercise your affected arm to help move fluid out of the arm. While your arm is elevated, open and close your hand and bend and straighten your elbow 15-20 times. Repeat this 3-4 times per day.

It is important to slowly return to your prior level of activity after surgery. This will lower your risk of injury and arm swelling from repeated or strenuous activity.

For the first 8 weeks after surgery, have all shots, IVs, blood draws or blood pressure tests done on the unaffected arm. If both arms are affected, use your leg when possible. Avoid infections by avoiding burns, cleaning even small cuts promptly with soap and water, wearing gloves when gardening, and using insect repellent when outdoors to avoid bug bites.

Always monitor your arm for swelling. Early detection is important. If you have any concerns, call your doctor. The sooner lymphedema is noticed, the easier it is to manage.

Who to Call

To reach your doctor, call one of these numbers Monday – Friday, 8:00 am to 5:00 pm

  • UW Health Breast Center (608) 266-6400

  • UW Health General Surgery Clinic at UW Hospital (608) 263-7502

  • UW Health General Surgery Clinic at 1 South Park (608) 287-2100

For Emergencies

  • UW Hospital Emergency Room (608) 262-2398

  • Meriter Hospital Emergency Room (608) 417-6206

After Hours

  • UW Hospital Clinics: Call UW Hospital Paging Operator at (608) 262-0486 and ask for the surgery resident on call. Give your name and phone number with the area code. The doctor will call you back.

  • UW Health 1 South Park – Call the number of your clinic. The answering service will contact the doctor on call. Give your name and phone number with the area code. The doctor will call you back.

Toll Free

If you live out of the area, call 1-800-323-8942.