Page 1 of 4
Sentinel Lymph Node Mapping and Excision of Sentinel Node(s)
What is a sentinel lymph node
This is a surgery that is used to determine if
certain types of cancer have spread beyond
the site of the tumor. It will show the doctor
if cancer cells may have spread to any
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 the way blood vessels carry
blood to all parts of the body.
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 surgeon can then decide if the cancer
has moved outside its usual location.
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 2) 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 to
determine this. A sentinel node cannot be
“biopsied.” It must be completely removed
so the entire node can be looked at to see if
cancer is inside the lymph node. Your
surgeon removes these lymph nodes and
sends them to a pathologist.
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
How the surgery is done
Prior to the surgery, patients receive an
injection of a radioactive tracer or dye near
or at the site of their cancer. This injection
and related 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
Your sentinel node surgery may take place
the same day as the radioactive tracer
injection or the following day. In the
operating room, the surgeon will inject a
blue dye near the area of the cancer about 5
minutes before the surgery. During the
surgery, your doctor looks at the lymph
Page 2 of 4
nodes to identify which ones have the blue
dye in them and also uses a probe to detect
the presence of the radioactive tracer in your
How do they tell if there is cancer in my
After the lymph nodes are removed a
pathologist looks at them under a
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 affect 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
region of the surgery.
Care of Your Sentinel Node Surgery
ξ You may have a gauze bandage over
your incision which you can remove
after 24 hours, if you have drainage from
your incision; place a new piece of
gauze over the site.
ξ Under any gauze dressing, your incision
will be covered with special tape called
Steri-Strips. These strips of tape are
usually removed at your post- operative
clinic visit but if they fall off before your
clinic visit that is ok.
ξ 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.
ξ You may shower 24 hours after your
surgery. Let water flow over the
surgical incision(s) and pat dry. Do not
soak in a tub or pool until you are seen
by your surgeon at your post-operative
The amount of pain may vary. You will be
given a prescription for narcotic pain
medicine. Use it as needed and as directed.
Do not drive a vehicle while taking narcotic
ξ Eat plenty of fiber (bran, oats, fruits
ξ Drink 6-8 glasses of water each day
to help prevent constipation.
ξ Take stool softeners if needed.
ξ 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 is
helpful 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 it. 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 as
this may cause a burn to the skin.
Signs of Seroma (fluid collection)
A seroma is a fluid-filled bulge that forms
under the skin in the place where the surgery
If you have a fluid collection or seroma that
is getting larger and causing pain or
Page 3 of 4
discomfort, please 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 is often accompanied by
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, extending your elbow fully. Cording
usually occurs anywhere from several days
to several weeks after your underarm
surgery. Treatment includes mainly moving
and stretching under the guidance of an
With removing some of the lymph nodes
under the arm during surgery, there is a
chance that lymph vessels have been
damaged. 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 and causes swelling,
or lymphedema. Though the risk of this is
low (1-8%) after a sentinel node biopsy, you
should be aware of the following signs and
symptoms to notify your doctor: achiness,
heaviness, fatigue, and/or numbness/tingling
of the involved arm.
To Reduce Risk of Arm Swelling After
Exercise your affected arm while it is
elevated by opening and closing your hand,
and bending and straightening your elbow
15-20 times. Repeat this 3-4 times per day.
This will assist your lymphatic system to
pump excess fluid out of the arm.
1) It is important to gradually return to
your prior level of activity after
surgery. This will reduce your risk of
strain from repeated or strenuous
activity, which can result in injury,
and has been associated with the
onset of arm swelling in some
2) 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, then use your leg when
possible. Try to avoid infections as
well 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.
3) Always monitor your arm for
swelling because early detection is
important. If you have any concerns,
then consult your doctor. The sooner
lymphedema is noticed the easier it
is to manage.
Page 4 of 4
Important Phone Numbers
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 UWHC (608) 263-7502
UW Health General Surgery Clinic at 1 South Park (608) 287-2100
UW Hospital Emergency Room (608) 262-2398
Meriter Hospital Emergency Room (608) 417-6206
ξ 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.
ξ UW Health 1 South Park – Call the number of your clinic and 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, you may use one of these numbers
ξ UW Hospital and Clinics 1-800-323-8942
ξ UW Medical Foundation (UWMF) 1-888-703-2778
Your health care team may have given you this information as part of your care. If so, please use it and call if you have any
questions. If this information was not given to you as part of your care, please check with your doctor. This is not medical advice.
This is not to be used for diagnosis or treatment of any medical condition. Because each person’s health needs are different, you
should talk with your doctor or others on your health care team when using this information. If you have an emergency, please call
911. Copyright ©8/2016. University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department
of Nursing. HF#7733.