Sentinel Lymph Node Biopsy
A sentinel lymph node
biopsy is a surgery that takes out
lymph node tissue to look for cancer. A sentinel node
biopsy is used to see if a known
cancer has spread from the original cancer site. A
sentinel node biopsy may be done instead of a more extensive surgery called
lymph node dissection. But if cancer is found in the sentinel lymph node at the
time of surgery, more surgery may be needed to remove additional lymph
The sentinel lymph node is the first node in a group of
nodes in the body where cancer cells may move to after they have left the
original cancer site and started to spread. For example, the sentinel node (SN)
for breast cancer is normally one of the lymph nodes under
Your doctor injects a blue dye or special tracer
substance or both into the area around the original cancer site. The dye or
tracer moves to the first lymph node (sentinel node) that drains close to the
cancer site. The dye or tracer makes a map pattern of lymphatic fluid. The map
can show where the cancer is likely to spread and which lymph node is most
likely to have cancer cells. Your doctor can see the dye or tracer with a
special device. The lymph node can be taken out, cut into very thin slices, and
looked at under a microscope at the time of surgery. If a sentinel node is
positive for cancer cells, additional surgery may be needed to remove more lymph
Other tests, such as a
culture, genetic tests, or immunological tests, may be
done on the lymph node sample.
Why It Is Done
A sentinel lymph node biopsy is done
- See if a known cancer, such as breast cancer or
melanoma, has spread to the lymph nodes.
- Remove a few lymph nodes
instead of removing all the lymph nodes in an area. If the sentinel lymph node
does not have cancer, this surgery takes less time, is simpler to do, and has a
lower chance of long-term problems, such as ongoing swelling of an arm or leg (lymphedema).
How To Prepare
Tell your doctor if you:
- Are or might be pregnant.
taking any medicines, especially medicines for depression, such as paroxetine (Paxil), fluoxetine (Prozac), amitriptyline (Limbitrol), or venlafaxine (Effexor).
- Are allergic to any medicines, including any
anesthetics or dyes.
- Have had bleeding
problems or take blood-thinners, such as aspirin or warfarin
- Have had a biopsy in the past.
- Have had
radiation treatment to the biopsy site.
Follow your doctor's instructions carefully. If you are
given a medicine (sedative) to make you relax or sleep
before the biopsy, do not eat or drink for 8 hours before the biopsy. Arrange
for someone to drive you home after the biopsy.
Talk to your
doctor about concerns you have regarding the need for the test, its risks, how
it will be done, or what the results may mean. To help you understand the
importance of this test, fill out the
medical test information form(What is a PDF document?).