About Sentinel Lymph Node Biopsy
What is the lymph system?
The lymph system is important in your body’s defense against infection.
It is made up of lymph vessels and lymph nodes. The lymph vessels collect fluid
and protein from surrounding body tissues. This fluid then goes through the lymph
nodes, which act to filter out and trap bacteria, viruses, cancer cells, and
other unwanted substances. Lymph nodes can be found clustered in various parts
of the body, including the neck, axilla (underarm area) and groin.
What is a sentinel lymph node biopsy?
The sentinel lymph
node biopsy is an alternative
to the axillary lymph node dissection when
all of the lymph nodes are removed. The sentinel
lymph node is the first node or nodes that
are “standing guard” for your breast.
If cancer cells are breaking away from the
tumor and traveling through the lymph system,
the sentinel node(s) are the first lymph nodes
to which cancer would spread. In a sentinel
node biopsy for breast cancer, your surgeon
looks under the arm (axilla) for the first
lymph node(s) that drain the breast. Only those
lymph nodes identified as sentinel lymph nodes
are removed. If the sentinel node(s) do not
have cancer, chances are the other nodes in
the axilla have not been affected and can be
left alone. If he sentinel lymph node biopsy
is positive, however, spread to other lymph
nodes is possible and a full axillary dissection
would be recommended.
How is a sentinel lymph node biopsy performed?
The sentinel node is identified by utilizing
a radioactive tracer, a blue dye, or both modalities.
If your surgeon utilizes the radioactive tracer,
you will go to Nuclear Medicine on the day
of surgery where you will receive a small amount
of radioactive tracer injected around the tumor
or under the nipple. A scan will be done to
trace the flow of the radioisotope through
the lymph system to find the location of the
sentinel node(s). This part of the procedure
takes 60-90 minutes.
You will then be taken to the operating room
where the surgeon injects a blue dye into the
area around the tumor or under the nipple. This
is done after you receive general anesthesia.
The blue dye flows through the lymphatic system
into the sentinel lymph node(s), coloring them
blue. The surgeon has a small device, called
a gamma probe that can be used like a Geiger
counter to look at the activity of the radioisotope
in the various lymph nodes that drain the breast.
This probe helps the surgeon find the location
of the sentinel lymph node(s).
Through a small incision under the arm, the
surgeon identifies any lymph nodes that are blue-stained,
radioactive or palpably abnormal, and these nodes
are removed. These are sent to the Pathology
lab for an immediate reading (frozen section).
If the node(s) have tumor in them, an axillary
node dissection is performed. If the sentinel
node(s) are clean, no further axillary surgery
is performed. There is a 5 percent chance that
the sentinel node(s) will be clean on the frozen
section, but may contain small amounts of tumor
when studied more extensively on the permanent
sections. If this happens, you will need to return
to the operating room for a completion axillary
dissection.
Remember that the radioisotope dye and lymph
node scan does not tell you that the cancer has
spread. They only mark the first node(s) that
the cancer cells might have spread to so that
the surgeon can remove them to be tested. Only
the pathologist, by looking under the microscope,
can tell whether cancer cells have spread to
the lymph nodes.
What are the risks of a sentinel lymph node
biopsy?
As with any surgery, there is a risk of bleeding,
infection and poor wound healing. Fluid or blood
could accumulate and require drainage. A small
percentage of patients, less than 1 percent,
may have an allergic reaction to the blue dye.
There will be some blue staining in the breast
skin for a few weeks to several months. You will
also have blue urine for a few days, which is
normal. There is a 2-3 percent chance of getting
arm swelling (lymphedema) following a sentinel
lymph node biopsy.
How will I look and feel after the sentinel
lymph node biopsy?
You will have a small scar under your arm. Initially
there will be some swelling and discomfort.
How long will I be in the hospital?
You may be discharged from the Ambulatory Procedure
Unit on the same day. Following surgery, you
will be in the recovery room until your discharge.
You will need to be picked up by a responsible
adult at the time of discharge. Please inform
family members that this process will take
most of the day.
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