Test Overview
A sentinel lymph node
is a surgery that takes out
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
nodes.
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
the arm.
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
nodes.
Other tests, such as a
, genetic tests, or immunological tests, may be
done on the lymph node sample.