Sentinel lymph nodes are part of the lymphatic system. They are found
in the axilla (armpit). The lymphatic system is an important part of the
immune system, helping to fight infection and diseases and working
as a drainage system to help remove excess fluid and waste products
from the body. It is made up of lymph fluid (formed when excess fluid
drains from the body), lymph vessels (tiny channels which carry lymph
fluid) and lymph nodes (small glands which act as filters when lymph
fluid drains through them). Sentinel lymph nodes are the first nodes to
receive lymph fluid which drains from the breast.
There is a small risk of allergic reaction to the dye used to locate the
sentinel lymph nodes, affecting approximately 1% of patients (one in
a hundred). Blue staining can affect the breast for several months after
surgery, but it will fade in time.
The dye can also cause your skin, urine and faeces to turn a blue/green
colour. This is temporary and will last for approximately 48 hours
after surgery. If you wear contact lenses it’s possible that you may
notice a blue tint appear on them, so it is recommended that you avoid
wearing contact lenses until the dye has left your body.