Sentinel Lymph Node Biopsy

What is the purpose of a sentinel lymph node biopsy?

You will have already been told that the lesion recently removed from your skin was a malignant melanoma.  Many patients ask if we can tell whether there has been any spread to the lymph glands when their melanoma is diagnosed.  A sentinel lymph node biopsy is the means by which we can detect the presence of melanoma cells in the lymph glands at this very early stage. This procedure can be offered by Yeovil District Hospital through the Plastic & Reconstructive Surgery Department at the Royal Devon & Exeter Hospital.
 
The sentinel node biopsy is performed at the same time as the margin of healthy skin is removed from the original site (wide local excision).  Once we have carefully looked at the gland under a microscope; we will be able to tell you whether or not it contains any melanoma cells.  If it does, then we can advise you on the possible role of additional treatment for your melanoma. 
 
If the gland does not contain any melanoma cells then nothing further needs to be done and it is likely that no early spread has taken place.

Without a sentinel lymph node biopsy, patients are simply examined in outpatient clinics for signs of gland enlargement.  This can only be detected once the melanoma cells have had time to grow in the gland.  When this is discovered, all the glands in this area are removed.
 
A sentinel lymph node biopsy is an established investigation in some cancer centres for patients who have been diagnosed with a number of different cancers including breast cancer and malignant melanoma.  It is offered to some patients with malignant melanoma. Patients who have undergone an excisional biopsy of a melanoma of ‘intermediate thickness’ are suitable for this procedure.

How is a sentinel lymph node biopsy performed?

This procedure is carried out under general anaesthetic.

You will need to come in the morning of your operation and have a small injection of x-ray dye or ‘radioisotope’ around the biopsy scar.  No anaesthetic is required for this.  The isotope, which is administered in tiny doses and is otherwise harmless, enables us to see on a special x-ray where the Sentinel Lymph gland is.

Later on the same day, your wide local excision operation will be carried out with you asleep and at the same time we will use a special probe which follows the isotope signal to locate the sentinel lymph node.  We can double check the position of the gland by using a blue dye, similarly injected at the site of the original tumour.  The sentinel lymph gland can then be removed through a small incision.  Most patients will go home the same day.

What are the possible side effects?

After a Sentinel lymph node biopsy, you are unlikely to have any problems, but sometimes the following may occur:

• A small collection of fluid called a seroma, this can be easily removed with a needle and syringe.

• A wound infection (as with any surgical operation)

• Bruising around the Sentinel Node Biopsy scar

Ref: 15-19-116
Review: 03/21