Sentinel lymph node biopsy

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What is a sentinel lymph node biopsy (SLNB)?

The most common place that melanoma skin cancer spreads to is the nearby lymph nodes. If your melanoma is deeper than 1mm  or if there are additional risk factors, your medical team will discuss the option of having a sentinel lymph node biopsy which would happen at the same time as your wide local excision. For more information on wide local excision see here.

We have produced two animated videos to help you understand sentinel lymph node biopsies.

Understanding lymph node biopsy

Our first animation explains the lymphatic system and why you may have been offered a sentinel lymph node biopsy.  

What happens during a sentinel lymph node biopsy

Our second  animation explains what happens during the procedure and the potential risks.

Most people are able to go home on the same day of their surgery, but general anaesthesia can affect your co-ordination and concentration, so youll need to avoid driving or drinking alcohol for 24-48 hours afterwards. Simple pain relief is usually all that is needed (paracetamol). Most people will need around a week off work, although this will vary depending upon where your melanoma was removed and the type of surgery required. You are likely to need to either see your local practice nurse or return to the dressing clinic in the hospital where you had your surgery for the first dressing change. Any further dressing changes will be discussed with you then.

The wounds will take several weeks to settle and at least 9 months or so for the scars to soften and settle. The final cosmetic outcome will depend upon what type of reconstruction has been needed for your surgery, how you heal, whether there were any problems during the healing phase, other medical conditions you have and if you are a smoker. Generally, most people are not troubled by their scars.

What happens next?

A pathologist (a specialist doctor) will very carefully slice the lymph node finely and examine this under a microscope and look for melanoma cells. Your medical team are gradually building up a picture of the extent of your melanoma which is also called the ‘stage’ of your melanoma. To understand melanoma staging, see melanoma staging explained.  

Once the information has been examined and reviewed which usually takes about 4 weeks, you will be invited back for an appointment to discuss the results of the sentinel lymph node biopsy and wide local excision.

We know that waiting for any results and additional information is a worrying time for you and your family. If you would like to discuss your concerns, please call our:

Melanoma Helpline on 0808 801 0777

If your result comes back as positive (positive sentinel lymph node biopsy), you will be considered for adjuvant therapy which may improve their survival. This is the main reason why patients choose to have this procedure in addition to a wide local excision.

For more information on adjuvant therapy and what this could mean for you.

What happens if I don’t have a sentinel lymph biopsy?

A positive node is found in about 20% (1 in 5) who are offered the procedure. If you are one of the 20% who have a melanoma deposit in your lymph node, but do not have a sentinel node biopsy, then at some time during your follow up, either you or your doctor will feel a lump, where the lymph nodes are. The few cells that would have been found had you had a sentinel node biopsy, will have grown such that they form a lump which you can feel. For the 80% of people who do not have any melanoma in their lymph node(s) and would have had a negative sentinel node biopsy, then the majority will not detect this lump. It is important to know that even if your sentinel node is negative, in a small number or patients (3-4%) the melanoma will come back in a different lymph node. That is why even if you have a negative sentinel node, you are likely to be followed up for 5 years.

Questions you may have

  • Can I exercise after my sentinel lymph node biopsy?
  • How long will the results take to arrive back?
  • How will I get my results?
  • Will I have a visible scar and what can be done to minimise the scarring?
  • What are the risks of a sentinel lymph node biopsy?
  • What may happen next?
  • How will I be followed-up after my surgery?
  • What is the stage of my melanoma and do I need further treatment?