Melanoma excision (wide local excision) and sentinel node biopsy are surgical procedures used in the management of melanoma, a type of skin cancer that arises from melanocytes, the cells responsible for producing skin pigment (melanin). The purpose of the procedures is to diagnose and treat melanoma in its early stages, which significantly improves the chances of successful treatment and reduces the risk of disease recurrence.
These procedures are indicated for patients with suspected or confirmed melanoma. They are particularly recommended when the melanoma is relatively thick or deep or has shown signs of spreading to nearby lymph nodes. The sentinel node biopsy helps determine if the cancer has spread to regional lymph nodes, guiding further treatment decisions.
Before the surgery, you will receive specific instructions from Dr Moar, which may include fasting, stopping certain medications such as blood thinners, and arranging transport home.
This procedure requires two steps:
Step 1: A preoperative lymphoscintigraphy
On the same day as the procedure (usually first thing in the morning) patients attend the Nuclear Medicine department at the hospital, for a lymphoscintigraphy scan. Before the scan, between one and four small injections are made near the melanoma site. After that, scans are performed. These can range in time from 10 to 15 minutes up to three hours, depending on how rapidly the lymphatic system is draining.
Step 2: The operation
The operation is performed under a general anaesthetic. The melanoma and a surrounding margin of healthy tissue is surgically removed (wide local excision). The excised tissue is sent for histopathological examination to ensure complete removal of the cancerous cells. Dr Moar will then identify the sentinel lymph node, which is the first lymph node that the cancer cells are likely to spread to from the primary tumour. This is done using a device that detects the radioactive substance that was injected earlier for the lymphoscintigraphy scan. The node is then removed and sent to be analysed for the presence of any cancer cells.
Patients may experience pain and discomfort after the surgery, which can be managed with prescribed pain medications. Other instructions may include:
- Keeping the surgical site clean and dry to minimise the risk of infection.
- Avoiding strenuous activities for a few weeks to aid the healing process.
- Attending follow-up appointments with Dr Moar for wound checks and pathology results review.
- Monitoring the surgical site for signs of infection, such as redness, swelling, or pus.
- Sometimes, a drain tube may need to be kept in for several days following the surgery.
As with any surgical procedure, there are potential risks involved, including bleeding and infection, seroma (fluid collection where the sentinel node was taken), scarring, nerve injury, and lymphedema, which can cause swelling to the affected limb.
Depending on the stage and severity of melanoma, other treatments may include:
- Wide Local Excision alone: Excision without sentinel node biopsy for very early-stage melanomas with a low risk of spreading, or in frail patients who might not be fit for a general anaesthetic and sentinel node biopsy. This will be assessed on a case-by-case basis.
- Mohs Surgery: Complete removal of the cancerous cells while preserving healthy tissue.
- Lymph Node Dissection: More extensive lymph node dissection if melanoma has spread to more nearby lymph nodes.
- Immunotherapy and Targeted Therapy: Systemic treatments for advanced cases or those at high risk of recurrence.