Lymph Node Surgery for Melanoma

The regional lymph nodes are the most common first site of spread for melanoma, and their assessment and surgical management is a critical component of melanoma staging and treatment. Lymph node status is one of the most important prognostic factors in melanoma — the presence of nodal metastases significantly influences staging, systemic treatment decisions, and long-term outcomes.

Lymph node surgery for melanoma encompasses two distinct categories: sentinel lymph node biopsy, which is a minimally invasive staging procedure to detect microscopic nodal spread, and therapeutic lymph node dissection, which involves the surgical removal of the lymph node-bearing tissue of an entire nodal basin when nodal involvement is confirmed.

At Breast & Surgical Oncology at The Poche Centre, lymph node surgery for melanoma is performed by Prof Andrew Spillane, a nationally recognised surgical oncologist who has dedicated a significant part of his academic and clinical career to the study and advancement of lymph node management in melanoma. He performs sentinel node biopsy and all regional lymph node dissections including axillary, groin, and neck dissection, and is a board member and Deputy Chair of the Melanoma and Skin Cancer (MASC) Trials Group.

The Lymphatic System and Melanoma Spread

Melanoma spreads primarily through the lymphatic system in its early stages, with cancer cells travelling from the primary tumour through lymphatic channels to the regional lymph nodes. The specific nodal basin that drains a given area of skin is determined by the anatomical location of the primary tumour.

Tumours on the upper limb, shoulder, and trunk above the waist typically drain to the axillary (armpit) nodes. Tumours on the lower limb, lower trunk, and perineum typically drain to the inguinal (groin) nodes. Tumours on the head and neck drain to the cervical (neck) nodes. Tumours on the trunk may have ambiguous or multiple drainage patterns, which is one of the reasons lymphoscintigraphy is so important in accurately identifying the sentinel node before surgery.

Sentinel Lymph Node Biopsy

Sentinel lymph node biopsy (SLNB) is the standard staging procedure for patients with melanoma where the risk of nodal spread is meaningful — generally for primary tumours with a Breslow thickness of 0.8 mm or greater, and in some thinner tumours with high-risk features such as ulceration or a high mitotic rate. It is the most accurate and least invasive method of determining whether microscopic melanoma has spread to the regional lymph nodes.

How It Works

The sentinel node is the first lymph node in the regional basin to receive lymphatic drainage from the primary melanoma site. If melanoma cells have spread via the lymphatics, they are most likely to be found in the sentinel node first. By removing and examining only the sentinel node, the pathologist can determine with high accuracy whether the remaining nodes in the basin are involved, without the need to remove them all.

Sentinel node identification uses the same dual-tracer technique as for breast cancer. A radioactive tracer is injected around the primary melanoma site before surgery, and lymphoscintigraphy is performed to map the lymphatic drainage and identify the location and number of sentinel nodes. In the operating theatre, blue dye is also injected, and a gamma probe is used to locate the radioactive sentinel node during the procedure.

The Procedure

Sentinel lymph node biopsy for melanoma is performed under general anaesthetic at the same time as the wide local excision of the primary tumour. The sentinel node is identified using the gamma probe and visual identification of blue-stained lymphatic channels, and is removed through a small incision in the relevant nodal basin. The sentinel node is sent for detailed pathological analysis using specific immunohistochemical staining techniques to maximise the sensitivity of detection.

What the Result Means

A negative sentinel node — no melanoma found — is the result in the majority of patients and is strongly reassuring. It indicates with high accuracy that the remaining nodes in the basin are free of disease, and no further lymph node surgery is required. The patient proceeds to surveillance.

A positive sentinel node — melanoma detected — upgrades the patient's stage to stage III and has direct implications for systemic treatment. Current evidence from the MSLT-II trial and the DeCOG-SLT trial has established that completion lymph node dissection does not improve melanoma-specific survival in patients with a positive sentinel node when compared with active surveillance with ultrasound of the nodal basin. Completion dissection is therefore no longer routinely recommended for all patients with a positive sentinel node, though it may still be appropriate in specific clinical situations including when macroscopic nodal disease is identified. Your surgeon will discuss the current evidence and the most appropriate management for your specific pathological findings.

The sentinel node result also determines eligibility for adjuvant systemic therapy — immunotherapy or targeted therapy — which has significantly improved outcomes for stage III melanoma in recent years.

Risks of Sentinel Node Biopsy

Sentinel lymph node biopsy is a well-tolerated and safe procedure. Risks are similar to those described for sentinel node biopsy in the breast cancer setting and include temporary swelling, bruising, and tenderness at the biopsy site, seroma formation, numbness from small sensory nerve disturbance, lymphoedema (risk is low after biopsy alone, approximately 2 to 5%), and the rare risk of allergic reaction to blue dye.

Axillary Lymph Node Dissection

Axillary lymph node dissection (ALND) for melanoma involves the surgical removal of the lymph node-bearing fatty tissue of the axilla, removing the nodes at levels I, II, and in some cases level III. It is performed when melanoma has been confirmed in the axillary nodes — either by positive sentinel node biopsy in specific clinical situations, or when palpable or imaging-detected axillary nodal disease is present at diagnosis (clinically apparent nodal disease).

The Procedure

Axillary dissection for melanoma is performed under general anaesthetic. A curved incision is placed in the axilla, and the axillary contents are carefully dissected to remove the nodal tissue while preserving the key neurovascular structures in the axilla including the axillary vein, the long thoracic nerve (which supplies serratus anterior), and the thoracodorsal nerve and vessels (which supply latissimus dorsi). An average of 15 to 25 nodes are removed and sent for pathological analysis.

Surgical drains are placed at the conclusion of the procedure and managed at home for five to ten days. Hospital stay is typically one to two nights.

Risks

The risks of axillary dissection for melanoma are similar to those for breast cancer axillary surgery. The most significant long-term risk is lymphoedema of the arm, affecting approximately 15 to 25% of patients. Other risks include seroma, wound infection, shoulder stiffness requiring physiotherapy, numbness of the inner upper arm from intercostobrachial nerve disturbance, and rarely, weakness from long thoracic or thoracodorsal nerve injury.

Lymphoedema physiotherapy input is coordinated as part of post-operative care, and prophylactic lymphovenous anastomosis (LVA) — a microsurgical technique that creates bypass connections between lymphatic vessels and small veins to reduce lymphoedema risk — can be discussed for appropriate patients at the time of axillary dissection.

Groin (Inguinal) Lymph Node Dissection

Groin lymph node dissection is performed when melanoma has spread to the inguinal lymph nodes, which drain the lower limb, lower trunk, genitalia, and perineum. It is the most commonly required regional dissection for lower limb and truncal melanomas.

Anatomy of the Groin Nodes

The groin lymph nodes are divided into two groups. The superficial inguinal nodes lie above the fascia lata (the deep fascia of the thigh) in the femoral triangle, arranged around the femoral vessels. The deep inguinal (iliac) nodes lie along the external iliac vessels within the pelvis, above the inguinal ligament. A standard groin dissection removes the superficial inguinal nodes. An extended or ilioinguinal dissection also removes the deep pelvic nodes and is performed when imaging or pathological findings suggest deep nodal involvement.

The Procedure

Groin dissection is performed under general anaesthetic. An incision is made in the groin, and the superficial inguinal nodal tissue in the femoral triangle is carefully dissected and removed, preserving the femoral vessels and the saphenous vein where possible. Preservation of the saphenous vein significantly reduces the risk of lower limb lymphoedema and is standard practice where the vein is not directly involved with tumour.

Where deep pelvic node dissection is required, the incision is extended or a separate lower abdominal incision is used to access the iliac nodes. Robotic or laparoscopic approaches to the pelvic dissection are increasingly used to minimise surgical morbidity.

Surgical drains are placed and hospital stay is typically two to four nights depending on the extent of the dissection.

Risks

The most significant risk of groin dissection is lymphoedema of the lower limb, which is more common and generally more severe than upper limb lymphoedema after axillary dissection, affecting approximately 30 to 50% of patients to some degree. Wound complications including seroma, infection, and wound breakdown are also relatively common in the groin due to the dependent position and skin mobility of the area, and occur in a meaningful proportion of patients. Other risks include numbness of the anterior thigh from femoral nerve branch disturbance, deep vein thrombosis, and hernia (after pelvic dissection).

Lymphoedema prevention and management with specialist physiotherapy, compression garments, and lymphatic massage is an integral part of post-operative care. Prophylactic LVA at the time of groin dissection is an option for appropriate patients and is discussed at the pre-operative consultation.

Careful surgical technique, preservation of the saphenous vein, and attention to wound closure significantly reduce the risk of wound complications and lymphoedema. Patients are advised to protect the affected leg from injury and infection long-term, as cellulitis is a common precipitant of lymphoedema exacerbation.

Neck (Cervical) Lymph Node Dissection

Neck dissection is performed when melanoma arising from the head or neck has spread to the cervical lymph nodes, or when sentinel node biopsy of a head or neck primary confirms nodal involvement in the cervical basin.

Anatomy of the Neck Nodes

The cervical lymph nodes are divided into six anatomical levels (I through VI), each draining specific regions of the head and neck. The extent of neck dissection performed depends on the location of the primary melanoma, the pattern of nodal involvement on imaging, and the sentinel node mapping results.

A selective neck dissection removes only the specific node levels at risk based on the primary tumour location and lymphoscintigraphy findings. A modified radical neck dissection removes all five lateral neck levels (I to V) while preserving the sternocleidomastoid muscle, internal jugular vein, and accessory nerve. A radical neck dissection — rarely performed today — additionally removes these structures when they are directly involved with tumour.

The parotid gland and its associated lymph nodes are an important regional nodal group for melanomas of the anterior scalp, face, and ear, and parotidectomy (superficial or total) with preservation of the facial nerve is performed when parotid nodal involvement is present.

The Procedure

Neck dissection is performed under general anaesthetic. The incision is designed to provide adequate access to the relevant neck levels while producing the least conspicuous scar, typically placed in a natural neck skin crease. The nodal tissue and fatty areolar tissue of the relevant neck levels are carefully dissected and removed, with meticulous preservation of the key structures of the neck including the accessory nerve (which supplies trapezius muscle and controls shoulder function), the internal jugular vein, the sternocleidomastoid muscle, the carotid artery, the vagus nerve, the hypoglossal nerve, the phrenic nerve, and the marginal mandibular branch of the facial nerve.

Surgical drains are placed at the conclusion of the procedure. Hospital stay is typically two to three nights.

Risks

The risks of neck dissection include injury to the accessory nerve causing weakness of shoulder elevation and abduction (the most functionally significant nerve injury risk in neck dissection), numbness of the ear and lower face from great auricular nerve disturbance, seroma, wound infection, lymphoedema of the face and neck, haematoma, chyle leak (when the thoracic duct is disturbed during left-sided dissection), and injury to other cranial nerves. Facial nerve injury during parotidectomy is a specific risk when the parotid gland is included in the dissection, and the degree of risk depends on the proximity of tumour to the nerve and the experience of the surgeon.

Shoulder physiotherapy is initiated early in the post-operative period to maintain shoulder function and range of movement, particularly when the accessory nerve has been at risk during the dissection.

Adjuvant Therapy After Lymph Node Dissection

For patients with confirmed stage III melanoma following lymph node surgery, adjuvant systemic therapy is now standard of care in most cases. Both immunotherapy (checkpoint inhibitors including pembrolizumab and nivolumab) and targeted therapy (BRAF and MEK inhibitors for BRAF-mutated tumours) have been shown in randomised trials to significantly reduce the risk of recurrence and improve survival after lymph node dissection for stage III melanoma.

The decision about adjuvant therapy is made by the multidisciplinary team in the context of the extent of nodal involvement, the presence of BRAF mutation, the patient's overall health, and other clinical factors. Prof Spillane's involvement with the MASC Trials Group means our patients have access to the most current clinical trial options and the latest evidence-based adjuvant treatment approaches.

Adjuvant radiotherapy to the nodal basin may also be considered in specific high-risk situations, including when there are multiple involved nodes, extranodal spread, or large nodal deposits, where the risk of regional recurrence is highest.

Follow-Up After Lymph Node Surgery

Following lymph node surgery for melanoma, regular surveillance is essential. Surveillance typically involves clinical examination of the operated nodal basin and all regional basins, cross-sectional imaging (CT or PET-CT), and regular skin checks for new primary melanomas. The frequency and duration of surveillance depends on the stage of disease and will be outlined by your surgeon and medical oncologist.

Early identification of recurrence allows prompt initiation of salvage surgery or systemic therapy, and is one of the most important goals of long-term follow-up.

Booking an Appointment

If you have been diagnosed with melanoma and require lymph node staging or treatment, or have been referred for lymph node dissection, a consultation with Prof Spillane can be arranged through our practice.

This page is intended as a general guide only and does not replace personalised medical advice. Lymph node management decisions for melanoma are complex and highly individual, and should always be made in the context of specialist surgical and multidisciplinary assessment.