Melanoma Surgery

Dr Shaw undertook rotations in Melanoma and Surgical Oncology in surgical training at RPA Hospital, and he participated in melanoma MDT clinics at the Melanoma Institute Australia.  He offers sentinel lymph biopsy procedures for melanoma.

What is melanoma?

Melanoma is an aggressive skin cancer that develops from the melanocytes (the pigment producing cells) and has a propensity to spread to lymph nodes and distantly.

There are many risk factors for melanoma including skin type 1, sun exposure in particular childhood sunburns, a high number of certain type of moles, family history of melanoma, and certain inherited genetic mutations.

When identified early and with appropriate treatment, melanoma can be effectively treated. Most early melanomas are treated with wide local excision with a margin of 1-2cm around the lesion.

What is a sentinel lymph node biopsy? Do I need one?

Melanoma has a propensity to spread via the lymphatic system, analogous to a plumbing system. The first lymph nodes that directly drain the site of the melanoma are called the sentinel nodes. A sentinel lymph node biopsy procedure is a surgical procedure to determine if the melanoma has spread to these draining lymph nodes.

A nuclear medicine study called a lymphoscintigraphy is used to map the lymph nodes draining a particular skin site. This is done within 24hrs prior to having a wide local excision of a melanoma. The radiolabel is injected around the melanoma, or excisional biopsy scar, and serial scans are taken of the tracer migrating to the lymph nodes. Similarly, patent blue dye is injected around the melanoma, or scar, at the time of surgery. These two tracers are used to locate and remove the sentinel nodes during surgery. The lymph nodes will then be examined in the pathology lab for any evidence of melanoma deposits. The absence or presence of melanoma in these lymph nodes is the most important prognostic factor, is essential for adequately staging melanoma, and is frequently a pre-requisite for participation in melanoma trials.

What are the risks of a sentinel node biopsy?

The risks depend on the site and number of sentinel nodes to be removed. Common complications such as minor bleeding or bruising or wound infections may occur. There is a roughly a 1 in a %/1000 risk of allergic reaction to the dye used for injection.

There is a small risk of lymphoedema from a sentinel node biopsy procedure. Lymphoedema is when fluid collects in an area of the body (commonly manifesting as swollen limb) because the disrupted lymphatic channels cannot effectively drain interstitial fluid. This occurs more frequently when removing a whole group of lymph nodes (lymphatic dissections) for advanced disease, but occurscan also occur rarely from sentinel lymph node biopsies. There is also a small risk of damage to local anatomical structures such as nerves depending on where the sentinel lymph nodes are located.