Melanoma is not as common as other types of skin cancer, but it is the most serious and potentially deadly. Possible signs of melanoma include a change in the appearance of a mole or pigmented area. Consult a doctor if a mole changes in size, shape, or color, has irregular edges, is more than one color, is asymmetrical, or itches, oozes, or bleeds. Melanoma can affect the skin only, or it may spread to organs and bones. It can be cured if it’s found and treated early.

Melanoma is most common in white skinned individuals, but it may rarely develop in those with dark skin as well. About one in fifteen white skinned New Zealanders are expected to develop melanoma in their lifetime – Australia and New Zealand have the highest reported rates of melanoma in the world. Melanoma was the third most common cancer registration in New Zealand in males (10.5% of all cancers registered) and in females (11.3% of all cancers) in 2007*.

The main risk factors for developing melanoma include:

• Sun exposure, particularly during childhood
• Blistering sunburn, especially when young Fair skin that burns easily
• Previous melanoma
• Previous non-melanoma skin cancer (basal cell carcinoma, squamous cell carcinoma)
• Family history of melanoma
• Large numbers of moles
• Abnormal moles (called atypical or dysplastic naevi)

A pigmented lesion (mole or freckle) should be checked by an experienced doctor if it has any of the characteristics described by the ABCDE’s of melanoma.

• Asymmetry
• Border irregularity
• Colour variation (tan, dark brown, black, blue, red, light grey)
• Diameter over 6mm
• Evolving (enlarging, changing freckle, mole or other skin lesion)

Not all such lesions prove to be malignant. Not all melanomas show these characteristics. Some melanomas are itchy or tender. More advanced lesions may bleed easily or crust over. Some melanomas lack pigment and are called amelanotic melanoma.

Your surgeon may suspect melanoma if their is a history of change in your skin lesion or if the skin lesion looks like a melanoma. The dermoscopic appearance is particularly helpful in the diagnosis of early melanoma. If your surgeon suspects melanoma he may recommend: 1) surgical removal with a 2 mm margin (cuff of tissue around the lesion) or 2) surgical removal of a small piece of the lesion. The latter is the favoured approach for skin lesions in the head and neck. The pathologist will assess the lesion and if melanoma is confirmed, a detailed description of the melanoma will be provided to guide further treatment.

When a diagnosis of melanoma is made, your surgeon will examine the neck to assess if cancer cells may have lymph nodes. Sometimes ultrasound examinations and special scans may be recommended.

Melanomas are generally treated with surgery. The extent of surgery depends on the thickness of the melanoma and its site. Most thin melanomas do not need extensive surgery. The lesion is removed using a local anaesthetic, and the defect is either stitched up or close with a skin graft or a flap of adjacent tissue. A small area of normal skin around the melanoma is excised to make sure that all the melanoma cells have been removed. Often this is done as a second procedure (re-excision) when the pathology has confirmed melanoma.

For thicker melanomas (those over 1 mm or so in thickness) the lymph glands in the neck may also be tested (sentinel node biopsy) or removed. If the melanoma is widespread, other forms of treatment may be necessary, but are not always successful in eradicating the cancer.

*www.moh.govt.nz/moh.nsf/indexmh/cancer-reg-deaths-2007-jun10?Open

For further information visit: Clinical Guidelines on the Management of Melanoma in Australia and New Zealand