Melanoma | Mate pukupuku kiri manauri

Melanoma is a type of cancer that begins in your skin's pigment cells, known as melanocytes.

Melanocytes produce a brown-coloured pigment called melanin. This gives skin its colour. When melanocyte cells group together in the skin they can form a mole.

Most moles are harmless. However, sometimes the melanocytes in them begin to grow and divide in an uncontrolled way and form a melanoma.

Melanoma is the most serious type of skin cancer and it can spread quickly. It is treatable if it is caught early, but if the cancer spreads to other parts of your body, it can be life-threatening.

Image: 123RF

Most melanomas are caused by overexposure to sunlight, or more specifically UV radiation. Each time your unprotected skin is exposed to UV radiation from the sun or other sources, such as sunbeds, the UV radiation causes changes to the structure of the melanocytes. 

This causes your skin to become permanently damaged. The damage worsens with more UV radiation.

Melanoma occurs most commonly on parts of your body that have been sunburned. However, it can appear in skin anywhere on your body – even on parts that aren’t usually exposed to the sun, such as the soles of your feet or under your toenails.

Melanoma can:

• appear as a new spot or mole
• be an existing spot, freckle or mole that changes colour, size or shape
• sometimes be itchy or bleed
• look different to other spots
• be raised (sticking out) and look shiny
• appear quickly.

See DermNet New Zealand for images of melanoma(external link).

If you are worried that you have a melanoma, see your doctor or a qualified skin check provider(external link) for an examination. If they think the mole or skin spot  is suspicious, they will arrange to take a small sample of your skin, known as a biopsy, or will arrange a tele-dermatological assessment with a dermatologist.

A biopsy is a simple procedure in which a part or all of the skin spot is surgically removed and sent to the lab for testing. This can be done at your doctors or you might be referred to a dermatologist or surgeon.

The results will be sent back to your doctor, who will let you know if melanoma or another type of skin cancer was found. If melanoma is found, your doctor will discuss with you what stage (how advanced) it is and the treatment required. 

A tele-dermatological assessment involves taking specific images of the skin spot. This is then securely electronically transferred to a specially trained dermatologist, who can assess the images and help diagnose whether the spot is a melanoma or not. This has the advantage of avoiding a biopsy when not necessary, while ensuring all melanomas are biopsied rapidly.

Stages

• Stage 0 – (melanoma in situ) abnormal cells found in the epidermis (outer layer of your skin). 
• Stage 1 – the melanoma is not more than 2mm thick.
• Stage 2 – the melanoma is more than 2 to 4mm thick with no spread to your lymph vessels or lymph nodes.
• Stage 3 – any thickness of melanoma that has spread to your lymph vessels or lymph nodes.
• Stage 4 – the melanoma has spread to other parts of your body. 

If a melanoma is caught early, it can normally be treated successfully. If it has spread to other parts of your body, it can be harder to treat.

Read more about treatment of skin cancer.

Do the following to reduce your risk of getting a melanoma:

• Protect your skin from the sun.
• Do not use sunbeds or sunlamps.
• Get your skin checked by your doctor and do regular self-checks. See skin self-checks.

Ways to protect your skin

• Avoid outdoor activities when the sun is strongest – between 10 am and 4 pm during September to April in New Zealand.
• Wear sunscreen and lip balm daily that offer SPF 30 or higher sun protection.
• Use sunscreen that offers broad-spectrum (UVA/UVB) protection and is water resistant. 
• Apply the sunscreen and lip balm to dry skin 15 minutes before going outdoors. 
• Apply the sunscreen to every part of your body that will not be covered by clothing. Reapply it every two hours if you are swimming or sweating.
• Whenever possible, wear a wide-brimmed hat, long sleeves and long pants. 
• Wear sunglasses to protect the skin around your eyes. 
• Avoid getting a tan and never use a tanning bed or sun lamp. 

See also skin cancer prevention and sun safety.

Melanoma NZ has a dedicated mobile spot check van, enabling New Zealanders around the country to have free skin cancer spot checks. Find out when it's next in your area(external link). 

If found and treated early, most melanomas are curable. The key is to have any skin changes or moles checked straight away.

There are a variety of smart phone apps that are marketed for skin checking and early melanoma detection. They allow you to take photos of your skin, and track and monitor changes to your skin lesions.

Be aware that not all skin checking apps are reliable. Apps that give you a risk assessment of your skin changes by enabling you to send images to a skin specialist for analysis are far more reliable and a safer option than apps that use automated computerised analysis algorithms to give you an analysis of skin cancer risk.

Read more about skin check apps.