Cancer Types

Melanoma Cancer

Information about melanoma cancer.

What is melanoma?

Melanoma is a form of cancer that develops from skin cells called melanocytes. These cells are found in the deeper layers of the skin and produce a protein called melanin. Melanin protects the skin by absorbing harmful ultraviolet radiation (UVR).

Who can be affected by melanoma?

The chance of developing melanoma cancer increases with age. Although most melanomas are found in people aged 50 years or older, melanoma cancer can be found in younger age groups (especially people aged 25–39 years). Melanoma is more common in males than in females.

Risk factors

Anything that can increase your risk of cancer is called a risk factor. Having one or more of these risk factors does not mean that you will develop melanoma.

The risk factors for melanoma cancer are:

  • Unprotected exposure to sunlight (UVR)
  • Sunburn at any age increases the risk of melanoma in later life (it is particularly risky if you had a history of sunburn in childhood)
  • A family (mother, father, sister or brother etc.) or personal history of skin cancer (any type) or unusual moles
  • Fair skin and red, blonde or fair hair
  • Use of sunbeds or sunlamps
  • A skin type that burns or freckles easily
  • Many moles (more than 50) or larger moles
  • Lowered immunity from a disease (e.g. some cancers) or medication (e.g. immunosuppressant drugs after an organ transplant)

Signs and symptoms

There may be no warning signs that you have melanoma cancer. Some signs and symptoms may include:

  • A change in an existing mole or freckle including: irregular edges, asymmetrical, different colours inside a freckle or mole, change in shape, colour or texture, itching, bleeding, pain
  • The appearance of a new mole or freckle
  • Any new, changing or unusual spot or sore on the skin
  • A sore on your skin that doesn't heal

If you notice any changes or new moles or freckles, contact your doctor immediately. Many other conditions can cause these changes, but its best to get them checked.

Finding melanoma cancer early

Melanoma can be successfully treated if it is discovered early. The sooner melanoma is identified and treated, the better.

It's important to check your skin regularly and talk to your doctor if you notice any changes. Melanoma can be detected using the ABCDEFG system, find out more about early detection here.

Make it a habit to check your skin regularly, including areas not usually exposed to the sun, and become familiar with the look of your skin.

Testing and diagnosis

Your doctor will do a skin examination which involves a careful skin check under good lighting. Your doctor will pay special attention to any spots that look suspicious.

Your doctor will use a dermoscope (a skin surface microscope) to examine your skin more carefully. Photography, including total body photography, may be used to record the appearance of spots on the skin.

Your doctor may suggest reviewing some spots later to see if they have changed.


A biopsy may also be suggested. The biopsy may be done by your doctor, or you may be referred to a specialist. Your doctor or specialist will give you a local anaesthetic to 'numb' the skin and will then use a scalpel to remove the suspected melanoma and some surrounding tissue. The tissue is then sent to a pathology laboratory for examination under a microscope.

Sometimes other types of biopsies may be performed, such as a punch biopsy (a small tool that takes a deeper sample of skin), a surgical biopsy (some or all of the skin spot is removed with a surgical knife), or a biopsy of the lymph nodes (to check that there are no melanoma cells in the lymph node).

Other tests may include X-rays, MRI or PET scans to check whether the melanoma has spread to other parts of the body.


The treatment for melanoma depends on the type and stage of melanoma (how far it has spread), your general health and preferences.

Treatments for melanoma can include surgery, radiotherapy and chemotherapy, targeted therapy and immunotherapy.

Helpful websites

Melanoma New Zealand