Early detection

If melanoma is recognised and treated early enough it is almost always curable. The first sign is often a change in the size, shape or colour of an existing mole, or the appearance of a new mole.

Checking yourself and your loved ones

Start by checking your entire body, including skin not normally exposed to the sun. You could ask for help from someone else to check difficult-to-see areas, such as your back, neck and scalp.

We recommend that you follow the ‘Ugly Duckling’ rule. The idea behind the Ugly Duckling rule is that you compare your moles with each other. If any mole stands out or looks different from that of nearby moles, it is the ugly duckling, and we advise you contact a doctor to get an expert opinion.

    Woman with mole on back

    Know the skin you are in

    Melanomas can often be detected using the ABCDEFG system below, although not all melanoma lesions show these characteristics.

    These images are indicative only. Look for the type of behavior described, rather than trying to match your lesion to the images.

    (Photos courtesy of Dr Anthony Tam & DermNet NZ)


    One half is different from the other half

    Border irregularity

    The edges are poorly defined e.g. notched, uneven or blurred

    Colour is uneven

    Shades of brown, tan and black are present (there may also be white, grey, red, pink or blue)


    Looks different from other spots, freckles or moles (“ugly duckling”)


    Any change in growth; new, elevated or painful


    To the touch


    Most are larger than 6mm and keep growing

    Woman in hospital bed giving thumbs up

    I was aware of melanoma but never for one second did I think my smudge was cancer. It was sore, as if I had stood on something. It was a rusty-coloured, smooth smudge, not instantly recognisable as a mole or freckle.

    – Amanda Lockyer