Sunspot or skin cancer: how to spot the difference

Above: Sunspots tend to crop up on areas of your skin that have had a lot of sun exposure over the years

Sunspots are little areas of hyperpigmentation, that are part of the ‘natural’ ageing process and are generally harmless (although they can be unsightly). They’re caused by years of sun exposure, which triggers pigment-producing cells called melanocytes in your skin to produce more pigment in a small concentrated area.

This excess pigment is triggered in response to injury (sun damage), sort of the way scar tissue forms after a cut or puncture wound. Unlike moles that tend to ‘stick out’ above the skin, sunspots aren’t raised at all - run your finger over a sunspot, and it will feel just as smooth as the skin around it.

Just because sunspots are considered harmless doesn’t mean they should be ignored however. The problem with sunspots (and with moles, for that matter) is that skin cancer in its earlier stages can look very much like a flat, brownish spot (see below). Which means that if you ignore an area of hyper pigmentation on your skin, you could be delaying treatment for what may turn out to be melanoma.

Above: Sunspots are little areas of hyperpigmentation.

So how can you tell the difference?

Here’s one of the major differences: sunspots tend to crop up on areas of your skin that have had a lot of sun exposure over the years. On the other hand, melanoma — the fastest growing and most deadly form of skin cancer — can appear anywhere, even in areas with no sun exposure or limited exposure to UV rays.

The other key difference is harder to detect with an untrained eye: a sunspot forms when the melanocytes overproduce pigment in a tiny area of your skin, while skin cancer forms when the cells themselves reproduce in an abnormal and rapid fashion. Eventually, these cancerous cells can spread to other areas of your body (a process called metastasis) and can be life-threatening.

The trouble is, the difference between a benign skin change and early skin cancer can be very subtle, which is why we recommend having your skin checked by an expert skin cancer detection service such as MoleMap every year.

Above: Early stages of skin cancer

The early signs of skin cancer – what to look for?

We also recommend checking your skin yourself (or asking someone to check it for you) at least every two to three months. Knowing the ABCDE and EFG guidelines below can help you identify the early signs of skin cancer:

• Asymmetry: If you draw an invisible line down the centre of a non-cancerous growth, the two sides will be almost identical in most cases; with skin cancer, the two sides will look different.
• Borders: Non-cancerous growths tend to have smooth edges or borders while skin cancers usually have irregular borders.
• Colour: While most moles are one consistent colour, skin cancers tend to have more than one colour, like red, brown, black, pink, or even blue.
• Diameter: Most melanomas have a diameter larger than a pencil (about 6mm); however, some melanomas can be quite small, especially in their early stages.
• Evolution: Any spot or growth that changes in size, shape, colour, or any other characteristic is more likely to be a melanoma.

Recently, Cancer Council announced an update to the diagnosis guidelines to include elevation, firmness, and growth (EFG):

• Elevated: The mole is raised above the skin.
• Firm: The spot is solid to the touch, firmer than the surrounding skin and doesn’t flatten if pressed.
• Growing: The mole is gradually getting larger.

While the ABCDE and EFG guidelines are a good starting point for evaluating a suspicious spot, the differences between a sunspot and early skin cancer can extremely difficult to detect without proper medical training. Even your doctor might have trouble detecting early skin cancer at a glance.

Only a specialist skin-mapping service such as MoleMap has the expertise and technology to detect the subtle differences between benign sunspots and cancerous growths such as basal cell carcinoma, squamous cell carcinoma, and melanoma - which is why we recommend choosing a regular, specialist skin cancer check.