Could YOUR mole be cancerous? Checking is as simple as ABCDE: Simple guide that doctors use to spot melanoma - after Sarah Ferguson's shock diagnosis

Moles that are uneven, change in colour or become itchy could be  a melanomaREAD MORE: What is melanoma? Questions about the skin cancer answered 

Sarah Ferguson last night revealed she is battling skin cancer.

The Duchess of York‘s shock revelation comes just months after she underwent an operation for breast cancer.

Sarah, the 64-year-old ex-wife of Prince Andrew, had several moles removed during reconstructive surgery following her mastectomy in June. 

One was later identified as cancerous.

Following her diagnosis with malignant melanoma — the fifth most common cancer in the UK — Sarah urged fans to ‘be diligent’ and check their moles. 

Around 16,000 Brits are diagnosed with melanoma each year. It is typically caused by exposure to UV light, which comes from the sun and artificial tanning beds. 

Melanoma can either start as a new mole, or in a mole you already have.

Here, MailOnline reveals the simple, ABCDE checklist that doctors use to spot melanomas…  

Sarah Ferguson has been diagnosed with malignant melanoma. Pictured: The Duchess of York at Christmas Morning Service at Sandringham Church

Sarah Ferguson pictured with her ex-husband Prince Andrew and Maria Laura Salinas at Royal Ascot in June 2019

A – asymmetrical

This refers to the symmetry of your mole.

Looking for moles with an uneven or irregular shape could help you spot an early sign of a melanoma.

That’s because, unlike normal moles which are usually round with smooth edges, melanomas are often not symmetrical.

They may have two different shaped halves and uneven edges, according to the NHS.

If a mole stands out and looks different to your other moles, it’s advised to get it checked by your GP.

B – border

This refers to the shape of the edges of your mole.

Melanomas are also more likely to have irregular edges or might have blurred or jagged edges, Cancer Research UK says.

For comparison, Macmillan says ordinary moles ‘usually have a clear, smooth-edged border’.

They can appear on any part of the body.

In men, melanomas are most commonly found on the back and in women the most common site is the legs, the charity says.

Sarah Ferguson pictured with her daughters Princess Beatrice (left) and Princess Eugenie (right) at the Masterpiece Midsummer Party at the Royal Hospital Chelsea in 2013

C – colour

This refers to the colour of your mole.

A mole with different shades and colours could be a melanoma.

Melanomas can have different shades from a mix of brown and black to red, pink, white or even a blue tint, says Macmillan.

However, normal moles are usually only shades of brown.

Some people with pale skin or fair hair get melanomas which are red and pink, but not brown, says Macmillan.

The charity adds that this is called amelanotic melanoma and is rare in comparison to other types of melanoma.

D – diameter 

This refers to the size of your mole and how wide it is.

Usually moles are only the size of the end of a pencil or smaller. But if you spot a mole that is more than 6mm wide it could be a melanoma.

Macmillan says that for people with lots of moles, including some that are above 5mm, they are likely to have been there for years without changing.

‘It is recommended that people with lots of moles or bigger moles get them checked by a dermatologist,’ the charity says. ‘This is important if you have had changes to moles in the past.’

E – evolving 

This refers to how your mole might be evolving and changing.

Most harmless moles stay the same shape over time, but melanomas often get bigger change shape and even colour.

The change in shape can include the area becoming raised or dome-shaped, says Macmillan. If the mole is flat, it may stay that way but become wider, it adds.

It’s not just size and shape to watch out for melanomas can also become swollen and sore.

This can cause them to become itchy or tingly, bleed and also appear crusty, the NHS warns.

Some melanomas develop from existing moles and grow on what was previously normal skin, says Cancer Research UK.

So, it is important to keep an eye on changes and if any ‘normal moles’ become itchy, swollen or start to become irritated.

But the earlier a melanoma is found the easier it is to treat, so it is important to see your GP as soon as possible if you have these skin changes, warns Cancer Research UK.