Sarah, Duchess of York has been diagnosed with malignant melanoma following the removal of a cancerous mole during treatment for breast cancer.

Melanoma is a type of skin cancer that can spread to other areas of the body.

Any diagnosis of melanoma is cancer, even if the term “malignant” is not used before it.

The NHS states that the main cause of melanoma is ultraviolet light, which comes from the Sun and is used in sunbeds.

Other factors that increase the chances of getting melanoma include having pale skin; red or blonde hair; blue or green eyes; a large number of freckles or moles and a family history of skin cancer.

The risk of melanoma increases with age, but compared to most other cancer types, it is also quite common in younger people, say Cancer Research UK.

– When to seek help?

A new mole or a change in an existing mole may be signs of melanoma.

Melanomas can appear anywhere on the body, but they are more common in areas that are often exposed to the Sun.

Some rarer types can affect the eyes, soles of the feet, palms of the hands or genitals.

NHS advice states that people should check their skin for any unusual changes.

– What is the test for melanoma?

Following a GP referral, a dermatologist will check a patient’s skin and ask them about any changes they have noticed.

The dermatologist may also cut out the mole and a small area of surrounding skin so it can be sent to a lab and checked for cancer – this is known as an excision biopsy.

The NHS says it should take about two weeks to get the results of the test back.

– What is the treatment?

Melanoma can often be treated, with several types of surgery used.

Surgery may include: removing the melanoma and an area of healthy skin around it – helping lower the chances of it coming back; removing swollen lymph glands if the cancer has spread to them; removing melanoma that has spread to other areas of the body.

Radiotherapy, medicines and chemotherapy are also sometimes used as treatments.

The specific treatment depends on the location of the cancer, if it has spread and the general health of the patient.