Melanoma can start in parts of the body other than the skin but this is very rare. The parts of the body that may be affected are the eye, the mouth, under the fingernails (known as subungual melanoma), the vulval or vaginal tissues or internally.
What are the symptoms of malignant melanoma?
Most melanomas start with a change in the appearance of normal skin. This can look like an abnormal new mole. Less than a third develop in existing moles.
It can be difficult to tell the difference between a mole and a melanoma, but the following checklist can be used to help. It is known as the ABCD list.
- Asymmetry – Ordinary moles are usually symmetrical in shape. Melanomas are likely to be irregular or asymmetrical.
- Border – Moles usually have a well-defined regular border. Melanomas are more likely to have an irregular border with jagged edges.
- Colour – Moles are usually a un1iform brown. Melanomas tend to have more than one colour. They may be varying shades of brown mixed with black, red, pink, white or a bluish tint.
- Diameter – Moles are normally no bigger than the blunt end of a pencil (about 6mm across). Melanomas are usually more than 6mm in diameter.
Normal moles can be raised up from the skin and/or may be hairy.
Itching, crusting or bleeding may also occur in melanomas – these are less common signs but should not be ignored.
Very few ordinary moles become melanomas but it is best to discuss any changes with your doctor – the earlier melanoma is discovered, the more successful the treatment.
How is it diagnosed?
Usually you will begin by seeing your GP (family doctor) who will examine you and if necessary, arrange for you to see a doctor who specialises in skin conditions (a dermatologist or a plastic surgeon).
It is often difficult to say by looking at a mole whether it is cancerous or not, and usually they will suggest an excision biopsy.
The mole is removed, using a local anaesthetic, and the wound is closed using stitches. The mole is examined under the microscope by a pathologist to see if any melanoma cells are present. You will normally get the results within 2 – 3 weeks. If it is a melanoma, further surgery, known as a wide local excision, will usually be done to make sure that all the melanoma cells in the area have been removed and to reduce the risk of it coming back again in that area.