There are three types of skin cancer and melanoma is the most dangerous one. It is caused by damage to the DNA of melatonin-producing skin cells in the basal layer of the epidermis. The abnormal cells multiply rapidly and form tumour growths called melanomas. There are four basic types of tumours.
Superficial Spreading Melanoma
This type of tumour grows slowly on the skin’s surface and will penetrate more deeply into the skin after a fairly long period of time. It appears as a small and flat patch on the skin. It is typically asymmetrical and has more than one colour. You will see this melanoma as small black, brown, flesh-coloured and white spots in the patch.
This is the most common of all types of melanoma. It is found in 7 of every 10 patients diagnosed with the condition. It rarely occurs in a benign mole, but this is perfectly possible. Most commonly, the tumour appears on the lower legs, the upper back or the trunk in men, but it can appear on any part of the body.
Lentigo Maligna appears in the form of a flat or slightly raised patch. The patch may have a flesh colour, white, pink, brown or black colour. It may have a combination of any of these colours. The tumour will remain on the surface of the skin for a long period of time before it penetrates down to the lower layers of the epidermis and the dermis.
This type of melanoma is most commonly found in elderly individuals. Most often, it appears on the face, ears, arms and the chest.
Acral Lentiginous Melanoma
Acral Lentiginous Melanoma is a type of tumour that is also superficial. It will not penetrate into the deeper layers of the skin quickly. The most specific thing about it is that it usually appears on the palms of the hands, on the foot soles or under the nails. It is clearly visible as a black or brown discoloration. This type of tumours spreads more quickly than its other superficial counterparts. It is most widespread in people with dark skin.
This tumour is quick to invade the lower layers of the skin and to spread to rest of the body via the lymphatic system. In most cases, it has already become invasive by the time of diagnosis. It looks like a raised bump on the skin. It may be black, brown, tan, blue, white, grey or red.
This is the least common type of melanoma. It occurs in no more than 10 to 15 per cent of all patients. Most often, this melanoma affects the elderly. It typically appears on the legs, arms and trunk. In men, it may appear on the scalp as well.