There are four main types of lesion to look for when checking for skin cancer.
This is the most common form of skin cancer, but also the least dangerous. It typically presents as an elevated skin-coloured lump with a shiny, pearl-like edge, a wound that does not heal, or a slightly crusty lump that grows slowly over time. If left untreated, it may ulcerate and invade deeper tissues.
The lesions are pre-cancerous; in 10 – 15% of cases they may develop into squamous cell carcinomas, so they should be treated to prevent progression. This occurs most commonly in middle-aged and elderly people, on areas most exposed to the sun such as the face, neck, ears, back of the hands and scalp. It presents as red-brown scaly and rough patches of skin.
This is the second most common form of skin cancer, occurring in areas of the skin that have had a lot of sun exposure, such as the face and scalp. It presents as a crusty lump which may grow quickly and become ulcerated and weepy. It can spread rapidly, especially if on the lips, ears, fingers and toes, or in immunosuppressed patients. Surgical treatment to remove the lesions is essential.
This is the least common form of skin cancer, but also the most dangerous. It can affect people of any age, unlike other types that are more common among older people. Varying hugely in appearance, it can present as a spot that becomes darkly pigmented or develops irregular edges or different colours over time, or as a rapidly-growing pink or red lump. It can spread internally, so immediate treatment is required.
In addition to these four main types of lesion, there are other, less common types of skin cancer.