Basal cell carcinoma appears predominantly in people with white skin and light-coloured eyes who tan with difficulty or those who have been exposed to the sun for a long time.

Lesions are localised in the areas exposed to the sun, such as the face, neck, back of the hands and forearms.

The most frequent sub-types of skin cancer are:

• Basal cell carcinoma (70-80% of skin cancers)
• Squamous cell carcinoma (20%)

1. Basal cell carcinoma

Basal cell carcinoma is a slow-growing skin cancer. It originates in the cells of the epidermis' basal layer and the pilosebaceous follicles, and it usually develops on areas of skin that are exposed to sun radiation.

2. Squamous cell carcinoma

This cancer originates in the intermediate layer of the dermis and also usually develops in areas of skin exposed to the sun, although it may also appear in areas that are not exposed, such as the tongue or the oral or genital mucosa (where it can be more aggressive).

It is faster-growing than basal cell carcinoma and is usually more aggressive.