Skin cancer is detected when there are changes in the skin, such as the appearance of tumors, patches or moles of various shapes and sizes. The most common cause of skin cancer is exposure to ultraviolet rays from the sun.

Skin cancer is considered a common disease and tends to develop in areas of the skin exposed to the sun. For precancerous skin lesions presented by Paget's disease and Bowen's disease, both are very rare.

Carcinoma is considered the most common type and can occur in almost any part of the body. Carcinoma (basal cell, squamous cell, transitional cell) can be life-threatening if not treated promptly. Therefore, early detection and treatment of this type of cancer will increase the likelihood of a cure.