Malignant diseases of the skin are becoming more common, the reason being increased cumulative exposure to ultraviolet radiation, which is due to an increasingly elderly population, increased outdoor activities, clothing styles, depletion of atmospheric ozone, and environmental pollutants. Non-melanoma skin cancers are epithelial cancers that originate from the epidermal keratinocytes or adnexal structures. Squamous cell carcinoma of the skin is a malignant tumor of keratinocytes. The lesions are mostly pigmented and may occur anywhere on the skin surface, to the inexperienced observer many of these basal cell carcinomas have the appearance of small naevi. Xeroderma pigmentosum is the name given to a group of rare, inherited disorders in which there is a faulty repair of damaged DNA and the development of numerous skin cancers. The satellite lesions develop around the primary malignant melanoma in many instances. It is a multifocal, neoplastic disorder of T-lymphocytes that primarily affects the skin.