Cancers of the skin are actually the most common of all malignant tumors. The skin is composed of many different kinds of cells which can give rise to a multiplicity and a wide variety of tumors. For example, patients with fair skin are most susceptible to ultraviolet exposure and subsequent development of benign and malignant growths. The key is to be able to differentiate the benign skin tumor from the premalignant or malignant growth, both clinically and histologically. Arise on sun exposed skin usually in older individuals.
Skin usually shows evidence of chronic sun damage.
Actinic keratoses may evolve eventually into squamous cell carcinomas. Bowen's disease Squamous cell carcinoma in situ. Bowen's disease may occur on mucosal surfaces such as the glans penis. Full thickness dysplasia of the keratinocytes with numerous large atypical cells with bizarre mitoses. These cell grow in groups and strands into the dermis.