Dermatologic lesions and risk for cancer.

There are three major types of skin cancer. Basal cell carcinoma and squamous cell carcinoma are both carcinomas from epithelial cells, whereas melanoma originates from the melanocytes of the skin. Although these skin cancers can develop without precursors, there are some skin lesions which may give rise to malignancies. In chronological order, we discuss the (potential) precancerous lesions of basal cell carcinoma (sebaceous nevus), squamous cell carcinoma (chronic inflammation, actinic keratosis, kerato-acanthoma, Bowen's disease, leukoplakia, and lichen sclerosus) and malignant melanoma (lentigo maligna and dysplastic naevi).