Nonmelanoma skin cancer: today's epidemic.

The practicing physician encounters many benign and malignant skin neoplasms daily. Basal cell carcinoma and squamous cell carcinoma represent the vast majority of the malignant tumors. Identification of predisposing factors, intrinsic and extrinsic, can decrease future tumor development. Early recognition, biopsy confirmation, and treatment selection can reduce patient morbidity.