Histopathologic considerations in the management of skin cancer.

A knowledge of the pathology and biologic behavior of skin cancers is essential for accurate diagnosis and effective treatment. The dual nature and newer concepts of squamous-cell carcinoma and basal-cell epithelioma are reviewed. Some difficulties encountered in differentiating the two are discussed, including the "basosquamous" problem, squamous metaplasia, and pseudoepitheliomatous hyperplasia. Sclerosis within basal-cell epitheliomas is discussed, specifically relating to its importance in treatment. Follicular involvement in epidermal malignant and pre-malignant lesions is presented as a possible cause of recurrence.