BASAL cell epithelioma is the most common skin carcinoma in the United States. Because these lesions rarely metastasize, their medical importance has been minimized by some, and others have approached treatment with a cavalier attitude. Fortunately, a majority of basal cell epitheliomas can be cured with a simple treatment approach, especially when the lesions are of the common "rodent ulcer" orsolidtype (Fig 1), containing only a small amount of fibrous stroma. However, the physician must realize that this carcinoma has an unusual number of clinical traits capable of invading cartilage and bone and extending along blood vessels and nerves, leading toward the recurrent, serious, and complicated cases (Fig'2). These variations include thesuperficial erythematoustype (Fig 3), which may resemble psoriasis or eczema. Treatment may be delayed because of clinical misinterpretation. Another form may bedeeply pigmented(Fig 4) and mistaken for a nevus, or malignant melanoma. The