Skin Cancer.

Keratinocyte carcinoma, traditionally termed nonmelanoma skin cancer, comprises basal cell and cutaneous squamous cell carcinoma and is the most common human malignancy. Basal cell carcinoma most commonly appears as a pearly pink, dome-shaped papule with prominent telangiectatic surface vessels. Squamous cell carcinoma most commonly appears as a firm, smooth, or hyperkeratotic papule or plaque, often with central ulceration. Cutaneous melanoma remains the most serious skin cancer worldwide, with progressively increasing incidence year by year. Clinicians should have a high index of suspicion that pigmented or otherwise unusual-appearing lesions may represent melanoma.