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.