Epidermoid carcinoma, that is, squamous cell carcinoma of the skin, is the most common malignant tumor of the lips. It occurs especially in men. Its primary causes are sun exposure, smoking, and chronic irritation. Leukoplakia is the most frequent precancerous lesion. Epidermoid carcinoma may appear clinically as a scaly erosion or an ulceration. Standard treatment is surgical excision with reconstruction.