Keratoses is a somewhat general term. It is generally used to describe two types of skin lesions. Actinic keratoses are the result of sun damage and are treated medically in several ways. They are considered to be precancerous in about 5 percent of cases. Seborrheic keratoses are those brown barnacle-like lesions that many people have and are not precancerous, although because of their dark color, can be mistaken for skin cancer. Seborrheic keratoses can be removed by scraping (called curettage), liquid nitrogen application, and by the GentleLase.