An actinic keratosis, also known as a solar keratosis, is a scaly patch on the skin that may be premalignant. It is more common in fair-skinned people, and is associated with those who are frequently exposed to the sun.
Malignant growths on the skin include squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and malignant melanoma. Chronic sun exposure is a risk factor for many forms of skin cancer, including SCC, BCC and melanoma. Individuals with large moles present at birth (giant congenital naevi) are also at risk of developing melanoma within the pre-existing mole. Skin lesions that enlarge or evolve over time should be examined by a doctor. Where necessary, the lesion may be excised completely or a portion of the lesion removed for analysis.