Which type of skin lesion is considered premalignant?

Actinic keratosis is classified as a premalignant skin lesion due to its potential to progress into squamous cell carcinoma if left untreated. This condition often arises from long-term sun exposure and is characterized by rough, scaly patches on sun-damaged skin. It serves as a warning sign that the skin is experiencing abnormal changes that could lead to malignancy.

In contrast, basal cell carcinoma and melanoma are forms of skin cancer, with basal cell carcinoma being the most common and least aggressive. Nevi, also known as moles, are typically benign growths and do not inherently carry the same risk of transformation into cancer as actinic keratosis does. Understanding these distinctions is crucial for the prevention and early detection of skin cancers.