Article
Denver - Proliferative actinic keratosis (PAK) is a subtype of actinic keratosis (AK) identifiable by its histological characteristics and distinguished by its aggressive behavior characterized by lateral growth, local dissemination, and transformation into frank squamous cell carcinoma, Leonard H. Goldberg, M.D., said at the annual meeting of the American College of Mohs Micrographic and Cutaneous Oncology.