New Histopathological Classification of Actinic Keratosis (Incipient Intraepidermal Squamous Cell Carcinoma)

Actinic keratoses are common, sun-induced lesions that have historically been regarded as “premalignant.” Evidence supports their inclusion along a continuum with squamous cell carcinoma. We propose a classification analogous to that used for cervical intraepithelial neoplasia.