Light micrograph of actinic, or senile, keratosis. This is a pre-cancerous area induced by ultraviolet light exposure, more common in fair-skinned people and those who are frequently in the sun. It can turn into a skin cancer called squamous cell carcinoma. Histologically, senile keratosis can show a variety of alterations such as epidermal thickening, hyperkeratosis, disordered epithelial layers, atypical keratinocytes with a loss of polarity, pleomorphism, and anaplasia, dermal lymphocyte infiltrates. |