Pre-cancerous lesions are abnormal growths in tissues that have the potential to develop into cancer if not monitored or treated. These lesions can occur in various parts of the body, including the skin, cervix, and colon. They often do not cause symptoms, making regular screenings important for early detection. Common types of pre-cancerous lesions include actinic keratosis on the skin and dysplasia in the cervix. While not all pre-cancerous lesions will progress to cancer, identifying and managing them can significantly reduce the risk of developing invasive cancer in the future.