Precancerous growths:

"Precancerous" growths describes abnormal areas of skin that are at increased risk to turn into skin cancer, mainly squamous cell carcinoma and possibly basal cell carcinoma. They are important to recognize as they are a sign that someone has had significant ultraviolet exposure from the sun or indoor tanning. Dermatologists treat these with the goal of reducing the number of skin cancers their patients develop.

Actinic keratoses (AKs) are rough, dry, scaly pink patches of skin that develop on the skin after years of exposure to ultraviolet (UV) rays of the sun or tanning beds. They feel like fine sandpaper. They usually appear after age 40 because they take years to develop. AKs are most likely to appear on the most commonly sun exposed areas: face, lips, ears, scalp, neck, backs of the hands and forearms, shoulders and back.

A dermatologist should evaluate anyone with AKs. Having AKs makes one more susceptible to other forms of skin cancer, including melanoma, as they are a measure of someone's prior UV exposure. 

Millions of Americans have AKs --- treatment for these lesions ranks as one of the most frequent reasons people consult a dermatologist.