Actinic keratosis are precancerous growths that can turn into squamous cell carcinoma.

Precancerous Growths

The term "precancerous" is used because these abnormal areas of skin are more likely to turn malignant than healthy skin. Precancerous growths (lesions) are visible to the naked eye, and they look different from normal cells when examined under a microscope.

What is Early Cancer?

When malignant changes occur to the skin, but haven't spread below the top layer of the skin (epidermis), they are called early cancers, or carcinoma in situ.

Actinic Keratosis

Actinic keratosis (AK), also known as solar keratosis, by far the most common precancer, is the result of prolonged exposure to sunlight. It is a small crusty or scaly bump or horn that arises on the skin surface. The base may be light or dark, tan, pink, red, or a combination of these...or the same color as your skin. The scale or crust is horny, dry and rough, and is often recognized by touch rather than sight. Occasionally it itches or produces a pricking or tender sensation. It can also become inflamed and surrounded by redness. In rare instances, actinic keratoses can bleed.

The skin abnormality or lesion develops slowly and usually reaches a size from an eighth to a quarter of an inch (2mm to 4mm) but can sometimes be as large as one inch. Early on, it may disappear only to reappear later. It is not unusual to see several AKs at a time. AKs are most likely to appear on the face, lips, ears, scalp, neck, backs of the hands and forearms, shoulders and back—the parts of the body most often exposed to sunshine. The growths may be flat and pink or raised and rough.

Actinic keratoses can be the first step leading to sqamous cell carcinoma (SCC). Some studies show that ten percent do advance, and 40-60 percent of SCCS begin as untreated AKs.