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  » Atlas of skin diseases  »  Actinic Keratosis
An actinic keratosis of the scalp. These lesions are often difficult to see. They are rough, sandpaper-like plaques occurring on sun-exposed surfaces. They are pre-malignant, since a small percentage of them develop into squamous cell carcinoma. The lesion here is darker than the surrounding skin; the lighter area is from the camera flash.