page_title: Actinic keratosis
section_title: Prognosis
hierarchical_section_title: Actinic keratosis / Prognosis
caption_attribution_description: Title: Pathology: Patient: Squamous Cell Carcinoma Description: Tends to arise from pre-malignant lesions, actinic keratoses; surface is usually scaley and often ulcerates (as shown here). Subjects (names): Topics/Categories: Pathology -- Patient Type: Color Slide Source: National Cancer Institute Author: Unknown photographer/artist AV Number: AV-8500-3609 Date Created: 1985 Date Entered: 1/1/2001 Access: Public
context_page_description: Actinic keratosis, sometimes called solar keratosis or senile keratosis, is a pre-cancerous area of thick, scaly, or crusty skin. Actinic keratosis is a disorder of epidermal keratinocytes that is induced by ultraviolet light exposure. These growths are more common in fair-skinned people and those who are frequently in the sun. They are believed to form when skin gets damaged by UV radiation from the sun or indoor tanning beds, usually over the course of decades. Given their pre-cancerous nature, if left untreated, they may turn into a type of skin cancer called squamous cell carcinoma. Untreated lesions have up to a 20% risk of progression to squamous cell carcinoma, so treatment by a dermatologist is recommended.
  Actinic keratoses characteristically appear as thick, scaly, or crusty areas that often feel dry or rough. Size commonly ranges between 2 and 6 millimeters, but they can grow to be several centimeters in diameter. Notably, AKs are often felt before they are seen, and the texture is sometimes compared to sandpaper. They may be dark, light, tan, pink, red, a combination of all these, or have the same color as the surrounding skin.
context_section_description: Untreated AKs follow one of three paths: they can either persist as AKs, regress, or progress to invasive skin cancer, as AK lesions are considered to be on the same continuum with squamous cell carcinoma (SCC). AK lesions that regress also have the potential to recur.
  Progression: The overall risk of an AK turning into invasive cancer is low. In average-risk individuals, likelihood of an AK lesion progressing to SCC is less than 1% per year. Despite this low rate of progression, studies suggest that a full 60% of SCCs arise from pre-existing AKs, reinforcing the idea that these lesions are closely related.
  Regression: Reported regression rates for single AK lesions have ranged between 15–63% after one year.
  Recurrence: Recurrence rates after 1 year for single AK lesions that have regressed range between 15–53%.
caption: Squamous cell carcinoma of the nose.  This skin cancer can develop from actinic keratoses if they are not treated.
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