Actinic keratosis is squamous cell carcinoma.

BACKGROUND: The prevalence of nonmelanoma skin cancer in the United States is alarming. It can be most appropriately treated if the earliest manifestation of cutaneous squamous cell carcinoma is recognized. METHODS: Clinical, histologic, and molecular biology, considerations were reviewed to determine whether actinic keratosis is the earliest clinical manifestation of cutaneous squamous cell carcinoma. RESULTS: The clinical, histologic, and molecular parameters of actinic keratosis are those of squamous cell carcinoma. CONCLUSION: Actinic keratosis does not transform, convert, or progress into cutaneous squamous cell carcinoma but is the earliest clinically recognizable manifestation of this malignancy.