The real face of actinic keratosis: field of cancerisation and squamous cell carcinoma

Actinic keratoses (AK) are lesions induced by ultraviolet (UV) rays. They are a frequent reason for dermatological consultation, especially in patients aged 60 years or older. Whereas AK have long been considered as precancerous lesions, some authors tend to consider them, on the basis of histopathologic and genetic data, as true in situ carcinomas. Is this concept valid today? Should we assimilate AK with the remaining skin carcinomas? What is the meaning of the concept of "field of cancerisation"? The present article will attempt to answer these questions.