Actinic Keratosis—Can Dermoscopy or RCM Differentiate AK (Not Full Thickness Atypia) from Full-Thickness Atypia/Invasive SCC?

Purpose of Review Actinic keratosis (AK) is the most common sun-induced preneoplastic lesion, and together with photo-aging and skin cancer, it places a huge burden on healthcare systems. The clinical distinction between AK and incipient squamous cell carcinoma (SCC) can be difficult, and therefore, clinical diagnosis is not always reliable and certain. Skin biopsies are sometimes mandatory, and physicians must be aware of the importance of accurate diagnosis and management, as other malignant neoplasms (melanoma, basal cell carcinoma) cannot always be reliably distinguished from AK, especially when pigmented and inflamed.