Abstract
Actinic keratoses (AK) are the most common precancerous lesions in the white Caucasian population due to long- -term exposure to ultraviolet (UV) radiation. Observations indicate its possible development into invasive cutaneous squamous cell carcinoma (cSCC).
About 60-70% of invasive cSCC arises in pre-existing AK. Bowen's disease, bowenoid papulosis together with intraepithelial neoplasias (erythroplasia Queyrat), including penile vulvar and anal intraepithelial neoplasias, are classified as a group of squamous cell carcinomas in situ (Cis).
Number of risk factors, especially UV radiation, chronic inflammation and infections with high-risk oncogenic HPV types 16 and 18, contribute to the etiology of Cis. Dermatoscopy, which is a highly sensitive, reliable, rapid and non-invasive diagnostic method, plays an important role in the diagnosis of AK.
AK and Cis therapy can be divided into treatment focused on individual lesions (so-called lesion-directed therapy - e.g. cryotherapy, curettage, electrodesication, shave excision) or treatment focused on large areas (so-called field-directed therapy - e.g. 5 fluorouracil, imiquimod, ingenol mebutate, diclofenac sodium, photodynamic therapy).