Features of interpretation of data of light and spectral dermatoscopy in patients with actinic keratosis

Actinic keratosis (AK) is a common disease that is formed as a result of excessive insolation of exposed skin areas. One of the possible options for the development of the disease is the transformation of AK into squamous cell carcinoma. The timely diagnosis of suspicious areas of AK with their subsequent excision and histological examination has great importance in the prevention of neoplastic transformations of the skin.The aim of our study was to identify dermatoscopic patterns of the initial stages of neoplastic transformation of actinic keratosis and a comparative analysis of the diagnostic effectiveness of digital dermatoscopy, two­color spectral dermatoscopy in relation to histological examination in a group of individuals suffering from actinic keratosis.There were 49 patients with AK under our supervision. All suspected cases of keratosis were additionally examined histologically. We analyzed the features of clinical forms and modified existing diagnostic methods. To expand the diagnostic capabilities of standard dermatoscopy, studies were performed in different ranges of light. Spectral dermatoscopy allowed estimating the potential foci of neoplastic transformation in blue and green light field (standard illumination range was suppressed). Particular attention was paid to areas of increased keratinization, areas of excessive vascularization with a predominance of superficial capillary network, micro­ulcers with loose edges that contrast well with the green spectrum, as well as dynamic changes in color in one field of study for 30 days.It was found that the use of spectral dermatoscopy increases the diagnostic capabilities of AK and allows identifying more accurately the early signs of neoplastic transformations associated with both pathological neoangiogenesis («strawberry» pattern, glomerular network) and pathological proliferation (pseudogranulations, pathological keratinization, etc.).