Evaluation of the dermatoscopic criteria for the early detection of SCC arising on an AK.

Abstract Background Advanced squamous cell carcinoma (SCC) can easily be discriminated from actinic keratosis (AK), based on clinical and dermatoscopic features. However, at the initial stage of dermal invasion, an SCC might still be clinically flat and its discrimination from AK remains challenging, even with the addition of dermatoscopy. Objective The aim of the present study was to investigate the clinical and dermatoscopic criteria that could suggest early invasion and serve as potent predictors to discriminate early SCC from AK. Methods Clinical and dermatoscopic images of histopathologically diagnosed AKs and early SCCs were evaluated by three independent investigators for the presence of predefined criteria. Results A total of 50 early SCCs and 45 AKs were included. The main positive dermatoscopic predictors of early SCC were dotted/glomerular vessels (OR=3.83), hairpin vessels (OR=12.12) and white structureless areas (OR=3.58), whereas background erythema represented a negative SCC predictor (OR=0.22). Limitations The retrospective evaluation of images. Moreover, the differential diagnosis included in the study is restricted between AK and early SCC. Conclusions We identified potent predictors for the discrimination of AK and early SCC that may better guide management decisions in the everyday clinical practice.