Dermoscopy is a widely accessible, inexpensive, and reliable noninvasive diagnostic tool that improves the accuracy of the clinical diagnosis of skin tumors. Most dermoscopic patterns correlate with specific histopathologic substrates. Accordingly, dermoscopy allows a better differentiation between specific subtypes of skin tumors. The common benign epithelial skin tumors, such as solar lentigo and actinic keratosis, typically display specific dermoscopic criteria, which allow their clinical recognition. The dermoscopic hallmark of all vascular tumors is a mixture of red-purple-blue at times black colors, which however present with different patterns. Adnexal tumors are generally considered as dermoscopic mimickers of basal cell carcinoma, but specific clues exist, facilitating the differential diagnosis. The sensitivity and specificity rate of dermoscopy in the diagnosis of basal cell carcinoma is reported to be 9 and 93 %, respectively. Dermoscopy reaches 98 % sensitivity and 95 % specificity in the diagnosis of actinic keratosis. Dermoscopy reaches 79 % sensitivity and 87 % specificity in the diagnosis of squamous cell carcinoma.
