Dermoscopy of Squamous Cell Carcinoma and Keratoacanthoma

Abstract

Dermoscopy improves the diagnostic accuracy for melanocytic and nonmelanocytic pigmented lesions compared with inspection with the unaided eye.^1-4 It is a valuable tool for pigmented and nonpigmented skin lesions. Dermoscopic criteria have been described for pigmented and nonpigmented Bowen disease (intraepithelial carcinoma)^5-9 and actinic keratosis,^10,11 two superficial forms of squamous cell carcinoma (SCC). However, few studies^12-18 have reported dermoscopic features of invasive cutaneous SCC or keratoacanthoma. A recent study¹⁹ focused on a progression model of actinic keratosis and intraepidermal carcinomas to invasive carcinoma but was limited to facial cases and did not contrast dermoscopic features of SCC with those of other malignant or benign nonpigmented neoplasms. The study aims to better characterize the dermoscopic features of SCC and keratoacanthoma and to explore dermoscopic criteria that differentiate them from each other and from other nonpigmented skin lesions.