ABSTRACT
This chapter provides an overview of the clinical and dermoscopic presentation of the most common benign pigmented nonmelanocytic lesions, including solar lentigo (SL), seborrheic keratosis (SK), actinic keratosis (AK), lichen planus-like keratosis (LPLK), and dermatofibroma (DF). It focuses on pigmented nonmelanocytic malignant skin tumors, with particular attention to basal and squamous cell carcinoma (BCC and SCC). Multiple clinical and etiologic varieties exist. Lentigines have a role as a marker for ultraviolet (UV) damage. Xeroderma pigmentosum (XP) is an autosomal recessive condition consisting of an inability of cells to repair DNA damage induced by exposure to UV light and certain chemicals. Dermoscopy features have been described especially for SLs, because of their differential diagnosis with melanocytic lesions. Physical examination of the skin aids in determination of tumor extent, subtype, and involvement of important cosmetic and functional structures. Pigmented Bowen's disease reveals several pigmented structures, including structureless brown to gray areas; brown dots; thick, pigmented lines; or a combination of these patterns.
