ABSTRACT
According to the fourth edition of the WHO Classification of Skin Tumors, keratinocyte tumors include a wide range of benign, premalignant, and malignant lesions arising from keratinocytes of the epidermis and adnexae. Keratinocyte malignancies, basal cell carcinomas (BCC), and cutaneous squamous cell carcinomas (cSCC) are collectively more common than all other cancers combined and are therefore the most frequently malignant neoplasms encountered in routine clinical and pathology practice. In this chapter we offer a comprehensive landscape of the main histological and molecular features of keratinocyte tumors and their precursors, except for Merkel cell carcinoma, discussed in a specific chapter.
