Tumours of Skin Appendages

Abstract

This chapter on cutaneous appendageal tumours covers the spectrum of lesions displaying eccrine, apocrine, sebaceous and follicular differentiation. It includes cysts, hamartomas and benign and malignant tumours. Traditionally, appendageal tumours have been classified according to rigid criteria separating lesions with eccrine, apocrine, sebaceous and follicular differentiation. This separation is clearly artificial and it is now acknowledged that lesions regarded as strictly eccrine may well have apocrine differentiation and lesions classified as purely follicular may exhibit apocrine differentiation reflecting the close embryological relationship between the pilosebaceous unit and the apocrine gland.