Circumscribed lesion that occurs mainly on the face and scalp and consists predominantly of sebaceous glands, abortive hair follicles and ectopic apocrine glands. It is generally present at birth or in early childhood, but at times it may arise in adult life. The slightly raised yellow, orange or light-brown plaques present a smooth or velvety surface. With puberty, they become raised, thickened, and nodular. Secondary neoplastic changes occur in 10 to 30 per cent of lesions, the most common neoplasms being basal cell carcinoma and syringocystadenoma papilliferum.
Nevus Sebaceous of Jadassohn, Sebaceous Nevus
Linear sebaceous nevus sequence, Nevus sebaceous of Jadassohn