A case of verrucous epidermal nevus contiguous with nevus sebaceus

During normal development of skin, pluripotential cells give rise to keratinocytes, sebaceus glands, hair follicles, apocrine glands, and eccrine glands. In epidermal nevi, these components emerge in an abnormal mixture within a circumscribed site. Many authors have categorized epidermal nevi according to their predominant component, however, there is often notable overlap which occurs within a single area or within contiguous areas. An 11-year-old female patient presented with linearly-arranged, multiple yellowish papules and a dark-brown colored verrucous plaque on the left occipital area, which had been present since birth. From the histopathological findings, the papules were diagnosed as nevus sebaceus and the plaque was diagnosed as verrucous epidermal nevus. Our present case gives support to the view that epidermal nevi have a spectrum of manifestations, including verrucous epidermal nevi and nevus sebaceus. To the best of our knowledge, this is the first report of a verrucous epidermal nevus contiguous to a nevus sebaceus in the Korean dermatological literature.