Rapidly growing pigmented tumor on a scalp nevus sebaceous of a pediatric patient: Observation or excision.

A 14-year-old girl presented with a new, rapidly growing, pigmented tumor on a previously existing yellowish, verrucous plaque on the scalp. The patient received complete surgical excision. Routine histology ruled out basal cell carcinoma (BCC) and the histological diagnosis was pigmented trichoblastoma arising in nevus sebaceous (NS). It is important to define management for new lesions developing in pediatric patients with existing nevus sebaceus.