Nevus Sebaceous

Nevus sebaceous is a distinctive growth most commonly found on the scalp, followed by the forehead and retroauricular region.^[69][70] Involvement of the neck and trunk is exceptional. A nevus of epithelial and nonepithelial skin components, nevus sebaceous sustains age-related modifications in morphology. The nevus occurs singly and is asymptomatic. Two thirds of cases are present at birth; the others develop in infancy or early childhood. Males and females are equally affected. The very rare nevus sebaceous of Jadassohn syndrome consists of the triad of a linear sebaceous nevus, convulsions, and mental retardation. A variety of congenital malformations of the ocular, skeletal, vascular, and urogenital systems have been described in association with nevus sebaceous.^[71][72] Neurological abnormalities have been reported in patients with sebaceous nevi, but the incidence is low. It is recommended that patients with sebaceous nevi have a neurological assessment and that imaging be performed on all those in whom clinical abnormalities are demonstrated, as well as on those patients with large nevi involving the centrofacial area.