solitary, round, firm nodules with a rubbery or doughy consistency on palpation, a smooth surface, and normal overlying skin Lesions are usually present at birth (but may not be appreciated until inflamed or infected) and tend to grow slowly Malignant transformation may occur but is rare Whereas some dermoids may be mobile, many are fixed to overlying skin or underlying periosteum Because these cysts form along areas of embryonic fusion, common sites include the nasal bridge, midline neck, or scalp; the lateral brow ( Fig 120.5 ); anterior margin of the sternocleidomastoid; and midline scrotum or sacrum An external ostium may or may not be visible A small percentage of patients with dermoid cysts may have other craniofacial abnormalities Occasionally, dermoids may have sinus tracts with deeper attachments extending intracranially or intraspinally Because the sinus tract can serve as a conduit for spread of secondary infection, midline lesions should have appropriate imaging (computed tomography [CT] and/or magnetic resonance imaging [MRI]) followed by elective excision Nasal Bridge Lesions Midline nasal masses in infants and children may be acquired (e.g., EIC) or congenital, the latter stemming from improper embryologic development (e.g., dermoid cyst, encephalocele, glioma) ED evaluation should focus on identifying lesions that require urgent subspecialist evaluation including encephalocele