Nasal dermal sinus and dermoid cyst with intrafalcial extension. Case report and review of literature.

Congenital nasal dermal sinus is an unusual lesion which comprises about 11%-12% of all cranial dermal sinuses. The sinus tract seldom extends intracranially and an associated intrafalcial inclusion cyst is extremely rare. The authors report a case of nasal dermal sinus and dermoid cyst with intrafalcial extension in a boy aged 1 year 4 month. Previous reports of this rare lesion are reviewed and the possible pathogenesis discussed.