The "stepped caudal exposure" technique for excision of nasal dermoids with intracranial extension.

Nasal dermoid sinus cysts (NDSCs) are rare congenital malformations derived from ectodermal and mesodermal tissues. There are numerous reports on surgical approaches for extirpation of NDSCs with intracranial extension. Here we describe the "stepped caudal exposure" approach, a technique that minimizes the risk for bacterial infection of the central nervous system from the nasal space. This procedure involves a stepwise osteotomy of the frontal and nasal bones that permits sufficient exposure to allow complete extirpation of NDSCs; it was used successfully to treat a 20-month-old boy with NDSC extending into the intracranial space and an infectious abscess. After NDSC extirpation and debridement of the abscess, the anterior skull base was reconstructed with bone grafts placed on both the intracranial and intranasal sides of the widened foramen cecum. Thereafter, each graft was covered by frontal pericranial flaps for blood supply. These modified surgical techniques may enhance the safety of surgical removal of NDSC, particularly in cases accompanied by infectious lesions such as abscesses.