Nasal-subfrontal giant schwannoma.

Subfrontal schwannomas are rare lesions. They can be misdiagnosed as olfactory meningiomas or neuroblastomas. We report a case of giant schwannoma involving the anterior cranial fossa; the frontal and ethmoid sinuses and nasal cavities. The patient presented with a year-long history of increasingly severe headache associated with insomnia. Examination revealed no neurological deficit except for the anosmia. Magnetic Resonance Imaging revealed a 9x5x3 cm intranasal-subfrontal extraaxial mass. Nasal biopsy indicated the presence of a schwannoma. The lesion was totally removed through a bifrontal craniotomy and the skull base was repaired with periosteal flap, fibrin glue and a split craniotomy graft. In addition to the cosmetic advantages over standard transfacial approaches, the extended subfrontal approach also provides early dissection of neural tissues, avoiding an inadvertent cerebrospinal fluid leak.