Infra-orbital nerve schwannoma: Report and review.

Extra-cranial schwannomas although common in head and neck region are very rarely seen originating from the infra-orbital nerve. We report a case of schwannoma arising from infra-orbital nerve in a 40-year-old male patient. The case presented as an isolated, asymptomatic, slow growing sub-cutaneous nodular swelling over left side of mid-face. On ultrasonography, a localized lesion within the sub-cutaneous tissue of cheek was observed, without involvement of orbital, maxillary sinus or underlying bone. Aspiration biopsy of the lesion showed spindle shaped cells predominantly arranged in Antoni A pattern around verocay bodies, with less organized Antoni B tissue in few places. Diagnosis of schwannoma, probably arising from terminal branch of infra-orbital nerve was established. The tumor was approached through skin incision. At the time of exploration, the lesion was found to emanate from the nerve trunk of peripheral branch of infra-orbital nerve, which was dissected and preserved. We correlate our experience with previously reported cases of infra-orbital nerve schwannoma.