Ancient schwannoma arising from mental nerve. A case report and review.

Schwannoma is an intraoral rare, benign neoplasm derived from the nerve sheath of peripheral nerves. "Ancient schwannoma" shows histopathological features, such as degenerative changes and atypical nuclei, and may easily be confused with malignant neoplasms. Ancient schwannoma of the head and neck region is relatively uncommon and very few cases had been reported in the oral cavity. We present a case of ancient schwannoma arising from the mental nerve in a 19 year old male which was of eight months duration. Examination revealed a 30 x 25 mm firm, strawberry-like mass in the periapical region of the left lower first premolar, extending anteriorly to the canine and posteriorly to the first molar, obliterating the buccal vestibule, with an intact overlying mucosa. Ultrasonography showed that the tumor was closely associated with the mental nerve on the left side, suggestive of a peripheral neural sheath tumor. Complete excision of the lesion was done under local anesthesia, preserving the mental nerve. The histological picture was strongly suggestive of ancient schwannoma (Antoni A type). There was no evidence of recurrence 18 months after excision. The clinicopathological aspects of this special case are discussed, and the literature regarding this entity is reviewed.