Schwannoma of the mental nerve: usefulness of preoperative imaging: a case report.

Schwannoma of the head and neck region is relatively uncommon. We report a case of schwannoma arising from the left mental nerve. A 21-year-old male presented at our hospital with a painless swelling of the left cheek. Because the lesion had rapidly increased in size, a malignant tumor was suspected. Magnetic resonance imaging (MRI), computed tomography, and ultrasonography were performed. MRI and ultrasonography revealed that the tumor was connected to the mental nerve. Both MRI and ultrasonography were found to be useful in making a preoperative diagnosis. It was possible to determine prior to surgery that this was a peripheral nerve sheath tumor. The lesion was completely resected. The pathological diagnosis was Antoni type A schwannoma. There has been no sign of recurrence 1 year after surgery.