Orbital schwannoma and neurofibroma: role of imaging.

Schwannomas are well-circumscribed ovoid masses that most commonly present in the superior orbit. Although it may be difficult to differentiate these benign masses from other orbital tumors on radiologic imaging, the CT and, in particular, the MR imaging characteristics can sometimes point to the diagnosis of a nerve sheath tumor. A definitive diagnosis can be made through correlation with histopathologic findings, however. In most cases, schwannomas have low malignant potential, and with total excision, recurrence is rare.