Orbital Schwannoma manifested as Tolusa Hunt syndrome

초록

The orbital schwannoma is one of benign tumors originated from Schwann cells of neural crest origin, usually involing the sensory nerves of the superior division of the trigeminal nerve, or the motor nerves to the extraocular muscles. Schwannoma is a rare tumor in the orbit, accounting 1% of all orbital tumors. However, the clinical features of orbital schwannoma still remained unclear. Here we described the case presenting the periorbital pain and diplopia, caused by the orbital tumors. A 58-year old woman with right periorbital pain, visited the hospital. She complained of slowly aggravating pain and intermittent subjective diplopia during upgaze. The neurologic examination and initial brain MRI showed the no abnomality. Jolly test and Ach-receptor antiboty test revealed negative. Initial diagnosis was Tolusa Hunt syndrome and we tried low dose steroids. However, her periorbital pain and limitation of abduction of Rt eye were aggravated and follow-up brain MR scans indicated the round shaped homogenourly enhancing mass at superolateral quadrand of right orbit. The histological diagnosis of benign schwannoma was made.The orbital schwannoma is a rare and benign orbital tumor and could be in the intra/extraconal space. This tumor could cause the diplopia, proptosis eyelid edema and periorbital pain. Usually, excision of the tumor is the choice of treatment with low recurrence rate. The orbital tumor should be considered as one of the curable causes for the slowly aggravating diplopia.