[Orbital schwannoma: clinical, imaging and surgical features]

Schwannoma, or peripheral glioma, is a rare tumor of the orbit (1% of orbital tumors). Its diagnosis remains difficult and can be established only by histological analysis. We discuss through this case report the clinical, radiological and surgical features of this tumor.

We report the case of a young 38-year-old woman with high myopia and no specific medical history, presenting with a rapidly progressive decrease in visual acuity of the right eye, associated with swelling of the supero-lateral orbit, and eccentric, non-pulsatile, ipsilateral proptosis. Clinical examination of the right eye revealed corrected visual acuity of 20/40, mobile swelling near the lacrimal gland and limitation of elevation and abduction. Slit lamp exam revealed secondary central corneal degeneration. Fundus exam was remarkable for stage I optic nerve head edema. Examination of the left eye was unremarkable. Orbital CT revealed a mass of 21.3mm×14.8mm, hypodense and heterogeneous, attached to the lacrimal gland, displacing the globe downward and inward, enhancing with contrast and without bone erosion. Excision of the tumor and the remaining stump of the gland was performed through a subciliairy skin incision followed by histological analysis confirming the diagnosis of schwannoma. No recurrence was noted after a follow-up of a year and a half.

Schwannoma is a rare tumor of the orbit. Its clinical and radiological diagnosis is always difficult. Only histological study allows confirmation of the diagnosis. The absence of recurrence is dependent upon total surgical excision.