title: Orbital oculomotor nerve schwannoma extending to the cavernous sinus: a rare cause of proptosis.
abstract: OBJECTIVE
  To report a case of orbital oculomotor nerve schwannoma extending to the cavernous sinus through the superior orbital fissure presenting with proptosis, but without any neurological sign.
  
  
  METHODS
  A 32-year-old man presented with axial proptosis of his left eye. Visual acuity and other ocular examinations were normal. Orbital magnetic resonance imaging revealed a well-defined fusiform retrobulbar lesion in the left orbit extending into the superior orbital fissure and left cavernous sinus measuring 43 mm × 21 mm × 19 mm and causing superomedial displacement of the optic nerve and axial proptosis. The patient was scheduled for surgery, and gross total excision was done. Postoperatively, the patient developed total third nerve palsy. Pre and postoperative third nerve deficit confirmed the origin of the tumor from the oculomotor nerve. Histopathological examination revealed schwannoma.
  
  
  CONCLUSIONS
  Orbital oculomotor nerve schwannoma, although rare, can be the cause of proptosis. Diagnosis can be confirmed histopathologically. It is a benign tumor; however, it can extend intracranially without any neurological symptoms. Therefore, neuroimaging is essential to rule out intracranial extension. Early surgical removal is mandatory.
authors.affiliation: Department of Ophthalmology, Hamdard Institute of Medical Sciences and Research, Jamia Hamdard, New Delhi, India.
authors.forename: Hina
authors.initials: H
authors.lastname: Kauser
authors.affiliation: Department of Ophthalmology, Hamdard Institute of Medical Sciences and Research, Jamia Hamdard, New Delhi, India.
authors.forename: Omar
authors.initials: O
authors.lastname: Rashid
authors.affiliation: Department of Ophthalmology, Hamdard Institute of Medical Sciences and Research, Jamia Hamdard, New Delhi, India.
authors.forename: Waseem
authors.initials: W
authors.lastname: Anwar
authors.affiliation: Department of Pathology, Hamdard Institute of Medical Sciences and Research, Jamia Hamdard, New Delhi, India.
authors.forename: Sabina
authors.initials: S
authors.lastname: Khan
keywords: Cavernous Sinus; Oculomotor Nerve; Proptosis; Schwannoma