Department of Pathology, Yonsei University Medical College, Seoul, Korea.
ABSTRACT
Optic nerve sheath meningioma arises from the arachnoid cap cell of optic nerve sheath and comprises most of primary orbital meningioma. We experienced a rare case of optic nerve sheath meningioma originating in the left orbit. A 44-year-old woman had suffered from visual disturbance in the left eye for 3 years and had only light perceptibility for the recent 6 months. The right eye was normal. Brain CT scan and MRI revealed a 2x0.8 cm sized fusiform solid mass in the left retrobulbar area. Under the impression of optic nerve tumor. excision of the mass including a small segment of the optic nerve was performed. The tumor was a yellowish firm, relatively well demarcated mass that encircled the optic nerve without infiltrating it. Microscopically it was a typical meningioma, meningothelial type. The recovery of visual acuity was impossible due to resection of optic nerve but there was no evidence of recurrence for u months.