Pediatric primary optic nerve sheath meningioma.

Primary optic nerve sheath meningioma (PONSM) is extremely rare among children. We report two cases of pediatric PONSM. The first case was a 12-year-old boy who presented with gradual visual loss of his right eye and was found to be associated with neurofibromatosis type 2. The second case was a 10-year-old boy who presented with gradual proptosis of his left eye with normal visual acuity. Severe visual loss is a common clinical manifestation of pediatric PONSM. Although the visual acuity in the second case was normal, his vision rapidly deteriorated to 20/200. In both cases, the diagnosis of PONSM was confirmed by magnetic resonance imaging, and a successful tumor growth control was achieved after stereotactic radiotherapy was implemented.