Blindness due to unrecognized bilateral optic nerve sheath meningioma in a 14-year-old girl (case report)

Primary optic nerve sheath meningioma in children are rare. They typically present with unilateral visual deterioration, and are frequently associated with optic nerve atrophy. They are often concomitantly diagnosed with Neurofibromatosis Type2 (NF2).

We report a case of a 14 year old girl who presented with a 10 year history of progressive visual loss, nystagmus and bilateral optic nerve atrophy. Since the age of 4 years, MRI studies, including MRI of both orbitae, had shown progressive bilateral optic atrophy without recognizable etiology. Leber's hereditary optic atrophy (LHON) and NF2 had both been ruled out genetically. At the age of 14 years, fat supression MRI of both orbitae with contrast agent revealed the diagnosis of bilateral meningotheliomatous optic nerve sheath meningioma. Although the patient's visual function was already severely compromised, with only perception of strong light sources still possible, a resection of the tumor along with optic roof decompression was performed with the aim to stabilize the remaining visual function.

Conclusion: Pediatric primary optic nerve sheath meningioma (PPONSM) are rare and their prognosis for survival is excellent. However, there is evidence that higher rates of tumor growth in younger patients exist. Therefore, early detection of the tumor is essential in order to initiate early intervention (surgery or conformal stereotactic radiotherapy) thus providing a good visual outcome. Since normal MRI techniques may not always detect PPONSM in the beginning, we strongly recommend MRI with a gadolinium contrast agent and fat suppression in pediatric patients with isolated unexplained optic atrophy. This might have prevented the almost complete loss of vision in our young patient due to PPONSM.