Optic nerve sheath meningioma coexisting with lateral rectus muscle schwannoma in a pediatric patient: a case report

Optic nerve sheath meningioma combined with schwannoma in a pediatric patient has not been previously reported. An 11-year-old patient presented with progressive right eye proptosis, accompanied by redness, photophobia, and tearing. Orbital examination revealed thickening of the right lateral rectus muscle and a retrobulbar lesion. The patient underwent retrobulbar resection and lateral rectus muscle biopsy of the right eye under general anesthesia. Histopathological examination demonstrated schwannoma of the right lateral rectus muscle and atypical meningioma of the retrobulbar lesion. Given the coexistence of these two tumors in a pediatric patient, neurofibromatosis type 2 (NF2) was considered in the differential diagnosis. There was no family history of NF2 or other hereditary tumor syndromes. No clinical features suggestive of NF2 were identified during clinical evaluation and follow-up. Genetic testing for NF2 was recommended but was declined by the patient’s family because of financial constraints. During follow-up, orbital MRI showed persistent thickening of the right lateral rectus muscle and a residual retrobulbar lesion at 3 months and 1 year postoperatively. Three years after surgery, marked enlargement of both lesions suggested tumor progression. Therefore, repeat surgery was performed, during which resection of the lateral rectus lesion and biopsy of the retrobulbar lesion were carried out under general anesthesia. A maximal safe resection strategy was adopted, consisting of partial resection of the lateral rectus lesion and biopsy of the retrobulbar lesion due to its close relationship with the optic nerve and the orbital apex. Histopathological examination confirmed schwannoma of the lateral rectus muscle and optic nerve sheath meningioma. This case demonstrates a rare coexistence of optic nerve sheath meningioma and schwannoma in a pediatric patient. It highlights the complexity of diagnosing multiple orbital tumors in children and underscores the importance of careful clinical evaluation and long-term follow-up.