A Rare Case of Optic Nerve Sheath Meningioma in a Pediatric Patient: Diagnosis and Endoscopic Endonasal Surgical Management

Abstract

We describe an unusual instance of a juvenile with proptosis and progressive one sided vision loss. Radiological imaging showed an intraorbital lesion indicative of optic nerve sheath meningioma (ONSM). An endoscopic endonasal surgical method was used for tumor excision, given the medial orbital position of the lesion and growing vision loss. Optimal exposure and decompression were obtained using careful dissection and intraoperative navigation. The patient had visual improvement in follow-up evaluations; the postoperative period was quiet. This instance underlines the value of endoscopic endonasal surgery in some individuals and contributes to the limited research on pediatric ONSM. Endoscopic techniques provide better access to the medial orbit with the least morbidity as compared to conventional treatments. Although surgery could be better in young patients with quickly advancing symptoms or in situations with secondary lesions, radiation is still the norm for adult ONSMs. Even in physically difficult environments, our study corroborates the results from previous literature suggesting the viability and safety of this strategy in pediatric populations. Particularly when visual function is at stake, endoscopic endonasal surgery is a feasible and efficient therapy choice for children with ONSM. Favorable results depend on early diagnosis and tailored surgical planning.

INTRODUCTION

Rising from the meningothelial (arachnoid cap) cells of the optic nerve sheath, optic nerve sheath meningioma (ONSM) is an uncommon, usually benign tumor. Roughly one-third of primary optic nerve tumors and roughly 1%–2% of all orbital cancers are these ones.[1] With a notable female majority and a peak occurrence between the ages of 30 and 50, they are most usually seen in middle-aged women.[2]

Located within the orbit, ONSMs come from the intraorbital section of the optic nerve sheath. Less often, they might come from the intracanalicular or intracranial portions of the optic nerve.[3] Though histologically benign, these tumors may cause major morbidity because of their closeness to important neuro-ophthalmic structures, which might cause progressive sight loss and ocular movement problems if left untreated.[4] Common presenting characteristics include proptosis, optic disc pallor or atrophy, visual field defects, especially central scotomas or peripheral field constriction, and color vision abnormalities. Unilateral or asymmetric situations might show relative afferent pupillary deficit (RAPD).[3,5]

The gold standard for assessing optic nerve abnormalities is, however, magnetic resonance imaging (MRI).[6] Reflecting enhancement of the meningioma surrounding the optic nerve, characteristic findings consist of a “tram-track” sign on axial images or a “doughnut” sign on coronal views.[7,8] Several factors, including the degree and development of visual impairment, tumor site, and patient age, affect management techniques for ONSM.[9,10] Minimally invasive neurosurgery procedures, such as endoscopic endonasal approaches (EEAs), have increased the viability of surgical treatment in anatomically difficult areas such as the orbital apex and suprasellar cistern.[1,11]

This case report, given its possible major visual morbidity, ONSM calls for early identification, correct diagnosis, and a meticulously customized multidisciplinary therapeutic strategy.

CASE PRESENTATION

A 9-year-old boy arrived at the outpatient ophthalmology clinic complaining of painless vision loss in the right eye and a right eye protrusion that had been increasing over many months. No history of trauma, fever, headache, or other systemic problems. There were no accompanying symptoms such as photophobia or diplopia. Until lately, when he started struggling with blackboard reading in school, the child’s academic performance and everyday activities had been said to be unaffected.

Considering the clinical results, imaging tests were done to assess the underlying cause. Raising concern for ONSM, a computed tomography (CT) scan of the orbit showed a well-defined intraconal mass in the right orbit with perioptic calcification. Subsequently, an MRI was done to offer further clarity. The MRI showed a nodular lesion that was unusual, T2-weighted hypointense [Figure 1] with consistent post-contrast enhancement affecting the right optic chiasm and suprasellar cistern. Extending to the orbital apex, the lesion was seen to abut the pituitary gland and stalk. The optic nerve’s intraocular and intraorbital sections also looked convoluted and swollen with peripheral enhancement [Figure 2a-c], which strongly pointed to ONSM.

Figure 1.

Brain MRI axial T2-weighted image shows a hypointense nodular lesion (white arrow) along the right optic nerve

Figure 2.

Brain MRI T1-weighted post-contrast sagittal image (a) shows enlarged right optic nerve with peripheral enhancement (white arrow), coronal (b) and axial images (c) show enhancing lesion in right optic nerve (white arrow), which is extending till orbital apex and optic chiasma abutting pituitary gland and stalk

We contacted a multidisciplinary team of ophthalmologists and neurosurgeons. A surgical intervention was intended after assessment of the hazards and the possibility of vision preservation. Using an EEA—a minimally invasive procedure allowing direct access to the orbital apex and neighboring structures—the patient had a right eye ONSM removed.

The patient had significant improvement postoperatively. Visual acuity in the right eye had risen to 6/18 at one-week follow-up; at the end of three months, it had gone on to 6/12. Visual fields also showed significant growth and a significant decrease in field constriction. The boy and his parents said they subjectively felt better in visual function and quality of life.

DISCUSSION

ONSMs are rare entities in children and present diagnostic difficulty due to their slow-growing nature and nonspecific initial symptoms. The EEA employed in this case provided several advantages, including reduced morbidity, excellent access to the orbital apex and suprasellar region, and avoidance of external incisions. The success of this intervention in the current case underscores the growing importance of minimally invasive techniques in managing orbital tumors.

Emphasizing the uncommonness of intraorbital meningiomas, Guedes et al.[12] point out that they make up just 0.2%–4% of all central nervous system meningiomas. Intraorbital meningiomas may be classed as primary, originating straight from the optic nerve sheath, or secondary, as extensions from intracranial malignancies.

Kim et al.[13] expand on the changing function of EEA in controlling skull base and orbital cancers, including spheno-orbital meningiomas. Though previous treatment paradigms have been dominated by conventional open cranial techniques, the literature today reveals a growing acceptance of less invasive techniques for well-chosen individuals.

Yang et al.[14] echo this feeling in the pediatric context as they address the viability of endoscopic endonasal optic nerve decompression even in very young infants with congenital optic canal stenosis.

Kızıltaş et al.[15] provide a more comprehensive look into orbital neurogenic cancers, including meningiomas, gliomas, and peripheral nerve sheath tumors. Meningiomas made up about 40% of all orbital neurogenic tumors in their research, most of which originated from the optic nerve sheath.

Though rare, particularly in pediatric patients, the research shows that a personalized strategy taking into account the tumor’s location, patient’s age, and visual function is essential. Though surgery remains the mainstay for primary ONSM, endoscopic endonasal routes are gaining momentum in some situations as they provide good results with less morbidity. Particularly in difficult situations, where minimally invasive surgery not only decompresses the tumor but also enables possible vision recovery, as new clinical series and case reports show, this paradigm change is noteworthy.

CONCLUSION

Though uncommon in the juvenile population, ONSM should be taken into account in situations with progressive, painless, one-sided vision loss accompanied by proptosis. Early diagnosis depends on quick identification and precise imaging. With the possibility of vision improvement, the endoscopic endonasal surgical technique presents a hopeful choice for safe tumor removal. This example emphasizes the need for interdisciplinary therapy and early surgical intervention in chosen young patients to maximize results and protect eyesight.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.