Pediatric optic nerve sheath meningioma

Natural history of primary paediatric optic nerve sheath meningioma: case series and review

PURPOSE

To study the natural history, clinical and radiological characteristics of primary paediatric optic nerve sheath meningioma (PPONSM).

METHODS

Retrospective study of eight paediatric patients who were treated between 1994 and 2016 at the University Hospital Zurich, Switzerland and the Royal Adelaide Hospital, Australia. Clinical records and imaging studies were reviewed.

RESULTS

The mean age at presentation was 11 years (range: 6-17 years). There were six female patients and two male patients. 2/8 patients had associated neurofibromatosis type 2. Patients were followed up for 71-297 months (mean 156±70 months). 6/8 patients were observed through the course of their disease and 2/8 patients were treated with radiotherapy. 2/8 patients who were observed had minimal change in vision and did not experience tumour growth after long-term follow-up.

CONCLUSIONS

This is the largest PPONSM case series with long-term data on patients treated conservatively. We highlight that a small subset of these tumours are indolent and can be managed using observation alone.

Analyses on the misdiagnoses of 25 patients with unilateral optic nerve sheath meningioma

AIM

To investigate clinical features of optic nerve sheath meningioma (ONSM) that was misdiagnosed, and to find methods to reduce the misdiagnoses.

METHODS

Retrospective series study. Twenty-five misdisgnosed patients with unilateral ONSM were collected from Jan. 2008 to Jan. 2015 and the clinical records reviewed.

RESULTS

Patients were misdiagnosed with acute papillitis most frequently (n=17), immediately followed by optic atrophy (n=8), ischemic optic neuropathy (n=5), acute retrobulbar optic neuritis (n=5), optic disc vasculitis (n=3). For each patient, the minimum frequency of misdiagnoses was once and the maximum was 4 times. As for the lasting time of being misdiagnosed, the shortest was 1.5mo and the longest was 45mo. Twenty-one cases (84%) were once treated with glucocorticoids, and its side effects was found in seventeen patients. Twenty patients (80%) complained with varying degree of vision loss. When a definite diagnosis was made, sixteen cases (64%) showed slight exophthalmos and eighteen cases (72%) had the tubular ONSM.

CONCLUSION

ONSM without loss obvious exophthalmos is easily misdiagnosed in clinic, and for most of these ONSMs are tubular.

Pediatric Optic Nerve Meningioma: Diagnostic and Therapeutic Challenges

A 13-year-old female presented with left unilateral proptosis, blurry vision, and diplopia. Clinical examination showed left sided visual acuity of 20/50, limited extraocular movement, 5-mm proptosis, and optic disc edema. CT and MRI displayed a large, intraconal, well-demarcated soft tissue mass with inferotemporal displacement of the optic nerve. The imaging appearance was unusual and diagnosis remained uncertain. Histopathologic analysis of the biopsy specimen confirmed the diagnosis of atypical syncytial meningioma. The tumor cells were positive for both androgen and progesterone receptors and the Ki67 stain was positive (proliferation index of 8%). The patient was treated with proton beam radiation therapy (total dose 50.4 GyE) that suppressed tumor growth and has preserved visual acuity to date (20/40). Differential diagnosis and approaches to therapy are explored.