Diagnosis and Treatment of Orbital Optic Nerve Sheath Meningioma

The First Case of 99mTc-FAPI Uptake in Optic Nerve Sheath Meningioma

ABSTRACT

This case study presents the first demonstration of FAPI ligand uptake in a patient with optic nerve sheath meningioma. The patient, a 23-year-old woman who had previously undergone surgery for refractory optic meningioma, was referred to our department for 177Lu-DOTATATE therapy. After 3 cycles of 177Lu-DOTATATE administration, her proptosis significantly decreased. Two months after her last therapeutic cycle, a 99mTc-FAPI scan was performed. The scan revealed a mass with moderately increased uptake in the left retro-orbital region. This study is believed to be the first to demonstrate FAPI ligand uptake in a patient with optic nerve sheath meningioma.

The use of an endoscopic endonasal approach for a secondary intraorbital meningioma: illustrative case

BACKGROUND

Meningiomas are the most frequent primary tumors in the central nervous system (CNS), but intraorbital location is uncommon and accounts for only 0.2% to 4% of all CNS meningiomas. Lesions in this compartment could be classified as primary, secondary, or ectopic. The close relationship with the optic nerve sheath is a landmark to identify the tumor as primary, whereas secondary tumors commonly come from an extension of an intracranial meningioma, and ectopic meningioma is a concept not yet completely established.

OBSERVATIONS

The authors present a rare case of a secondary intraorbital meningioma operated through an endoscopic endonasal approach. Secondary meningiomas at the medial orbit are very uncommon, given their more common superior and lateral location as an extension of sphenoid meningiomas. The endoscopic endonasal route provides direct access to the medial orbit. The authors present an illustrative case of a meningioma located at the medial orbit and resected through an endoscopic endonasal approach that provided excellent visualization and anatomical exposure. Additionally, the authors review the concept and possible similarities between secondary and ectopic intraorbital meningiomas.

LESSONS

An endoscopic endonasal approach should be considered as a feasible treatment option for intraorbital meningiomas, especially if they are in the medial orbital wall.

Long-Term Visual Function After Fractionated Stereotactic Radiotherapy for Primary Optic Nerve Sheath Meningioma: A Retrospective Analysis of 34 Subjects

Objective

To evaluate long-term visual function after fractionated stereotactic radiotherapy (FSRT) for primary optic nerve sheath meningioma (PONSM).

Methods

This 22-year retrospective study included 34 subjects (34 affected eyes) with PONSM who were treated with FSRT exclusively. Subjects with a history of biopsy/resection were excluded. Visual function, including visual acuity (VA) and visual field mean deviation (VF MD), was evaluated at presentation (pre-radiotherapy; pre-RT) and at the final follow-up (post-radiotherapy; post-RT); treatment complications were also evaluated. Treatment success was defined as either stabilization or improvement of visual function.

Results

The median pre-RT VA and pre-RT VF MD were 0.70 logarithm of the minimum angle of resolution (logMAR; range: 0.0–2.9 logMAR) and −15.4 decibels (dB) (range: −31.4 to −3.2 dB), respectively. The median total dose of FSRT was 50 Gy (range: 45–54 Gy) and the median number of fractions was 25 (range: 25–30). The median follow-up interval was 89 months (range: 6–251 months). The median post-RT VA and post-RT VF MD were 0.48 logMAR (range: 0.0–2.9 logMAR) (p = 0.010) and −6.8 dB (range: −20.6 to −1.6 dB) (p = 0.005), respectively. Among the 34 included eyes, VA was successfully treated in 29 eyes (85.3%) and worsened in 5 eyes (14.7%). Of the 14 eyes with both VA and reliable VF MD at pre-RT and post-RT time points, VF MD was successfully treated in 13 eyes (92.8%) and worsened in one (7.2%); overall visual function was successfully treated in 13 eyes (92.8%) and worsened in 1 eye (7.2%). Complications occurred in one subject (2.9%; radiation retinopathy).

Conclusion

Approximately 90% of PONSM subjects exhibited long-term treatment success in terms of VA, VF MD, and overall visual function after FSRT. Additionally, the incidence of complications was low. Therefore, FSRT is effective and safe treatment for PONSM.

Bilateral paediatric optic nerve sheath meningioma

At birth, the patient was noted to have microphthalmia and optic atrophy in her left eye with no apparent cause. In early childhood, the vision in that eye began to deteriorate. A few years later, disc swelling was noted in the contralateral right eye. Neuroimaging was normal and a subsequent lumbar puncture found borderline high opening pressure. Vision and visual fields in the right eye remained stable until the patient was in early adolescence when she started to complain of blurred vision. Her pattern visual evoked potential showed a 75% reduction in P100 amplitude compared with the previous year. Repeat neuroimaging was suggestive of bilateral meningiomas and a biopsy was performed to confirm this. Subsequently, the patient was treated with proton beam therapy to salvage vision in her right eye. This is a novel case of meningioma presenting with enophthalmos due to contraction of the retrobulbar optic nerve.

[Results of radiation therapy for optic nerve sheath meningioma]

Optic nerve sheath meningioma (ONSM) is a slow-growing benign tumor that tends to extend intracranially. The tumor is characterized by vision disturbance, optic nerve atrophy and edema. At present, radiotherapy is recommended as the treatment of choice for ONSM.

PURPOSE

To assess the neuro-ophthalmic symptomatology of ONSM and how it changes in response to radiotherapy.

MATERIAL AND METHODS

In the period from 2004 to 2018, 112 patients with ONSM aged 17 to 76 years underwent stereotactic radiotherapy. In 91 patients, visual functions varied from light perception to 1.0; in 21 patients the affected eye was blind. The prospective follow-up of 103 patients lasted 6 months to 10 years (mean follow-up duration was 57 months). Studied patients underwent either conventional fractionated radiotherapy with Novalis (n=88) or hypofractionation radiotherapy with CyberKnife (n=24).

RESULTS

According to ophthalmological examination, in 60.5% of cases an improvement of visual functions was observed, 39.5% of patients had visual functions remain stable at the initial level. No vision impairment during irradiation was detected. Vision deterioration in the long-term follow-up was observed in 2 patients: extended tumor growth in one case and radio-induced retinopathy in the other.

CONCLUSION

The study showed that this method of treatment for ONSM is effective and safe, allowing preservation of visual functions and in some cases - its improvement, while tumor growth remains under control.

Clinical, Pathologic, and Radiologic Features of Orbital Solitary Fibrous Tumors and Meningiomas

A wide variety of benign and malignant tumors can arise from different structures in the orbital and peri-orbital area, affecting the eye and the optic nerve. This spectrum of tumors includes primary and metastatic carcinomas, lymphomas, melanomas, soft tissue tumors, and primary tumors of the retina, optic disc, and optic nerve. These also extend to relatively rare entities such as solitary fibrous tumor and meningioma of the orbit and optic nerve, which can present with very similar clinical and radiologic features, although the tumor grades, treatment plans, and outcomes can vary widely. In this report, we present two clinical cases of solitary fibrous tumor [central nervous system (CNS) World Health Organization (WHO) grade 2 and 3) and compare their clinical presentation, radiologic and histologic features, treatment, and clinical outcomes to a group of three orbital meningiomas (CNS WHO grade 1 and 2). In the context of these five cases of orbital lesions, we review the current clinical, pathologic, and radiologic literature on orbital tumors, focusing primarily on solitary fibrous tumors and meningiomas, along with an expanded discussion on the diagnostic criteria of both entities, as well as the treatment and prognosis of these lesions.

Radiotherapy for the treatment of optic nerve sheath meningioma: A systematic review and meta-analysis

OBJECTIVES

The management of Optic Nerve Sheath Meningiomas (ONSM) has suffered a significant shift due to new radiation techniques. However, there is no conclusive information on which approach presents better results in the literature. This meta-analysis aims to evaluate the outcomes of different radiotherapy (RT) modalities in the management of ONSM.

METHODS

A systematic review based on an electronic search was performed in MEDLINE, EMBASE, Cochrane, and Lilacs databases. Eligible studies included patients with ONSM treated with RT. Two reviewers independently assessed the eligibility of potential studies, extracted data, and performed the meta-analysis. Outcomes of interest were tumor control, visual acuity (VA), visual field, and complications.

RESULTS

Thirty-nine non-comparative studies involving 736 eyes with ONSM treated with RT were included. Six different techniques were studied: 2-dimensional RT (2DRT), 3D-conformal RT (3CRT), Stereotactic Fractionation RT (SFRT), stereotactic radiosurgery (SRS), intensity-modulated RT (IMRT), and proton beam therapy (PBT). With a mean follow-up period of 46 months, tumor control was 97,4% (95% CI: 98-100%). No difference was observed regarding the rate of final VA post-treatment among the modalities. The 3CRT showed substantially higher rates of complication than other techniques.

CONCLUSIONS

RT produces remarkable tumor control. New radiation modalities such as SFRT, IMRT, SRS, and PBT resulted in better therapeutic results with fewer complications than 2DRT and 3CRT. Thus, they should be the preferential choices for treating ONSM regardless of initial clinical presentation.

Treatment of Recurrent Optic Nerve Sheath Meningioma With a Secondary Course of Radiotherapy

Optic nerve sheath meningiomas (ONSM) are benign neoplasms found surrounding the optic nerve that can affect vision, and potentially lead to blindness. The use of radiotherapy has been advocated to improve visual outcomes and minimize the risk of complications. We present a case of a 58-year-old woman who was treated with a second course of radiotherapy 27-years after initial radiotherapy for recurrent ONSM. The patient responded well to the second course of radiotherapy with good clinical and visual outcomes. This case report supports evidence that treatment with radiotherapy can improve visual outcomes in patients with recurrent ONSM with mild to moderate re-irradiation-related side effects.

[Treatment and management of orbital tumors]

BACKGROUND

There are various options for the conservative treatment of the most frequent orbital tumors. These can delay, complement or be superior to the surgical approach, which is often prone to complications.

OBJECTIVE

This article gives a summary of the possible treatment options for the most common orbital tumors in childhood and adulthood.

METHODS

A literature search was carried out and the possible treatment pathways are presented.

RESULTS

1. Frequent orbital tumors in childhood: a systemic treatment with noncardioselective beta blockers is the primary treatment for capillary orbital hemangiomas. In cases of no response, steroids, interferon alpha or cyclophosphamide are treatment options. Observation is a possible option for smaller dermoid cysts, in cases of progression excision can become necessary. Symptomatic optic nerve gliomas can also be observed and in cases of progression treated with chemotherapy, mTOR/MEK inhibitors or radiotherapy (children > 5 years). Rhabdomyosarcomas are biopsied and subsequently treated by radiotherapy and chemotherapy. 2. Frequent orbital tumors in adulthood: asymptomatic cases of cavernous hemangiomas of the orbit can just be observed. Symptomatic hemangiomas can be surgically excised or treated with radiotherapy. For meningiomas of the optic nerve sheath radiotherapy is a very effective treatment. Surgical excision should be reserved for cases with no prognosis of visual acuity. There is also the option to treat with antiprogesterone. Orbital lymphomas with purely orbital involvement can be treated with radiotherapy, chemotherapy or the application of rituximab.

CONCLUSION

There are now very effective conservative treatment options for many orbital tumors. In some cases a surgical procedure can be avoided and a good visual function can be retained.

68Ga-DOTATOC-PET/MRI-A Secure One-Stop Shop Imaging Tool for Robotic Radiosurgery Treatment Planning in Patients with Optic Nerve Sheath Meningioma

Optic nerve sheath meningiomas (ONSM) are rare but can lead to irreversible blindness. Hybrid imaging may enhance tumor delineation and diagnostic accuracy via receptor binding. However, relevant clinical data for ONSM are lacking. We evaluated the feasibility of receptor-based hybrid imaging prior to robotic radiosurgery (RRS). We retrospectively analyzed all of our institution's patients with suspected ONSM who underwent combined positron emission tomography and magnetic resonance imaging (PET/MRI) with gallium-68-labeled (DOTA0-Phe1-Tyr3) octreotide (Ga68-DOTATOC) before RRS between 2018 and 2019. Eight patients with ten suspected ONSM (female = 7; median age, 51.2 years; IQR, 43.0-66.0) were included. Nine out of ten ONSM were deemed PET-positive with a median standard uptake value (SUV) max of 5.6 (IQR, 2.6-7.8). For all nine ONSM that presented 68Ga-DOTATOC uptake, hybrid PET/MRI was used for target volume contouring prior to RSS. At a median follow-up of 11.7 months (IQR, 9.4-16.4), tumor control was achieved in all patients. Radiosurgery resulted in the improvement of visual acuity in two of eight patients, whereas six showed stable vision. Ga68-DOTATOC-PET/MRI can be used for target volume contouring prior to RRS for ONSM as it enables safe treatment planning and improves diagnostic accuracy.

Primary and Secondary Optic Nerve Sheath Meningioma

Objective  This study was aimed to review issues relating to the recognition, radiographic diagnosis, monitoring, and management of primary and secondary optic nerve sheath meningioma (ONSM). Design  This study is a review of peer-reviewed literature combined with illustrative case studies. Participants and Methods  A literature search was conducted via the PubMed database using pertinent search terms. Selected articles were limited to those written or translated into English. Additional works cited within articles were also included. Individual cases were drawn from the experience of a tertiary academic neuroophthalmic and orbital practice. Tables summarize radiotherapeutic and surgical studies, excluding single case reports and studies focusing on meningioma of intracranial origin. Main Outcome Measurements  Review of reported surgical and radiotherapeutic series is the primary measurement. Results  The natural history of optic nerve sheath meningiomas is primarily characterized by progressive ipsilateral vision loss. Diagnosis is typically based on radiographic imaging findings, with biopsy remaining indicated in some patients. Management strategies may include observation, radiation, and/or surgical intervention, or a combination of these approaches. The role of surgery, especially with respect to primary ONSM (pONSM), remains controversial. Advancement of radiotherapy techniques has shifted modern treatment paradigms in pONSM toward radiation as primary treatment, as surgical outcomes are inferior in major studies. Although radiation remains the treatment of choice in many cases, selected patients may benefit from surgery, especially in the setting of secondary ONSM (sONSM). Conclusion  A wide variety of radiotherapeutic and surgical treatment modalities for ONSM exist. The specific indications for each management strategy continue to be redefined.

Atypical acute presentation of an optic nerve sheath meningioma

PURPOSE

Primary optic nerve sheath meningiomas (ONSM) are benign lesions that typically present with findings of painless proptosis (59%), optic nerve pallor (55%), and decreased peripheral vision (35%). Herein we share an atypical case of a patient who presented acutely with periorbital pain and optic nerve head edema, and was ultimately determined to have a low-grade optic nerve meningioma.

OBSERVATIONS

A 36-year-old healthy woman presented with acute onset of left periorbital discomfort. She was found to have intact visual acuity, full peripheral vision, and ipsilateral optic nerve edema. MRI imaging revealed a large intraconal mass partially encircling the left optic nerve. Incisional biopsy revealed a diagnosis of meningioma, WHO grade 1.

CONCLUSIONS

Low-grade optic nerve sheath meningiomas may uncommonly present with acute pain and optic nerve head swelling, and absence of classic disease features.

Optic nerve sheath meningioma

PURPOSE OF REVIEW

Optic nerve sheath meningiomas (ONSMs) are rare benign tumors of the anterior visual pathway which present with slowly progressive and painless vision loss and account for approximately 2% of all orbital tumors. This article provides an overview as well as an update on the ONSMs with regards to cause, epidemiology, clinical presentation, diagnosis, and management in adults and pediatric population.

RECENT FINDINGS

The clinical presentation and prognosis of ONSMs can vary and largely depend on the location of tumor as well as the histologic type. Overall, the diagnosis is based on clinical presentation, examination, and neuroimaging findings. Nevertheless, delays in diagnosis or misdiagnosis are not uncommon and can result in higher morbidity rates. Recent advances in diagnostic as well as more effective and less-invasive treatment options are discussed in this review.

SUMMARY

ONSMs are a rare cause of slowly progressive and inexorable visual loss. Although ONSM diagnosis depends on the characteristic clinical and radiologic findings, prompt diagnosis, and appropriate management is critical for favorable visual outcomes. Thus, current focus is optimizing diagnostic as well-treatment methods for patients with ONSMs.

The falciform ligament: Anatomical study with microsurgical implications

OBJECTIVES

The current study aims to increase awareness of the falciform ligament and its anatomical and surgical relationships, for the benefit of the neurosurgeon.

PATINENTS AND METHODS

Twenty-four sides from twelve Caucasian cadaveric heads (all fresh-frozen) were used in this study. The length and thickness of the falciform ligament were recorded. The relationship of the falciform ligament to the optic nerve was also observed and documented. Finally, the force needed to avulse the falciform ligament was recorded.

RESULTS

In all specimens, the ligament was identified as a continuation of the outer dural layer, forming a roof at the entrance of the optic canal. The mean medial-to-lateral length, anteroposterior length, and thickness of the falciform ligament were 7.97 mm, 2.12 mm, and 0.26 mm, respectively. The mean distance from the medial attachment of the ligament to the midline was 5.54 mm. For the undersurface of the falciform ligament, the optic nerve occupied the middle third in 50.0 %, the lateral third in 44.4 %, and the medial third in 5.6 % of sides. The mean optic nerve diameter at the entrance of the optic canal was 4.20 mm. The mean failure force was 2.47 N.

CONCLUSION

The anatomical measurements and relationships provided in this description of the falciform ligament serve as a tool for surgery selection and planning, as well as an aid to improving microsurgical techniques, with the final goal being better patient outcomes.

Optic Nerve Sheath Diameter Ultrasound: Optic Nerve Growth Curve and Its Application to Detect Intracranial Hypertension in Children

PURPOSE

First, to create an optic nerve growth curve from normal optic nerve sheath diameter (ONSD) values measured by using B-scan ultrasonography in subjects 0-18 years of age. Second, to identify age-appropriate cutoff values of ONSD to be used in the diagnosis of intracranial hypertension (IHT).

DESIGN

Prospective cross-sectional study.

METHODS

B-scan ocular ultrasonography was performed on both eyes of 215 subjects 0-18 years of age, divided into 3 groups: 165 healthy children, 29 children with IHT (all >4 years of age), and 21 children with optic disc drusen (ODD).

RESULTS

There were no statistically significant differences in between the ONSDs of healthy children and those in subjects with ODD. An optic nerve growth curve was created by using ONSDs measured in healthy subjects 0-18 years of age, using the equation: ONSD = ln [33.15] - (-0.18 × ln [children's age]). The curve showed a progressive increase of ONSD up to 10 years of age, and it remained constant until the age of 18. For this reason, 2 different cutoff values were calculated for age groups 4-10 and 11-18. Values were 4.10 mm and 4.4 mm, respectively, with a 100.0% sensitivity and a specificity ranging from 83.9% to 98.8%. A sensitivity of 28.6% was reached for the population of subjects 4-18 years of age with a threshold value of 5 mm, as used in published reports.

CONCLUSIONS

The ONSD continued to enlarge gradually until the age of 10. Therefore, 2 different cutoff values for the age groups 4-10 and 11-18 were calculated, considering the ONSDs of subjects 11-18 years of age overlapping with those of adults. No patients with IHT <4 years old were found. Further studies are needed to evaluate the correct cutoff values for these ages.

The Role of Endonasal Endoscopic Optic Nerve Decompression as the Initial Management of Primary Optic Nerve Sheath Meningiomas

Background  The management of optic nerve sheath meningiomas (ONSMs) remains controversial. Surgical decompression through traditional resective techniques has been associated with significant morbidity. While radiation therapy, the current modality of choice is not exempt of risks. Transnasal endoscopic optic nerve decompression (EOND) offers a direct route to the orbit, optic canal, and orbital apex, providing a minimally invasive alternative. Objective  The main objective of this article is to assess EOND as the initial management of symptomatic patients with primary ONSM. Methods  Patients with ONSMs without a history of radiotherapy who underwent EOND were retrospectively reviewed. Postoperative imaging, duration of follow-up, and visual outcomes at the last ophthalmology visit were assessed. Results  Four women (age range 25-63 years) with primary ONSMs that underwent EOND were identified. All patients displayed subjective and objective baseline signs of vision loss. Additionally, baseline proptosis, diplopia, optic nerve atrophy, and ocular pain were identified. In none of the cases, the optic nerve sheath was breached. Following EOND, all patients deferred treatment with adjuvant radiotherapy. At a mean postoperative follow-up of 14 months, all patients were clinically stable without evidence of disease progression on imaging or physical examination. At last ophthalmologic evaluation, three out of four showed objective improvements from baseline visual acuity and visual field (remaining patient had baseline optic nerve atrophy). Conclusion  These results suggest that EOND could be a viable initial treatment modality of selected primary ONSM cases. Further studies are warranted to determine long-term efficacy and its role in a stepwise progression of management, preceding radiotherapy.

Optic nerve sheath meningiomas: prevalence, impact, and management strategies

Optic nerve sheath meningiomas are rare benign neoplasms of the meninges surrounding the optic nerve. They are a significant cause of morbidity. While the mortality rate is practically zero, these tumors can blind or disfigure patients. Given that the clinical course can be variable, and treatment has the capacity to cause morbidity itself, the management of these patients can be difficult. We review the literature to discuss the prevalence of optic nerve sheath meningiomas, the association with neurofibromatosis type 2, natural history, and management options and strategies.

Visual Outcomes and Local Control After Fractionated Stereotactic Radiotherapy for Optic Nerve Sheath Meningioma

PURPOSE

To review the outcomes of patients with optic nerve sheath meningiomas (ONSM) treated with fractionated stereotactic radiotherapy.

METHODS

Patient characteristics, treatment, and outcomes were analyzed for all patients with primary and secondary ONSM treated from 2001 to 2012. Clinically significant visual acuity change was defined as a 2-line change on the Snellen eye chart from pre-fractionated stereotactic radiotherapy.

RESULTS

Forty-one patients were treated: 23 patients with primary ONSM and 18 patients with secondary ONSM. The median age at diagnosis was 56 years. The median visual follow up was 3.8 years and the median radiologic follow up was 4.4 years. At diagnosis, 36% had normal vision (20/20-20/40), 10% had mild impairment (<20/40-20/60), 20% had moderate visual impairment (<20/60-20/200), 27% had severe impairment (<20/200), and 7% had no light perception. Common acute side effects were headache (32%) and nausea (15%); 15% of patients required corticosteroids during stereotactic radiotherapy. Chronic toxicities included retinopathy (7%), pituitary dysfunction (13%), chronic ocular pain (5%), and cataracts (2%). Visual acuity was stable in 65%, improved in 27%, and decreased in 8% of patients. Visual fields were stable in 70%, improved in 21%, and reduced in 9%. Actuarial 5-year local control rates were 100% for primary ONSM and 88% for secondary ONSM. Actuarial 5-year visual preservation rates were 100% for primary ONSM and 86% for secondary ONSM.

CONCLUSIONS

Fractionated stereotactic radiotherapy for primary and secondary ONSM was well tolerated and provides excellent local control and visual preservation. Longer follow up is required to determine the risk of late ocular and pituitary sequelae.

Optic Nerve Sheath Meningioma: Preliminary Analysis of the Role of Radiation Therapy

Background

The purpose of this study was to evaluate the treatment outcome of our optic nerve sheath meningioma (ONSM) case series in terms of preventing tumor growth and preserving vision in ONSM patients.

Methods

Between July 2003 and March 2015, 1,398 patients with intracranial meningioma were diagnosed at Seoul National University Bundang Hospital. Among them, only 13 patients (0.93%) were diagnosed with ONSM and enrolled in the present study. Tumor volume changes of ONSM patients and their visual acuity were evaluated before and after treatments.

Results

The median follow-up time was 50 months (range, 12–133 months). Visual acuity was evaluated in 12 of 13 patients, and visual acuity was found to be preserved in 9 of 12 patients (75%). Tumor volume was reduced in all patients. The tumor control rate was 100% in the present study. The difference in tumor volume between pretreatment and last follow-up was statistically significant (p=0.015).

Conclusion

Intensity-modulated radiotherapy (IMRT) and gamma knife radiosurgery (GKS) could maintain visual acuity and stabilize tumor volume in ONSM patients, suggesting that IMRT and GKS may be effective therapies for ONSM. However, which treatment is the more effective modality must be confirmed by prospective studies and longer-term follow-up.

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.

Diagnosis of optic nerve sheath meningioma during optic nerve sheath decompression

Optic nerve sheath meningioma (ONSM) is typically diagnosed based on clinical suspicion and imaging characteristics and is most often treated with radiation. Historically, biopsy, optic nerve sheath decompression, and debulking surgeries have been avoided for fear of optic nerve vascular disruption and tumor spread into the orbit. This is a case of a 48-year-old man who presented with unilateral optic disc edema, declining visual acuity, and a visual field defect. Despite an initial improvement with acetazolamide, his vision subsequently worsened. With an elevated lumbar puncture opening pressure and imaging showing right optic nerve sheath enhancement, the differential diagnosis included ONSM, perineuritis and idiopathic intracranial hypertension (IIH). Optic nerve sheath decompression (ONSD) with biopsy was performed, simultaneously decompressing the nerve and yielding a sample for pathologic analysis. A pathologic diagnosis of ONSM was made and treatment with radiation was subsequently initiated, but vision began to improve after the surgical decompression alone.

Somatostatin Receptor SPECT/CT using 99mTc Labeled HYNIC-TOC Aids in Diagnosis of Primary Optic Nerve Sheath Meningioma

Primary optic nerve sheath meningiomas (ONSM) are rare, benign and slow growing tumor involving the intra-orbital/intra-canalicular segment of the optic nerve. Untreated, they can potentially lead to visual deterioration. Magnetic resonance (MR) is the gold standard imaging modality for diagnosing the entity. Often, a clinical dilemma exists to narrow the differential diagnosis of an enhancing intra-orbital mass on MR. Molecular imaging provides a high degree of precision in diagnosing meningioma in view of relatively high levels of somatostatin receptor expression by these tumors. The following case demonstrates the potential clinical utility of somatostatin receptor SPECT using ^99mTc- labeled HYNIC-TOC in clinical diagnosis of ONSM.

A rare case of bilateral optic nerve sheath meningioma

A 60-year-old female presented with gradual, painless, progressive diminution of vision, and progressive proptosis of left eye since 7 years. Ophthalmological examination revealed mild proptosis and total optic atrophy in the left eye. Magnetic resonance imaging (MRI) and computed tomography (CT) brain with orbit showed bilateral optic nerve sheath meningioma (ONSM) involving the intracranial, intracanalicular, intraorbital part of the optic nerve extending up to optic chiasma and left cavernous sinus.

Magnetic resonance imaging of optic nerve

Optic nerves are the second pair of cranial nerves and are unique as they represent an extension of the central nervous system. Apart from clinical and ophthalmoscopic evaluation, imaging, especially magnetic resonance imaging (MRI), plays an important role in the complete evaluation of optic nerve and the entire visual pathway. In this pictorial essay, the authors describe segmental anatomy of the optic nerve and review the imaging findings of various conditions affecting the optic nerves. MRI allows excellent depiction of the intricate anatomy of optic nerves due to its excellent soft tissue contrast without exposure to ionizing radiation, better delineation of the entire visual pathway, and accurate evaluation of associated intracranial pathologies.

IgG4-related disease initially presented as an orbital mass lesion mimicking optic nerve sheath meningioma

We report a case of an optic nerve mass lesion associated with IgG4-related disease. A 39-year-old man presented with right blurred vision and proptosis 8 years before admission. Magnetic resonance imaging showed a mass lesion in the center of the right orbit, which was diagnosed as optic nerve sheath meningioma by neuroradiologists and neurosurgeons. Irradiation was selected for treatment of the lesion on the basis of the radiological diagnosis; subsequently, the lesion gradually reduced in size. However, regrowth of an optic nerve mass lesion observed during the previous 2 years caused remarkable exophthalmos, and removal of the orbital mass lesion was performed via a transcranial orbital approach. Pathological examinations resulted in a diagnosis of IgG4-related disease, and hematological tests revealed an elevated level of serum IgG4. Additional radiological examinations showed mass lesions in the left maxillary nerve, bilateral inferior alveolar nerves, paravertebral tissue, and left kidney. Treatment with oral steroids has produced a reduction in the size of these lesions.

Optical coherence tomography shape analysis of the peripapillary retinal pigment epithelium layer in presumed optic nerve sheath meningiomas

BACKGROUND

Geometric morphometrics (GM) was used to compare the shape of the peripapillary retinal pigment epithelium-Bruch's membrane (ppRPE) layer imaged on spectral domain optical coherence tomography (SD-OCT) of patients with presumed optic nerve sheath meningiomas (pONSM) and normal subjects.

METHODS

We compared 2 groups: 30 normals to 10 patients (11 eyes) with pONSM. We digitized 20 equidistant semi-landmarks on OCT images of the ppRPE-layer, spanning 2500 μm on each side of the neural canal opening (NCO). Data were analyzed using standard GM techniques including a generalized least squares Procrustes superimposition, principal component analysis (PCA), thin-plate spline, and permutation statistical analysis to evaluate differences in shape. We also analyzed other variables with respect to shape including tumor size-proximity to the globe, age, retinal nerve fiber layer, and optic disc height.

RESULTS

All pONSM patients were female (age 37-66 years); 10 had unilateral and 1 had bilateral optic nerve involvement. Ten of the eyes had optic disc edema at presentation, 4 went on to develop shunt vessels, and 4 had optic atrophy. The ppRPE-layer bordering the NCO in normals is V-shaped pointing away from the vitreous; the ppRPE-layer in pONSM is indented causing an inverted-U shaped deformation skewed nasally toward the vitreous. PCA showed a significant difference between normals and pONSM (permutation, n = 10,000, P = 0.001). The size and proximity of the tumor to the globe correlates with the shape of the ppRPE-layer (r = 0.75, P = 0.04). Correlation between shape variables and RNFL thickening (r = 0.51), optic disc height (r = 0.67), and age (r = 0.67) were not statistically significant.

CONCLUSION

The shape of the RPE layer in pONSM is characterized by an inverted-U shape or indentation that differs significantly from normals. It is indistinguishable from the shape we previously reported in papilledema and is not caused by disc edema. The mechanism in pONSM is unknown but may involve a change in the compliance of the nerve and/or localized sequestration of cerebrospinal fluid in the distal optic nerve sheath.

Genetic profiling by single-nucleotide polymorphism-based array analysis defines three distinct subtypes of orbital meningioma

Orbital meningiomas can be classified as primary optic nerve sheath (ON) meningiomas, primary intraorbital ectopic (Ob) meningiomas and spheno-orbital (Sph-Ob) meningiomas based on anatomic site. Single-nucleotide polymorphism (SNP)-based array analysis with the Illumina 300K platform was performed on formalin-fixed, paraffin-embedded tissue from 19 orbital meningiomas (5 ON, 4 Ob and 10 Sph-Ob meningiomas). Tumors were World Health Organization (WHO) grade I except for two grade II meningiomas, and one was NF2-associated. We found genomic alterations in 68% (13 of 19) of orbital meningiomas. Sph-Ob tumors frequently exhibited monosomy 22/22q loss (70%; 7/10) and deletion of chromosome 1p, 6q and 19p (50% each; 5/10). Among genetic alterations, loss of chromosome 1p and 6q were more frequent in clinically progressive tumors. Chromosome 22q loss also was detected in the majority of Ob meningiomas (75%; 3/4) but was infrequent in ON meningiomas (20%; 1/5). In general, Ob tumors had fewer chromosome alterations than Sph-Ob and ON tumors. Unlike Sph-Ob meningiomas, most of the Ob and ON meningiomas did not progress even after incomplete excision, although follow-up was limited in some cases. Our study suggests that ON, Ob and Sph-Ob meningiomas are three molecularly distinct entities. Our results also suggest that molecular subclassification may have prognostic implications.

[Results of fractionated targeted proton beam therapy in the treatment of primary optic nerve sheath meningioma]

INTRODUCTION

Optic nerve sheath meningioma (ONSM) is a common benign neoplasm arising from the arachnoid tissue encapsulating the optic nerve and affects mainly middle aged women. It is a slow-growing tumor for which there is still no consensus on treatment.

PURPOSE

To evaluate the safety and efficacy of fractionated targeted proton beam therapy (PBT) in the treatment of ONSM and to define its role in the treatment of these tumors.

METHODS AND MATERIALS

We performed a retrospective analysis of 15 patients (13 women and 2 men), mean age 41.8 years, presenting with primary ONSM, followed at the Fondation Ophtalmologique Adolphe de Rothschild (Paris) between September 2006 and August 2013. After a multidisciplinary consultation, all were treated with PBT at a total dose of 52.2 Gy Eco, in fractions of 1.8 Gy Eco, at the Institut Curie (Paris). Patients underwent standardized follow-up including ophthalmologic examinations, visual field testing and imaging every 6 months. Study parameters were post-treatment visual acuity, tumor size on MRI, and treatment side effects

RESULTS

We separated the patients into 3 distinct groups: patients treated by PBT after an observation period (4/15), patients treated by PBT after primary surgery (5/15) and patients treated by PBT as primary treatment (6/15). Visual acuity improved in 3 cases, deteriorated in 1 and remained stable in 11 cases. Tumor size on MRI remained stable in 100 % of cases following PBT. No serious adverse effects were recorded after a mean follow-up of 22.4 months (8-79 months).

CONCLUSION

Our experience confirms the efficacy and the safety of proton beam therapy in patients with ONSM. PBT presents a promising alternative to surgery and conventional radiotherapy in the treatment of the MGNO. It seems to be effective in controlling tumor size and stabilizing visual function, at the cost of very low toxicity. Additional studies are needed to accurately determine the decision-making criteria and the ideal timing of this treatment.

Optic nerve sheath meningioma: a case report with 15-year follow-up

Meningiomas are benign neoplastic lesions of arachnoidal cells of the meninges. These tumors may arise wherever meninges exists, such as in the nasal cavity, paranasal sinuses, middle ear, and mediastinum. Optic nerve sheath meningiomas (ONSMs) are usually unilateral and occur predominantly in middle-aged females, although they may be present at any age. We present a case of a 55-year-old female with ONSM diagnosed when she was 40 years old. Diagnosis and follow-up was based on the clinical picture, CT orbit scan, and magnetic resonance imaging.

Idiopathic orbital pseudotumour

Idiopathic orbital pseudotumour (IOP) is a benign inflammatory condition usually confined to the orbit. This may involve single or multiple intraorbital structures. Extraorbital extension can also occur. The imaging appearances often mimic other orbital diseases. Both computed tomography (CT) and magnetic resonance imaging (MRI) are frequently used to investigate orbital diseases, and it is important for radiologists to be aware of the variety of imaging appearances that occur in IOP. We present the imaging appearances in histopathologically confirmed cases of IOP and discuss the clinical features, natural history, and differential diagnosis of this condition.

Primary orbital meningioma: a study of six cases at a single institution

Primary orbital meningioma is a rare tumor of the anterior visual pathway and constitutes approximately 2% of all orbital tumors and 1-2% of all meningiomas. The differentiation from secondary orbital meningioma of intracranial origin is sometimes difficult on image. As the tumor often leads to visual loss if left untreated and surgical intervention inevitably causes morbidity, the timing and modality of treatment are very important. We carried out the study involving six cases (mean age: 42.7 years, male to female ratio: 1:5) of primary orbital meningioma to further elucidate its behavior. The clinical signs and symptoms, diagnosis, treatment strategies, and follow-up information are recorded for all cases. The most frequent initial symptoms were visual complaints (100%) and proptosis (67%). In five cases, the diagnosis was based on pathologic findings and the tumors were all grade I meningiomas. In one case, however, the diagnosis was based on radiographic and clinical findings, lacking histologic confirmation. Five patients were operated on, four underwent tumor removal, and one received eyeball exenteration. One patient was treated with Novalis radiotherapy. The mean follow-up period was 8.8 years (range from 9 months to 15 years). All patients experienced loss of vision during the course without exception. No recurrent tumor was found in five cases during follow-up. In case 5, whose eyeball was exenterated, developed recurrent meningioma 7 years later. She received radiotherapy but the tumor was out of control. She expired 8 years after eyeball exenteration. The primary orbital meningioma is aggressive in behavior despite its benign histopathologic features. Loss of vision is frequently seen even after treatment. The tumor could be fatal if surgery and radiotherapy fail to control its intracranial extension.

Tilted optic disks

Tilted optic disks are a common finding in the general population. An expression of anomalous human development, the tilted disk appears rotated and tilted along its axes. Visual sequelae described with tilted optic disks include myopia, astigmatism, visual field loss, deficient color vision, and retinal abnormalities. Although the natural course of tilted optic disks is nonprogressive, the anomaly can be mistaken for tumors of the anterior visual pathway, edema of the optic nerve head, or glaucoma. A thorough examination of patients with tilted disk includes refraction, dilated fundus examination, and visual field testing. At times, neuroimaging may be necessary to arrive at the correct diagnosis. Until normative data are validated for tilted disks, the role of new imaging technologies for the optic nerve head is limited. Familiarity with the spectrum of ophthalmoscopic appearance and the clinical manifestations of tilted disks may be the most critical factors in avoiding misdiagnosis.

Intraorbital meningiomas: a pathologic review using current World Health Organization criteria

CONTEXT

Meningiomas represent approximately 4% of all intraorbital tumors and can arise from the optic nerve or extend into the orbit from adjacent structures.

OBJECTIVE

To examine a cohort of intraorbital meningiomas and use the current World Health Organization (WHO) scheme to assess the effect of changes to the classification of tumors at this site.

DESIGN

The histopathology and clinical findings of intraorbital meningiomas resected between 1968 and 2008 at our institution were reviewed according to the WHO 2007 classification scheme.

RESULTS

A total of 51 intraorbital meningiomas were reviewed. The mean age at presentation was 45 years, but 5 tumors arose in children. Two patients were known to have neurofibromatosis type 2, and 1 had inherited retinoblastoma. Orbital meningiomas were more frequently encountered in women (30 cases) than in men (21 cases). In 21 patients, the tumor was associated with the optic nerve. The most common (25 of 51 tumors; 49%) histopathologic subtype was meningothelial. Most (47 of 51; 92%) of the tumors were WHO grade I. Four tumors (8%) were WHO grade II, with 4 or more mitotic figures per 10 high-power fields, brain invasion, chordoid histology, or a combination of these features.

CONCLUSIONS

Intraorbital meningiomas were most frequently of the meningothelial or transitional subtypes and were WHO grade I. One relatively common intracranial subtype, fibrous meningioma, was not encountered. The percentage of WHO grade II tumors in the orbit (8%) is similar to that reported for intracranial tumors using the current grading scheme.

Primary optic nerve tumours

PURPOSE OF REVIEW

Advances have been made in the treatment of primary optic nerve tumours. With a focus on the last few years' publications, recommendations for clinical management are being developed.

RECENT FINDINGS

In low-grade optic nerve glioma, two divergent developments are observed: an increasing reluctance in treating such tumours because of reports about treatment toxicity (secondary tumours, moyamoya syndrome) and a steady and marked improvement both in radiotherapy and chemotherapy. Many reports on beneficial effects of radiotherapy on optic nerve meningioma have been published. Radiotherapy does not only preserve but in many cases even improves or restores visual function and has, therefore, become the therapy of choice in this tumour.

SUMMARY

Establishing a treatment plan in cases of optic nerve glioma is difficult and must be made on an individual basis. Although both chemotherapy and radiotherapy can stabilize and sometimes improve vision in progressive tumours, chemotherapy is the preferred modality in children younger than 9 years and in patients with neurofibromatosis 1. In functionally progressive optic nerve meningioma with useful visual function, multifractioned stereotactic conformal radiotherapy is the treatment of choice.