Optic nerve glioma mimicking an optic nerve meningioma

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.

Concomitant meningioma and glioma within the same optic nerve in neurofibromatosis type 1

A patient with neurofibromatosis type 1 and the rare finding of concomitant meningioma and optic pathway glioma within the same optic nerve is presented. A 4-year-old boy was admitted to our hospital with right-sided proptosis. He also had numerous café-au-lait macules and axillary freckling on physical exam. According to National Institutes of Health (NIH) criteria, he met the diagnostic criteria for neurofibromatosis type 1. On magnetic resonance imaging (MRI), a mass originating from the right optic nerve sheath with normal appearance of the optic nerve was observed, which was consistent with optic nerve sheath meningioma. Another mass lesion was observed in the prechiasmatic region of the same optic nerve, which was consistent with optic nerve glioma. Two different types of optic pathway tumors in the same optic nerve is an extraordinary case. It is important to recognize imaging findings of these tumors and make correct diagnosis.

Medulloepithelioma of the ciliary body and optic nerve: clinicopathologic, CT, and MR imaging features

The definitive diagnosis of medulloepitheliomas of the ciliary body and optic nerve is made by histopathologic examination. Familiarity with rare tumors aids clinicians in accurately diagnosing this rare neoplasm. CT and MR imaging findings can be helpful, especially if the mass is confined in an area of the ciliary body without involvement of the retina. The characteristic findings of cystic changes and possible calcification are suggestive of medulloepithelioma rather than melanoma. The more common and ominous retinoblastoma shares some radiologic features with medulloepithelioma, however, and is thus often a consideration. Clinical diagnosis of medulloepitheliomas of the optic nerve and central nervous system (CNS) is more challenging. The diagnosis is often made by histopathologic examination. Lastly, coexisting CNS tumors and anomalies have been reported in association with intraocular medulloepitheliomas and should be recognized.

Primary tumours of the optic nerve and its sheath

PURPOSE

To describe the clinical, neuroimaging, and pathologic features of primary tumours of the optic nerve and its sheath.

METHODS

Review of published cases and personal series.

RESULTS

The most common primary tumour of the optic nerve is the benign glioma. This low-grade astrocytoma usually can be followed without intervention. Progression of visual symptoms and signs may necessitate either surgery to remove the tumour or radiation therapy. The most common tumour of the optic nerve sheath is the meningioma. The optimum treatment for this lesion is stereotactic or three-dimensional conformal fractionated radiation therapy, which generally results in stabilization or improvement in vision. A variety of other primary tumours may mimic, in both manifestations and imaging appearance, the more common glioma or meningioma. In such cases, the correct diagnosis may not be made until a biopsy is performed or the nerve is removed.

CONCLUSION

Primary tumours of the optic nerve and its sheath are not uncommon. Diagnosis can often but not always be made by the results of a complete examination combined with imaging studies, particularly CT scanning and MR imaging. Management depends on the presumed or histologically verified nature of the tumour.

Optic nerve sheath meningiomas. Role of MR imaging

Optic nerve meningiomas usually are seen in middle-aged and elderly women, and present as a slowly progressing axial proptosis and loss of vision. CT and MR imaging are the most valuable diagnostic tools to evaluate these tumors. This article reviews the MR imaging and CT characteristics of optic nerve sheath meningiomas and discusses features that may distinguish optic nerve sheath meningiomas from simulating lesions.