Elsevier

World Neurosurgery

Volume 97, January 2017, Pages 557-564
World Neurosurgery

Original Article
A Retrospective Analysis of Vision-Impairing Tumors Among 467 Patients with Neurofibromatosis Type 2

https://doi.org/10.1016/j.wneu.2016.10.080Get rights and content

Background

Vision is important for patients with hearing loss caused by neurofibromatosis type 2 (NF2). Tumors adjacent to the anterior visual pathway can potentially impair the vision. Only a few case reports and small-series studies have been reported.

Objective

To evaluate the clinical features of tumors adjacent to the anterior visual pathway in a large series of patients with NF2.

Methods

Seventy-three patients with potentially vision-impairing tumors were carefully screened from among 467 patients with NF2.

Results

Among the 73 patients, 31 had intraorbital tumors, 21 had suprasellar meningiomas, and 21 had medial sphenoid ridge meningiomas. Of the 31 patients with intraorbital tumors, 17 had optic nerve sheath meningiomas, 9 had intraorbital schwannomas, 3 had spheno-orbital meningiomas, 1 had an anterior cranial fossa-orbital meningioma, and 1 had a cranio-orbital schwannoma. To the date of the last follow-up, 43 patients (58.9%) experienced visual loss. In most cases, hearing loss tended to occur earlier than visual loss. Six patients underwent early operations, and they recovered well without any further vision damage. Six other patients underwent operations after having no functional visual ability in the affected eyes, and their visual ability was not saved.

Conclusions

Tumors adjacent to the anterior visual pathway, although uncommon in patients with NF2, can cause progressive visual loss. Early surgical intervention seems to be the primary treatment strategy, except for in patients' optic nerve sheath meningiomas. If patients adopt a wait and see policy, regular visual examination seems to be mandatory.

Introduction

Neurofibromatosis type 2 (NF2) is a rare, autosomal dominantly inherited tumor predisposition syndrome caused by inactivating mutations of the NF2 tumor suppressor gene on chromosome 22q12.1 NF2 is characterized by the presence of bilateral vestibular schwannomas, which occur in 90%–95% of patients.2 Other nervous system tumors mainly include meningiomas, schwannomas of other cranial nerves and spinal nerve roots, and ependymomas. However, neurofibromas are rarely found in patients with NF2.3

Most patients with NF2 develop bilateral progressive hearing loss. Almost 90% of patients have their hearing ability impaired before the age of 45 years.4 Researchers have attempted various methods to preserve their patients' hearing ability. Some molecule-targeted agents, such as bevacizumab and lapatinib, have succeeded in prolonging the preservation of hearing in some patients.5, 6 However, the outcome of bilateral deafness cannot be avoided in most cases. The treatment effects of hearing restoration options, such as the cochlear implant and auditory brainstem implant, remain unsatisfactory.7 Therefore, vision becomes increasingly important in patients with NF2 for communication as the disease progresses and hearing decreases.

In patients with NF2, various ocular manifestations have been identified, such as juvenile cataracts, epiretinal membranes, combined pigment epithelial detachments and retinal hamartomas, and optic disc gliomas.8 Most of these complications do not significantly impair the vision. In some patients with NF2, tumors can damage the anterior visual pathway, causing serious visual loss, sometimes even bilaterally.9, 10, 11 These tumors can cause disastrous hearing loss in patients with NF2 if left untreated. It is essential to know the clinical features and prognosis of these tumors adjacent to the anterior visual pathway. Only a few case reports and small-series studies have been reported. Here, we present a detailed analysis of these potentially vision-impairing tumors in a large series of patients with NF2.

Section snippets

Methods

Between May 2006 and May 2016, 467 patients with NF2 presented at the Department of Neurosurgery, Beijing Tian Tan Hospital. All the patients underwent enhanced cranial magnetic resonance imaging examinations and fulfilled the Manchester criteria12 for the diagnosis of NF2. Their cranial magnetic resonance images were carefully reviewed to find tumors adjacent to the anterior visual pathway, mainly including the optic nerve and chiasma. The tumors were categorized into the following 3 groups:

General Characteristics

Among the total of the 467 patients with NF2, 235 (50.3%) were male, and 232 (49.7%) were female. The age at diagnosis ranged from 1 to 70 years, with a mean age of 30.6 years (standard deviation [SD] ± 13.5 years; Figure 1A). Seventy-three patients with NF2 (15.6%) had tumors adjacent to the anterior visual pathway. The mean age at diagnosis in the 73 patients was similar to that in the other 394 patients (28.8 ± 12.1 years vs. 31.0 ± 13.8 years; t test, P = 0.195; Figure 1B). These 73

Discussion

Vision is undoubtedly important for patients with NF2 with hearing loss. However, many factors can threaten the patient's precious visual ability, such as various ocular manifestations, increased intracranial pressure, corneal opacification secondary to cranial nerve damage, and tumors adjacent to the anterior visual pathway. Tumors adjacent to the anterior visual pathway can originate from the intraorbital tissues, clinoid process, TS, suprasellar cistern, sphenoid ridge, cavernous sinus, and

Conclusions

Tumors adjacent to the anterior visual pathway were not common in patients with NF2. An evident male prevalence could be observed. These tumors could cause progressive visual loss if left untreated, causing disastrous hearing loss in patients with NF2. Early surgical intervention seems to be the primary treatment strategy, except for cases of ONSM. Seriously impaired visual ability is difficult to reverse. If patients adopt the wait and see approach, regular visual examination seems to be

References (37)

  • M.E. Baser et al.

    Increasing the specificity of diagnostic criteria for schwannomatosis

    Neurology

    (2006)
  • M.A. Karajannis et al.

    Phase II trial of lapatinib in adult and pediatric patients with neurofibromatosis type 2 and progressive vestibular schwannomas

    Neuro Oncol

    (2012)
  • S.R. Plotkin et al.

    Hearing improvement after bevacizumab in patients with neurofibromatosis type 2

    N Engl J Med

    (2009)
  • M.M. Bosch et al.

    Ophthalmologic findings and long-term course in patients with neurofibromatosis type 2

    Am J Ophthalmol

    (2006)
  • M.M. Bosch et al.

    Optic nerve sheath meningiomas in patients with neurofibromatosis type 2

    Arch Ophthalmol

    (2006)
  • I.A. Cunliffe et al.

    Bilateral optic nerve sheath meningiomas in a patient with neurofibromatosis type 2

    Br J Ophthalmol

    (1992)
  • H. Kiratli et al.

    Neurofibromatosis type 2: optic nerve sheath meningioma in one orbit, intramuscular schwannoma in the other

    Orbit

    (2008)
  • D.G. Evans et al.

    A clinical study of type 2 neurofibromatosis

    Q J Med

    (1992)
  • Cited by (5)

    • Extraocular Orbital and Peri-Orbital Masses

      2023, Neuroimaging Clinics of North America
    • Neurocutaneous disorders

      2020, Neurodevelopmental Disorders: Comprehensive Developmental Neuroscience
    • Primary and Secondary Optic Nerve Sheath Meningioma

      2021, Journal of Neurological Surgery, Part B: Skull Base

    Conflict of interest statement: This study was supported by the National Science Foundation of China (grant no. 81372715), the Natural Science Foundation of Beijing (grant no. 7162057), the High Level Developing Program of Health and Technical Personnel of the Beijing Health System (grant no. 2014-2-008), and the National Natural Science Funds for Distinguished Young Scholars (grant no. 81502390).

    View full text