Vestibular schwannoma

Changed by Francis Deng, 18 Oct 2021

Updates to Article Attributes

Body was changed:

Show markup changes

Vestibular schwannomas, also known as acoustic neuromas, are relatively common tumours that arise from the vestibulocochlear nerve (CN VIII) and represent ~80% of cerebellopontine angle (CPA) masses. Bilateral vestibular schwannomas are strongly suggestive of neurofibromatosis type 2 (NF2).

On imaging, they classically present as a solid nodular mass with an intracanalicular component that often results in widening of the porus acusticus. They usually show intense contrast enhancement and, when larger, cystic degeneration can be present. Haemorrhagic areas may also be seen, but calcification is typically not present.

Terminology

Vestibular schwannomas are commonly known as acoustic neuromas, which is a misnomer. The term vestibular schwannoma is preferred as these tumours most frequently arise from the vestibular portion of the vestibulocochlear nerve and arise from Schwann cells ¹³. A mixture of the terms, acoustic schwannoma, may also be seen.

Epidemiology

Vestibular schwannomas account for ~8% ¹⁵ of all primary intracranial tumours ² and 75-90% of cerebellopontine angle masses ^1,2,8. The vast majority (95%) of solitary lesions are sporadic. Bilateral vestibular schwannomas are highly suggestive of neurofibromatosis type 2 (NF2), although bilateral tumours are encountered in the familial form of vestibular schwannomas in the absence of other stigmata of NF2 ⁵.

Although they usually occur between the fourth to sixth decades of life, with a median age of 50 years ¹¹, individuals with NF2 tend to be present them earlier, with a peak incidence around the third decade of life. Although rare, vestibular schwannomas may occur in children.

Clinical presentation

The typical presentation is with adult-onset sensorineural hearing loss or non-pulsatile tinnitus. In some patients, this goes unnoticed, and presentation is delayed until the lesion is much larger and presents with symptoms related to mass effect. Possibilities include cerebellar and brainstem symptoms (e.g. cranial nerve dysfunction, other than vestibulocochlear), or hydrocephalus due to effacement of the fourth ventricle.

Pathology

Vestibular schwannomas are benign tumours (WHO grade 1), which usually arise from the intracanalicular segment of the vestibular portion of the vestibulocochlear nerve (CN VIII) ^2,4. They were classically described as originating near the transition zone between glial and Schwann cells but contemporary data suggests they can originate at any point along the nerve ^8,16,17. In over 90% of cases, these tumours arise from the inferior division of the vestibular nerve ⁸. Less than 5% cases arise from the cochlear component of the vestibulocochlear nerve (CN VIII) ¹³.

They are well-circumscribed encapsulated masses which, unlike neuromas, arise from but are separate from nerve fibres ⁷, which they usually splay and displace rather than engulf.

They can display two types of growth pattern:

Antoni A
- elongated cells with cytoplasmic processes arranged in fascicles ⁷
- little stromal matrix
- Verocay bodies: nuclear-free zones of processes lying between regions of nuclear palisading
Antoni B
- loose meshwork of cells
- less densely cellular
- microcysts and myxoid change

Immunohistochemical staining is usually positive for S-100 protein ¹¹.

Radiographic features

Location

most have an intracanalicular component, often widening the porus acusticus (trumpeted IAM sign) (up to 90%) ⁵
- a small "CSF cap" typically remains, separating intracanalicular tumour from the cochlea; however, growth laterally through the cochlea (transmodiolar) or vestibule (transmacular) into the middle ear may occasionally occur
- involvement of the IAC fundus is associated with decreased rates of hearing preservation
- extracanalicular extension may result in an "ice cream cone" appearance, presumed to represent tumour growth inwards along a path of least resistance
a minority are purely extracanalicular, merely abutting the porus acusticus (~20%) ^1,5
rarely, small tumours may be confined to the labyrinth (see intralabyrinthine schwannoma) ⁴
the location and extension can be classified according to the Koos grading scale

Tumour consistency

small tumours tend to be solid, but larger tumours commonly demonstrate cystic degeneration ²
may have haemorrhagic areas
typically without calcification

CT

May show erosion and widening of the internal acoustic canal (IAC). The density of these tumours on non-contrast imaging is variable, and often they are hard to see, especially on account of beam hardening and streak artifact from the adjacent petrous temporal bone.

Contrast enhancement is present but can be underwhelming, especially in larger lesions with cystic components. Many cysts are loculations of CSF adjacent to a vestibular schwannoma, others represent cystic degeneration within schwannomas.

MRI

T1
- slightly hypointense to the adjacent brain (63%) or isointense to it (37%)^²
- may contain hypointense cystic areas
T2
- heterogeneously hyperintense to adjacent brain ⁵
- fluid intensity cystic areas
- may have associated peritumoural arachnoid cysts ³
T1 C+ (Gd)
- contrast enhancement is intense
- however, heterogeneous in larger tumours

Post-operational MRI

Linear enhancement may not indicate a tumour, but if there is nodular enhancement, suspect tumour recurrence (requires follow-up MRI).

Treatment and prognosis

There is variability in the rate of growth of vestibular schwannomas, and as such, the decision to treat requires consideration of the patient's age and co-morbidities. The options include ⁶:

observation and follow-up
stereotactic radiosurgery
microsurgery: number of approaches are possible, including ⁸:
- retrosigmoid (transmeatal) (suboccipital)
  - able to preserve hearing
  - can be used for large tumours
  - limited view of the internal auditory canal
  - has a greater chance of residual tumour (in the lateral aspect of internal auditory canal)
- middle cranial fossa
  - best for small intracanalicular tumours
  - able to preserve hearing
- translabyrinthine
  - careful skeletonisation of the facial nerve required (i.e. intraoperative facial nerve monitoring by needle electromyography with continuous stimulation)
  - loss of hearing guaranteed

Overall tumour recurrence is low, ranging between 1-9% ⁸.

History and etymology

The tumor was first described in 1777 by Dutch anatomist Eduard Sandifort (1742-1814) ^12,14.

Schwann cells, and hence schwannomas, are named after the German physician and physiologist Theodor Schwann (1810–1882) ¹³.

The first case in which a patient survived surgical resection of a vestibular schwannoma was in 1894. The procedure was performed by British surgeon Sir Charles Balance ¹².

Differential diagnosis

The most frequent ~~differentials to be considered~~differential considerations for a cerebellopontine angle mass are the following:

meningioma
- usually more homogeneous in appearance: significant signal heterogeneity with cystic or haemorrhagic areas is more typical of vestibular schwannomas than meningiomas (although cystic meningiomas do occur)
- meningiomas tend to have a broad dural base
- usually lack the trumpeted internal acoustic meatus sign
- large meningiomas often located asymmetrically relative to the IAC
- calcification more common
epidermoid
- no enhancing component
- very high signal on DWI
- does not widen the internal auditory canal
metastasis
- uncommon
- usually does not remodel the internal auditory canal, as metastases are usually present for only a short time
ependymoma
- centred on the fourth ventricle
- does not extend into the internal auditory canal
- usually younger patients

The differential for an intracanalicular vestibular schwannoma includes the following:

vascular enhancement at the fundus of the internal auditory canal (such as the venous plexus around the nerve sheath or capillaries in the meninges) ¹⁸
Scarpa (vestibular) ganglion¹⁹
low-flow vascular malformation (cavernous hemangioma) ²⁰

Practical points

What the surgeon wants to know

In addition to general remarks about the size and location of the tumour, significant findings that influence surgical management include ⁸:

how close to the fundus of the IAC the tumour reaches
anatomical variations
- high-riding jugular bulb
- dehiscent jugular bulb
- aberrant internal carotid artery
- aberrant course of the facial nerve
- pneumatisation of the petrous apex
- size and location of the sigmoid sinus

-<p><strong>Vestibular schwannomas</strong>, also known as <strong>acoustic neuromas</strong>, are relatively common tumours that arise from the <a href="/articles/vestibulocochlear-nerve">vestibulocochlear nerve (CN VIII)</a> and represent ~80% of <a href="/articles/cerebellopontine-angle-mass">cerebellopontine angle (CPA) masses</a>. Bilateral vestibular schwannomas are strongly suggestive of <a href="/articles/neurofibromatosis-type-2-3">neurofibromatosis type 2 (NF2)</a>.</p><p>On imaging, they classically present as a solid nodular mass with an intracanalicular component that often results in widening of the <a href="/articles/porus-acusticus-internus">porus acusticus</a>. They usually show intense contrast enhancement and, when larger, cystic degeneration can be present. Haemorrhagic areas may also be seen, but calcification is typically not present.</p><h4>Terminology</h4><p><strong>Vestibular schwannomas</strong> are commonly known as <strong>acoustic neuromas</strong>, which is a misnomer. The term vestibular schwannoma is preferred as these tumours most frequently arise from the vestibular portion of the vestibulocochlear nerve and arise from Schwann cells <sup>13</sup>. A mixture of the terms, <strong>acoustic schwannoma</strong>, may also be seen. </p><h4>Epidemiology</h4><p>Vestibular schwannomas account for ~8% <sup>15</sup> of all primary intracranial tumours <sup>2</sup> and 75-90% of cerebellopontine angle masses <sup>1,2,8</sup>. The vast majority (95%) of solitary lesions are sporadic. Bilateral vestibular schwannomas are highly suggestive of <a href="/articles/neurofibromatosis-type-2-3">neurofibromatosis type 2 (NF2)</a>, although bilateral tumours are encountered in the familial form of vestibular schwannomas in the absence of other stigmata of NF2 <sup>5</sup>.</p><p>Although they usually occur between the fourth to sixth decades of life, with a median age of 50 years <sup>11</sup>, individuals with NF2 tend to be present them earlier, with a peak incidence around the third decade of life. Although rare, vestibular schwannomas may occur in children.</p><h4>Clinical presentation</h4><p>The typical presentation is with adult-onset <a href="/articles/sensorineural-hearing-loss-snhl">sensorineural hearing loss</a> or non-pulsatile <a href="/articles/tinnitus">tinnitus</a>. In some patients, this goes unnoticed, and presentation is delayed until the lesion is much larger and presents with symptoms related to <a href="/articles/intracranial-mass-effect-summary">mass effect</a>. Possibilities include cerebellar and brainstem symptoms (e.g. cranial nerve dysfunction, other than vestibulocochlear), or <a href="/articles/hydrocephalus">hydrocephalus</a> due to effacement of the fourth ventricle. </p><h4>Pathology</h4><p>Vestibular schwannomas are benign tumours (WHO grade 1), which usually arise from the intracanalicular segment of the vestibular portion of the <a href="/articles/vestibulocochlear-nerve">vestibulocochlear nerve (CN VIII)</a> <sup>2,4</sup>. They were classically described as originating near the <a title="Transition zone (nerve)" href="/articles/transition-zone-nerve">transition zone</a> between glial and Schwann cells but contemporary data suggests they can originate at any point along the nerve <sup>8,16,17</sup>. In over 90% of cases, these tumours arise from the inferior division of the vestibular nerve <sup>8</sup>. Less than 5% cases arise from the cochlear component of the vestibulocochlear nerve (CN VIII) <sup>13</sup>.</p><p>They are well-circumscribed encapsulated masses which, unlike neuromas, arise from but are separate from nerve fibres <sup>7</sup>, which they usually splay and displace rather than engulf.</p><p>They can display two types of growth pattern:</p><ul>
+<p><strong>Vestibular schwannomas</strong>, also known as <strong>acoustic neuromas</strong>, are relatively common tumours that arise from the <a href="/articles/vestibulocochlear-nerve">vestibulocochlear nerve (CN VIII)</a> and represent ~80% of <a href="/articles/cerebellopontine-angle-mass">cerebellopontine angle (CPA) masses</a>. Bilateral vestibular schwannomas are strongly suggestive of <a href="/articles/neurofibromatosis-type-2-3">neurofibromatosis type 2 (NF2)</a>.</p><p>On imaging, they classically present as a solid nodular mass with an intracanalicular component that often results in widening of the <a href="/articles/porus-acusticus-internus">porus acusticus</a>. They usually show intense contrast enhancement and, when larger, cystic degeneration can be present. Haemorrhagic areas may also be seen, but calcification is typically not present.</p><h4>Terminology</h4><p><strong>Vestibular schwannomas</strong> are commonly known as <strong>acoustic neuromas</strong>, which is a misnomer. The term vestibular schwannoma is preferred as these tumours most frequently arise from the vestibular portion of the vestibulocochlear nerve and arise from Schwann cells <sup>13</sup>. A mixture of the terms, <strong>acoustic schwannoma</strong>, may also be seen. </p><h4>Epidemiology</h4><p>Vestibular schwannomas account for ~8% <sup>15</sup> of all primary intracranial tumours <sup>2</sup> and 75-90% of cerebellopontine angle masses <sup>1,2,8</sup>. The vast majority (95%) of solitary lesions are sporadic. Bilateral vestibular schwannomas are highly suggestive of <a href="/articles/neurofibromatosis-type-2-3">neurofibromatosis type 2 (NF2)</a>, although bilateral tumours are encountered in the familial form of vestibular schwannomas in the absence of other stigmata of NF2 <sup>5</sup>.</p><p>Although they usually occur between the fourth to sixth decades of life, with a median age of 50 years <sup>11</sup>, individuals with NF2 tend to be present them earlier, with a peak incidence around the third decade of life. Although rare, vestibular schwannomas may occur in children.</p><h4>Clinical presentation</h4><p>The typical presentation is with adult-onset <a href="/articles/sensorineural-hearing-loss-snhl">sensorineural hearing loss</a> or non-pulsatile <a href="/articles/tinnitus">tinnitus</a>. In some patients, this goes unnoticed, and presentation is delayed until the lesion is much larger and presents with symptoms related to <a href="/articles/intracranial-mass-effect-summary">mass effect</a>. Possibilities include cerebellar and brainstem symptoms (e.g. cranial nerve dysfunction, other than vestibulocochlear), or <a href="/articles/hydrocephalus">hydrocephalus</a> due to effacement of the fourth ventricle. </p><h4>Pathology</h4><p>Vestibular schwannomas are benign tumours (WHO grade 1), which usually arise from the intracanalicular segment of the vestibular portion of the <a href="/articles/vestibulocochlear-nerve">vestibulocochlear nerve (CN VIII)</a> <sup>2,4</sup>. They were classically described as originating near the <a href="/articles/transition-zone-nerve">transition zone</a> between glial and Schwann cells but contemporary data suggests they can originate at any point along the nerve <sup>8,16,17</sup>. In over 90% of cases, these tumours arise from the inferior division of the vestibular nerve <sup>8</sup>. Less than 5% cases arise from the cochlear component of the vestibulocochlear nerve (CN VIII) <sup>13</sup>.</p><p>They are well-circumscribed encapsulated masses which, unlike neuromas, arise from but are separate from nerve fibres <sup>7</sup>, which they usually splay and displace rather than engulf.</p><p>They can display two types of growth pattern:</p><ul>
-</ul><p>Overall tumour recurrence is low, ranging between 1-9% <sup>8</sup>.</p><h4>History and etymology</h4><p>The tumor was first described in 1777 by Dutch anatomist <strong>Eduard Sandifort</strong> (1742-1814) <sup>12,14</sup>.</p><p>Schwann cells, and hence schwannomas, are named after the German physician and physiologist <strong>Theodor Schwann</strong> (1810–1882) <sup>13</sup>.</p><p>The first case in which a patient survived surgical resection of a vestibular schwannoma was in 1894. The procedure was performed by British surgeon <strong>Sir Charles Balance</strong> <sup>12</sup>.</p><h4>Differential diagnosis</h4><p>The most frequent differentials to be considered are:</p><ul>
+</ul><p>Overall tumour recurrence is low, ranging between 1-9% <sup>8</sup>.</p><h4>History and etymology</h4><p>The tumor was first described in 1777 by Dutch anatomist <strong>Eduard Sandifort</strong> (1742-1814) <sup>12,14</sup>.</p><p>Schwann cells, and hence schwannomas, are named after the German physician and physiologist <strong>Theodor Schwann</strong> (1810–1882) <sup>13</sup>.</p><p>The first case in which a patient survived surgical resection of a vestibular schwannoma was in 1894. The procedure was performed by British surgeon <strong>Sir Charles Balance</strong> <sup>12</sup>.</p><h4>Differential diagnosis</h4><p>The most frequent differential considerations for a cerebellopontine angle mass are the following:</p><ul>
+</ul><p>The differential for an intracanalicular vestibular schwannoma includes the following:</p><ul>
+<li>vascular enhancement at the fundus of the internal auditory canal (such as the venous plexus around the nerve sheath or capillaries in the meninges) <sup>18</sup>
+</li>
+<li>
+<a href="/articles/vestibular-ganglion">Scarpa (vestibular) ganglion</a> <sup>19</sup>
+</li>
+<li>low-flow vascular malformation (cavernous hemangioma) <sup>20</sup>
+</li>

References changed:

1. Wolfgang Dähnert. Radiology Review Manual. (2003) ISBN: 9780781738958 - <a href="http://books.google.com/books?vid=ISBN9780781738958">Google Books</a>
2. Mulkens T, Parizel P, Martin J et al. Acoustic Schwannoma: MR Findings in 84 Tumors. AJR Am J Roentgenol. 1993;160(2):395-8. <a href="https://doi.org/10.2214/ajr.160.2.8424360">doi:10.2214/ajr.160.2.8424360</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/8424360">Pubmed</a>
3. Tali E, Yuh W, Nguyen H et al. Cystic Acoustic Schwannomas: MR Characteristics. AJNR Am J Neuroradiol. 1993;14(5):1241-7. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8332755">PMC8332755</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/8237710">Pubmed</a>
4. Mafee M, Lachenauer C, Kumar A, Arnold P, Buckingham R, Valvassori G. CT and MR Imaging of Intralabyrinthine Schwannoma: Report of Two Cases and Review of the Literature. Radiology. 1990;174(2):395-400. <a href="https://doi.org/10.1148/radiology.174.2.2404313">doi:10.1148/radiology.174.2.2404313</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/2404313">Pubmed</a>
5. Robert A. Morantz, J. W. Walsh. Brain Tumors. (1993) ISBN: 9780824788261 - <a href="http://books.google.com/books?vid=ISBN9780824788261">Google Books</a>
6. R. A. Jahrsdoerfer. Head and Neck Surgery: Ear. (1996) ISBN: 9780865776609 - <a href="http://books.google.com/books?vid=ISBN9780865776609">Google Books</a>
7. Vinay Kumar, Stanley Leonard Robbins, Abul K. Abbas et al. Robbins and Cotran Pathologic Basis of Disease. (2005) ISBN: 9780721601878 - <a href="http://books.google.com/books?vid=ISBN9780721601878">Google Books</a>
8. Silk P, Lane J, Driscoll C. Surgical Approaches to Vestibular Schwannomas: What the Radiologist Needs to Know. Radiographics. 2009;29(7):1955-70. <a href="https://doi.org/10.1148/rg.297095713">doi:10.1148/rg.297095713</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/19926756">Pubmed</a>
9. Wu E, Tang Y, Zhang Y, Bai R. CT in Diagnosis of Acoustic Neuromas. AJNR Am J Neuroradiol. 1986;7(4):645-50. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8334647">PMC8334647</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/3088942">Pubmed</a>
10. Fortnum H, O'Neill C, Taylor R et al. The Role of Magnetic Resonance Imaging in the Identification of Suspected Acoustic Neuroma: A Systematic Review of Clinical and Cost Effectiveness and Natural History. Health Technol Assess. 2009;13(18):iii-iv, ix. <a href="https://doi.org/10.3310/hta13180">doi:10.3310/hta13180</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/19358774">Pubmed</a>
11. Lin E & Crane B. The Management and Imaging of Vestibular Schwannomas. AJNR Am J Neuroradiol. 2017;38(11):2034-43. <a href="https://doi.org/10.3174/ajnr.A5213">doi:10.3174/ajnr.A5213</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/28546250">Pubmed</a>
12. Silk P, Lane J, Driscoll C. Surgical Approaches to Vestibular Schwannomas: What the Radiologist Needs to Know. Radiographics. 2009;29(7):1955-70. <a href="https://doi.org/10.1148/rg.297095713">doi:10.1148/rg.297095713</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/19926756">Pubmed</a>
13. Dublin A. Acoustic Neuroma or Vestibular Schwannoma? Skull Base. 2009;19(5):375. <a href="https://doi.org/10.1055/s-0029-1220205">doi:10.1055/s-0029-1220205</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/20190950">Pubmed</a>
14. Luyendijk-Elshout A. The Elegant Anatomist. The Italian Medical Connections of Eduard Sandifort (1742-1814). Nieuwe Ned Bijdr Geschied Geneeskd Natuurwet. 1989;(34):305-20. - <a href="https://www.ncbi.nlm.nih.gov/pubmed/11612801">Pubmed</a>
18. Hakim A & Wagner F. An Important Pitfall in Diagnosing Intracanalicular Vestibular Schwannoma. AJNR Am J Neuroradiol. 2019;40(10):E58-9. <a href="https://doi.org/10.3174/ajnr.a6192">doi:10.3174/ajnr.a6192</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/31439629">Pubmed</a>
19. Wu Y, Karandikar A, Goh J, Tan T. Imaging Features Differentiating Vestibular Ganglion from Intracanalicular Schwannoma on Single-Sequence Non-Contrast Magnetic Resonance Imaging Study. Ann Acad Med Singap. 2020;49(2):65-71. - <a href="https://www.ncbi.nlm.nih.gov/pubmed/32246707">Pubmed</a>
20. Bonfort G, Veillon F, Debry C, Kehrli P, Chibbaro S. VIIIth Nerve Cavernous Hemangioma Mimicking a Stage 1 Acoustic Schwannoma. Neurochirurgie. 2015;61(5):352-5. <a href="https://doi.org/10.1016/j.neuchi.2015.07.003">doi:10.1016/j.neuchi.2015.07.003</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/26428864">Pubmed</a>
1. Dähnert W. Radiology review manual. Lippincott Williams & Wilkins. (2003) ISBN:0781738954. <a href="http://books.google.com/books?vid=ISBN0781738954">Read it at Google Books</a> - <a href="http://www.amazon.com/gp/product/0781738954?ie=UTF8&tag=radiopaediaor-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=0781738954">Find it at Amazon</a><div class="ref_v2"></div>
2. Mulkens TH, Parizel PM, Martin JJ et-al. Acoustic schwannoma: MR findings in 84 tumors. AJR Am J Roentgenol. 1993;160 (2): 395-8. <a href="http://www.ajronline.org/cgi/content/abstract/160/2/395">AJR Am J Roentgenol (abstract)</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/8424360">Pubmed citation</a><div class="ref_v2"></div>
3. Tali ET, Yuh WT, Nguyen HD et-al. Cystic acoustic schwannomas: MR characteristics. AJNR Am J Neuroradiol. 14 (5): 1241-7. <a href="http://www.ajnr.org/cgi/content/abstract/14/5/1241">AJNR Am J Neuroradiol (abstract)</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/8237710">Pubmed citation</a><div class="ref_v2"></div>
4. Mafee MF, Lachenauer CS, Kumar A et-al. CT and MR imaging of intralabyrinthine schwannoma: report of two cases and review of the literature. Radiology. 1990;174 (2): 395-400. <a href="http://radiology.rsna.org/content/174/2/395.abstract">Radiology (abstract)</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/2404313">Pubmed citation</a><div class="ref_v2"></div>
5. Morantz RA, Walsh JW. Brain tumors, a comprehensive text. Informa HealthCare. (1994) ISBN:0824788265. <a href="http://books.google.com/books?vid=ISBN0824788265">Read it at Google Books</a> - <a href="http://www.amazon.com/gp/product/0824788265?ie=UTF8&tag=radiopaediaor-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=0824788265">Find it at Amazon</a><div class="ref_v2"></div>
6. Naumann HH, Jahrsdoerfer R, Helms J. Head and neck surgery. George Thieme Verlag. (1996) ISBN:0865776601. <a href="http://books.google.com/books?vid=ISBN0865776601">Read it at Google Books</a> - <a href="http://www.amazon.com/gp/product/0865776601?ie=UTF8&tag=radiopaediaor-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=0865776601">Find it at Amazon</a><div class="ref_v2"></div>
7. Kumar V, Abbas AK, Fausto N et-al. Robbins and Cotran pathologic basis of disease. W B Saunders Co. (2005) ISBN:0721601871. <a href="http://books.google.com/books?vid=ISBN0721601871">Read it at Google Books</a> - <a href="http://www.amazon.com/gp/product/0721601871?ie=UTF8&tag=radiopaediaor-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=0721601871">Find it at Amazon</a><div class="ref_v2"></div>
8. Silk PS, Lane JI, Driscoll CL. Surgical approaches to vestibular schwannomas: what the radiologist needs to know. Radiographics. 2009;29 (7): 1955-70. <a href="http://dx.doi.org/10.1148/rg.297095713">doi:10.1148/rg.297095713</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/19926756">Pubmed citation</a><div class="ref_v2"></div>
9. Wu EH, Tang YS, Zhang YT et-al. CT in diagnosis of acoustic neuromas. AJNR Am J Neuroradiol. 7 (4): 645-50. <a href="http://www.ajnr.org/cgi/content/abstract/7/4/645">AJNR Am J Neuroradiol (abstract)</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/3088942">Pubmed citation</a><div class="ref_v2"></div>
10. Fortnum H, O'Neill C, Taylor R et-al. The role of magnetic resonance imaging in the identification of suspected acoustic neuroma: a systematic review of clinical and cost effectiveness and natural history. Health Technol Assess. 2009;13 (18): iii-iv, ix-xi, 1-154. <a href="http://dx.doi.org/10.3310/hta13180">doi:10.3310/hta13180</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/19358774">Pubmed citation</a><span class="auto"></span>
11. Lin E & Crane B. The Management and Imaging of Vestibular Schwannomas. AJNR Am J Neuroradiol. 2017;38(11):2034-43. <a href="https://doi.org/10.3174/ajnr.a5213">doi:10.3174/ajnr.a5213</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/28546250">Pubmed</a>
12. Portia S. Silk, John I. Lane, Colin L. Driscoll. Surgical Approaches to Vestibular Schwannomas: What the Radiologist Needs to Know1. (2009) RadioGraphics. 29 (7): 1955-70. <a href="https://doi.org/10.1148/rg.297095713">doi:10.1148/rg.297095713</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/19926756">Pubmed</a> <span class="ref_v4"></span>
13. Dublin A. Acoustic neuroma or vestibular schwannoma?. (2009) Skull base : official journal of North American Skull Base Society ... [et al.]. 19 (5): 375. <a href="https://doi.org/10.1055/s-0029-1220205">doi:10.1055/s-0029-1220205</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/20190950">Pubmed</a> <span class="ref_v4"></span>
14. Luyendijk-Elshout AM. The elegant anatomist. The Italian medical connections of Eduard Sandifort (1742-1814). (1989) Nieuwe Nederlandse bijdragen tot de geschiedenis der geneeskunde en der natuurwetenschappen. <a href="https://www.ncbi.nlm.nih.gov/pubmed/11612801">Pubmed</a> <span class="ref_v4"></span>

ADVERTISEMENT: Supporters see fewer/no ads

{"current_user":null,"inclusions":[{"imageId":608,"studyId":6269,"caseSlug":"acoustic-schwannoma-2","caption":"Case 1","thumbnail":"https://prod-images-static.radiopaedia.org/images/608/2d7d56b5f4a9514fad1a6592589509_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":25854460,"studyId":53890,"caseSlug":"acoustic-schwannoma-intracanalicular-2","caption":"Case 2: intracanalicular schwannoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/25854460/d5062bf8ea01f356463b88cb48b569_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":394,"studyId":6270,"caseSlug":"acoustic-schwannoma-recurrent","caption":"Case 3","thumbnail":"https://prod-images-static.radiopaedia.org/images/394/29df28f3ebb7ca96e8e085d24860c5_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":779,"studyId":6328,"caseSlug":"acoustic-schwannoma-intracanalicular-4","caption":"Case 4","thumbnail":"https://prod-images-static.radiopaedia.org/images/779/eae0b2928dae7020f0bdab2175d99d_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"probable"},{"imageId":2843,"studyId":6388,"caseSlug":"acoustic-schwannoma-intracanalicular-7","caption":"Case 6","thumbnail":"https://prod-images-static.radiopaedia.org/images/2843/9ae180e2e9abfd8537090399157a74_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":20862,"studyId":7130,"caseSlug":"acoustic-schwannoma-large-with-cystic-change-1","caption":"Case 7","thumbnail":"https://prod-images-static.radiopaedia.org/images/20862/c12bd62d45ee743445f65e9820ab2a_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":482138,"studyId":10504,"caseSlug":"acoustic-schwannoma-intracanalicular-3","caption":"Case 8","thumbnail":"https://prod-images-static.radiopaedia.org/images/482138/7da725790720899f1044987e75adad_big_gallery.jpg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":15034,"studyId":6796,"caseSlug":"acoustic-neuroma-1","caption":"Case 10","thumbnail":"https://prod-images-static.radiopaedia.org/images/15034/fc5fabadfca0aad356c456186d0db5_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":1192021,"studyId":14122,"caseSlug":"acoustic-neuroma-6","caption":"Case 12","thumbnail":"https://prod-images-static.radiopaedia.org/images/1192021/735b84173576783364c5e367ce4e86_big_gallery.jpg","isStack":false,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":1337227,"studyId":14724,"caseSlug":"vestibular-schwannoma-33","caption":"Case 13","thumbnail":"https://prod-images-static.radiopaedia.org/images/1337227/855c60c9649aab0b2318c4089d2b053e18d9e04eee1e28e6f6539c501118bc22_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":1395220,"studyId":14992,"caseSlug":"acoustic-schwannoma-4","caption":"Case 14 ","thumbnail":"https://prod-images-static.radiopaedia.org/images/1395220/eb80f519824b0a8cdf96608d31df88_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":1429565,"studyId":15187,"caseSlug":"acoustic-neuroma-7","caption":"Case 15","thumbnail":"https://prod-images-static.radiopaedia.org/images/1429565/04baf5b5b624165ca16320c669f3a0_big_gallery.jpg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":1813067,"studyId":16893,"caseSlug":"vestibular-schwannoma-intrameatal","caption":"Case 16: very small lesion on right","thumbnail":"https://prod-images-static.radiopaedia.org/images/1813067/53704cf488a848544c186cae250f65_big_gallery.jpg","isStack":true,"diagnosticCertainty":"probable"},{"imageId":2452440,"studyId":19878,"caseSlug":"acoustic-schwannoma-5","caption":"Case 17","thumbnail":"https://prod-images-static.radiopaedia.org/images/2452440/ca6e70ea5219f2bd8383ebb66841f0539de784898ba595661aa6451b772a4166_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"probable"},{"imageId":2666634,"studyId":20649,"caseSlug":"vestibular-schwannoma-2","caption":"Case 18","thumbnail":"https://prod-images-static.radiopaedia.org/images/2666634/89c1f01b2dc088433c37d0dcc759c7_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":3281673,"studyId":22824,"caseSlug":"acoustic-neuroma-9","caption":"Case 19: huge","thumbnail":"https://prod-images-static.radiopaedia.org/images/3281673/92e9e96b1fbc6ab51ff799664e79ba_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":3332133,"studyId":22911,"caseSlug":"vestibular-schwannoma-3","caption":"Case 20","thumbnail":"https://prod-images-static.radiopaedia.org/images/3332133/3ff929a79cd6da31d65c16ca3700dc_big_gallery.jpg","isStack":true,"diagnosticCertainty":"probable"},{"imageId":4895064,"studyId":25637,"caseSlug":"neurofibromatosis-type-2-16","caption":"Case 21: bilateral with NF2","thumbnail":"https://prod-images-static.radiopaedia.org/images/4895064/46ddf677f0afd24f10e0edfe610be6b47bf684c83b94f64a797168639051d60e_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":5141528,"studyId":26092,"caseSlug":"acoustic-schwannoma-20","caption":"Case 22","thumbnail":"https://prod-images-static.radiopaedia.org/images/5141528/00d449fd183b4910a17a190afa7339_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":5314234,"studyId":26489,"caseSlug":"acoustic-schwannoma-11","caption":"Case 23","thumbnail":"https://prod-images-static.radiopaedia.org/images/5314234/7d1ac25cd766c934caae315112bec9_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":5793201,"studyId":27607,"caseSlug":"cystic-acoustic-schwannoma","caption":"Case 24","thumbnail":"https://prod-images-static.radiopaedia.org/images/5793201/9790e3f68a6e87d071a2c9abde0c22_big_gallery.jpg","isStack":true,"diagnosticCertainty":"probable"},{"imageId":7200153,"studyId":29911,"caseSlug":"acoustic-schwannoma-16","caption":"Case 25","thumbnail":"https://prod-images-static.radiopaedia.org/images/7200153/487323f9381b011abf781fb1523d4a_big_gallery.jpg","isStack":true,"diagnosticCertainty":"probable"},{"imageId":7238821,"studyId":29979,"caseSlug":"acoustic-schwannoma-cystic","caption":"Case 26","thumbnail":"https://prod-images-static.radiopaedia.org/images/7238821/3907e3a1127c911308eb94df45c7c9_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":7242145,"studyId":29981,"caseSlug":"acoustic-schwannoma-17","caption":"Case 27","thumbnail":"https://prod-images-static.radiopaedia.org/images/7242145/59fe04eef3832521e3dfb3754a9072_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":8007527,"studyId":31220,"caseSlug":"vestibular-schwannoma-4","caption":"Case 28","thumbnail":"https://prod-images-static.radiopaedia.org/images/8007527/c7ca4cbd6a58c5e7cdefd1a9293e93_big_gallery.jpg","isStack":true,"diagnosticCertainty":null},{"imageId":8100119,"studyId":31469,"caseSlug":"acoustic-neuroma-8","caption":"Case 29","thumbnail":"https://prod-images-static.radiopaedia.org/images/8100119/e3ac09ea5781da477d26516d5d2142_big_gallery.jpg","isStack":false,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":9319982,"studyId":33544,"caseSlug":"cystic-acoustic-schwannoma-1","caption":"Case 30: cystic","thumbnail":"https://prod-images-static.radiopaedia.org/images/9319982/4032d8d508d4c694a51aad15421af6_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":13223378,"studyId":39024,"caseSlug":"acoustic-schwannoma-intracanalicular-5","caption":"Case 31: intracanalicular schwannoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/13223378/7319f4953df173247b89b91f78be52_big_gallery.jpg","isStack":true,"diagnosticCertainty":"probable"},{"imageId":16388596,"studyId":42566,"caseSlug":"neurofibromatosis-type-2-bilateral-acoustic-neuromata-1","caption":"Case 32: bilateral","thumbnail":"https://prod-images-static.radiopaedia.org/images/16388596/17ea82895deebea903d0f78c754e16_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":42653218,"studyId":71843,"caseSlug":"acoustic-schwannoma-trumpeted-internal-acoustic-meatus-sign","caption":"Case 33: with trumpeted IAM sign","thumbnail":"https://prod-images-static.radiopaedia.org/images/42653218/17353b3ceb66cd7bdaa65ee6b045ff_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"probable"},{"imageId":50410466,"studyId":79626,"caseSlug":"vestibular-schwannoma-12","caption":"Case 34","thumbnail":"https://prod-images-static.radiopaedia.org/images/50410466/748e082528f1ed0e55c69d47cac528_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":52954666,"studyId":92049,"caseSlug":"neurofibromatosis-type-2-23","caption":"Case 35: bilateral - likley NF2","thumbnail":"https://prod-images-static.radiopaedia.org/images/52954666/2a136c181ffc7a9cd487e9d9400c36_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":54014495,"studyId":100291,"caseSlug":"intracanalicular-acoustic-schwannoma-2","caption":"Case 36: intracanalicular","thumbnail":"https://prod-images-static.radiopaedia.org/images/54014495/990011_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":54508872,"studyId":103660,"caseSlug":"acoustic-schwannoma-36","caption":"Case 37","thumbnail":"https://prod-images-static.radiopaedia.org/images/54508872/005_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":58446367,"studyId":120636,"caseSlug":"vestibular-schwannoma-30","caption":"Case 38","thumbnail":"https://prod-images-static.radiopaedia.org/images/58446367/4._big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":61463883,"studyId":133366,"caseSlug":"vestibular-schwannoma-37","caption":"Case 39","thumbnail":"https://prod-images-static.radiopaedia.org/images/61463883/3b86aa88ec20fc69a3811c3bfb3ba313a246178ba572df8c7e7d15de3812408e_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":53332820,"studyId":94901,"caseSlug":"acoustic-neuroma-28","caption":"Case 40","thumbnail":"https://prod-images-static.radiopaedia.org/images/53332820/8402a5d46edfeb13c43b525a18aa92_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":63533657,"studyId":141674,"caseSlug":"vestibular-schwannoma-47","caption":"Case 41","thumbnail":"https://prod-images-static.radiopaedia.org/images/63533657/e5c657d3fd94e430516233e9cc237167c1e5d858c204f2f318eaeda767967ff9_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":64786166,"studyId":146488,"caseSlug":"vestibular-schwannoma-46","caption":"Case 42","thumbnail":"https://prod-images-static.radiopaedia.org/images/64786166/1dcec0e5e97edf156173d1acb009bdf7767f5e7a05c24c8c4edbe62b429ba6d7_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"}],"ddx_inclusions":[{"imageId":24033,"studyId":7525,"caseSlug":"meningioma-extending-into-internal-acoustic-canal","caption":"Cerebellopontine angle meningioma","thumbnail":"https://prod-images-static.radiopaedia.org/images/24033/a50b773aa6807be27bd6092e285291_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":63685949,"studyId":142395,"caseSlug":"internal-auditory-canal-meningioma","caption":"Internal auditory canal meningioma","thumbnail":"https://prod-images-static.radiopaedia.org/images/63685949/6df266ec1a4edb406a6318422a06fa8e98a53a26e319607b03c1a1702b893885_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":7516689,"studyId":30516,"caseSlug":"glossopharyngeal-nerve-schwannoma","caption":"Glossopharyngeal nerve schwannoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/7516689/6045b2dd635efd967a05a65dc3d8f8_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":23532760,"studyId":50369,"caseSlug":"jugular-foramen-schwannoma-6","caption":"Jugular foramen schwannoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/23532760/dcefaff5f96a5c46c507bb2a54b441_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":246,"studyId":6310,"caseSlug":"epidermoid-cyst-cerebellopontine-angle-1","caption":"Epidermoid","thumbnail":"https://prod-images-static.radiopaedia.org/images/246/22db6c20b1661329de68851932ab54_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"}],"lang":"us"}