Imaging Studies

See the list below:

Meningioma
- Computed tomography (CT) scanning findings
  - Hyperintense compared with the cerebellum on noncontrast images
  - May demonstrate calcifications within or at the periphery of the tumor
  - May be a broad attachment to the petrous ridge
  - Less likely to show enlargement of the internal auditory canal (IAC) than vestibular schwannomas
- MRI findings
  - Variable intensity on T2-weighted images and either isointense or slightly hypointense to brain on T1-weighted images
  - Can be heterogeneous as a result of calcifications and cystic foci within the tumor
  - Dural tail sign, characterized by enhancement of the dura adjacent to an enhanced primary lesion, possible on contrast-enhanced MRI
Epidermoid
- CT scanning findings
  - Hypointense to brain
  - Do not enhance (enhancement suggests an associated malignancy or infection)
  - Irregular margins with variable involvement of the IAC
- MRI findings
  - Heterogeneous and hypointense to brain on T1-weighted images
  - Homogeneous and isointense or hyperintense to brain on T2-weighted images
  - Nonenhancing (allows them to be differentiated from schwannomas, meningiomas, and chondromas, which have similar intensity characteristics)
Facial nerve schwannoma
- CT scanning findings
  - Identical to vestibular schwannoma within the IAC except for possible anterosuperior IAC erosion or erosion of facial nerve canal in labyrinthine segment
  - May have enlargement of geniculate ganglion and fallopian canal (more common)
- MRI findings
  - Isointense or mildly hypointense to brain on T1-weighted images
  - Mildly hyperintense to brain on T2-weighted images
  - Enhances with gadolinium contrast
Lower cranial nerve schwannoma
- Enlargement of jugular foramen with cranial nerve IX, X, and XI tumors
- Enlargement of hypoglossal canal with cranial nerve XII tumors
Arachnoid cyst^[5]
- CT scanning findings
  - Typically smooth surface lesion isointense with CSF
  - Nonenhancing
- MRI findings
  - Isointense or hypointense with brain on T1-weighted images
  - Hyperintense to brain on T2-weighted images
Cerebral angiography
- Cerebral angiography is used when involvement of a large vessel is suspected or preoperative embolization is required.
- It is used to assess patency in vessels encased by tumor.
- Balloon test occlusion can aid in determining likelihood of catastrophic stroke if internal carotid artery sacrifice is contemplated.
- Preoperative embolization can be performed in vascular tumors to effectively decrease amount of blood loss.

Treatment & Management

Farhoud A, Khedr W, Aboul-Enein H. Surgical Resection of Cerebellopontine Epidermoid Cysts: Limitations and Outcome. J Neurol Surg B Skull Base. 2018 Apr. 79 (2):167-72. [QxMD MEDLINE Link].
Berkowitz O, Iyer AK, Kano H, Talbott EO, Lunsford LD. Epidemiology and Environmental Risk Factors Associated with Vestibular Schwannoma. World Neurosurg. 2015 Dec. 84 (6):1674-80. [QxMD MEDLINE Link].
Eliezer M, Tran H, Inagaki A, et al. Clinical and Radiological Characteristics of Malignant Tumors Located to the Cerebellopontine Angle and/or Internal Acoustic Meatus. Otol Neurotol. 2019 Oct. 40 (9):1237-45. [QxMD MEDLINE Link].
Goebel S, Mehdorn HM. A missing piece? Neuropsychiatric functioning in untreated patients with tumors within the cerebellopontine angle. J Neurooncol. 2018 Jul 7. [QxMD MEDLINE Link].
Haberkamp TJ, Monsell EM, House WF, Levine SC, Piazza L. Diagnosis and treatment of arachnoid cysts of the posterior fossa. Otolaryngol Head Neck Surg. 1990 Oct. 103(4):610-4. [QxMD MEDLINE Link].
Tan NC, Macfarlane R, Donnelly N, et al. A 2 and 5-Year Longitudinal Analysis of 671 Consecutive Patients Diagnosed with Unilateral Vestibular Schwannoma. Otol Neurotol. 2022 Jul 1. 43 (6):702-8. [QxMD MEDLINE Link].
Baroncini M, Thines L, Reyns N, Schapira S, Vincent C, Lejeune JP. Retrosigmoid approach for meningiomas of the cerebellopontine angle: results of surgery and place of additional treatments. Acta Neurochir (Wien). 2011 Oct. 153(10):1931-40; discussion 1940. [QxMD MEDLINE Link].
Kunert P, Smolarek B, Marchel A. Facial nerve damage following surgery for cerebellopontine angle tumours. Prevention and comprehensive treatment. Neurol Neurochir Pol. 2011 Sep-Oct. 45(5):480-8. [QxMD MEDLINE Link].
Acioly MA, Liebsch M, de Aguiar PH, Tatagiba M. Facial Nerve Monitoring During Cerebellopontine Angle and Skull Base Tumor Surgery: A Systematic Review from Description to Current Success on Function Prediction. World Neurosurg. 2011 Nov 1. [QxMD MEDLINE Link].
Shew M, Muelleman T, Harris M, et al. Petrous Apex Pneumatization: Influence on Postoperative Cerebellopontine Angle Tumor Cerebrospinal Fluid Fistula. Ann Otol Rhinol Laryngol. 2018 Jun 1. 3489418781934. [QxMD MEDLINE Link].
Agarwal V, Babu R, Grier J, et al. Cerebellopontine angle meningiomas: postoperative outcomes in a modern cohort. Neurosurg Focus. 2013 Dec. 35(6):E10. [QxMD MEDLINE Link].

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Author

Jack A Shohet, MD President, Shohet Ear Associates Medical Group, Inc; Clinical Professor, Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine, School of Medicine

Jack A Shohet, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Neurotology Society, California Medical Association

Disclosure: Medical Advisory Board Member, consultant for: Envoy Medical.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Gerard J Gianoli, MD Clinical Associate Professor, Departments of Otolaryngology-Head and Neck Surgery and Pediatrics, Tulane University School of Medicine; President, The Ear and Balance Institute; Board of Directors, Ponchartrain Surgery Center

Gerard J Gianoli, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American College of Surgeons, American Neurotology Society, American Otological Society, Society of University Otolaryngologists-Head and Neck Surgeons, Triological Society

Disclosure: Nothing to disclose.

Chief Editor

Arlen D Meyers, MD, MBA Emeritus Professor of Otolaryngology, Dentistry, and Engineering, University of Colorado School of Medicine

Arlen D Meyers, MD, MBA is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, American Head and Neck Society

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Cerescan; Neosoma; MI10;<br/>Received income in an amount equal to or greater than $250 from: Neosoma; Cyberionix (CYBX)<br/>Received ownership interest from Cerescan for consulting for: Neosoma, MI10 advisor.

Acknowledgements

Douglas D Backous, MD Director of Listen for Life Center, Department of Otolaryngology-Head and Neck Surgery, Virginia Mason Medical Center

Douglas D Backous, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Auditory Society, American College of Surgeons, American Laryngological Rhinological and Otological Society, American Medical Association, Association for Research in Otolaryngology, North American Skull Base Society, Society for Neuroscience, and Washington State Medical Association

Disclosure: Nothing to disclose.

Sections Skull Base Tumor and Other CPA Tumors
Overview
Workup
Treatment
References

Skull Base Tumor and Other CPA Tumors Workup

Imaging Studies

References

Tables

Contributor Information and Disclosures

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