eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > Skull Base

Skull Base, Tumors, Other CPA Tumors: Workup

Author: Jack A Shohet, MD, Associate Clinical Professor, Department of Otolaryngology-Head and Neck Surgery, University of California Irvine; Otolaryngologist, Shohet Ear Associates Medical Group, Inc
Contributor Information and Disclosures

Updated: Feb 12, 2009

Workup

Imaging Studies

  • 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 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 cyst1
    • 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.

More on Skull Base, Tumors, Other CPA Tumors

Overview: Skull Base, Tumors, Other CPA Tumors
Workup: Skull Base, Tumors, Other CPA Tumors
Treatment: Skull Base, Tumors, Other CPA Tumors
Follow-up: Skull Base, Tumors, Other CPA Tumors
References
[ CLOSE WINDOW ]

References

  1. Haberkamp TJ, Monsell EM, House WF, Levine SC, Piazza L. Diagnosis and treatment of arachnoid cysts of the posterior fossa. Otolaryngol Head Neck Surg. Oct 1990;103(4):610-4. [Medline].

  2. Langman AW, Jackler RK, Althaus SR. Meningioma of the internal auditory canal. Am J Otol. May 1990;11(3):201-4. [Medline].

  3. Lo WM. Tumors of the temporal bone and cerebellopontine angle. In: Som PM, Bergeron RT, eds. Head and Neck Imaging. St. Louis, Mo: Mosby; 1991.

  4. McElveen JT, Saunders JE. Tumors of the cerebellopontine angle: neuro-otologic aspects of diagnosis. In: Wilkins RH, Rengachary SS, eds. Neurosurgery. New York, NY: McGraw-Hill; 1996:1038-1048.

  5. Nadol JB. Cerebellopontine angle tumors. In: Nadol JB, Schuknecht, HF, eds. Surgery of the Ear and Temporal Bone. New York, NY: Raven Press; 1993:391-413.

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

skull base tumors, skull tumors, CPA tumors, cerebellopontine angle tumors, intracranial tumors, posterior fossa neoplasms, lateral skull base neoplasms, nonacoustic cerebellopontine angle tumors, non-acoustic CPA tumors, vestibular schwannomas, acoustic neuromas, lipomas, vascular malformations, hemangiomas, meningiomas, epidermoids, cholesteatomas, facial schwannomas, lower cranial nerve schwannomas

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Jack A Shohet, MD, Associate Clinical Professor, Department of Otolaryngology-Head and Neck Surgery, University of California Irvine; Otolaryngologist, Shohet Ear Associates Medical Group, Inc
Jack A Shohet, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Medical Association, American Neurotology Society, American Tinnitus Association, and California Medical Association
Disclosure: Envoy Medical Consulting fee Consulting

Medical Editor

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.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Gerard J Gianoli, MD, Clinical Associate Professor, Department of Otolaryngology-Head and Neck Surgery, Tulane University School of Medicine; Vice President, The Ear and Balance Institute; Chief Executive Officer, 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, and Triological Society
Disclosure: Nothing to disclose.

CME Editor

Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders
Christopher L Slack, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, and American Medical Association
Disclosure: Nothing to disclose.

Chief Editor

Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, 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, and American Head and Neck Society
Disclosure: Covidien Corp Consulting fee Consulting; US Tobacco Corporation unstricted gift unknown

 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.