Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Skull Base Tumor and Other CPA Tumors Treatment & Management

  • Author: Jack A Shohet, MD; Chief Editor: Arlen D Meyers, MD, MBA  more...
 
Updated: Feb 24, 2016
 

Medical Therapy

Diuretic therapy may provide symptomatic relief in a minority of patients with arachnoid cysts. Otherwise, options for management of lesions in the cerebellopontine angle (CPA) include observation with serial imaging, radiation therapy, or surgery. Chemotherapy is an option only for occasional malignant lesions. Therapeutic embolization for vascular tumors has had limited success.

Next

Surgical Therapy

Surgical approaches vary depending on the pathologic entity as well as the size and involvement of adjacent structures. Although complete excision is planned for most cases, the intimate involvement of surrounding structures may impose unwarranted morbidity if complete excision is attempted. Meningiomas are excised completely more readily than epidermoids, whereas adequate therapy for arachnoid cysts is drainage.

Standard approaches to the CPA include the translabyrinthine, suboccipital (retrosigmoid), or middle fossa craniotomies (see Skull Base, Acoustic Neuroma (Vestibular Schwannoma)). The choice of approach is based on specific location and hearing status. Occasionally, these craniotomies can be combined or performed in addition to an infratemporal fossa dissection for larger tumors.[3]

Previous
Next

Preoperative Details

See the list below:

  • Neurotologic evaluation
    • Obtain a patient history as it relates to presenting symptoms.
    • Perform a complete physical examination including cranial nerve and cerebellar testing.
  • Audiologic testing
    • Testing most commonly reveals high-frequency sensorineural loss.
    • Flat mid- and low-frequency sensorineural losses have been described.
    • Speech discrimination is usually diminished out of proportion to degree of loss on affected side.
    • Little relationship exists between severity of hearing loss and size of lesion.
    • Conductive loss occurs with middle ear involvement of facial nerve schwannomas or paragangliomas.
  • Auditory-evoked brainstem response (eg, ABR, BAER)
    • Abnormal I-V interpeak latencies, a significant interaural latency difference for wave V, and poor waveform morphologic characteristics are suggestive of retrocochlear pathology on ABR.
    • Preoperative assessment is required when hearing preservation surgery is to be attempted.
  • Vestibular testing
    • Testing may be helpful in patients presenting with vestibular symptoms.
    • Abnormal electronystagmography (ENG) findings may result from direct compression of the vestibular nerve, brain stem, or cerebellum.
    • Localizing specific vestibular nerve involvement based on laboratory vestibular testing alone is unlikely.
  • Radiographic imaging: Plain radiography has virtually no role in the diagnosis of these lesions.
  • CT scanning: Bone algorithms can help delineate bony involvement and destruction. CT scanning helps determine the location of jugular bulb.
  • Contrast MRI of the head and internal auditory canals
    • This is the criterion standard for diagnosis.
    • Perform magnetic resonance angiography (MRA) or magnetic resonance venography (MRV) on patients with suspected vascular lesions as a screening technique.
    • Angiography prior to embolization is the criterion standard in assessing the vascular tributaries to various tumor types.
  • Ventricular shunting or drainage: This is considered for large tumors.
Previous
Next

Intraoperative Details

See the list below:

  • Use neuroanesthetic techniques with continuous blood pressure monitoring.
  • Positioning of patient is based on approach to be used.
  • Administer perioperative prophylactic antibiotics for 24 hours.
  • Use applicable cranial nerve monitoring techniques (eg, intraoperative ABR, facial and lower cranial nerve monitoring).
  • Obtain proximal control of the internal carotid artery and internal jugular vein in the neck in patients with lesions with involvement of these vessels.
  • Consider the administration of mannitol and/or diuretics before craniotomy.
  • Stereotactic operative techniques can be used for selected lesions.
  • Meticulously wax temporal bone air cells.
  • Seal off the eustachian tube if the middle ear is opened.
  • Attempt watertight closure of the dura and/or skin.
Previous
Next

Postoperative Details

See the list below:

  • Continuous intensive care unit monitoring with frequent neurologic checks is imperative in the immediate postoperative period.
  • Maintain meticulous eye care when facial nerve function is compromised.
  • Appropriately manage comorbid medical conditions.
  • Institute speech and physical therapy as soon as possible.
Previous
Next

Follow-up

See the list below:

  • Guidelines for follow-up care depend on the type of lesion and morbidity.
  • Typically, an enhanced MRI is obtained 6 months to 1 year after surgery and at variable periods thereafter.
  • Malignant lesions require more frequent follow-up care.
Previous
Next

Complications

Contemporary surgical and anesthetic techniques have minimized morbidity for these lesions. Careful preoperative assessment and control of comorbid conditions can further diminish the risks of complication. Complications from these procedures can include the following:

  • Permanent hearing impairment or complete hearing loss on the operative side
  • Temporary or permanent facial paralysis[4, 5]
  • Exposure keratitis or corneal ulcer
  • Ipsilateral facial hypesthesia
  • Lower cranial nerve deficits (eg, dysphagia, hoarseness, aspiration)
  • Cerebrospinal fluid leak (eg, otorrhea, rhinorrhea)
  • Infection (eg, wound, meningitis, intracranial abscess
  • Intraoperative hemorrhage
  • Hematoma
  • Seizures
  • Stroke
Previous
Next

Outcome and Prognosis

The outcome and prognosis for cure from surgical resection depends on the histology, size, and location of the tumor and the approach chosen. Cessation of tumor growth from primary radiation also depends on the specific factors listed above. Expected facial palsy rates are high for primary facial schwannomas. The effect on quality of life from facial nerve palsy is quite significant. Results also depend on the experience and skills of the surgeon.

In a study of 34 patients who underwent surgery for CPA meningiomas, Agarwal et al found that the rate of permanent cranial nerve deficits was significantly greater in patients with tumors of more than 3 cm in size than in those with smaller meningiomas (45.5% vs 5.9%, respectively). It was also found that deficits of the lower cranial nerves occurred only in patients whose tumors extended into the jugular foramen. No association was found between tumor extension into the internal acoustic canal and either postoperative complications or cranial nerve deficits. Among all patients, 5.9% suffered postoperative facial nerve palsy.[6]

Previous
Next

Future and Controversies

Further advances in surgical techniques and radiotherapy are being made. Endoscopic surgical techniques in the cerebellopontine angle (CPA) have improved visualization of the tumor and adjacent structures. Stereotactic methods have improved accuracy of the delivery of microsurgical dissection and radiation therapy, thus minimizing damage to adjacent tissue. New radiation delivery protocols, although incompletely followed up, show some promise as primary or adjuvant therapy of some of these lesions.

Previous
 
Contributor Information and Disclosures
Author

Jack A Shohet, MD President, Shohet Ear Associates Medical Group, Inc; Associate 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, American Medical Association, California Medical Association

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Envoy Medical <br/>Received consulting fee from Envoy Medical for medical advisory board member. 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 Otological Society, Society of University Otolaryngologists-Head and Neck Surgeons, Triological Society, American Neurotology Society, American Academy of Otolaryngology-Head and Neck Surgery, American College of Surgeons

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Vesticon<br/>Received none from Vesticon, Inc. for board membership.

Chief Editor

Arlen D Meyers, MD, MBA 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;RxRevu;SymbiaAllergySolutions<br/>Received income in an amount equal to or greater than $250 from: Symbia<br/>Received from Allergy Solutions, Inc for board membership; Received honoraria from RxRevu for chief medical editor; Received salary from Medvoy for founder and president; Received consulting fee from Corvectra for senior medical advisor; Received ownership interest from Cerescan for consulting; Received consulting fee from Essiahealth for advisor; Received consulting fee from Carespan for advisor; Received consulting fee from Covidien for consulting.

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.

References
  1. 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. [Medline].

  2. 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. [Medline].

  3. 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. [Medline].

  4. 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. [Medline].

  5. 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. [Medline].

  6. Agarwal V, Babu R, Grier J, et al. Cerebellopontine angle meningiomas: postoperative outcomes in a modern cohort. Neurosurg Focus. 2013 Dec. 35(6):E10. [Medline].

Previous
Next
 
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.