Acoustic Neuroma
Basics
Description
Acoustic neuromas (vestibular schwannomas) are slow-growing, benign, intracranial, extra-axial tumors originating from the vestibulocochlear nerve.
- Originated from Schwann cells of the nerve sheath
- Usually arise in the internal auditory canal near the cerebellopontine angle
- Most are unilateral; bilaterally seen in neurofibromatosis type 2 (NF2)
Epidemiology
- 6–10% of all intracranial tumors
- 80–90% of cerebellopontine angle tumors
- 95% of cases are unilateral.
- Present most commonly in the 5th to 6th decades, although signs and symptoms can occur earlier
- Female predominance
- 5% of acoustic neuromas are a result of NF2.
- Bilateral acoustic neuroma occurring in NF2 present before age 30 years
Incidence
- 1/100,000 per year
- Asymptomatic lesions may be more common.
Prevalence
3,000 diagnosed annually in the United States
Etiology and Pathophysiology
- Compression of acoustic and facial nerve when located within internal acoustic canal
- Compression of brainstem, 4th ventricle, and trigeminal nerve when tumor is at the cerebellopontine angle
- Vestibular schwannomas are related to the NF2 gene and its product merlin. Merlin acts as a tumor suppressor and as a mediator of contact inhibition. Thus, deficiencies in both NF2 genes lead to vestibular schwannoma development.
Genetics
- Unknown for unilateral acoustic neuroma
- NF2: bilateral acoustic neuromas
- Autosomal dominant
- Gene located on chromosome 22q11
Risk Factors
- High-dose ionizing radiation
- Pregnancy and epilepsy may increase risk.
- There is some literature suggesting that smoking cigarettes may be protective. However, further research must be conducted to support these claims.
- No proven increase in risk of acoustic neuroma with regular use of a mobile phone
Commonly Associated Conditions
- NF2
- Pregnancy may accelerate the growth of the tumor.
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Citation
Domino, Frank J., et al., editors. "Acoustic Neuroma." 5-Minute Clinical Consult, 34th ed., Wolters Kluwer, 2026. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116007/all/Acoustic_Neuroma.
Acoustic Neuroma. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2026. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116007/all/Acoustic_Neuroma. Accessed July 17, 2025.
Acoustic Neuroma. (2026). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (34th ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116007/all/Acoustic_Neuroma
Acoustic Neuroma [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2026. [cited 2025 July 17]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116007/all/Acoustic_Neuroma.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Acoustic Neuroma
ID - 116007
ED - Domino,Frank J,
ED - Baldor,Robert A,
ED - Golding,Jeremy,
ED - Stephens,Mark B,
BT - 5-Minute Clinical Consult, Updating
UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116007/all/Acoustic_Neuroma
PB - Wolters Kluwer
ET - 34
DB - Medicine Central
DP - Unbound Medicine
ER -