A 45-year-old woman presents with unilateral progressive sensorineural hearing loss, tinnitus, and mild unsteadiness. MRI with gadolinium shows a 2.5 cm enhancing mass in the right internal auditory canal extending into the cerebellopontine angle. The most common nerve of origin of an acoustic neuroma (vestibular schwannoma) is:

• A Superior vestibular nerve ✓
• B Cochlear nerve
• C Facial nerve
• D Inferior vestibular nerve

Explanation

Acoustic neuromas (vestibular schwannomas) most commonly arise from the Schwann cells of the superior division of the vestibular nerve (superior vestibular nerve), specifically at the glial-Schwann cell junction (Obersteiner-Redlich zone) within the internal auditory canal. Despite the name 'acoustic neuroma', they arise from vestibular nerve Schwann cells, not from the cochlear nerve. The superior vestibular nerve origin is more common than the inferior vestibular nerve.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.