A 38-year-old female presents with a right-sided unilateral sensorineural hearing loss of gradual onset, tinnitus, and mild unsteadiness. MRI with gadolinium shows a 2.5 cm mass in the internal auditory canal and cerebellopontine angle with intense enhancement. The most likely origin of this tumor is from which cell type?
- A Schwann cells of the superior division of the vestibular nerve ✓
- B Schwann cells of the inferior division of the vestibular nerve
- C Schwann cells of the cochlear nerve
- D Meningothelial arachnoid cells of the posterior fossa dura
Correct answer: A. Schwann cells of the superior division of the vestibular nerve
Explanation
Acoustic neuromas (vestibular schwannomas) arise from Schwann cells at the glial-Schwann cell junction (Obersteiner-Redlich zone) of the vestibular nerve. The majority (90%) originate from the superior division of the vestibular nerve within the internal auditory canal. Despite the name 'acoustic neuroma,' they arise from the vestibular nerve, not the cochlear nerve. They present with unilateral SNHL (due to compression of cochlear blood supply), tinnitus, and vestibular symptoms. Meningiomas arise from arachnoid cells and have dural tail on MRI.
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.