Vestibular schwannoma

Findings

There is a unilateral 4mm x 3mm x 2mm enhancing ovoid lesion in the left auditory canal near the left CPA.

Differential diagnosis:
- Vestibular schwannoma
- Epidermoid cyst
- Meningioma
- Arachnoid cyst
- Aneurysm
- Facial nerve schwannoma
- Metastatic lymphoma


Diagnosis: Vestibular schwannoma


Key points

Benign tumor of Schwann cells that encircle the vestibulocochlear nerve in the CPA and IAC
Most common mass in CPA
Often presents with progressive hearing loss
100% enhance; appears as "filling defect" in CSF on T2
Rarely associated with dural tail or arachnoid cyst
Unilateral enhancing CPA mass is vestibular schwannoma until proven otherwise
Usually slow growing with peak age 40-60yrs
If complete hearing loss has occurred, resection will not help restore hearing