Presentation
Right sided sensorineural hearing loss.
Patient Data
There is a lesion filling the right internal auditory canal, involving the fundus and extending into the right cerebellopontine angle. It measures 17 mm (TR) x 19 mm (AP) x 21 mm (CC).
Appearances are consistent with a right sided acoustic neuroma. There is cystic degeneration within the cisternal component. No convincing evidence of extension into the cochlea.
Incidental nasopharyngeal Thornwaldt cyst.
Case Discussion
Vestibular neuromas (=Schwammomas) can undergo cystic degeneration.
Remember the order of nerves in the IAC.'7up, Coke down' :
https://radiopaedia.org/articles/internal-auditory-canal-nerves-mnemonic?lang=gb
DDx for CPA angle lesions 'SAME' :
https://radiopaedia.org/articles/cerebellopontine-angle-mass-mnemonic?lang=gb