Preoperative planning for a cystic lesion in the left cerebellar pontine angle. There is a cystic lesion in the left cerebellopontine angle cistern that measures up to approximately 25 mm. There is associated posterior deviation of the left cranial nerve 7 and 8 complex and mass effect upon the brainstem, left middle cerebellar peduncle, and left cerebellar hemisphere. There is a small developmental venous anomaly in the right inferior frontal gyrus. There is scattered mild mucosal thickening in the paranasal sinuses. There is a small amount of fluid signal in the right mastoid air cells. The major cerebral flow voids are intact. The orbits, skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable.
Limited preoperative planning MRI demonstrates a left cerebellopontine angle cistern cyst that measures up to approximately 25 mm with associated posterior deviation of the left cranial nerve 7 and 8 complex and mass effect upon the brainstem, left middle cerebellar peduncle, and left cerebellar hemisphere. 