NEOPLASM

Vestibular schwannoma: cone-shaped internal auditory canal-cerebellopontine angle cistern lesion. Unliateral sensorineural hearing loss.

Trigeminal schwannoma: would not enter the internal auditory canal; tracks along trigeminal nerve into Meckel's cave.

Meningioma: enhancing dural based mass asymmetric to the entrance of the IAC

Fibrous dysplasia: expansile, centered in medullary space of bone, variable density (sclerotic, GG); low SI in ossified and fibrous portions of the lesion.