Internal Acoustic Meatus Trumpeting

A trumpeted internal acoustic meatus is an indirect sign of an acoustic schwannoma and is useful in helping differentiating between this and other cerebellopontine angle entities, especially from a meningioma which typically does not extend into the meatus.
To see other images of this case please visit Radiopaedia.org here.
Reference:
1. Robert I. Grossman - Neuroradiology: The Requisites
Credit: Dr Frank Gaillard
http://www.radpod.org