middle ear cavity
1-congenital cholesteatoma.. occurs within mesotympanum(anterosuoerior portion of middle ear cavity)
2-cholesterol granuloma of middle ear: as in petrous apex, s/s
- conductive hearing loss
- cranial nerve dysfunction, e.g. CN VII
3-glomus tympanicum: origin at cochlear promontory, enculf the ossicles (no erosion), bright enhancement.(cholesteatoma=erosion)
MRI:multiple flow void-vessels- in the tumor (salt and pepper appearance).