Cholesterol granuloma of the petrous apex. A post mortem study on temporal bones

Otitis media (OM) is an infection localized in the middle ear: mastoid, middle ear cavity, Eustachian tube. The classification of OM includes otitis media with effusion, otitis media without effusion, and chronic otitis media. A rare complication of chronic otitis is cholesterol granuloma of the petrous apex. It may develop in any aerated portion of the temporal bone but most commonly develops when a pathologic process obstruct the air cell tracts to the petrous apex preventing normal aeration.