Cholesterol granuloma of the middle ear invading the cochlea

Abstract

Objectives: To report a second case of cholesterol granuloma of the middle ear invading the cochlea.

Material and methods: A 54-year-old woman, who had undergone right-side tympanoplasty with stapedectomy, complained of intermittent right-side otorrhea associated with cophosis. Otomicroscopy found anterior eardrum perforation with mucopurulent effusion. Computed tomography (CT) showed a lesion filling the tympanic cavity, exposing the tympanic facial nerve, with destruction of the ossicles; the vestibule and cochlea were ossified except for the basal turn. The petrous apex was normal. Magnetic resonance imaging (MRI) showed invasion of the cavity and basal turn of the cochlea by a mass in heterogeneous hypersignal on T-1 weighted images, non-enhanced by gadolinium injection, and hyperintensity on T2-weighted images. Cholesterol granuloma of the middle ear was suspected, with surgery indicated due to the facial nerve exposure and cochlear invasion.

Results: A brownish-yellow compressive mass invading the basal turn of the cochlea, suggestive of cholesterol granuloma, was removed. Histologic examination confirmed diagnosis.

Conclusion: Direct invasion of the otic capsule by cholesterol granuloma is extremely unusual. Surgery is indicated in such cases, to avoid onset of neurologic complications.