Middle Ear Cholesterol Granuloma without Tympanic Membrane Perforation / 대한이비인후과학회지

ABSTRACT

Cholesterol granuloma is a histopathologic term used to describe the giant cell reaction to cholesterol deposits that occurs in sequestered, fluid-filled air cells that are normally pneumatized compartments of the temporal bone. It is a benign lesion which is known to be found in the middle ear cavity, mastoid air cells and petrous apex. Although cholesterol granuloma is a pathologic term describing a tissue response to cholesterol crystals, it is now recognized as a clinical disease entity especially in cases of unilateral blue eardrum without tympanic membrane perforation. Three factors are considered to play an important role in the development of cholesterol granulomas obstruction of ventilation, microhemorrhage, and impaired drainage. Cholesterol granulomas are often found as pathologic lesions like granulation tissue in the middle ear and mastoid cavities during middle ear surgeries in patients with chronic otitis media or cholesteatoma. Cholesterol granulomas of the middle ear typically present as conductive hearing loss and a blue eardrum, whereas those at the petrous apex are incidentally identified or manifest as bony erosion with sensorineural hearing loss, tinnitus, vertigo, or cranial nerve impairment. Cholesterol granulomas in middle ear cavity and mastoid air cells are related with Eustachian tube dysfunction, so initial treatment of cholesterol granuloma is the insertion of ventilation tube in many cases. However, it is often necessary for the complete cure to do excision of the lesion through tympanomastoidectomy surgery.