Cholesteatomas or “skin cysts” are abnormal skin growth in the middle ear or mastoid cavity and can slowly dissolve bone and affect important nearby structures such as hearing and balance organs, facial nerve, and the brain.
Chronic Ear Disease
Recurrent ear infections over many years could lead into what is known as chronic ear disease. This condition usually manifests itself as recurrent ear drainage, conductive hearing loss and tympanic membrane perforation. At times this condition could lead into development of more aggressive pathology such as cholesteatoma and tympanosclerosis.
Cholesteatoma
Cholesteatoma is an abnormal growth of the outer layer of the skin known as squamous epithelium. The true cause of cholesteatoma is still unknown but has been attributed to problems with middle ear ventilation as well as abnormal migration of the tympanic membrane and middle ear mucosa. Since the outer layer of human skin constantly remodels and sheds to the outside world, when these cells are implanted into the middle ear or mastoid cavity they will continue to grow and destroy the surrounding structures. Unfortunately many important structures live in the middle ear and mastoid cavity such as balance canals, organs of hearing, middle ear bones, and the facial nerve. By dissolving the bone around them, these skin cysts also known as cholesteatomas, may cause hearing loss, facial nerve paralysis, balance issues, or other major problems. The treatment of cholesteatoma in most cases is microsurgery.
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| Early cholesteatoma starting from the ear drum | Late cholesteatoma extending into the mastoid cavity |
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| A complete tympanic membrane perforation with cholesteatoma | Close-up of the inside of the cholesteatoma looking through the perforation with an endoscope |
Tympanosclerosis
This condition is usually a long-term sequela of chronic ear disease. The true cause of this condition is also unknown since many patients with chronic ear disease will never develop true tympanosclerosis. In this condition the middle ear and tympanic membrane are affected by dense scar like connective tissue which over time may become calcified. This dense scar tissue, particularly when it’s calcified, will prevent normal mobility of the tympanic membrane and middle ear bones causing conductive hearing loss. Microsurgery of the middle ear could correct this problem but unfortunately at times tympanosclerosis may recur.