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Cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process. Although these are not strictly speaking tumours or cancers, they can still cause significant problems because of their erosive and expansile properties resulting in the destruction of the bones of the middle ear (ossicles), as well as their possible spread through the base of the skull into the brain. They are also often infected and can result in chronically draining ears. ==Signs and symptoms== The majority (98%) of patients with cholesteatoma have ear discharge or hearing loss or both in the affected ear. Other more common conditions, such as otitis externa, may also present with these symptoms, but cholesteatoma is much more serious and should not be overlooked. If a patient presents to a doctor with ear discharge and hearing loss, the doctor should consider the patient to have cholesteatoma until the disease is definitely excluded. Other less common symptoms (all less than 15%) of cholesteatoma may include: pain, balance disruption, tinnitus, ear ache, headaches and bleeding from the ear. There can also be facial nerve weakness. Balance symptoms in the presence of a cholesteatoma raises the possibility that the cholesteatoma is eroding the balance organs, which form part of the inner ear. On initial inspection, an ear canal full of discharge may be all that is visible. Until the doctor has cleaned the ear and inspected the entire tympanic membrane, cholesteatoma cannot be either confirmed or excluded. Once the debris is cleared, cholesteatoma can give rise to a number of appearances. If there is significant inflammation, the tympanic membrane may be partially obscured by an aural polyp. If there is less inflammation, the cholesteatoma may present the appearance of 'semolina' discharging from a defect in the tympanic membrane. The posterior and superior parts of the tympanic membrane are most commonly affected. If the cholesteatoma has been dry, the cholesteatoma may present the appearance of 'wax over the attic'. The attic is just above the ear drum. The patient may commonly also have clinical signs of conductive hearing loss. Less frequently, there may be signs of imbalance or facial weakness. If untreated, a cholesteatoma can eat into the three small bones located in the middle ear (the malleus, incus and stapes, collectively called ossicles), which can result in nerve deterioration, deafness, imbalance and vertigo. It can also affect and erode, through the enzymes it produces, the thin bone structure that isolates the top of the ear from the brain, as well as lay the covering of the brain open to infection with serious complications (rarely even death due to brain abscess and septicemia). Both the acquired as well as the congenital types of the disease can affect the facial nerve that extends from the brain to the face and passes through the inner and middle ear and leaves at the anterior tip of the mastoid bone, and then rises to the front of the ear and extends into the upper and lower face. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cholesteatoma」の詳細全文を読む スポンサード リンク
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