Cholesteatoma of middle ear NOS(중이진주종)

Ⅰ. 서론

Cholesteatoma of the middle ear, often referred to as middle ear cholesteatoma, is a pathological condition characterized by the abnormal growth of skin cells in the middle ear and/or mastoid process. This condition is frequently classified as “not otherwise specified” (NOS) when typical features and classifications do not fit neatly into established categories. The middle ear is a small air-filled space located behind the eardrum, and its primary functions include sound transmission and pressure regulation. In a healthy state, this space is lined with a thin layer of epithelium, which serves to protect and lubricate the ear. However, when a cholesteatoma develops, this normal lining begins to proliferate, leading to the formation of a destructive and expanding cystic sac that can cause significant local damage. The exact etiology of cholesteatoma is multifactorial, with the most common factors including eustachian tube dysfunction, which can cause negative pressure in th…