先天性中耳真珠腫3症例

Three Cases of Congenital Cholesteatoma

I．はじめに

　鼓膜に穿孔や耳漏など中耳炎を疑わせる所見がなくかつ伝音性ないしは混合性の難聴があれば，耳小骨奇形，耳硬化症，外傷性耳小骨離断，先天性中耳真珠腫などが疑われる。最近われわれは先天性中耳真珠腫と思われる3症例を経験したので，若干の文献的考察を加え報告する。

　We report three cases of cholesteatoma with an intact tympanic membrane which were suspected as congenital cholesteatoma.

　All patients underwent tympanoplasty and then we found cholesteatoma, which was completely separated from the tympanic membrane and were thought to originate from the surroundings of the incudo-stapedial joint. Postoperatively their hearing acuity improved.

　It is difficult to diagnose congenital cholesteatoma preoperatively. However, high resolution CT in our two cases demonstrated homogenous soft tissue densities which coincided with the location of the cholesteatoma. It was thought to be very useful to diagnose congenital cholesteatoma preoperatively.