両側性真珠腫とretraction pocket

Bilateral Cholesteatoma and Retraction Pocket

I．はじめに

　両側性中耳真珠腫症例または一側中耳真珠腫の反対側に鼓膜弛緩部のretraction pocketが存在する症例には時々遭遇し，臨床的にはそれほど稀ではない印象がある。これらの症例は真珠腫の発症機序ならびにその治療を考える意味で非常に興味深いものがある。しかし現在まで両側性真珠腫およびretraction pocketの頻度に関する本邦の報告は皆無といって過言ではない。そこで私どもは中耳真珠腫と弛緩部のretraction pocket症例について統計学的に検討し，発症機序ならびに治療について若干の考察を加えた。

　The contralateral ears of 210 ears operated on for cholesteatoma or retraction pocket of pars flaccida (RP) were analyzed. Bilateral cholesteatoma and bilateral RP were found in 19 (9%) and 4 (2%) cases respectively, and unilateral cholesteatoma associated with contralateral RP were found in 30 (14%) out of 210 cases. Whereas only 3 (2%) out of 143 cases operated on for chronic otitis media with central perforation had cholesteatoma or RP in the contralateral ears. These observations suggested that the contralateral ears of cholesteatoma cases are prone to have either RP or cholesteatoma. Since the differential diagnosis between cholesteatoma and RP is somewhat difficult, it seems necessary to follow carefully the changes of RP of the contralateral ear. Exploratory atticotomy should be considered when otoscopic findings suggest the formation of cholesteatoma.