術後性乳突部嚢胞の1例

Postoperative Mastoid Cyst: Report of a Case

I．はじめに

　慢性中耳炎において乳突蜂巣の炎症性病変に続発してコレステリン肉芽腫が形成されることは，日常臨床ではしばしば経験することである。またコレステリン肉芽腫を伴った乳突部嚢胞も稀ながら症例報告が認められるが，その成因についてはまだ明らかではない。今回私どもは中耳手術後30年以上の経過の後に，コレステリン肉芽腫を伴って嚢胞を形成した症例を経験したので，若干の文献的考察とともに報告する。

A 54-year-old male with mastoid cyst was presented. The patient received simple mastoidec-tomy in the right ear when he was 20 years old. Aural discharge had appeared on and off post-operatively. The audiogram revealed a conductive hearing impairment of about 65 dB and radiologic examination showed a bony defect in the mastoid area. A mastoid cyst, filling in the mastoid cavity, was eradicated. The cyst had incomplete septum with cholesterol granuloma adjoining the cyst wall. Reported cases of mastoid cyst in the Japanese literature were reviewed and the pathogenesis of the disease was discussed on the basis of the histopathological findings.