乳突非削開鼓室形成術後の外耳道真珠腫例

抄録

Cholesteatomas rarely develop postoperatively as a complication of ear surgery for noncholesteatomatous disease, although the disease is not infrequently seen to recur following surgery for cholesteatomatous middle ear. It has been reported that lateralization of the tympanic graft and postoperative stenosis of the external auditory canal favor the formation of cholesteatomas.
This paper presents a case of an external auditory canal cholesteatoma that developed postoperatively in the ear following tympanoplasty without mastoidectomy. A 56-year-old man, who had undergone bilateral tympanoplasty elsewhere 13 years previously for persistent otorrhea and hearing loss, presented in 1998 with episodic hearing loss and ear discharge in his right ear. Examination of the ear showed a crust located in the posterosuperior part of the auditory canal. A CT scan revealed a round soft tissue density in the external canal, of which the posterior osseous part appeared to be eroded. The lesion was compatible with cholesteatoma in the external auditory canal. The patient underwent an excision of the cholesteatoma and canaloplasty. The patient has been free of his disease for six months postoperatively.
It is suggested that a canal skin incision permits development of an inclusion cyst, giving rise to the formation of cholesteatoma in the external auditory canal.