特異な経過を示した聴神経腫瘍

A Case of Cerebellopontine Tumor Showing Unusual Clinical Course

　I．はじめに

　聴神経腫瘍は脳腫瘍のなかでglioma，下垂体腺腫，meningiomaについで多く，脳腫瘍全体の10％前後を占めている。近年，神経耳科学の進歩，CTの普及に伴って聴神経腫瘍の早期診断法が確立され，治療成功例も数が増している。しかし，診断に注意を要する非定型的症例もかなり報告されている。今回われわれは，内耳道拡大は認められず，同側の中耳炎手術後の伝音難聴の存在により聴力検査では診断が困難であった聴神経腫瘍症例を経験したので報告する。

　A 48-year-old man suddenly noticed tinnitus in his right ear and rotatory vertigo lasting for about 1 hour in March, 1979. In August, 1979 he had paracsthesia in his right face. Audiological examinations revealed a severe conductive hearing loss without recruitment in his right ear. Tomograms of the internal auditory canals revealed no destruction. Since he underwent tympanoplasty in his both ears in 1974, postoperative cholesteatoma was most suspected. However, he developed by-posthesia in his right face, abscence of corneal reflex of the right eye and no caloric reaction, and CTscan was taken and showed a cerebellopontine tumor.