Abstract
A case of the arachnoid cyst of the middle fossa surgically treated is reported. A 6-years-old boy complained of the buldging of the right temporal region since 3 years ago and it became gradually enlarged. Neither symptoms and signs of increased intracranial pressure nor other neurological abnormalities were noted. CT scan revealed a large low density area in the right middle fossa and other neuroradiological examinations also suggested arachnoid cyst of the right middle fossa. Because of the fear that the lesion might be a expanding lesion, craniotomy was performed and the cystic space was opened to the other subarachnoid cisterns. Postoperative CT scan suggested the decreased displacement of the right anterior horn of the lateral ventricle.
