Neurological Surgery No Shinkei Geka Volume 24, Issue 7 (July 1996)

Acoustic neurinoma located exclusively in cerebellopontine angle cistern (“cisternal” acoustic neurinoma):a case report Iwao YAMAKAMI 1 , Nobuo OKA 1 , Akira YAMAURA 1 1Department of Neurosurgery, Chiba University School of Medicine Keyword: acoustic neurinoma , cerebellopontine angle , hearing , internal auditory meatus pp.661-664
Published Date 1996/7/10
  • Abstract
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This is a case report of acoustic neurinoma which was located exclusively in the cerebellopontine angle (CPA) cistern and which did not extend into the inter-nal auditory meatus (“cisternal” acoustic neurinoma) The 43-year-old female patient had signs of the left trigeminal nerve impairment including left face neural-gia. However, she did not have any neurootological symptom. No abnormal bony changes in the internal auditory meatus (IAM) were found by high-resolution bone-window CT. MRI showed a left CPA tumor of 25mm not extending into the IAM. The tumor was totally removed by the lateral suboccipital approach. Itoriginated from the vestibular nerve medial to the porus acusticus and was located exclusively in the CPA cistern. No tumor extension into the IAM was con-firmed. The cochlear nerve was involved in the tumor capsule and could not be preserved. The pathological diagnosis was that it was a neurilemmoma. Early dia-gnosis of “cisternal” acoustic neurinoma is difficult be-cause it does not show neurootological symptoms in the early stage. The lateral suboccipital approach is appropriate for the removal of a “cisternal” acoustic neurinoma. However, in spite of the good preoperative hearing, the preservation of hearing is difficult because of the large tumor size.

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Neurological Surgery 脳神経外科
24巻7号 (1996年7月)
電子版ISSN 1882-1251 印刷版ISSN 0301-2603 医学書院