Abstract
Acoustic neuroma, properly called vestibular schwannoma, arises from the Schwann cells of the vestibular transitional zone of the vestibulocochlear nerve as the most frequent tumour of the posterior fossa. Its incidence is estimated at 1.2 vestibular schwannoma per a population of 100 000/year.
As to size, vestibular schwannoma is classified into grades I to IV. Its benign variety threatens the patient with hearing and balance impairment; uncontrolled growth can lead to death.
About one third of small vestibular schwannoma show hardly any growth, the larger ones grow aggressively. The author's conclusion is based on 33 years of experience with hundreds of surgically treated vestibular schwannoma (now at the ENT Department of Head and Neck Surgery, CU 1st Medical Faculty and FN Teaching Hospital, Prague Motol).
Three different therapeutic strategies are currently used: 1. Wait and rescan - close follow-up with regular MRI and hearing tests.
Growing tumours require active intervention. 2. Stereoradio-surgery using the Leksell gamma knife is a suitable option for small tumours (grades I and II).
Irradiation for larger vestibular schwannoma is decreasingly efficacious. 3. Microsurgery with intraoperative monitoring of facial and acoustic nerve function offers scope for radical removal of vestibular schwannoma of any size (grades I-IV) and for the preservation of facial nerve function and, of late, hearing, too.
The larger the tumour, the more difficult it is. The demanding nature of microsurgery requires the patients' concentration in special centres with neurosurgical and ENT cooperation.
The worst results are achieved with only a partial resection and follow-up stereoradiosurgical treatment. Secondary microsurgery can hardly prevent the patient's disability.