Cystic vestibular schwannoma - Clinical and experimental studies

The cystic variant of vestibular schwannoma (VS) presents a therapeutic dil emma. Several studies have previously demonstrated that the surgical outcom e in this tumour entity is less favourable than that of solid rumours of co mparable size. The "wait and scan" policy has not been recommended for thes e tumours, as the cystic elements expand, causing displacement of the brain stem and compression of the 4th ventricle, resulting in hydrocephalus. The large tumour size at diagnosis and the cystic contents do not support the r ole of radiosurgery as a therapeutic option. We have previously published t he surgical outcome of 23 cystic VS. The present study includes 44 patients (44 cystic tumours) in a series of 773 tumours (5.7%) who underwent surger y in the period 1976 to 1996. This paper presents the neuroradiological and histological features of the tumours, as well as the results of tumour spe cimen implantation and surgery in athymic nude mice. Therapeutic options ar e also discussed.