A 70 years old female referred to the Department of Neurosurgery Rigshospital, due to 3-4 months of increasing ataxia of lower extremities and poor hearing of the left ear. A CT with contrast revealed 4x4x3 cm cystic tumor originating from the left internal auditory canal and extends into the posterior fossa, compressing the 4. Ventricle causing obstructive hydrocephalus moreover the CT revealed via the lateral suboccipital approach. Due to adherence to the brainstem a small remnant of the tumor mass was not totally removed. Postoperatively the patient still had hydrocephalus that demanded shunt insertion. A control CT performed in 1995 revealed a growth of the tumor remnants and a 2,5 x 2 cm cystic tumor was demonstrated The ventricle system became normal and no hydrocephalus was seen. It was decided not to reoparate but to observe the patient. In 1998 the patient was referred to the Department of Neurology Gentofte University Hospital, due to left side facial palsy. Acute CT scanning revealed a 5x4x3 cm cystic tumor, displacing the 4. Ventricle. What may be concluded from this report is that the growth of the cystic tumors are significantly higher compared to the non cystic VS, patients with cystic VS should not be offered the non immediate surgical option "wait and scan" and leaving tumor remnants at surgery of cystic VS is a risky matter as the remnants well grew fast. The latter conclusions is in accordance with what have previously been published on growth of the cystic variant of VS.