Benign cystic tumours of the cerebellum.

In a series of 4.915 surgically treated intracranial tumours and other space-occupying lesions, excluding those due to trauma, the two main groups of benign cerebellar tumours were found to be the astrocytomas (172) and the cystic haemangioblastomas (35). Cerebellar astrocytomas represented 3.5% of all the brain tumour material and 8% of the total number of gliomas. The clinical features are reviewed, and the necessity for surgical and histological verification of the posterior fossa tumours of childhood and youth is emphasized. Preoperative positive contrast ventriculography was usually performed followed by temporal ventricular drainage or ventriculo-peritoneal shunting. Cystic astrocytomas predominated. Radical removal of the solid part of these should be carried out. Total post-operative case mortality varied between 16 and 22% but has become lower in recent years. Good late results varied between 40 and 70%. Angioblastomas of the cerebellum are usually benign tumours, with a cystic component in 70% or more. Usually they represent the most important part of the so-called Lindau complex with possible associated angiomatosis of the retina (von Hippel-Lindau disease) and, more rarely, visceral lesions or haemangioblastomas of the spinal cord. Cystic cerebellar angioblastomas represented 0.7% of all brain tumours. The proportion of male patients was double that of females and the age peak appeared between 30 and 40 years. An increase of red blood cells above five million per mm3 appeared in 9% of our cases. The value of vertebral angiography is emphasized. After emptying the cyst careful removal of the nodule gives a good late result in more than 70% of patients. However, recurrences have been noted in the literature in about 14% of patients due to the frequency of multiple tumour nodules in the posterior fossa (10% in some vertebral angiographic series). Finally, a most careful clinical and radiological search for other lesions in the rest of the body is imperative in these patients.