Third ventricle gliomas. Report of 7 cases with benign clinical behaviour.

Neoplasms of the third ventricle are lesions arising within the ventricular cavity, often free but more often pedunculated. True third ventricle tumours are surgically removable. In a consecutive surgical series of 580 intracranial tumours the authors operated on 27 lesions of the third ventricle, 7 of which were benign gliomas. The histological diagnosis was polar spongioblastoma in 5 cases and fibrillar subependymal astrocytoma in 2 cases. The dominant clinical features were a slowly progressive or intermittently increased intracranial pressure syndrome, and mental and visual disturbances. CT and CSF contrastographic studies provided the essential diagnostic data for the therapeutic plan. CT scans at follow-up studies confirmed the successful removal of the lesions. A right trans-ventricular approach was employed in all cases. Depending on the size and position of the lesion, removal was performed through the foramen of Monro or through a sub-choroidal approach. In two patients a ventriculo-atrial shunt was necessary in spite of tumour removal. No surgical mortality occurred and patients are well at a follow-up time of from 2 to 6 years.