[Clinical aspects and pathology of intracranial subependymoma--18 personal cases and review of the literature].

Intracranial subependymomas are rare, benign tumours (WHO grade I) occupying a special position compared to the other ependymal neoplasms. They often remain asymptomatic and, in consequence, are found incidentally at autopsy. In the present study clinico-pathological data of 84 symptomatic (8 own cases) and 58 asymptomatic tumours (10 own cases) are summarised. Subependymomas are more frequently situated in the fourth (58.4%) than in the lateral ventricle (38.0%). They occur predominantly in middle-aged and elderly males. Tumours in the lateral ventricles manifest themselves more often than those in the fourth ventricle. In general, asymptomatic subependymomas do not exceed a diameter of 1.2 cm. The nature of symptoms, with a median symptomatic period of 12 months, is usually associated with hydrocephalus, which is present in more than 80% of the symptom-producing subependymomas. Growth within the ventricular lumen and sharp demarcation from the surrounding brain tissue allow a complete removal in half of the cases. Radical extirpation can be achieved more often in patients with subependymomas located in the lateral ventricles than in those with tumours arising from the floor of the fourth ventricle. The high operative mortality, at a rate of 28.8% so far, mainly refers to the period before microsurgical technique was established. Recurrences are very rare, spinal seeding has not been found to date. For the assessment of long-term results further detailed compilation and documentation of individual follow-ups is necessary.