Abstract
Introduction: Intracranial subependymoma (WHO grade 1) account for 0.2-0.7% of all central nervous system (CNS) tumours. They are intraventricular tumours and present as incidental findings or cause hydrocephalus. The study aim was to evaluate the management and outcome following surgical resection of subependymoma. Materials and Methods: Retrospective, single centre case note review in adults with WHO grade 1 subependymoma diagnosed between 1990-2015. Ependymomas and subependymal giant cell astrocytomas were excluded. Tumour location, extent of resection (defined as gross total resection (GTR), sub-total resection (STR) or biopsy) and the WHO performance status (PS) were recorded at time of presentation and at follow- up. Results: 13 patients (7 male; 6 female) with a mean age of 47.6 years (range 33-58 years) were included. Mean follow-up was 62.7 months (range 24-216). 5 patients had incidental findings; 8 patients had symptomatic tumours (headache, cerebellar ataxia, cranial nerves deficits). PS at diagnosis was 0 (n=8) and 1 (n=5). Tumours were located in the 4(th) (n=9), lateral (n=2 left, n=2 right) and 3(rd) ventricle (n=1). 12 patients underwent craniotomy for excision (GTR n=11; STR n=1) and 1 craniectomy for co-existing Chiari Malformation (biopsy n=1). Early post- operative PS was 0 (n=3) and 1 (n=10). At last follow-up PS was 0 (n=11) and 1 (n=2). 2 patients developed symptomatic post-operative hydrocephalus (13.3%) and required ventriculoperitoneal shunt. There was no recurrence following GTR, and no growth following STR or biopsy. Only 2 patients, remains in PS 1 at last follow- up, while 84.6% are symptom free and PS 0. Conclusions: Typical neuroradiology appearance is diagnostic of subependymoma. When diagnosis is secure subependymoma are known to be indolent tumours. Whilst modern neurosurgery is safer, surgical resection should be restricted to those with symptomatic tumours given the risk of post-operative hydrocephalus. Incidental subependymoma could be followed with surveillance MRI without the need for surgery.