Extent of resection predicts risk of progression in adult pilocytic astrocytoma.

Pilocytic astrocytomas are rare tumours in adults. Presentation, management and prognostic factors are poorly characterised. Retrospective single centre study from 2000 to 2016. 50 cases were identified (median age 29 years; range 16-76). Symptoms at presentation were neurological deficit ( = 21), headache ( = 18) and seizures ( = 6). Five were incidental findings. Five patients had hydrocephalus at presentation and required emergent management, two by endoscopic third ventriculostomy and three by external ventricular drain. Symptoms were present for a median of 16 weeks (range 1 week to 34 years). Surgery consisted of gross total resection ( = 23), subtotal resection ( = 21) or biopsy ( = 6). Progression occurred in 20 patients at a median time of 7 years following surgery and was asymptomatic in just over half of these cases. A greater degree of resection (complete vs. subtotal) was associated with longer time to progression (Kaplan-Meier analysis, log rank test = 3.58,  = 0.059). At their first progression 12 patients underwent re-resective surgery and the remainder received radiotherapy. The median 5-year survival was 80%. In adult patients with a pilocytic astrocytoma, a macroscopic resection should be the aim at the first resective operation. Emergency management of hydrocephalus may be required in the first instance.