Growing versus non-growing vestibular schwannomas: assessment of natural history.

Abstract

Vestibular schwannomas can demonstrate great heterogeneity in their behaviour; approximately one-third will grow and two-thirds will not. This study aimed to determine whether there are factors present at diagnosis that can help predict outcomes. This retrospective cohort study compared data from 735 patients from the past 20 years. Analysis of serial magnetic resonance imaging was carried out to place patients into growing and non-growing cohorts. Factors including size, age, follow-up time and presence of balance symptoms were compared. The median size of a growing vestibular schwannoma at diagnosis was 13 mm, whereas the non-growing median size was 10.65 mm (p < 0.001). Balance symptoms were present in 60.76 per cent of growing vestibular schwannoma patients but only in 38.75 per cent of patients with non-growing vestibular schwannomas (p < 0.001). This study highlights initial tumour size and balance symptoms as potential predictors of whether or not a vestibular schwannoma will grow; these results better facilitate our understanding of vestibular schwannoma natural history.