Conservative Management of 15-mm and Larger Vestibular Schwannomas

Aims and Objectives: This study was conducted to assess the clinical, audiological, and radiological outcomes of conservative management of vestibular schwannomas (VSs) with extracanalicular diameter of 15 mm or larger.

Setting: Tertiary care hospital.

Methods: Retrospective study of case notes and scans from the date of referral to the last visit. Tumor size changes were evaluated over time with clinical symptoms/signs and hearing changes. The tumor was considered to be growing when it increased by more than 2 mm from its initial size.

Results: There were 45 patients with a mean age of 61.4 years (+/− 10.7 years) years and male-to-female ratio of 1.6:1. The initial tumor size ranged from 15–31 mm with a mean of 20.1 (+/− 4.3) mm. The duration of follow-up ranged from 6 months to 14 years. The median follow-up duration was 3 years, with an interquartile range of 1 year 4 months to 6 years 4 months. Clinical features worsened in six patients (13.3%) and 50% occurred in patients with growing VSs. The mean hearing thresholds deteriorated from 73.4 to 80.9 dB. Hearing deterioration was significantly more in growing tumors (8.9 dB/year) compared with non-growing ones (1.1 dB/year). Tumors grew, remained stable, or regressed in size in 11 (24.4%), 30 (66.7%) and 4 (8.9%), respectively. The overall mean tumor growth rate was 0.9 (+/−2.2) mm/year, but in growing tumors it was 3.6 (+/−2.9) mm/year.

Conclusions: The outcomes from this study were equal if not better than those reported for smaller tumors. This study shows that 15 mm and larger tumors can be offered conservative management.