Expectant management of vestibular schwannoma: a retrospective multivariate analysis of tumor growth and outcome.

We conducted a retrospective observational study to assess the consequences of conservative management of vestibular schwannoma (VS). Data were collected from tertiary neuro-otological referral units in United Kingdom. The study included 59 patients who were managed conservatively with radiological diagnosis of VS. The main outcome measures were growth rate and rate of failure of conservative management. Multivariate analysis sought correlation between tumor growth and (i) demographic features, (ii) tumor characteristics. The mean tumor growth was 0.66 mm/y. 11 patients (19%) required intervention. Mean time to intervention was 37 months with two notable late "failures" occurring at 75 and 84 months. Tumors extending into the cerebellopontine angle (CPA) grew significantly faster than intracanalicular tumors (p = 0.0045). No association was found between growth rate and age, sex, tumor laterality, facial nerve function, and grade of hearing loss. Conservative management is acceptable for a subset of patients. Tumors extending into the CPA at diagnosis grow significantly faster than intracanalicular tumors. No growth within 5 years of surveillance does not guarantee a continued indolent growth pattern; surveillance must therefore continue.