Subjects will be followed as outpatients for five years, during which clinical, radiologic and serum biomarker evaluation will be performed annually. Auditory testing will be performed annually for patients with measurable hearing. Patients with initially untreated vestibular schwannomas will be followed annually with vestibular testing. Ophthalmologic evaluation will performed every one to three years, depending on the severity of ocular lesions. Peri-operative speech and swallowing reassessments will be performed as medically indicated, when tumors that may affect these abilities are treated. Functional status testing will be repeated peri-operatively and annually thereafter when tumors that may affect independent functioning are treated.