Study of Aspirin in Patients With Vestibular Schwannoma

Inclusion Criteria: * Radiographic diagnosis of vestibular schwannoma (NF2-associated or sporadic). * Age≥12 years. * Ability to provide informed consent.Pediatric patients must provide assent in addition to their parents'/guardians' consent. Adult patients who cannot consent for themselves will not be eligible to participate in this study. * Ability to swallow tablets. Exclusion Criteria: * Inability to perform volumetric measurements of vestibular schwannoma(s). * Inability to tolerate MRI with contrast. * Daily use of aspirin within the last two months. Occasional use of aspirin for pain relief is not exclusionary. * Known allergy to aspirin. * Impairment of gastrointestinal function or gastrointestinal disease that may significantly alter the absorption of aspirin. * Pregnant or lactating women. * Patients with serious medical illnesses (e.g. severe asthma) that in the option of the investigator could prevent participation in the trial. * Active bleeding diathesis. * Hydrocephalus from brainstem compression. * Febrile illness or flu-like illness in children and adolescents less than 18 years of age.