 This will be a multi-center, proof of concept phase 0 study to assess the suppression of p-AKT in Vestibular Schwannoma VS and meningiomas by AR-42 in adult patients undergoing tumor resection. AR-42 is a small molecule which crosses the blood brain barrier BBB in rodents, but the investigators are not certain yet if it will penetrate human VS. Meningiomas are outside the BBB, but seem to be unusually resistant to all current medical treatments. The primary endpoint of the bioactivity of suppression of p-AKT by AR-42 was selected as drug activity seems more informative than bioavailability. Our preclinical data and others have shown dose dependent suppression of p-AKT by AR-42 in both VS and meningiomas. 