I had the same unwanted news. I had a bassline MRI to see if, after looking at so many other possible causes, my frequent lightheadedness had a neural basis. No problem there (and my lightheadedness has since stopped) BUT there was a meningioma the size of a kidney bean. It's not causing any problems now, and I am old so it's on watch status. I felt lucky, as you, to have discovered it early by accident. I have 2 friends who did not discover this problem until they had very serious symptoms. They were the size of fists! They are almost always benign and slow growing. So please worry less.