Hi Marilyn,
I am curious as to what led you to have the MRI in the first place? My AN was found by accident, and I feel very fortunate that it was caught when it was small. I wasn't having any bothersome problems at the time of diagnosis so I chose to watch and wait. These ANs usually grow slowly, and they often give one enough time to make an informed decision about what to do--W&W, surgery, or radiation. As for size, my doctor said he has seen ANs as small as 2mm cause problems and larger ANs cause no problems (or at least presenting problems). In my opinion, you should stay on top of your symptoms and not focus so much on the size of your AN. My AN grew this past year, not much as you can see from my signature, but I started having symptoms. I have decided to go ahead with treatment, but I think a lot of people in my situation would be content to W&W a little longer. The most important thing to remember, in my opinion, is to do what feels right for your. Gather your info, and you will eventually know in your "gut" what to do--but, be patient. The gut feeling doesn't always come to you overnight. Best wishes to you in your journey. This board is a great support so you are on your way to becoming informed.
Nancy