It can definitely be scary. (See my Mammogram thread).
Lipoma's are nothing to worry about for the most part. It's like a fatty tumor made of... well...fat cells that are contained in their own little capsule. They're usually just below the skin. I have one on my collar bone, and another on the back of my head that I plan to get removed. The one on my head you can't see, but I know it's there!!
They are non-cancerous, and can not turn into cancer. The fact that you found it speaks volumes as to it being a lipoma. Rarely do cancerous tumors appear like that. The results being non-specific are actually a good thing. It means it doesn't look like cancer. Your doc is just being vigilant, and the MRI will probably just confirm what everyone else thinks already. Of course no matter what anyone else tells you, it won't put your mind at ease until you get a definitive result, so try and hold on to the "non-specific" findings as great news, and resign yourself to the fact that you've got a lipoma.