Well, after yesterday's visit to Children's, I think we both walked away feeling better. I will copy her diagnosis from the doctor later, but the gist is: it has something to do w/ her first ribs more than likely. We are supposed to monitor it and watch it. If Bee experiences any numbness in her arm or hand, or it falls asleep often, or one hand is cold and one hand is warm, then we need to return to Children's. The doctor does not want to do surgery at this time if he doesn't have to. He said she is young and if it had to happen, the older she is, the better. Since the area the lump is located in is sensitive and full of nerve endings and blood vessels, because she is so small, it would more than likely be a complicated surgery. Dr. A. did admit that this was the first time he'd seen something like this.
Regardless, we are relieved to have a more specific idea of what is wrong and what we need to look for and pay attention to.