Please help!!!

Ok I'm officially freaking out - 
My daughter has slight torticollis in her neck on the right side.  Nothing to worry about but she is starting physical therapy. on the same side she has this rock hard lump in her bicep. It doesnt move and it almost looks like she just has a big bicep muscle. So I took her to the pediatrician and he referred me to an orthopedist because he wasn't sure what it was 
I went to the orthopedist today and he sent her for X-rays to make sure bones were ok.  The xray came back showing a mass in her bicep area. Dr said he hasn't seen anything like this before and now I have an ultrasound tomorrow morning 
As if I wasn't freaking out enough as I'm holding her I found another of these lumps but smaller on her left wrist 
Does anyone have any kind of experience with this or can shed some light on what it is.  It's taking all of me not to break down into hysterics that my baby girl isn't ok