What Does A Lump In The Under Arm Indicate?

Hello,
Yes, it started with a lump under my arm. I have an MRI and it showed it was a fatty tissue because nothing showed up. Now I am feeling them along my rib cage, in my lower back closer to my tail bone. I feel them on my inner and outer thighs..... Is this just that I'm getting fat? They feel like just fat deposits.... I find my legs ache when I sleep. I am very active. I used to be an aerobic instructor and still work out every day with treadmill, elliptical, classes, video tapes etc. I eat pretty good I think.... Not sure if there is some type of fatty deposit disease that could cause problems with circulation etc....