I have a lump on the back of both of my thighs. The one of my left leg is slightly larger than the one on the right. Both are located about 4-5 inches above the crease in the back of my knee. It extremely hard and hurts when i touch it. It's about the size of a quarter. I didn't notice it until a few months ago and I always forgot about it when I went to the doctor as it hasn't really been bothering me until here lately. It seems to be more sensitive to touch. I've been looking things up online but haven't had much success. Unlike what I've been reading from other people's questions, mine doesn't appear to move or have a rubbery consistency. It's more like a hard marble that is glued in place. Any advice you can give or thoughts on what these might be are greatly appreciated.