Lately I have been having pain that runs down from my hip to my foot it feels like a nerve it hurts when I clench my butt or sneeze but it all happens when I'm up. I can walk because it hurts . I also have swollen lyhpm nodes since February and I have a swollen knee on my right side and I have lung pain and back pain. My back pain and my pain that runs down from my hip to my foot all happen a few months ago. I'm afraid if it's osteosarcoma :( all of my pain is on my right side.