What Could Painful Lump Beside Left Rib Indicate?

Hello, it s sort of difficulty to explain my situation because I don t know exactly what s going on with my body. I ll start by telling about the lump/knot or some sort on/under/beside my left rib. I ve been to several hospitals in the central Florida area, at the most they ve told me that my cartilage was swollen but have yet to tell me why it is swollen. Now this problem has been ongoing off and on (pain and growth wise)for at least 4+ years after the birth of my first child in 2009. A couple of months ago my physician sent me to see a General surgeon who had an MRI done on me, he then referred me to see a thoracic surgeon whom have yet to tell me what they saw on the MRI results but still refuses to do any type of surgery on me. Granted I m young of age 24 (that was his verbal reason for not proceeding saying it would distort my figure which it already is doing) he suggested pain management when clearly something is gradually pressing my left rib cage out and up, I can t stand for long periods of time which means I could barely work or interact with my children. Is there suggestions, comments, heck even concerns for what I ve told you? Thanks in advance