Hi guys I got a cyst on my left testicle which I have had for the last 20 years. It has always ached but in the last month it has become really painful, and the pain radiates into my stomach, lower back and down my left leg. I went to the doctors a few days ago and they said the pains are nothing to do with my cyst but could be IBS. I find this really weird as I can feel the pain in my testicle and when touched a pain shoots down my left leg. Can a cyst turn cancerous as I don't believe this is IBS and I'm getting worried?? The doctor said there is no need for an ultrasound as the cyst hasn't changed size. Any advice would be great. Lump is about size of a marble, with a smaller lump attached. Thanks Carl