At the end of April I had an open left radical nephrectomy. The cancer had already metastasized to the liver and lungs before the surgery. (Diagnosed with a rare kidney cancer in the middle of May.) I have since recovered from surgery and all seems to be going well in that respect except that about 6 weeks ago my flank started to hurt again and this week, my left shoulder. Hurts the most when I breathe too deeply and abruptly. My left shoulder was incredibly painful just after the nephrectomy and that was from referred pain from the diaphragm- which was irritated with all the shifting around to remove the kidney and surrounding lymph nodes. Now, the latest CT scan does not show any lesions or swollen lymph nodes in the area. I just started Nivolumab but the pain has been building over weeks. Are lung mets likely the reason? How best to treat the pain associated with this?