My husband has breast cancer that has gone into lymph nodes and bones in his back and pelvis. He had problems with his left shoulder which was the same side of his mastectomy. He had pet scans and the cancer dr didn't think his pain was cancer related. He was sent to an orthopedic dr who gave him a cortisone shot which didn't help. Now after doing another MRI they found that there are tumors. Wouldn't this have shown in the Pet scan?? Could the cortisone shots have made it worse??

Why wouldn't the cancer doctor have found this??