Hello Susan. I have been on a very similar trip to yours. I have had breast cancer and after having chemo, a lumpectomy and radiation I was put on Anestrozole. Shortly after that I had a colonoscopy and was given Cipro as I have diverticulitis. Two days after taking the Cipro I developed the shoulder pain and f elt like I had been hit by a truck, I was not able to get out of bed in the morning due to aches and pains all over. I went to three different doctors to get diagnosed including my oncologist who told me to stop taking the Anestrozole for 2 weeks, before they diagnosed PMR. I was immediately put on 10 mgs. of Prednisone and the pain stopped straight away. I am now back on Anestrozole, down to 2 mgs from 10 of Pednisone, and apart from still getting fatigued and dizzy am doing fine. I do think my "trigger" was the Cipro, but that's just my opinion. The fact that you don't have breast tissue is an issue for your doctor to answer.