My mother had a double masectomy 3 years ago. It was her decision to have both removed, but afterward the doctor informed us that it was actually the unlikely breast that had more cancerous cells. She did not have chemo, but takes tomoxficin. Approx. 8 mths. ago she found a small cyst in the "unlikely" breast. Hard, moveable with your finger and the oncologist today could not confine it to attempt to aspirate it. Could this just be a benign cyst that formed? What are the chances?