This is terrible news. I had a recurrence on my chest wall 2 weeks after a unilateral mastectomy. I can’t believe they were giving me a choice of a lumpectomy. That would have been a huge disaster. As a result of a botched surgery and being undertreated I had to get really involved in my treatment ( full time job). I was seriously worried about the other breast and wouldn’t move forward with reconstruction until it was removed. Both breasts are now gone and I have double recovered which looks amazing. The surgeon who took off the other side told me that a prophylactic mastectomy reduces BC to 5%. Unfortunately, you need to go back for more aggressive treatment. If they had taken them both off you wouldn’t be experiencing this. It is a blessing that you found it and can address it immediately. I had chemo, radiation, and hormone therapy. I take an AI (which reduces the cancer recurrence by 50%) and a CDK 4/6 inhibitor ( which reduces recurrence by 33% or an absolute value of 7 %). My cancer was very aggressive grade 3 with a 70% chance of distant metastasis. So the hormone meds are amazing. My recommendation is to return to surgery and take both breasts away. It is my understanding that surgery is 56% of the cure. Wishing you the best on this extended journey.