It’s common lumpectomy does not remove all the abnormal cells all at once. I had Atypical Ductal Hyperplasia on my left breast and had lumpectomy a year ago. The recent biopsy found the same “high risk benign” cells grew out again right next to the lumpectomy area from a year ago. My surgeon recommends me mastectomy this time so that she can be sure to remove all the abnormal cells.