Good day How likely is it for fat necrosis to occur 12 months post op? I had DCIS in left breast, oestrogen +, nodes clean. I opted to have a bilateral mastectomy. Calcifications found in right breast. Reconstruction with silicone implants behind the chest wall12 months ago. I've discovered a lump as big as a pea in my right breast a week ago. Nothing showed up on the sonar although the dr could feel the lump. When I found DCIS lump, Sonar and mammo didn't pick it up either. Thank you