I have had 4 surgeries for ADH, ranging 4-8 years apart. All were initially seen on mammo and/or MRI w/contrast. No lesions were ever palpable. I had either a stereotactic or MRI -guided biopsy, depending on which scan first identified the concern. I underwent lumpectomy for ALL of them because that surgery is the Gold Standard treatment for ADH. There are several reasons for proceeding with surgery, including as high as 5%-30% incidence of upstaging from ADH to cancer when surrounding tissue is reviewed by pathology. An initial biopsy, even with 6 core samples, doesn’t 100% rule out presence of malignancy nearby. I am blessed with a general surgeon who specializes in diseases of the breast. His lack of hesitation has kept me cancer free by not leaving pre-cancerous cells to transmute. Wishing you all the best with your decision.