"Ask the Expert” features answers by our experts to your clinical questions. Question: What is the optimal management of ductal carcinoma in situ (DCIS) with close surgical margins following mastectomy?A 55-year-old woman had screening mammograms showing suspicious microcalcifications in the right lateral outer quadrant. Stereotactic core biopsy showed DCIS, cribiform type, with high-grade microcalcification. The biopsy specimen was 80% ER-positive, and 80% PR-positive. Breast MRI showed enhancement...