Ductal carcinoma in situ (DCIS) is a heterogeneous entity that has continued to perplex clinicians and patients despite extensive efforts to characterize its behavior andbesttreatmentstrategies.Asastand-alone diagnosis, it poses no mortality risk, yet the local therapyoptions range frommastectomy to limited excision, with or without radiation therapy (RT). The majority of current DCIS cases are amenable to wide excision to negative margins. Mastectomy (with or without reconstruction) typically is reserved for multicentric DCIS, lesions too extensive to encompass within a cosmetically acceptable excision,situationsinwhichriskreductionisa goal (ie, patients with a known BRCA1/2 mutation), or patients with a strong personal preference for mastectomy. The accompanying article by Wood outlines the dilemma of how best to treat patients with DCIS in the modern era, who often present with small, localized disease. It bears mentioning that the technology of mammography has improved such that it is not uncommon todiagnose small lesions and that the natural history of these lesions is uncertain.