What Should You Do when DIN Is Found on Core Needle Biopsy?

Background: Flat ductal intraepithelial neoplasia (DIN) is a pathologic entity that is also known as flat epithelial atypia and is described to be a form of columnar cell hyperplasia of uncertain clinical significance. As widespread screening mammography has been implemented and more lesions are targeted for biopsy, the prevalence of this pathologic finding has increased, and there has been no clear consensus on follow-up. Objective: To determine whether surgical excision is warran more...