Ductal carcinoma in situ in core biopsies containing invasive breast cancer: correlation with extensive intraductal component and lumpectomy margins.

Background And Objectives: The diagnosis of invasive breast cancer is most commonly made on image-guided core biopsy (CB). The presence of extensive intraductal component (EIC), as identified on subsequent lumpectomy, is associated with an increased risk of positive margins and need for further surgery. CBs demonstrating invasive breast cancer may also contain ductal carcinoma in situ (DCIS), although the significance of this finding is unclear.