A practical approach to breast ductal carcinoma in situ and tumors with an extensive intraductal component.

Current problems in the pathological assessment and subclassification of ductal carcinoma in situ of the breast are reviewed, both in its pure form and in association with invasive disease. The different clinical significance of these 2 types of presentations is emphasized, with particular reference to breast-conserving surgery. Adherence to the variably defined concept of extensive intraductal component may not be necessary if completeness of excision of intraductal disease can be demonstrated. A uniform approach is presented for the examination of surgical margins around intraductal carcinoma, regardless of the presence of invasion, using radiological-pathological correlation of sliced specimens.