Pathology of preinvasive and excellent-prognosis breast cancer.

Our review of recent developments in breast cancer involving evaluation of cellular and tissue samples is targeted at indicators of elevated risk of sufficient magnitude to attain clinical significance; lesions unassociated with metastatic capacity but of sufficient risk to attain that capacity that formal treatment is necessary, ie, ductal carcinoma in situ; and indicators of good prognosis in invasive cancer. Ductal carcinoma in situ has been the subject of much recent discussion. We highlight particularly the area of stratification or classification within this group of lesions. The importance of the extensiveness of ductal carcinoma in situ in the prediction of local recurrence within the conserved breast is included. Also discussed are advances in diagnostic techniques, specifically core needle biopsies performed under mammographic and ultrasonographic guidance.