Displacement of carcinomatous epithelium in surgical breast specimens following stereotaxic core biopsy.

A variety of needling procedures in the breast may lead to dislodgment and displacement of fragments of breast carcinoma into tissue outside the target lesion of the needling procedure. To assess how frequently displaced fragments of carcinoma are seen in surgical breast specimens following stereotaxic core needle biopsies, slides were reviewed from 43 consecutive cases of breast carcinoma in which surgical excision and/or mastectomy had been performed following an initial diagnostic stereotaxic 14-gauge core biopsy procedure. In 12 of 43 (28%) cases, displaced carcinomatous fragments were identified outside of the main tumor mass. These patients were subjected to other needling procedures that included local anesthetic injection at the time of core biopsy (43 cases), needle localization (22 of 43 cases), suture placement (18 of 43 cases), and fine-needle aspiration (1 of 43 cases). Attributing carcinomatous displacement solely to the core needle biopsy is complicated by these additional needling procedures. In 18 instances, local anesthetic injection by 25-gauge needle was the only needling procedure other than the core biopsy. In 7 of these 18 (39%) cases, fragments of displaced carcinoma were observed outside the main tumor mass. The authors have previously observed only one case in which a 25-gauge needle was associated with epithelial displacement, suggesting that the core biopsy was more likely to have been the cause of displaced epithelium in these cases. Long-term clinical follow-up will be necessary to determine the biologic and clinical significance of these findings.