A prospective study of seeding of the skin after core biopsy of the breast.

BACKGROUND The number of core biopsies done for breast abnormalities is increasing. The risk of skin seeding resulting from core biopsy is unknown. METHODS Consecutive patients diagnosed with breast cancer were studied. The skin and subcutaneous fat surrounding the site of core needle penetration were excised and studied by routine histologic staining. Findings were correlated with other clinical variables. RESULTS Eighty-nine consecutive patients were studied. Thirty-one had stereotactic core biopsies, 23 had vacuum-assisted biopsy, 8 had multiple-puncture biopsy, and 58 had ultrasound-guided core biopsy. Two patients who were biopsied using multiple-puncture biopsy were found to have nests of cancer cells in the dermis. One of these patients had recurrence in the skin biopsy site at 34 months. CONCLUSION Skin seeding may be important in light of increasing use of image-directed biopsy, and particularly for cases in which the biopsy puncture site is outside the index quadrant and in which no radiation is anticipated.