Marking of wire-localized breast biopsies for mammographically detected microcalcifications.

Impalpable breast lesions that are detected during screening mammography for breast cancer must be accurately identified and adequately sampled in biopsy specimens. Open wire-localized breast biopsy using hookwires remains the main method of sampling these lesions in centres without expensive stereotactic facilities. However, the hookwires can shift or become dislodged in the biopsy specimen. We have successfully modified a simple technique for the localization of impalpable lesions in these biopsies. The insertion of a small hypodermic needle into the fixed specimen with the assistance of the compression paddle and crosshairs on the mammography machine resulted in the precise localization of clusters of microcalcifications in 15 of 16 (94%) cases. In contrast, calcifications were identified in sections taken in the plane of the hookwire in only three cases (19%). The rate of detection of malignancy was 50% and the majority of malignant lesions were represented by ductal carcinoma in situ.