When have mammographic calcifications been adequately sampled at needle core biopsy?

AIMS: To determine if the number of flecks of calcification retrieved at st ereotaxic core needle biopsy or the number of core samples obtained contain ing calcification are related to biopsy sensitivity, and to determine how m any calcifications or cores containing calcification the radiologist should aim to retrieve when sampling mammographic microcalcification. MATERIALS AND METHODS: A retrospective review was performed of core specime n radiographs from 57 consecutive patients who had stereotaxic core needle biopsies of impalpable malignant microcalcifications without an associated mammographic mass. The total number of calcifications retrieved and the num bers of cores containing calcification were correlated with findings at cor e and surgical histology, RESULTS: Increasing retrieval of calcification elements visible on specimen radiography was associated with increasing sensitivity of the biopsy. Five or more flecks of calcium gave an absolute sensitivity of 100%. Increasing numbers of core samples obtained containing radiographically demonstrable calcification was also associated with increasing sensitivity. Three or mor e cores containing calcium resulted in a 100% absolute sensitivity for mali gnancy. CONCLUSION: To ensure adequate sampling of calcification at core biopsy, an optimum of either three or more cores containing calcium or five or more f lecks of calcium in total is required. Achieving this target ensures a high pre-operative diagnosis rate for malignant microcalcifications. (C) 2000 T he Royal College of Radiologists.