Analysis of false-negative results after US-guided 14-gauge core needle breast biopsy

To determine the false-negative rate and to evaluate the clinical, radiologic or histologic features of false-negative results at ultrasound (US)-guided 14-gauge core needle biopsy (CNB). A total of 3,724 masses from 3,308 women who had undergone US-guided 14-gauge CNB and who had a rebiopsy or at least 2 years' follow-up were included. The histology of CNB was correlated with the rebiopsy or long-term imaging follow-up. In cases of missed cancer, the time interval between CNB and rebiopsy, the reasons for rebiopsy, and the procedural or lesion characteristics were analysed. Of 1,706 benign CNBs, 50 additional malignancies were found at excision (false-negative rate, 2.5% of 1,982 with a final diagnosis of malignancy). Of 50 false negatives, 41 were found immediately of which 28 had rebiopsy because of imaging-histological discordance. Regarding the frequency of malignancy according to the reasons for rebiopsy, suspicious imaging finding (24%) showed significantly higher frequency than suspicious clinical findings or request (1%). Regarding the characteristics except invasiveness, no significant differences in false-negative rates were found. Most false negatives were found immediately and imaging-histological discordance was the most important clue. Careful correlation of clinical, radiological and histological results as well as appropriate follow-up is essential.