Imaging-histologic discordance at sonographically guided percutaneous biopsy of breast lesions

OBJECTIVE: To determine the frequency of imaging-histologic discordance at percutaneous breast biopsy and to evaluate differences in clinical and radiologic findings between pathologically upgraded lesions and non-upgraded lesions. MATERIALS AND METHODS: From February 2000 to June 2005, we reviewed 386 cases that had suspicious imaging findings but yielded benign histology at US-core needle biopsy and that underwent subsequent excisional biopsy. In 74 of 386 cases, the benign histology at core needle biopsy could not provide a satisfactory explanation for the radiologically suspicious lesions. The clinical, radiologic and histologic findings were reviewed for those 74 cases that were classified as the upgrade group and the non-upgrade group after excisional biopsy. RESULTS: The upgrade rate was 17.6% (95% confidence interval, 10.6-27.8%, 13 of 74 cases) revealed upgraded pathology at the subsequent excisional biopsy. Besides the size of masses, there were no statistically significant differences in imaging findings between the upgrade and non-upgrade groups at excisional biopsy. CONCLUSION: This upgrade rate of 17.6% suggests that excisional biopsy or re-biopsy is warranted in those cases presenting imaging-histologic discordance at US-guided core biopsy.