Stereotaxic core biopsy of breast carcinoma: accuracy at predicting invasion.

PURPOSE: To assess the accuracy with which stereotaxic core biopsy of breast carcinoma predicts the presence of invasion. MATERIALS AND METHODS: Stereotaxic core biopsy was performed in 63 breast carcinomas in 59 patients in the prone position. All patients subsequently underwent surgery. Histopathologic results of stereotaxic core biopsy and surgery were correlated. RESULTS: Results of stereotaxic core biopsy and surgery were concordant in 58 (92%) of the 63 cases, yielding invasive carcinoma in 46 cases and ductal carcinoma in situ (DCIS) in 12 cases. Results were discordant in five cases (8%), including three cases for which stereotaxic core biopsy results indicated DCIS but surgery yielded invasive ductal carcinoma. The positive predictive value of stereotaxic core biopsy for the presence of invasion was 98% (47 of 48 cases) and the negative predictive value was 80% (12 of 15 cases). CONCLUSION: Stereotaxic core biopsy of breast carcinoma can help confirm invasion with high accuracy but cannot reliably indicate the absence of tumor invasion when only DCIS is found.