Stereotactic breast biopsy: a study of first core samples.

Stereotactic core needle biopsy (SCNB) is a sensitive and specific indicator of breast pathology. Commonly the first biopsy core is taken from the center of the lesion in question. Multiple cores are then taken from points peripheral to the central core. The sensitivity and specificity of the central core to diagnose breast disease is unclear. We compared the pathology of the central core biopsy with that of the remaining cores in a prospective study to determine the sensitivity and specificity of the central core to diagnose breast disease. All patients undergoing SCNB for breast lesions in a single surgical office during a 7-month period were eligible for inclusion. One hundred thirty-three patients with first cores from 145 biopsy sites were included. The histologic diagnosis from 117 (81%) of the first cores from these 145 biopsy sites were representative of their respective samples as a whole. Seventy-seven (53%) of the first cores were in complete agreement with the final histologic diagnosis whereas 40 (28%) had minor differences with the histologic diagnosis that had little or no clinical significance. Twenty-eight (19%) central core samples did not agree with the final pathologic diagnosis. Seven of these 28 patients each had a final diagnosis of cancer missed by the central core biopsy. The first core sample had a sensitivity for cancer detection of 79 per cent and specificity 100 per cent. SCNB remains a sensitive and specific identifier of breast pathology. When mammographic evidence of calcifications was the primary indication for SCNB (n = 75) calcification was present in the central core in 51 (68%). In these 51 patients the central core biopsy was in agreement with the final histologic diagnosis in 46 (90%) specimens. Histologic review of the first core sample alone lends no increased benefits and in fact misrepresents the pathology present in a significant number of patients. When analyzed as an independent predictor of breast pathology the first core is a more sensitive indicator than subsequent individual cores, but the most accurate predictor of pathology is examination of the entire group of core samples. This study confirms the need for acquisition of multiple cores from each lesion in question.

Stereotactic core-needle breast biopsy by surgeons: minimum 2-year follow-up of benign lesions.

OBJECTIVE: To evaluate the reliability of stereotactic core-needle breast biopsy (SCNB) performed by surgeons to detect histologically benign tissue. SUMMARY BACKGROUND DATA: Stereotactic core-needle breast biopsy is widely used to obtain tissue for definitive pathologic diagnosis of mammographically suspicious breast lesions. It has an incidence of malignancy detection similar to that of open biopsy. The potential for sampling error is a concern. Minimal data regarding follow-up and failure rate are available, especially from series performed exclusively by surgeons. METHODS: Pertinent medical records of all patients who underwent SCNB between April 1995 and October 1997 were reviewed. Breast lesions were classified by mammographic Breast Imaging-Reporting and Data Systems (BI-RADS) categories before SCNB. Benign biopsy specimens were classified as nonproliferative or proliferative. Malignant lesions and those with atypical histopathology by SCNB were excluded from this analysis. All lesions initially reported as benign were followed up mammographically for at least 2 years for any suspicious change requiring repeat biopsy. RESULTS: During the 31-month period, SCNB was performed on 694 lesions in 619 patients. Histologic evidence of malignancy was found in 112 lesions (16%). The initial histologic diagnosis for the remaining 582 lesions was benign. Four hundred lesions were available for follow-up; of these, 373 (93%) were mammographically categorized as BI-RADS 3 (probably benign) or 4 (suspicious). Three hundred forty-three lesions were categorized as nonproliferative and 151 as proliferative (94 had combined nonproliferative and proliferative histology). Follow-up ranged from 24 to 48 months (mean 33 months). During the follow-up period, 87 lesions (21.8%) underwent either image-guided or open biopsy. At the time of follow-up rebiopsy, ductal carcinoma in situ was found in four lesions and infiltrating ductal carcinoma was found in one, for an overall false-negative rate of 4.3% (5/117) and a negative predictive value of 98.8% (395/400). For the five false-negative cases, the interval from initial SCNB to definitive diagnosis ranged from 7 to 36 months. No correlation was found between the type of initial histopathology and development of malignancy. CONCLUSIONS: These results support SCNB as an alternative to open biopsy and show the reliability of SCNB when benign pathology is obtained. However, given the possibility of sampling error and the nature of breast disease, close mammographic and clinical follow-up is necessary. The false-negative rate and negative predictive value in this series compare favorably with those in other reports, supporting the fact that surgeons can confidently use SCNB in the evaluation and treatment of breast disease.