Ultrasound-guided mammotome vacuum biopsy for the diagnosis of impalpable breast lesions

OBJECTIVES: To assess the diagnostic accuracy of ultrasound-guided mammotome vacuum biopsy in impalpable breast lesions. METHODS: Seventy-three patients who presented with impalpable breast lesions that were suspicious for malignancy at mammography and/or sonography were included in the study. In the first instance the women underwent ultrasound-guided fine-needle aspiration cytology, then, 3 days later, histological biopsy with an ultrasound-guided mammotome device. The patients with both cytological and histological diagnoses of malignancy underwent surgery; those with a negative (for malignancy) cytological diagnosis, but with a histological diagnosis of atypical hyperplasia or sclerosing adenosis, underwent surgical biopsy. RESULTS: The diagnostic accuracy of fine-needle aspiration cytology was 67.2%; the sensitivity was 86.7%, the specificity was 48.4%, the negative predictive value was 78.9% and the positive predictive value was 61.9%. In comparison, the diagnostic accuracy of histological sampling by mammotome vacuum biopsy was 97.3%; the sensitivity was 94.7%, the specificity was 100%, the negative predictive value was 94.6% and the positive predictive value was 100%. Thus there was a statistically significant difference in diagnostic accuracy between fine-needle aspiration cytology and mammotome vacuum biopsy (67.2% vs. 97.3%; chi2 test, P < 0.001). The 2.7% (2/73) failure rate of mammotome biopsy was likely to be due to an error in the positioning of the needle. The subsequent surgical biopsy proved that two cases, negative for malignancy by mammotome biopsy, were in fact malignant. CONCLUSIONS: Our data confirm the value of sonography for the diagnosis of breast carcinoma in the preclinical phase and the efficacy of ultrasound sampling using a mammotome device to confirm the diagnosis in impalpable breast lesions.