Ultrasound-guided Tru-cut biopsy of the breast.

Ultrasound-guided automated Tru-cut needle biopsy may be used as an alternative to fine needle aspiration cytology for the assessment of discrete mass lesions of the breast. This is a retrospective study of 187 biopsies, comparing the results with a final diagnosis obtained from subsequent excision or outpatient follow-up. Biopsies were performed using a spring-loaded gun under ultrasound guidance. Invasive malignancy was demonstrated in 114 biopsies, 98 of which were subjected to surgery, with no false-positives. Twelve biopsies contained 'atypical cells', pre-invasive malignancy or risk factors for invasive carcinoma, ten of which proved to be invasive malignancy on excision. Normal or benign tissue was found in 61 biopsies, but of those that proceeded to excision biopsy, 16 were invasive or in situ carcinoma. The sensitivity of the procedure for detecting significant pathology was 88.7%, and the specificity 100%. When used as part of triple assessment, the sensitivity increases to 97.9%. Ultrasound-guided Tru-cut needle biopsy is a well-tolerated and reliable procedure for providing a tissue diagnosis of malignancy before definitive treatment, and obviating the need for formal excision biopsy of lesions for which there is a low index of suspicion.