RESUMEN
<p><b>OBJECTIVE</b>To investigate the accuracy, consistency and related affecting factors in pathological results of breast lesions diagnosed by ultrasound-guided core needle biopsy (CNB) and conventional excision histopathology.</p><p><b>METHODS</b>The clinical data of 177 consecutive cases of breast lesions examined by ultrasound-guided CNB and subsequently excised were reviewed from Jan. 2003 to Nov. 2009. The agreement of pathological diagnosis between the CNB and subsequent excision pathology was analyzed.</p><p><b>RESULTS</b>There were 136 cancers in the final diagnosis after surgical excision among 386 breast lesions and 129 of them were diagnosed by CNB. The sensitivity (true positive) of CNB was 94.9%, false negative rate was 5.1%, specificity (true negative) was 100%, false positive rate 0, Youden's index was 0.949, and positive predictive value and negative predictive value were 100% and 85.4%, respectively. Condensation rate was 96.0% and Kappa value was 0.895.</p><p><b>CONCLUSION</b>Ultrasound-guided CNB with histopathological assessment is accurate in diagnosis of breast lesions and has a great consistency with conventional excision pathology. It is a reliable method for the diagnosis of breast lesions to avoid an over-reliance on excision pathological examination.</p>