Accuracy and upgrade rates of percutaneous breast biopsy: the surgeon's role.

We sought to evaluate the impact of needle core size and number of core samples on diagnostic accuracy and upgrade rates for image-guided core needle biopsies of the breast. A total of 234 patients underwent image-guided percutaneous needle biopsies and subsequent surgical excision. Large-core needles (9 gauge or less) were used in 14.5 per cent of cases and the remainder were performed with smaller core needles. More than four core samples were taken in 78.9 per cent of patients. In 71.8 per cent of cases, needle biopsy pathology matched surgical excision pathology. After surgical excision, upgraded pathology was revealed in 10.7 per cent of cases. Of 11 patients (52.4%) with benign needle core pathology who had upgraded final pathology on surgical excision, 10 had a Breast Imaging Recording and Data System score 4 or 5 imaging study. Lesions smaller than 10 mm were more likely to be misdiagnosed (P = 0.01) or have upgraded pathology (P = 0.009). Other predictors of upgraded pathology were patient age 50 years or older (P = 0.03) and taking four or fewer core samples (P = 0.003). Needle core size did not impact accuracy or upgrade rates. Surgeons should exercise caution when interpreting needle biopsy results with older patients, smaller lesions, and limited sampling. Discordant pathology and imaging still mandate surgical confirmation.