With improvements in breast imaging and minimally invasive interventions, detection of early breast cancer has increased. However, with the improved diagnostic capabilities, the risk of false-positive benign lesions as well as lesions classified as B3 by histopathology has also increased. Varying rates of malignancies are associated with B3 lesions, raising the question of whether such lesions should always be surgically removed. The results of our retrospective analysis should assist in this decision-making process.307 core needle or vacuum-assisted needle biopsies in which B3 lesions were found were examined. The most common lesions were intraductal papillomas (44 %), atypical ductal hyperplasia (22.8 %), flat epithelial atypia (9.4 %), phyllodes tumours (6.5 %), radial scars (5.9 %), LIN 1 (4.9 %), complex fibroadenomas (3.3 %) and LIN 2 (1.6 %). The frequencies depended considerably on whether the tissue was obtained by core biopsy or vacuum biopsy. Stereotactic vacuum biopsy was generally performed in the case of microcalcification not apparent on sonography. Lesions visible on ultrasound had core needle biopsy.Surgery was performed in 254 cases and a malignancy was found in 27.2 % on the final histopathology. Malignancy was found in 24.6 % of 114 cases initially diagnosed as intraductal papilloma. Similarly, cancer was discovered in 48.4 % of the 62 cases of atypical ductal hyperplasia, in 2.4 % of the 41 cases of flat epithelial atypia, complex fibroadenoma and phyllodes tumour, in 20.7 % of the 29 cases of LIN 1 and radial scar as well as in 50 % of the 8 cases of LIN 2, adenomyoepithelioma and atypical apocrine metaplasia.These data indicate the necessity for complete surgical removal of a B3 lesion when it is discovered using the core needle or vacuum-assisted biopsy technique. The decision not to perform surgery can be made when the risk of associated malignancy is deemed low in the clinical pathology conference, but careful follow-up is essential.