Management of B3 breast lesions: Potential clinical implications from a retrospective study conducted in an accredited Breast Unit following the 2024 EUSOMA guidelines

B3 breast lesions present significant challenge in breast surgery. Despite their relatively low risk of malignancy without cellular atypia, overtreatment remains common. We retrospectively evaluate the management of B3 lesions in an accredited-EUSOMA Breast Unit, comparing 10-years practices with 2016 and 2019 international Consensus Conferences and with 2024 EUSOMA guidelines. The study included 354 patients diagnosed with B3 lesions, evaluating guideline adherence, malignancy risk in non-adherent cases, and biopsy-to-final pathology concordance. Adherence to guidelines varied by lesion type, with 46.3 % of cases potentially involving avoidable surgeries, 9.1 % of which were found to be malignant. Additionally, discrepancies between biopsy and final histology were significant, with 43.2 % of lesions showing different histological types. These findings emphasize the importance of updated guidelines to reduce overtreatment, encourage minimally invasive treatments and highlight the need of multidisciplinary discussions in managing B3 lesions, especially when there is a discrepancy between imaging and preoperative biopsy.