Introduction: Breast lesions of uncertain malignant potential (B3) include a heterogeneous group of histological entities associated with a variable risk of concurrent or subsequent carcinoma. The term upgrade refers to the identification of ductal carcinoma in situ (DCIS) or invasive carcinoma in the surgical specimen following an initial B3 diagnosis obtained by percutaneous biopsy.
Objective: To evaluate radiopathologic correlation, therapeutic management, and upgrade rate in B3 lesions diagnosed at our institution.
Materials and Methods: A single-center retrospective observational study was conducted. All breast biopsies performed between July 2024 and August 2025 with a histological diagnosis of B3 lesion obtained by core needle biopsy or vacuum-assisted biopsy (VAB) were included. Clinical, imaging, histological variables, therapeutic management, and final pathological outcomes were analyzed.
Results: A total of 759 breast biopsies were analyzed, identifying 42 B3 lesions (5.53%). The predominant imaging finding was microcalcifications (73.8%). Diagnosis was made by VAB in 76.2% of cases. The most frequent lesion was flat epithelial atypia (52.3%). Surgical treatment was performed in 59.5% of patients. The overall upgrade rate was 16.7%, with half of the upgraded cases corresponding to DCIS.
Conclusion: The frequency of B3 lesions and the observed upgrade rate are consistent with the literature. Radiopathologic correlation and appropriate patient selection allow for individualized management, reducing unnecessary surgeries without compromising oncologic safety.