Impact of Contrast-Enhanced Mammography on Breast Imaging Reporting and Data System (BI-RADS) Reclassification: Correlation With Histopathology and Clinical Outcomes.

PURPOSE: This study aims to evaluate how contrast-enhanced mammography (CEM) modifies the Breast Imaging Reporting and Data System (BI-RADS) classification initially assigned on digital mammography (DM), and to assess the accuracy of CEM-driven upgrades, downgrades, and confirmations using histopathology as reference.

METHODS: This was a retrospective observational study that included symptomatic patients who underwent both DM and subsequent CEM within a short interval. The initial BI-RADS grading was assigned based on DM findings, while CEM findings were categorized as either correct or incorrect upgrades, downgrades, or confirmations, based on final histopathology or follow-up results. The study included 60 patients across all grades of BI-RADS.

RESULTS: Among patients initially assigned BI-RADS 0-5 on DM, CEM correctly upgraded 12 lesions and correctly downgraded six lesions. CEM also incorrectly upgraded seven lesions and incorrectly downgraded two lesions. The BI-RADS category was correctly confirmed in the remaining 33 patients. The lesions upgraded in several BI-RADS 0 and 4 cases were occult or subtle enhancement revealed as invasive carcinoma on histopathology. False-positive upgrades were seen in cases of fibroadenoma and sclerosing adenosis, while false-negative downgrades occurred in two BI-RADS 5 lesions that showed no enhancement but proved malignant on histopathology. CEM also aided in downgrading post-surgical and inflammatory changes accurately, improving confidence in excluding recurrence or malignancy.

CONCLUSION: CEM improves the diagnostic performance of digital mammography by providing additional functional information related to tumor vascularity, allowing more accurate characterization of breast lesions. In this study, CEM correctly upgraded, downgraded, or confirmed BI-RADS classifications in the majority of patients, particularly in cases with dense breast tissue and indeterminate mammographic findings. By revealing mammographically occult malignancies and confidently excluding benign or post-treatment changes, CEM reduced diagnostic uncertainty and supported more appropriate patient management. Although false-positive and false-negative findings were observed, these limitations underscore the need for careful interpretation alongside conventional imaging and clinical correlation.