From the 2023 HVPA National Conference
Houda Bouhmam MD (Rutgers Robert Wood Johnson Medical School), Ellen Lee MD
In the United States, more than 1 million breast biopsies are performed annually, and approximately 80% of cases are benign. The new BI-RADS provides specific PPV cut-off points for BI-RADS subcategories 4A/4B/4C, which align with certain specific radiographic findings. The use of these subcategories is optional in the new edition but is strongly encouraged. The controversy here is that tissue diagnosis is still recommended for all BIRADS 4 lesions. The objective of this study is to describe pathology results for BI-RADS 4 screening mammograms and to discuss the benefits of BI-RADS 4 subcategories in predicting the likelihood of malignancy. This study reviews the pathology results of screening mammograms that were classified as BI-RADS 4 in a six-month period of 01/01/2021 to 06/31/2021. Mammograms without reported pathology results and those with at least one mammographic finding classified as BIRADS 5 or higher were excluded from this evaluation. The pathology results were divided into three categories: benign, high risk and malignant. Of the 346 breast lesions biopsied, 52 lesions were malignant (15%), 280 lesions were benign (81%), and 13 lesions were high risk (4%). The PPV for malignancy was 15%. Invasive ductal carcinoma was the most common malignant pathology. Fibroadenoma was the most common benign pathology. BI-RADS 4 includes many patients who do not have malignant or even high-risk lesions. Category 4 subdivisions are encouraged in practice because of their potential benefits, but little is known about their utilization and outcomes. Our study results align with many previous studies in that BI-RADS 4 biopsy rate is high for benign breast tissue. A study by Elvareci et al., where 37.8% of evaluated cases were malignant, concluded that biopsy is required because BI-RADS criteria are not sufficient for discriminating between malignant and benign lesions. However, many studies support the usefulness of subcategories 4A, 4B, and 4C in predicting the likelihood of malignancy. Thus, it is recommended to implement them in practice to potentially reduce benign biopsies. Future studies will assess the impact of this implementation on biopsy rate and pathology results.