Accuracy of imaging of BI-RADS 4 subcategorizations in breast lesion diagnosis: Radiologic-pathologic correlation.

Objectives: To correlate breast imaging-reporting and data system (BI-RADS) category 4 lesions with histopathology results to assess the accuracy of subcategorization.

Methods: A retrospective study was carried out from September 2021 to June 2022. A total of 247 breast lesions were reviewed categorized as BI-RADS 4 using ultrasound (US) and digital mammography. Feature analysis of the lesions were obtained using BI-RADS terminology and assigned to subcategories (4A, 4B, and 4C). Pathological analysis was carried out on tissue obtained through US-guided core biopsy. A p-value of <0.05 was considered significant.

Results: Of the 247 lesions, 135 were categorized as subcategory 4A, 68 as 4B, and 44 as 4C. Overall, 41 (16.6%) had malignant lesions, while 206 (83.4%) had benign lesions. The mean age of the patients with benign versus malignant lesions was (43.18±14.02 vs. 51.24±14.15 years; p<0.001). Mean size of benign versus malignant lesions was (1.93±1.65 vs. 3.82±3.89 cm; p<0.001). Findings were compared with histopathology, and the positive predictive value fell within the reference range for subcategories 4C (>70%). High reliability was observed between the 2 readers, with a weighted Cohen's Kappa value of 0.79 (0.73-0.85). Significant disagreements in the assignment of features on radiological lesion characterization were observed between the 2 readers regarding lesion density, shape, echo pattern, vascularity, and borders.

Conclusion: The results of this study contribute to the existing body of knowledge, emphasizing the need for standardized guidelines for the characterization of BI-RADS 4 subcategories and improved diagnostic accuracy in the management of breast lesions.