Accuracy of mammographic findings in breast cancer: correlation between BI-RADS classification and histological findings* Acurácia dos achados mamográficos do câncer de mama: correlação da classificação BI-RADS e achados histológicos

OBJECTIVE: The present study was aimed at evaluating the BI-RADS® classification accuracy in mammography. Additionally, the frequency of different findings was described and the interobserver agreement was evaluated. MATERIALS AND METHODS: Mammographic images of 115 patients were independently and blindly reviewed by two specialists in compliance with BI-RADS recommendations, and later compared with histological data. The BI-RADS accuracy in mammography was evaluated. The interobserver agreement was analyzed with the Cohen’s kappa (κ) test, and the differences between groups were evaluated with the chi-squared test. RESULTS: The present study demonstrated that the mammographic accuracy ranged from 75% to 62% in the differentiation between benign and malignant lesions with the utilization of the BI-RADS classification. Statistically significant interobserver agreement was observed in the description of masses margins (κ = 0.66). A low agreement rate was identified in the description of masses borders (shape) (κ = 0.40) and calcifications, both in relation to their distribution (κ = 0.24) and morphology (κ = 0.36). CONCLUSION: The present study demonstrated the BI-RADS accuracy in the differentiation between benign and malignant lesions. The interobserver agreement was poor in the analysis of calcifications morphology and distribution, but a progressive increase in the positive predictive values was observed in the subcategory 4.