Breast Imaging Reporting and Data System (BI-RADS) is a comprehensive guideline to standardize breast imaging reporting and as per its recommendations, any lesion with likelihoods of malignancy greater than 2% (BI-RADS 4 and 5) are deemed as suspicious and tissue diagnosis is recommended.

Purpose. To assess the positive predictive value (PPV) for breast cancer in BI-RADS categories 4a, 4b, and 4c. To evaluate the impact of demographic, clinical presentation and mammographic morphological variables influencing PPV values in BI-RADS 4 subgroups. Defining low-risk parameters where close follow up can be recommended rather than biopsy.

Materials and methods. Retrospective study on medical records of 123 patients with a BI-RADS 4 score regarding demographics, clinical presentation, mammography, and biopsy are performed. Predictive values and Odds ratio are calculated using logistic regression and chi-square analysis.

Results. PPV for BI-RADS subcategories 4a, 4b and 4c, were 34%, 89% and 97%, respectively. BI-RADS 4c patients tend to be older (50.2 + 12.2years) with larger mass (44+16mm) at presentation than 4a. Postmenopausal status and advanced patient age are seen more associated with malignancy outcomes in the BI-RADS 4a sub-category. Benign outcomes are seen in all cases with the BI-RADS 4a subcategory in less than 40 years of age group.

Conclusion. Immediate biopsy is recommended for all lesions with BI-RADS 4b, 4c and 4a score with age more than 40 years but additional imaging or follow up can be advised in patients less than 40 years in BI-RADS 4a subgroup. A higher rate of observed PPV in BI-RADS 4a and 4b categories in the present study could be due to the subjectiveness of the category assignment.