Evaluation of Two-Year Follow-Up of Patients with BI-RADS 3 Breast Ultrasound Lesions in a Single Private Ultrasound Study.

Background: This study assessed the frequency and progression rate of BI-RADS 4 or BI-RADS 2 during a two-year follow-up of patients with BI-RADS 3 on ultrasound screening. Materials and Methods: This descriptive cross-sectional study was conducted on patients with BI-RADS 3 lesions who entered to study from 2013 to 2018 and underwent an ultrasound on the months of 6 Results: The study included six hundred-four patients with BI-RADS 3 lesions at baseline. Participants' mean ± SD (median, min-max) age was 413 ± 9.7 (40, 19-75). By month 24, BI-RADS 3 changed to BI-RADS 2 in 585 (96.6%) and BI-RADS 4 in 19 (3.1%) cases.Considering the size of breast lesions, the breast sensitivity and specificity for predicting size progression and changing to BI-RADS 4 were as follows: For long axis diameter, 12 mm at baseline with 72.22% sensitivity and specificity of 71.53% and 16 mm in 6 months follow-up with sensitivity of 75% and specificity of 83.78%.For short axis diameter, 6 mm at baseline with a sensitivity of 83.33% and specificity of 62.89% and 8 mm in 6 months follow-up with a sensitivity of 66.67% and specificity of 83.48%. Conclusion: The breast lesion size was the most crucial factor in altering the BI-RADS 3 to 4.