Diagnostic Follow-Up of BI-RADS 0: Rates of Biopsy and Malignancy in a Single-Center Cohort

Aim: Previous studies have largely focused on delays and non-adherence among patients assigned BI-RADS 0 on mammography. However, data describing diagnostic outcomes among patients who return for supplemental imaging (SI), particularly in tertiary care settings, remain limited. The aim of this study was to evaluate follow-up patterns after BI-RADS 0 mammography and to assess diagnostic outcomes, including BI-RADS reassignment, biopsy rates, and malignancy yield, among patients who completed SI.Materials and Methods: Mammograms performed at our institution between November 2023 and April 2025 were retrospectively reviewed. Patients assigned BI-RADS 0 and recalled for SI were included. Time to SI, post-imaging BI-RADS categories, biopsy performance, and pathology outcomes were analyzed. Due to skewed distributions, time-related variables were summarized primarily using medians, and appropriate non-parametric statistical tests were applied.Results: Of 780 patients assigned BI-RADS 0, 672 (86.15%) returned for SI. Most patients completed SI promptly, with 95.4% returning within 60 days. Following SI, the majority were reassigned BI-RADS 1–3, while 9.68% were categorized as BI-RADS 4 or 5. Biopsy was performed in 9.67% of patients, and malignancy was identified in 1.49% of the overall cohort. All patients with BI-RADS 5 findings and a subset of those with BI-RADS 4 findings were diagnosed with malignancy. Patients with malignant pathology underwent biopsy sooner than those with benign findings, reflecting appropriate clinical prioritization.Conclusions: In this tertiary care cohort, most BI-RADS 0 recalls were resolved rapidly with SI, and only a minority required biopsy. Malignancy rates were consistent with expected BI-RADS-associated risks, providing real-world reassurance regarding the efficiency and clinical appropriateness of diagnostic evaluation after BI-RADS 0 assessments.