Abstract PS4-08-05: Evaluating Idiopathic Granulomatous Mastitis Using the Inflammatory Breast Cancer Scoring System: A Comparative Study Highlighting the Role of Pain as a Diagnostic Criterion

Abstract Evaluating Idiopathic Granulomatous Mastitis Using the Inflammatory Breast Cancer Scoring System: A Comparative Study Highlighting the Role of Pain as a Diagnostic Criterion Background: Idiopathic granulomatous mastitis (IGM) is an inflammatory condition which has similar characteristics to inflammatory breast cancer (IBC). We sought to utilize the published IBC scoring system to compare scores between patients diagnosed with IBC and GM. Methods A retrospective chart review of patients with biopsy proven IGM and IBC from January 2014 to September 2024 was performed. Patient demographics, diagnostic imaging, clinical assessments, and treatments used (oral or intralesional steroids and immunomodulatory drugs) were reported from the EHR. The IBC scoring system1 was used, which included 6 of the 7 reported criteria: timing of symptoms, skin changes, breast swelling, erythema, nipple abnormalities, and breast imaging findings. Lymphatic tumor cell emboli biopsy results were excluded from GM patients, and the maximum modified score was 42. We separately compared scores with and without biopsy results. We then applied the proposed classifications of the DEFINITELY IBC (total score ≥ 42); STRONG POSSIBILITY (25-41); WEAK POSSIBILITY (14-24); and NOT IBC < 14). We then examined a separate pain score from 1-10 as a separate predictor. T-test was used for statistical analysis. Results 8 patients with IBC were identified and compared with 77 patients with GM. Patients with diagnosed IBC had a higher average score of 21.5 compared to 17.8 for those with diagnosed GM. However, at each score category there was no overall statical difference in average scores (Table1). When a separate pain scale score was evaluated, patients with GM presented with a significantly higher average pain reported than those with IBC (7.8 vs 2.3, p= .00008) Conclusion Patients with IGM present with similar characteristics to IBC. When utilizing the IBC scoring system for diagnosis, GM patients had similar scores as those with IBC. Most had scores in either weak or strong possibility of IBC categories. However, the most significant difference noted between these 2 groups is the maximum pain reported by the patients. Given this similarity, we propose a new scoring criterion with the inclusion of pain for prediction of GM. Citation Format: J. Tsai, K. Stone, I. Wapnir, J. Hong. Evaluating Idiopathic Granulomatous Mastitis Using the Inflammatory Breast Cancer Scoring System: A Comparative Study Highlighting the Role of Pain as a Diagnostic Criterion [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS4-08-05.