White Blood Count Can Be a Practical Guide for the Differential Diagnosis of Breast Abscess and Idiopathic Granulomatous Mastitis.

Introduction and aim Idiopathic granulomatous mastitis (IGM) is an inflammatory disease of the breast and has the same symptoms and radiologic imaging as breast abscess (BA). The aim of this study is to evaluate the use of inflammatory markers as white blood count (WBC), C-reactive protein (CRP), and neutrophil to lymphocyte ratio (NLR) as a potentially useful tool for the differential diagnosis of BA and IGM. Methods In this retrospective study, we analyzed 31 patients with IGM and 47 patients with BA between January 2013 and April 2020. Age, symptoms, symptomatic breast side, microbiological culture, complete blood count, and C-reactive protein (CRP) values of patients were analyzed. Receiver operating characteristic (ROC) curve analysis was used to define the optimal cut-off for WBC, CRP, and NLR. Results WBC was significantly higher in the BA group compared to the IGM group (11.45 vs. 9.78; p=0.042), but no difference was found for CRP and NLR between these groups (p=0.146, p=0.081, respectively). In ROC analysis results in BA group, cut-off values, the best sensitivity and specificity for WBC, CRP, and NLR were 8.46 × 103 /μL (81%-70%), 1.5 mg/dl (77-76%), and 2.93 (70-82%), respectively. For IGM group, cut-off values, the best sensitivity and specificity for WBC, CRP and NLR were 8.49 × 103 /μL (74-70%), 1.5 mg/dl (61-76%) and 2.29 (64-72%), respectively. Conclusion This study showed that CRP and NLR cannot be used as a useful tool for differential diagnosis of IGM; furthermore, WBC is a parameter that can act as a practical guide for the differential diagnosis of BA and IGM.