Background Idiopathic granulomatous mastitis (IGM) is a rare inflammatory disease of the breast with a high recurrence rate. The serum albumin to globulin ratio (AGR) is a relatively novel biomarker in inflammatory diseases, and one whose role in the recurrence of IGM remains unknown. This study primarily investigated the potential risk factors for IGM recurrence and whether AGR can be used as a predictive factor. Methods Patients diagnosed with IGM from pathology reports between 2016 and 2021 were enrolled in the study, and their medical records were analyzed retrospectively. The patients were divided into two groups – recurrence and non-recurrence. Clinical, demographic characteristics, and laboratory parameters were compared. Results Eighty-five patients were included in the study, recurrence being detected in 16 (18.8%) of these, with a median follow-up time of 39.99±18.93 months. No relationship was determined between childbearing, breastfeeding, disease severity, or therapeutic approaches and IGM recurrence. While AGR was significantly lower in the recurrence group (p < 0.001), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) results were comparable in the two groups (p = 0.472 and p = 0.421, respectively). Multivariate analysis identified low AGR (odds ratio (OR): 50.7, 95% CI 5.93–434.1 P < 0.001) and smoking (OR: 4.45, 95% CI 1.04–18.9 P = 0.044) as independent risk factors for IGM recurrence. Conclusion The study findings indicated that AGR at a cut-off value of ≤1.179 at diagnosis and smoking exhibited a remarkable performance in predicting the recurrence of IGM. Developing new risk stratification systems for IGM recurrences and using AGR in these classifications may increase the success of treatment. Trial Registration This study was registered with ClinicalTrials.gov, NCT05409586.

Background: The albumin/globulin ratio (AGR) is one of several indicators of inflammation and immunity. This ratio has a prognostic significance in many malignant diseases. Previous studies have demonstrated a relationship between inflammatory mediators and post-operative pancreatic fistula (POPF). This study aimed to evaluate the relationship of AGR, a relatively new indicator, with post-operative pancreatic fistula (POPF). Methods: Pancreaticoduodenectomy (PD) patients between 2017 and 2020 were retrospectively analyzed and divided into two groups: (1) with and (2) without clinically relevant POPF (CR-POPF). The two groups were compared in terms of pre-operative–post-operative AGR and clinicodemographic characteristics. AGR was calculated as albumin/total protein–albumin, and the cutoff point for AGR was determined according to Youden’s index. Results: CR-POPF developed in 21% of 121 patients who underwent PD. No differences between the groups in terms of age, gender, comorbid disease status, pancreatic duct width, and anastomosis technique were found. Pre- and post-operative day-3 (POD3) albumin levels and AGR were found to be significantly lower in the CR-POPF group. Multivariate analysis showed that AGR and pancreatic tissue stiffness are independent risk factors for POPF development. Conclusion: Low AGR is an independent risk factor for the development of CR-POPF. To reduce the incidence of POPF, this ratio should be maintained at an optimal level. The use of AGR as a useful tool for predicting POPF in pancreaticoduodenectomy patients is suggested.