Personalized Treatment Outcomes in Idiopathic Granulomatous Mastitis: A Retrospective Study of Ninety-Two Patients

Idiopathic granulomatous mastitis (IGM) is a rare benign inflammatory breast disease with a high risk of relapse. The study objective was to evaluate relapse predictors and treatment outcomes in a large cohort of IGM patients.

We retrospectively analyzed female patients diagnosed with IGM (2018-2024) at the Central Military Hospital, Baku. Diagnosis was confirmed by core needle biopsy. Patients were managed with systemic therapy (corticosteroids and/or immunosuppressants) when clinically indicated; local measures (e.g., aspiration/drainage, intralesional steroid) were used selectively in localized disease. Relapse was defined as reappearance of clinical or radiological findings after remission. Univariable and multivariable logistic regression models were applied to identify independent predictors.

The cohort consisted of 92 patients. Relapse occurred in 22/85 methotrexate-treated patients (25.9%), with most relapses occurring between the third and fifth months. No relapse events were observed in the azathioprine subgroup (n = 7). However, this finding should be considered observational only due to the small numbers and zero-event data. In multivariable analysis, erythrocyte sedimentation rate (ESR) >20 mm/h (and angiotensin converting enzyme >52 U/L, where applicable) were associated with relapse, whereas apparent associations with tumor necrosis factor alpha inhibitors and cyclosporine likely reflect confounding by indication because these agents were used as rescue therapy in refractory/relapsing disease. Elevated ESR was also associated with prolonged treatment duration (p = 0.006).

A structured and individualized treatment approach may contribute to favorable clinical outcomes in patients with IGM. Observed relapse patterns support the importance of risk-adapted management rather than a uniform therapeutic strategy. Given the retrospective design and limited subgroup sizes, these findings should be interpreted cautiously and considered hypothesis-generating. Prospective, multicenter studies are required to validate relapse-associated factors and optimize treatment strategies.