Drug-free remission is an achievable target with immunosuppressive treatment in idiopathic granulomatous mastitis.

Background: Idiopathic granulomatous mastitis (IGM) is a rare inflammatory breast disease, in which there is no clear established treatment algorithm. Several physicians keep away from using immunosuppressive (IS) treatments in routine clinical practice.

Aims: This study aimed to evaluate the rates of drug-free remission of the patients with IGM in a period of 3-year follow-up.

Methods: This retrospective study conducted with 55 biopsy-proven IGM patients, who were followed up between February, 2011, and November, 2021, in rheumatology outpatient clinic of Gulhane Training and Research Hospital. The demographic and clinical characteristics of the patients were obtained from patients' files. The 3-year follow-up data were assessed for long-term outcome analyses.

Results: There were 55 female patients with a mean age of 36.8 ± 6.3 years. Fifty-four (98.1%) patients were in drug-free remission at the end of 3 years. The median duration of drug-free remission in patients receiving methotrexate (MTX), only corticosteroid (CS), and azathioprine was 19.7, 32.9, and 14.7 months, respectively. The drug-free remission duration for the patient who received cyclosporine A as IS was 28.3 months. The median duration of IS treatment was 15.8 months, and the median duration of treatment with CS and other IS combination was 6.7 months. Recurrence was observed in 4 (80%) patients without IS therapy after surgery, of whom MTX was used in 3 (75%) patients and achieved remission.

Conclusions: IS agents provide high rate of prolonged drug-free remission and should be considered a part of routine medical care of the patients with IGM.