Idiopathic granulomatous mastitis: Multicenter study

INTRODUCTION: Idiopathic granulomatous mastitis (IGM) is a rare, benign, chronic inflammatory breast disease of unknown etiology. There is no standardized treatment since its etiology is still unclear. In this multicentre study, we aimed to present the demographic, treatment, and follow-up characteristics of IGM cases monitored by rheumatology clinics.
METHODS: This retrospective study was performed in 13 different rheumatology centers. A total of 108 IGM patients were included in the study. Demographic and clinical data were obtained retrospectively from patient files.
RESULTS: The most commonly administered drugs were, in order of frequency, corticosteroid (CS) (91.7%), methotrexate (MTX) (74.1%), antibiotics (63%), non-steroidal anti-inflammatory drugs (NSAIDs) (41.7%), azathioprine (AZA) (13.9%), colchicine (5.6%) and TNF inhibitors (0.9%). The most commonly used form of immunosuppressive (IS) treatment was MTX and CS combination 78 (72.2%). The ratio of patients receiving CS alone was 19 (17.6%). The ratio of patients who were operated on only and did not use IS drugs was 6.5%. The ratio of patients who received no treatment was 2.8%. Among the drugs used, MTX and CS alone use were independent risk factors for relapse; (p=0.027, p=0.011, respectively). The relapse rate was higher in patients receiving CS alone.
DISCUSSION AND CONCLUSION: IS drugs including CS, MTX, AZA, or TNF inhibitors are seem to be efficient in the treatment of IGM. CS alone use is associated with relapse, especially the use of other IS drugs such as MTX is effective in reducing relapse in IGM.