The effectiveness of local steroid injection for the treatment of breast-limited idiopathic granulomatous mastitis: A randomized controlled clinical trial study.

<b>Introduction:</b> Idiopathic granulomatous mastitis (IGM) is a rare, non-specific inflammatory breast disease. There are severalcontroversies regarding its standard treatment.<b>Aim:</b> We aimed to evaluate the efficacy of local corticosteroid injection compared to systemic steroids and combined treatment of both in IGM patients.<b>Methods:</b> In this randomized controlled clinical trial study, 115 IGM patients were randomly allocated to three groups of localsteroid injection (Betamethasone, n = 37), systemic steroid treatment (Prednisolone + MTX, n = 37), or combined treatment ofboth (n = 41) for a follow-up period of 10 months. Clinical presentations and outcomes were compared between the groups.<b>Results:</b> The mean age of the study patients was 35.6 years. The mean time to complete remission was 3.17, 4.33, and 6.37 months, and the relapse rate during the treatment was 0%, 5.26%, and 13.33% in the injection, combined, and systemic therapy groups, respectively. There was no significant difference between the clinical response to treatment rate and the recurrence rate during the follow-up between the groups. Four patients in the combined therapy group and 3 patients in the systemic therapy group had steroid side effects, with no side effects in the injection group.<b>Conclusions:</b> Steroid injection therapy is more effective than combined therapy and systemic therapy in terms of remission and relapse rate during the treatment, and is as effective as systemic therapy in the clinical response to treatment rate and the recurrence rate during the follow-up period. Regarding the lack of side effects of the steroid injection therapy, this approach could be considered among the first-line treatment options.