Intralesional Steroid Injections for Management of Granulomatous Mastitis: A Systematic Review of Treatment Protocols and Clinical Outcomes

Abstract

Introduction: Although idiopathic granulomatous mastitis (GM) of the breast is a benign condition, it can be locally aggressive and frequently chronic, causing significant pain and distress to the patient. Treatment often involves multiple disciplines including general practice, breast surgery/physicians, rheumatology and/or immunology. Traditional options for treatment include observation, oral steroids, methotrexate and/or surgery, all with variable outcomes. A more recent alternative treatment option involves intralesional steroid injections. Methods: Using PRISMA methodology, a systematic review of intralesional steroid injection for the management of GM was conducted. Medline, PubMed, Embase and Cochrane databases were searched for original studies reporting treatment protocols and clinical outcomes, published up to the end of September 2023. Results: Nine eligible studies reported outcomes in 474 patients undergoing treatment of GM with intralesional injections. All studies reported success (improvement in clinical and/or imaging appearance) with intralesional injections. Studies that had a comparison group showed statistically significantly fewer side effects compared to oral steroids or surgical management. The recurrence rate was less for intralesional injections than for other treatments in all studies except one. No studies included patient-reported outcomes. Conclusion: There is consistent evidence for the safety, efficacy and low recurrence rate with intralesional steroid injections for GM. The existing literature is heterogenous with respect to injection protocols, and the optimal protocol is unclear. Future research should compare the various steroid agents and dose/frequency of administration. Future studies should include cost analysis and patient-reported outcomes to ensure that the treatment is cost-effective and acceptable to people with idiopathic GM.