Granulomatous Mastitis: Comparison of Novel Treatment of Steroid Injection and Current Management.

BACKGROUND: Granulomatous mastitis (GM) is a rare entity of benign origin. Multiple treatment strategies, including surgical procedures, can have sequelae of recurrence, nonhealing wounds, and protracted pain. Even after GM is diagnosed, the best management strategy remains controversial. We sought to evaluate intralesional steroid injection as a potential treatment for GM. MATERIALS AND METHODS: Electronic medical records from 2003 to 2017 of patients diagnosed with benign breast lesions were retrospectively reviewed. Patients with pathologically confirmed GM were identified. All treatment methods were documented, which included observation, oral steroids, methotrexate, steroid injection, and surgical excision. Primary outcome was time to resolution. Effectiveness was based on relief of symptoms along with duration of symptoms from initial time of diagnosis to full relief. Analysis of variance was used to compare outcomes between groups. RESULTS: Of the 49 patients with confirmed GM diagnoses, 57% had observation only, 24% had steroid injection, and 19% had surgical resection. The average time to resolution differed significantly among the three groups (11.5 mo from the start of observation, 2.0 mo from the time of steroid injection, and 0.5 mo from the time of surgical excision, P < 0.001). CONCLUSIONS: Intralesional steroid injection is an effective treatment of GM. Selective management is appropriate for patients with GM, and surgical resection is not required for most patients.