Background: Idiopathic granulomatous mastitis (IGM) is a chronic, inflammatory breast condition of benign nature that can clinically mimic breast cancer. Patients frequently present with a large, painful breast mass with associated inflammatory changes of the skin, and possible ulceration or fistula of the breast. Attempted methods for symptomatic relief include surgical excision and medical therapies including oral corticosteroids. Due to the success of treating dermatologic conditions with intralesional steroid injections, it was hypothesized that injecting the subdermal lesions of IGM may benefit patients with this disease. The use of intralesional steroid injections for the treatment of IGM has not been previously described in the literature.
Methods: Retrospective chart review was performed on a series of four patients with IGM who received intralesional steroid injections between August 2017 and April 2018. Patients were selected for treatment with injections based on their subjective report of painful breast lesions, lesion characteristics including size and depth, and the patient's desire to stop oral steroid therapy due to side effects despite active or residual disease. Data were collected on demographics, initial physical examination findings, prior and current treatments, characteristics of disease, details of injections performed, objective and subjective response to treatment, and recurrence.
Results: All patients presented with breast pain and either a mass, swelling, or hardness of the breast. Each patient received between one and three injection treatments, with one to four lesions treated in each session. Patients demonstrated improvement in subjective and objective symptoms after 87.5% of injection sessions (7 out of 8) by the subsequent follow-up visit (21-34 days). During the study period, three patients experienced resolution of at least one breast lesion within about 2 months (31-139 days, mean 68 days) without recurrence. One patient had four breast lesions that completely resolved (35-217 days, mean 88 days), but three of them recurred (63-217 days, mean 149 days).
Conclusion: In a small group of patients with idiopathic granulomatous mastitis, intralesional steroid injections were associated with an improvement in both subjective symptomatic relief and objective breast lesion characteristics in most cases. This treatment was associated with a good rate of lesion resolution and a low short-term recurrence rate.
Citation Format: Manst DJ, Ganschow PS, Marcus EA, Holden C, Datta S. Intralesional steroid injection: A novel method to treat the symptoms of idiopathic granulomatous mastitis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-14-10.