Pos1194 Advancing the Treatment of Idiopathic Granulomatous Mastitis: The Case for Medical Management Over Surgical Approaches

Background: Inflammatory granulomatous mastitis (IGM) is a rare benign chronic inflammatory disorder of the breast commonly seen in women of childbearing age. It is characterized pathologically by chronic granulomatous inflammation of the breast lobules without necrosis. This was first described in 1972 by Kessler and Wolloch as a benign disease entity.IGM may be unilateral or bilateral, a self-limited or persistent and recurring disease, and may leave disfiguring scars. Being a rare disease there's a lack of valid data without any agreed consensus on management [1-4]. Objectives: Our study evaluates Disease-Modifying Antirheumatic Drugs (DMARDs) in treating IGM, emphasizing multidisciplinary treatment approach and long-term care. We aim to support a transition from surgical to an interdisciplinary approach to medical management in IGM treatment. Methods: This is a retrospective study on the medical management of 52 patients of biopsy proven inflammatory granulomatous mastitis. IGM diagnosis involves a breast biopsy, preferably a core biopsy, revealing non-caseating granuloma with epithelioid histiocytes and multinucleated giant cells within breast lobules, possibly containing microabscesses. It is crucial to note that IGM is a diagnosis made through exclusionary criteria. Results: Our study examined 52 female patients with breast inflammation symptoms, confirmed by clinical examination, imaging, and biopsy. The mean age was 34 years. Two patients showed clinical and radiological signs of inflammation but had no granulomas in biopsies. Seven (13%) improved with a brief course of non steroidal anti-inflammatory medication, requiring no further treatment. Forty-five patients (87%) initially received medium-Dose prednisone, In eight patients (17%) there was complete resolution of inflammation and did not require DMARDs initiation. The remaining 37 (82%) with ongoing inflammation requiring steroids, were prescribed DMARDs, mainly Methotrexate, except in specific cases due to health conditions. Methotrexate was effective for 29 (80%) patients of which 16 (55%) completed treatment, and in thirteen (45%) patients the treatment is ongoing. Alternatives DMARDs included azathioprine,mycophenolate mofetil and calcineurin inhibitors (cyclosporine and tacrolimus). The study observed bilateral breast disease in four patients, panniculitis in five, and arthralgia in five. Patient demographics included six nulliparous women and five who had their last childbirth over a decade ago. Conclusion: Our findings highlight the effectiveness of an interdisciplinary approach in medical management using DMARDs, particularly Methotrexate, in treating IGM. A high remission rate and favorable response to DMARDs emphasizes the role of medical management for this rare, less understood disorder, and an important step towards improving patient outcomes. REFERENCES: [1] Ringsted S, Friedman M. A rheumatologic approach to granulomatous mastitis: A case series and review of the literature. Int J Rheum Dis. 2021 Apr;24(4):526-532. PMID: 33523600; PMCID: PMC8152827. [2] Hovanessian Larsen LJ, Peyvandi B, Klipfel N, Grant E, Iyengar G. Granulomatous lobular mastitis: imaging, diagnosis, and treatment. AJR Am J Roentgenol. 2009 Aug;193(2):574-81. doi: 10.2214/AJR.08.1528. PMID: 19620458. [3] Postolova A, Troxell ML, Wapnir IL, Genovese MC. Methotrexate in the Treatment of Idiopathic Granulomatous Mastitis. J Rheumatol. 2020 Jun 1;47(6):924-927. doi: 10.3899/jrheum.181205. Epub 2019 Jun 15. PMID: 31203215. [4] Di Xia F, Ly A, Smith GP. Mycophenolate mofetil as a successful therapy for idiopathic granulomatous mastitis. Dermatol Online J. 2017 Jul 15;23(7):13030/qt51g1k0zm. PMID: 29469699. Acknowledgements: NIL. Disclosure of Interests: None declared.