Idiopathic granulomatous mastitis (IGM) is a chronic, non-cancerous inflammatory breast disease with unknown causes, characterized by symptoms such as skin redness, a firm and tender breast mass, and mastalgia. It often mimics breast abscesses or malignancies, particularly inflammatory breast cancer, and lacks standardized treatment options. Diagnosis relies on core needle biopsy and histopathological examination. The prevailing etiological theory suggests IGM is an autoimmune disease, as some patients respond well to steroid treatment, and the presence of erythema nodosum or other autoimmune conditions supports this. The review discusses the autoimmune features of IGM, its potential etiologies, and immune-mediated pathogenesis, proposing immunotherapeutic strategies. IGM is associated with erythema nodosum and arthritis, which are also autoimmune manifestations. It can coexist with other autoimmune diseases like systemic lupus erythematosus and Sjögren's syndrome, indicating shared etiopathogenesis. Seasonal fluctuations in IGM onset have been observed, suggesting environmental factors may influence its development. Pregnancy and lactation are risk factors for IGM recurrence, and hormonal imbalances, such as hyperprolactinemia, may contribute to its pathogenesis. Trauma and ductal epithelial damage can trigger IGM, while smoking and microorganisms are also potential risk factors. The immune pathogenesis of IGM involves cellular dysregulation, cytokine activity, and HLA expression. Conventional treatments include steroids and immunosuppressive agents like methotrexate and azathioprine. Emerging biologic agents, such as TNF inhibitors and B-cell depleting drugs, show promise in treating IGM. Despite these advances, the exact mechanisms and effective treatments remain areas of ongoing research. The review highlights the need for further studies to clarify the etiology, immunological mechanisms, and optimal therapeutic approaches for IGM.Idiopathic granulomatous mastitis (IGM) is a chronic, non-cancerous inflammatory breast disease with unknown causes, characterized by symptoms such as skin redness, a firm and tender breast mass, and mastalgia. It often mimics breast abscesses or malignancies, particularly inflammatory breast cancer, and lacks standardized treatment options. Diagnosis relies on core needle biopsy and histopathological examination. The prevailing etiological theory suggests IGM is an autoimmune disease, as some patients respond well to steroid treatment, and the presence of erythema nodosum or other autoimmune conditions supports this. The review discusses the autoimmune features of IGM, its potential etiologies, and immune-mediated pathogenesis, proposing immunotherapeutic strategies. IGM is associated with erythema nodosum and arthritis, which are also autoimmune manifestations. It can coexist with other autoimmune diseases like systemic lupus erythematosus and Sjögren's syndrome, indicating shared etiopathogenesis. Seasonal fluctuations in IGM onset have been observed, suggesting environmental factors may influence its development. Pregnancy and lactation are risk factors for IGM recurrence, and hormonal imbalances, such as hyperprolactinemia, may contribute to its pathogenesis. Trauma and ductal epithelial damage can trigger IGM, while smoking and microorganisms are also potential risk factors. The immune pathogenesis of IGM involves cellular dysregulation, cytokine activity, and HLA expression. Conventional treatments include steroids and immunosuppressive agents like methotrexate and azathioprine. Emerging biologic agents, such as TNF inhibitors and B-cell depleting drugs, show promise in treating IGM. Despite these advances, the exact mechanisms and effective treatments remain areas of ongoing research. The review highlights the need for further studies to clarify the etiology, immunological mechanisms, and optimal therapeutic approaches for IGM.