Idiopathic Granulomatous Mastitis: Overview and Imaging Findings

Ultrasound (US) and mammography play significant roles in the diagnosis of IGM.However, due to the non-specific nature of imaging findings, definitive diagnosis generally requires histopathological evaluation and exclusion of other conditions. 7There are various treatment options for IGM, including surgical resection, abscess drainage, steroids, methotrexate, and watchful waiting.However, no consensus has been established on the optimal treatment approach, which is often based on clinical experience and tailored to the patient and the severity of the disease. 8This review discusses imaging findings, pathophysiology, clinical presentation, and treatment approaches for IGM based on the current literature. Etiology and PathophysiologyIn the pathophysiology of IGM, it is proposed that damage occurs in the ductal epithelial cells of the breast for various reasons.This damage leads to the leakage of luminal secretions into the lobular stroma of the breast, which subsequently triggers a local inflammatory response induced by the migration of macrophages and lymphocytes to the area, followed by the formation of a granulomatous reaction. 9Since the exact cause of IGM remains unclear, most cases are termed "idiopathic".However, it is believed that certain "environmental stimuli" can trigger an inflammatory granulomatous reaction, primarily in genetically predisposed individuals.There are three hypotheses that are thought to be responsible for the pathogenesis of IGM: autoimmunity, infection, and hormonal disorders. 10Additionally, alpha-1 antitrypsin deficiency, oral contraceptives (OCs), smoking, breastfeeding, and pregnancy are considered potential predisposing factors.The presence