Idiopathic Granulomatous Mastitis: Overview and Imaging Findings

<p>Abstract<br>Idiopathic granulomatous mastitis (IGM) is a benign inflammatory breast disease characterized by non-caseating granulomas in the lobules of breast tissue.<br>IGM primarily affects women of childbearing age. The actual prevalence of IGM is unknown although it is considered rare. Although the exact cause remains<br>unclear, various triggers, such as autoimmunity, hormonal factors, and infectious agents, are believed to play a role in its pathophysiology. Imaging techniques,<br>particularly ultrasound (US) and mammography, play vital roles in the preliminary diagnosis. The most common imaging findings are focal asymmetry on<br>mammography and hypoechoic lesions that tend to coalesce and form tubular extensions on US. Advanced imaging techniques, including elastography<br>and magnetic resonance imaging, can aid in diagnosis, although none of these findings are pathognomonic, necessitating histopathological evaluation for<br>definitive diagnosis. Unlike infectious mastitis, antibiotics are not recommended for the treatment of IGM unless there is an accompanying bacterial infection.<br>IGM should be considered in patients with mastitis that does not resolve despite prolonged antibiotic treatment. Corticosteroids are an effective first-line<br>therapy for patients with histopathologically proven symptomatic IGM. Accurate diagnosis and treatment are crucial because of the potential for IGM findings<br>to be mistaken for malignancy. This review discusses the general characteristics and imaging findings of IGM based on the current literature.<br>Keywords: Idiopathic granulomatous mastitis, ultrasound, mammography, magnetic resonance imaging, breast elastography, differential diagnosis</p>