The Imaging of Idiopathic Granulomatous Mastitis: A Narrative Review.

Background: Imaging has an established role in the diagnosis and management of idiopathic granulomatous mastitis (IGM). The main purpose of this article is to explain an imaging-based diagnostic approach for IGM and describe the imaging findings of the disease. Methods: The PubMed database was searched to find the articles published in English from January 2004 to December 2021 using the terms "idiopathic granulomatous mastitis", "imaging", and “radiology.” The search yielded 60 articles initially, of which 17 papers mainly concentrating on the imaging of IGM were assessed. Results: Ultrasound and mammography are the two commonly used modalities for evaluating IGM patients. Focal asymmetry and irregular high-density mass are the most common mammographic findings. Irregular hypoechoic mass with tubular extensions is a frequent ultrasound finding. Magnetic resonance imaging (MRI) can be used as a complementary modality, but it does not usually change the disease management. The most important differential diagnosis of IGM include breast cancer, infectious mastitis, and tuberculous mastitis. There is currently no agreedupon schedule for the imaging follow-up of IGM patients. Conclusion: The commonly used imaging modalities for evaluating IGM include ultrasound with or without mammography. There is currently no consensus for the imaging follow-up of these patients.