Idiopathic Granulomatous Mastitis: How to identify by Imaging Features?

Document Type : Original Article


The Departments of Diagnostic & Interventional Radiology1, National Cancer Institute NCI, Cairo University, Radiography and Medical Imaging Technology Program2, Faculty of Applied Health Sciences Technology, Misr University for Sciences and Technology, Radiology Consultant at Baheya Foundation3, Radiology Department4, Mansoura Chest Hospital, Ministry of Health & Population and The Department of Surgery & The Department of Diagnostic & Interventional Radiology5, Theodor Bilharz Research Institute


Abstract Background: Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory disease of the breast with obscure etiology that mimics invasive carcinoma both clinically and radiologically. Since the disease can mimic both clinically and radiologically breast cancer and other inflammatory breast conditions and has a complete different management plan, there is an urge for proper and rapid diagnosis. A multimodality imaging approach and characterization of imaging features are essential in making this correct diagnosis. Aim of Study: The aim of this study is to assess the different radiological findings and eliciting the typical appear-ance of idiopathic granulomatous mastitis. We highlighted the various findings by different imaging techniques. Patient and Methods: This study included 41 patients examined by different imaging modalities and later patholog-ically all cases proved to have IGM. The initial modality was selected depending on the age of the patient and then comple-mentary studies were tailored according to each patient condition and availability. Results: In our study, IGM appears as a unilateral disease in (92.7%), and of bilateral distribution in (7.3%), manifested by conventional MG as breast asymmetrical density in (77.1 %), and mass densities in (22.9%) with about (17.1%) had asso-ciated architectural distortion. On U/S it appeared as multiple hypoechoic lesions/pockets in (73.2%) with tubular extensionsin (65.9%) and abscess with sinus formation and skin opening in (70.7%) of the patients. Associated edema of the surrounding tissues was in (78%), Skin thickening in (53.7%) and reactive ipsilateral axillary lymph nodesin (80.5%). On Doppler application mean RI calculated was 0.51 in (34.1 %). On Contrast studies (68.8%) of the patients showed combined mass and non-mass enhancement patterns and (25%) showed non-mass enhancement pattern. All patients were pathologically proven to have IGM. Conclusion: The imaging findings of idiopathic granulo-matous mastitis overlap with those of malignancy. The most common presentation is a focal asymmetric density on mam-mography and an irregular hypoechoic mass with tubular extensions on ultrasound, combined mass and non-mass enhancement. Core biopsy is typically diagnostic.