Clinical and Radiological Differences Between Fistular and Non-Fistular Idiopathic Granulomatous Mastitis

Background: Idiopathic granulomatous mastitis (IGM) is a rare and benign chronic inflammatory breast disease. The disease is usually associated with recurrent attacks and may result in the formation of fistulas. Fistula or ulceration on the skin of the breast makes it difficult to medication treatment and may necessitate extensive skin excision in patients undergoing surgery. Objectives: This study aimed to compare the clinical and radiological findings between fistular and non-fistular idiopathic granulomatous mastitis. Patients and Methods: The clinical and radiologic findings of 52 women with a histopathology diagnosis of idiopathic granulomatous mastitis were retrospectively evaluated. All the patients were assessed using ultrasonography and magnetic resonance imaging. Of the 52 patients, 20 underwent mammography. The findings in patients with fistular and non-fistular idiopathic granulomatous mastitis were compared. Results: Erythema, ulceration, and nipple changes were more common in patients with fistular idiopathic granulomatous mastitis. While the most common finding in ultrasounography in fistular IGM patients were collection areas with complicated cysts consistent with abscess, the finding in non-fistular IGM patients were multiple irregularly shaped hypoechoic masses. In magnetic resonance imaging, the most common finding in fistular IGM patients was non-mass lesions with regional clustering ring enhancement, whereas the most frequent finding in non-fistular IGM patients was non-mass lesions with regional heterogeneous enhancement. There were statistically significant differences between findings of both groups. Conclusion: There are differences in the clinical and radiologic findings of fistular and non-fistular idiopathic granulomatous mastitis. Ultrasonography and magnetic resonance imaging could be useful in identifying patients with a high risk of developing fistulas.