Abstract

Idiopathic granulomatous mastitis (IGM) is a breast non-systemic and chronic inflammatory disease that mimics abscesses, mastitis or breast cancer of low incidence, with much controversy on its diagnosis and successful treatment. The aim of this study is to retrospectively associate in an integral manner, the clinical characteristics, and the radiologic findings in order to develop an algorithm to make diagnosis and treatment of this entity easy. A retrospective analysis was performed with 16 patients for whom histologically IGM diagnoses were confirmed and were treated in our center between January 2011 and December 2016. Clinical characteristics, radiological, and histological reports, as well as treatment regime and outcome were included in the analysis.

The clinical characteristics of the patients were very heterogeneous. The imaging studies performed were breast sonography and/or mammography, most of them with a BI-RADS classification of 4B (62%), no MRI was conducted or deemed necessary. Histological specimens were obtained with core needle biopsies (n=6) or excisional biopsy of the breast mass (n=10). Patients were divided into three groups depending on the treatment they received; 1) pharmacological-only group (n=4) treated with antibiotic and prednisone; 2) surgical-only group stereotactically guided surgery (n=6); or 3) pharmacological and surgical-group (n=6) treated with pre-surgical antibiotic and pre and/or post-surgical prednisone. Recurrence occurred in two patients of the pharmacological-only group and in two patients of the pharmacological-surgery group, whereas there was no recurrence in the surgical-only group.

Idiopathic granulomatous mastitis is a breast-limited entity, with a chronic and generally benign course, with unknown etiology; but if not treated correctly there is a possibility of recurrence. Radiologic protocols are not sufficiently precise to establish a differential diagnosis, and while histopathological diagnosis is obligatory.

Clinical treatment guides must be developed for which we strongly recommend the following diagnosis and treatment algorithm for patients with granulomatous mastitis.

Keywords

Idiopathic granulomatous mastitis, Periductal mastitis, Sarcoidosis, Hormonal imbalance, Breast mass, Magnetic resonance imaging, Breast imaging reporting and data system, Local manifestations, Axillary lymphadenopathy, Ulceration, Fistulae development, Smoking, Pregnancy, Breast-feeding, Epithelioid histiocytes, Parenchymal echogenicity, Corticosteroids, Ductal hyperplasia, Mammography