Idiopathic granulomatous mastitis. Case report

Abstract

Idiopathic granulomatous mastitis is a rare, benign chronic disease. Its etiology is not clear; however, the disease has been associated with breastfeeding, use of oral contraceptives, and an autoimmune component. The characteristic presentation is an inflammatory reaction with non-caseating granulomas. Histological features include signs of chronic granulomatous inflammation with giant cells, leukocytes, epithelioid cells, and macrophages, as well as microabscesses. In the differential diagnosis, all causes of granulomatous changes should be excluded. Due to its low frequency, the treatment is difficult to standardize and optimize. We present the case of a 36-year-old woman with a painful nodule in the right breast. Clinical presentation and imaging raised suspicion of carcinoma. Histopathology revealed acute and chronic inflammation, infiltration of macrophages and giant perivascular histiocytes with granulomatous giant cell reaction, with no signs of malignancy and suggestive of a granulomatous process. Stains were negative for fungi and mycobacteria.