Idiopathic Granulomatous Lobular Mastitis: An Imitation of Breast Carcinoma

Abstract

Since idiopathic granulomatous lobular mastitis, also known as idiopathic granulomatous mastitis or granulomatous lobulitis, was first described by Kessler and Wolloch in 1972, no consensus on the ideal and definitive treatment for this phenomenon has been reached thus far. Idiopathic granulomatous lobular mastitis mostly frequently observed in women of childbearing age within a few years of pregnancy with a higher incidence in patients of Hispanic, Native American, Middle Eastern, and African descent. This entity, per se, is a rare, benign, chronic inflammatory breast condition of unknown aetiology mimicking two common breast disorders. The first is breast inflammations or infection, such as cystic neutrophilic granulomatous mastitis; granulomatous mastitis due to Corynebacterium;other infections with granulomas, mycobacteria, fungi, cat scratch disease, and Brucella; granulomatosis with polyangiitis (Wegener's granulomatosis); sarcoidosis; and squamous metaplasia of lactiferous ducts. The second is breast carcinoma in some challenging cases. Of note, no consensus, per se, has been declared on its therapeutic management. The following vignette case described in this report involves idiopathic granulomatous lobular mastitis imitating breast carcinoma. It is important to note that, the aetiology of idiopathic granulomatous lobular mastitis is unknown, its diagnosis is difficult, and physicians should be vigilant and aware of this condition in order of abstaining from an overtreatment for malignancy or overlooking a true malignancy.

Keywords: breast; breast cancer pathology; breast neoplasms; breast pathology; cd68+; granulomatous mastitis; histopathology (hp); idiopathic; mastitis; mimicking.

Figure 1. A photomicrograph, revealing the disseminated reactions in histiocytic cells (Immunohistochemistry, CD68; Original magnification, x100).