Role of conservative therapy prior to surgery in xanthogranulomatous mastitis: a case report.

Background: Xanthogranulomatous mastitis is an extremely rare condition that is characterised by the infiltration of the breast parenchyma by foamy histiocytes. There have been only 26 reported cases amongst 10 publications. The clinical and radiological presentation of xanthogranulomatous mastitis often causes diagnostic confusion due to its similarity to breast cancer and other forms of chronic inflammatory mastitis. A histological diagnosis is often required either by core needle biopsy or excisional biopsy. Upon review of the literature, surgical excision was the most predominant mode of management. Case Description: We present a case of xanthogranulomatous mastitis in a 40-year-old female who presented with clinical and radiological features of breast malignancy. This was a significantly large mass with a dimension of 90.7 mm by 36.4 mm, which if surgically excised, would have led to permanent cosmetic changes. Multiple core needle biopsies were completed to consider other differentials of histiocytic lesions including cystic neutrophilic granulomatous mastitis, histiocytoid lobular breast carcinoma, Rosai-Dorfman disease and Erdheim-Chester disease. Conclusions: Clinical improvement was noted with reduction in size from prolonged antibiotic therapy suggesting an initial conservative approach in the management of xanthogranulomatous mastitis. By contributing our experience with xanthogranulomatous mastitis, we also present a review of literature on its aetiology, clinical features, and management of this pathology.