Xanthogranulomatous Mastitis, A Rare Pseudotumoral Breast Lesion (Case Report and Literature Review)

Xanthogranulomatous mastitis (XM) is a rare inflammatory breast condition, first described as a distinct histopathological entity by Shin et al. in 2015. Its pathophysiology remains unclear, but it often mimics inflammatory breast carcinoma clinically and radiologically, necessitating a multidisciplinary diagnostic approach. We report the case of a 47-year-old perimenopausal woman presenting with a painful, firm nodule in the inferomedial quadrant of the left breast, initially suspected to be malignant. Imaging (mammography and ultrasound) classified the lesion as ACR 4a, prompting a biopsy that revealed histiocytic infiltration. Surgical excision confirmed XM, with histopathology showing granulomatous inflammation, foamy histiocytes, and absence of malignancy. Postoperative follow-up at six months showed no recurrence. This case highlights the diagnostic challenges of XM, which can be mistaken for breast cancer due to overlapping clinical and radiological features. Definitive diagnosis relies on histopathological examination, excluding differentials such as tuberculous mastitis or medullary carcinoma. Management typically involves wide surgical excision, though medical therapy (corticosteroids, NSAIDs) may be considered for localized cases. Long-term surveillance is recommended due to the risk of recurrence. Our report underscores the importance of histology in avoiding misdiagnosis and ensuring appropriate treatment of this rare benign condition.