A Rare Case of True Carcinosarcoma of the Breast

Abstract Background True carcinosarcoma of the breast is an extremely rare condition, accounting for 0.08–0.2% of all breast malignancies. The correct definition of this tumor requires both a carcinomatous component and a malignant non-epithelial component of mesenchymal origin, without evidence of a transition zone between the two elements. Case presentation We present a case of a 49-year-old woman presenting with a 4 cm mass at the level of her left breast upper-outer quadrant with a histologic diagnosis of true carcinosarcoma of the breast. Discussion The most appropriate therapeutic regimens for breast carcinosarcoma are still unclear because of the rarity of this condition, but Breast Conserving Treatment (BCT) followed by adjuvant chemotherapy seems to provide a prognosis equalling that of usual Invasive Ductal Carcinoma of the breast.