CASE 1: A 64-year-old woman with right breast cancer had a partial mastectomy and radiotherapy four years ago was admitted to our hospital because of right breast mass. The vacuum associated biopsy of tumor resulted in breast sarcoma, thus a nipple-spearing mastectomy was performed. The final histological diagnosis was stromal sarcoma, and was identical to histological findings of malignant fibrous histiocytoma. Three months after the operation, a chest wall recurrence appeared. Although tumor resection with latissimus dorsi flap was performed, there were pleural dissemination and malignant pleural effusion. She died six months after the first surgery. CASE 2: A 60-year-old woman was admitted to our hospital because of left breast mass, but she refused a further clinical examination. She readmitted fourteen months later due to a huge sized left breast mass with necrosis and smelling discharge. CT scan showed a huge tumor of left breast and multiple lung metastases. Biopsy of the tumor resulted in breast sarcoma. Total mastectomy with split thickness skin grafting was performed. The final histological diagnosis was identical to the first case. A local recurrence appeared thirty days after the operation, and she died fifty-one days after the operation.