Sarcoma of the breast is a special type of breast cancer, named because it contains both cancer and sarcoma components. It is a tumor in which cancer and sarcoma occur together in the ipsilateral breast tissue. It is less common clinically. It often occurs in women of middle age or older, and the age of onset is usually older than 50 years. Histologically, it consists of a mixture of malignant mesenchymal tissue and malignant epithelial tissue. The pathogenesis of breast carcinosarcoma can be the carcinoma of the mesenchymal component of breast cancer or the malignant transformation of the epithelium of breast fibroma, the epithelium of lobular cystic sarcoma and the periductal connective tissue respectively. Some scholars have also observed by electron microscopy that it may be the result of differentiation of hepatocytes, which can differentiate in multiple directions, into both sarcoma and carcinoma. Symptoms of breast cancer sarcoma 1. Single or multiple round nodules or lumps in the breast, with no specific site of onset. The longest diameter is reported to be 4-13cm (median 7.5cm), hard and poorly defined, with enlarged ipsilateral axillary lymph nodes. 2. When the tumor invades the skin, “orange peel-like” changes appear, and there can be nipple invagination and axillary lymph node and blood channel metastasis. The diagnosis of breast cancer sarcoma is often difficult without histological evidence, and the diagnosis based on clinical manifestations is often misdiagnosed as breast cancer, so the diagnosis of breast cancer sarcoma has to rely on the combination of histological diagnosis and imaging diagnosis. The imaging diagnosis of breast cancer sarcoma can be made by X-ray, CT scan, MRI, etc. The imaging diagnosis of breast cancer sarcoma can be presented as an irregular mass in the breast, the size of the mass is variable, similar to or smaller than the size of palpation; most of the edges of the mass are smooth, some of the edges are sharp-angled or irregular, the density of the mass is not uniform, fine dot-like or small tadpole-like calcifications can be seen, and its distribution is consistent with the ducts. The distribution is consistent with the direction of the ducts. The breast structure of the tumor is disturbed and the blood vessels nearby are significantly thicker than those of the opposite breast. Since breast cancer sarcoma has both cancer and sarcoma components, the x-ray presentation of breast cancer sarcoma can be any of the above characteristics. 4. Treatment of breast cancer sarcoma 1. Since blood and lymphatic metastasis can occur, radical surgery should be performed as early as possible if the disease is clearly a cancer sarcoma. In early stage, if the lesion is small and the boundary is clear, modified radical surgery or total mastectomy can be considered. 3. For advanced cases with lymph node and blood channel dissemination, chemotherapy and radiotherapy should be added before radical surgery.