The nomenclature of malignant tumors includes mainly carcinoma and sarcoma. Carcinoma is usually a collective term for malignant tumors originating from epithelial tissue; whereas malignant tumors occurring from mesenchymal tissue are collectively referred to as sarcomas. It should be emphasized, however, that in pathology cancer refers to malignant tumors of epithelial tissue origin, whereas the usual term cancer refers to all malignant tumors in general, including carcinomas and sarcomas. Tumors of mesenchymal origin are tumors originating from mesenchymal tissues, which are divided into benign and malignant tumors, and the components of mesenchymal tissues include fat, mesothelium, skeletal muscle, smooth muscle, blood vessels, and histiocytes. The malignant mesenchymal tumors include pleural mesothelioma, liposarcoma, rhabdomyosarcoma, smooth muscle sarcoma, hemangiosarcoma, fibrosarcoma, osteosarcoma, chondrosarcoma, etc., and the prognosis is equivalent to cancer. Symptoms of sarcoma can be localized formation of lumps, dyspnea, etc. Its metastatic mode is mainly lymphatic metastasis and hematogenous metastasis. In terms of treatment, it must be treated at an early stage, and early patients can be treated with surgery and postoperative radiotherapy; if it develops to an advanced stage, it may lose the chance of surgery.