1) Abnormal growth of the cells comprising the soft tissue, excluding metastatic tumours that arise in the soft tissue. This concept specifically refers to tumours with malignant characteristics.

2) A usually aggressive malignant mesenchymal cell tumour most commonly arising from muscle, fat, fibrous tissue, bone, cartilage, and blood vessels. Sarcomas occur in both children and adults. The prognosis depends largely on the degree of differentiation (grade) of the tumor. Representative subtypes are liposarcoma, leiomyosarcoma, osteosarcoma, and chondrosarcoma. -- 2004

3) A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.