A sarcoma is a rare cancerous tumor or mass of abnormal tissue originating from either the soft tissues or the bones. Tumors may be benign or malignant. Benign tumors are not cancerous and do not spread to other parts of the body whereas. Sarcomas are malignant tumors which are cancerous and can spread to other parts of the body. Bone sarcomas are cancerous tumors that develop in bones. Bone sarcomas may grow, compressing and destroying the healthy bone tissue. Bone sarcomas are rare but the most common types include osteosarcomas, chondrosarcomas, and Ewings sarcoma.