Rhabdomyosarcoma are malignant tumors which resemble developing skeletal muscle. These tumors most commonly grow in the arms or legs, but can also develop in the head or neck area, as well as the urinary and reproductive organs. Synovial Sarcoma is a malignant tumor made up of cells which resemble the cells in joints. However, synovial sarcoma does not necessarily arise in any joint, and the name is probably a misnomer, since the cancer cells are probably quite different from normal joint cells. Synovial sarcomas can arise in any location in the body, and it often appears in young adults.
Angiosarcoma are malignant tumors that resemble blood or lymphatic vessels.
Fibrosarcoma is cancer of the fibroblast-type cells in the body which form scars and do other important connective functions. Desmoid Tumor is not strictly a sarcoma since it is not technically a malignancy. However, since it has risk of coming back, it is a tumor which generally should be managed by a team skilled in sarcoma management. It is a class of diseases which arise from very primitive cells in the body. Although this is usually thought of as a bone tumor, Ewing Sarcoma is increasingly recognized to arise in soft tissues in the body as well.