SOFT TISSUE SARCOMAS ARE cancerous tumors that develop in various soft tissues of the body. Soft tissues connect, surround, and support body structures and organs. They include muscles, tendons, fat, nerves, blood vessels, connective tissues, and synovial tissues (connective tissue around joints and tendons).

Several types of soft tissue sarcomas are diagnosed in young people—the most common one is rhabdomyosarcoma. Other soft tissue sarcomas include alveolar soft part sarcoma, fibrosarcoma, hemangiopericytoma, leiomyosarcoma, liposarcoma, malignant fibrous histiocytoma, malignant peripheral nerve sheath tumor (also known as neurofibrosarcoma or malignant schwannoma), and synovial sarcoma. About 700 children and teens are diagnosed with a soft tissue sarcoma in the United States every year; almost half of those tumors are rhabdomyosarcoma.

This chapter first looks at the structure and function of muscles and connective tissues. Then it describes who gets soft tissue sarcomas, what the signs and symptoms are, how they are diagnosed, and how the prognosis is determined. Finally, the chapter discusses current treatments for rhabdomyosarcoma and other soft tissue sarcomas.