Soft tissue sarcoma is rare cancer type that starts in the soft tissues of the body. Soft tissues are tissues that support or connect other organs or body parts. These are muscles, nerves, fat, tendons, ligaments, blood vessels, deep skin tissues, and synovial tissues (joint lining). Most often, soft tissue sarcomas develop in the limbs. But it can begin and spread anywhere in the body. Types of Soft Tissue Sarcomas There are a number of soft tissue sarcoma types. Some are common, others are rare. Some soft tissue sarcomas mainly affect adults; while others can develop in people of all age groups. Soft tissue sarcomas are categorized as per their start location. Some examples are Fat tissue tumors like liposarcoma Fibrous tissue tumors such as fibroblastic sarcoma Muscle cell tumors like leiomyosarcoma Tumors in the lymph or blood vessels like lymphangiosarcomas and angiosarcoma Cancer in the tendons such as clear cell sarcoma Cancer around the nerve cells such as neurogenic sarcoma Joint lining tissue cancer like synovial sarcoma Skin cell tumors like dermatofibrosarcoma protuberans In the abdomen tissue like desmoplastic small round cell tumor In the legs such as alveolar soft-part sarcoma Causes and Risk Factors Cancer develops due to cell mutations.