Soft tissue sarcoma is a cancer that starts in soft tissues of the body, including muscle, tendons, fat, lymph vessels, blood vessels, nerves, and tissue around joints. The tumors can be found anywhere in the body but often form in the arms, legs, chest, or abdomen.
Signs of soft tissue sarcoma include a lump or swelling in soft tissue. Sometimes there are no signs or symptoms until the tumor is big and presses on nearby nerves or other parts of the body.
Both children and adults can develop soft tissue sarcoma. Treatment often works better in children and they may have a better chance of being cured than adults.
There are many types of soft tissue sarcoma, based on the type of soft tissue cell in which the cancer formed. Different types may be treated differently.
Rhabdomyosarcoma is the most common type of soft tissue sarcoma in children. It begins in muscles that are attached to bones and help the body move. Most rhabdomyosarcomas are diagnosed in children younger than 10 years. Rhabdomyosarcomas usually form lumps near the surface of the body and are found early.
Gastrointestinal stromal tumors are soft tissue sarcomas that form in soft tissues of the gastrointestinal tract, usually in the stomach or small intestine. They are most common in adults, and may be benign (not cancer) or malignant (cancer). Gastrointestinal stromal tumors often do not cause early symptoms.
Ewing sarcoma, Kaposi sarcoma, and uterine sarcoma are other types of soft tissue sarcoma.
Radiation therapy and certain diseases and inherited conditions can increase the risk of soft tissue sarcoma.
Soft Tissue Sarcoma. National Cancer Institute. Bethesda, MD, https://www.cancer.gov/types/soft-tissue-sarcoma