Childhood soft tissue sarcoma is a disease in which malignant (cancer) cells form in soft tissues of the body.
Soft tissues of the body connect, support, and surround other body parts and organs. The soft tissues include the following:
- Tendons (bands of tissue that connect muscles to bones).
- Synovial tissues (tissues around joints).
- Blood vessels.
- Lymph vessels.
Soft tissue sarcoma may be found anywhere in the body. In children, the tumors form most often in the arms, legs, or trunk (chest and abdomen).
There are many different types of soft tissue sarcomas.
The cells of each type of sarcoma look different under a microscope. The soft tissue tumors are grouped based on the type of soft tissue cell where they first formed.
Rhabdomyosarcoma is the most common type of childhood soft tissue sarcoma. It begins in muscles that surround bone. Rhabdomyosarcoma is not discussed in this summary. (See the PDQ summary on Childhood Rhabdomyosarcoma Treatment for more information.) This summary is about the other types of soft tissue sarcoma:
Fibrous (connective) tissue tumors
- Desmoid tumor.
- Malignant fibrous histiocytoma (MFH). This is also called undifferentiatedpleomorphic sarcoma or spindle cell sarcoma. (See the PDQ summary on Osteosarcoma and Malignant Fibrous Histiocytoma of Bone Treatment for more information on MFH of bone.)
- Plexiform histiocytic tumor.
Fat tissue tumors
Smooth muscle tumors
Peripheral nervous system tumors
- Malignantschwannoma (malignant peripheral nerve sheath tumor).
Bone and cartilage tumors
- Extraosseous myxoid chondrosarcoma.
- Mesenchymal chondrosarcoma.
Tumors with more than one type of tissue
- Malignant mesenchymoma.
- Malignant Triton tumor.
- Malignant ectomesenchymoma.
Tumors of unknown origin (the place where the tumor first formed is not known)
- Alveolar soft part sarcoma.
- Clear cell sarcoma (malignant melanoma).
- Desmoplastic small round cell tumor.
- Epithelioid sarcoma.
- Synovial sarcoma.
- Undifferentiated soft tissue sarcoma.
Blood and lymph vessel tumors
Besides rhabdomyosarcomas, the most common soft tissue sarcomas in children are in joint tissue, connective tissue, and nerve tissue.
Soft tissue sarcoma occurs in children and adults. Soft tissue sarcoma in children may respond differently to treatment, and may have a better outcome than soft tissue sarcoma in adults. (See the PDQ summary on Adult Soft Tissue Sarcoma Treatment for more information on treatment in adults.)
Having certain diseases and inherited disorders can increase the risk of developing childhood soft tissue sarcoma.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for childhood soft tissue sarcoma include having the following inheriteddisorders: