Soft Tissue Sarcoma
Sarcomas are rare cancers that develop in the muscle, bone, nerves, cartilage, tendons, blood vessels and the fatty and fibrous tissues
Soft tissue sarcomas are cancerous (malignant) tumors that originate in the soft tissues of your body. Soft tissues connect, support and surround other body structures. The soft tissues include muscle, fat, blood vessels, nerves, tendons and the lining of your joints (synovial tissues). A large variety of soft tissue sarcomas can occur in these areas.
Soft tissue sarcomas aren't common. But soft tissue sarcomas are very serious, especially if diagnosed when the disease is more advanced.
Although there are various types of soft tissue sarcoma, they generally share similar characteristics, produce similar symptoms and are treated in similar ways.
A soft tissue sarcoma usually produces no signs and symptoms in its early stages. As the tumor grows, it may cause:
- A noticeable lump or swelling
- Pain, if it presses on nerves or muscles
- A blockage in the stomach or intestines or gastrointestinal bleeding if the tumor is located in the abdomen or digestive tract
Soft tissue sarcomas can occur anywhere in your body, but the most common types of soft tissue sarcomas are gastrointestinal stromal tumors and soft tissue sarcomas that affect the extremities. About 60 percent of soft tissue sarcomas occur in the arms, legs, buttocks, hands or feet. Another 20 percent occur in the chest and abdomen. About 10 percent are found in the head and neck.
Soft tissue sarcomas go by a variety of names, depending on the tissue in which they originate. Examples of some sarcomas and their locations include:
- Rhabdomyosarcoma More common in children, this sarcoma occurs in the skeletal muscles.
- LeiomyosarcomaOccurs in the smooth muscles — muscles not under voluntary control. Found most commonly in the uterus, gastrointestinal tract or lining of blood vessels.
- Hemangiosarcoma Affects blood vessels, especially in areas that have previously received radiation treatment.
- Kaposi's sarcoma A malignancy that occurs in blood vessel walls. Often affects people with immune deficiencies, such as HIV/AIDS.
- >Lymphangiosarcoma Affects the lymph vessels and is sometimes seen in a limb with chronic swelling (lymphedema). This can be from an area of prior radiation therapy or certain rare chronic infections.
- Synovial sarcoma Tissue around joints such as knees and ankles are affected. Typically occurs in children and young adults.
- Neurofibrosarcoma Occurs in the peripheral nerves.
- Liposarcoma Fatty tissue, often in your legs and trunk, is affected.
- Fibrosarcoma Fibrous tissue in your arms, legs or trunk may be affected.
- Malignant fibrous histiocytoma A fibrous tissue tumor more likely to occur in the legs.
- Dermatofibrosarcoma Grows in the tissue beneath your skin, and often develops in your trunk or limbs.
Generally, the cause of most soft tissue sarcomas is unknown. One of the few soft tissue sarcomas that has a known cause is Kaposi's sarcoma. It occurs in people with defective immune systems and is caused by a virus known as human herpes virus 8 (HHV-8).
Additionally, in some cases, sarcomas may be hereditary, such as in:
- Basal cell nevus syndrome. In addition to an increased risk of basal cell skin cancer, people with this disorder are more likely to develop rhabdomyosarcoma or fibrosarcoma. It's caused by a genetic defect.
- Inherited retinoblastoma. This rare form of childhood eye cancer may increase a child's risk of soft tissue sarcoma and is due to inheritance of a mutated retinoblastoma gene.
- Li-Fraumeni syndrome. This condition is characterized by an increased risk of many malignancies, including sarcomas, breast cancer, brain cancer and others. People with this syndrome appear to be particularly susceptible to the side effects of radiation therapy.
- Gardner's syndrome. This hereditary disease leads to precancerous and cancerous growths in the intestines and abdomen.
- Neurofibromatosis. This condition results in developmental changes in the nervous system, causing nerve sheath tumors. About 1 in 20 people with neurofibromatosis develops malignant tumors.
- Tuberous sclerosis. Benign tumors, seizures and learning problems are common with this disease, as is an increased risk of rhabdomyosarcoma.
- Werner's syndrome. A defect in the gene RECQL2 causes numerous health problems, including an increased risk of soft tissue sarcomas.
Radiation is occasionally associated with sarcomas. These have usually occurred as a side effect of radiation therapy given for other cancers, such as breast cancer or lymphoma. Such serious side effects may become less common as radiation therapy offers more refined dosing strategies and more precise tumor targeting.
Another factor that may increase your risk of soft tissue sarcoma is exposure to high doses of chemicals such as:
- Vinyl chloride, used in making plastics
- Dioxin, an unwanted byproduct of incineration
- Herbicides that contain the chemical phenoxyacetic acid