Synovial Sarcoma: Questions and Answers

  • Synovial sarcoma is a rare type of soft tissue sarcoma that occurs mostly in young adults.
  • The most common symptoms are swelling or a mass, occasionally accompanied by pain or tenderness.
  • Surgery is the usual treatment for synovial sarcoma.
  • People are encouraged to enroll in clinical trials that explore new treatments.
  1. What is synovial sarcoma?
  2. Synovial sarcoma is a type of soft tissue sarcoma. Soft tissue sarcomas are cancers of the muscle, fat, fibrous tissue, blood vessels, or other supporting tissue of the body, including synovial tissue. Synovial tissue lines the cavities of joints, such as the knee or elbow, tendons, and bursae. Although synovial sarcoma does not have a clearly defined cause, genetic factors are believed to influence the development of this disease.

  3. How often does synovial sarcoma occur?
  4. Synovial sarcoma is rare. It accounts for between 5 and 10 percent of the approximately 10,000 new soft tissue sarcomas reported each year. Synovial sarcoma occurs mostly in young adults, with a median age of 26.5. Approximately 30 percent of patients with synovial sarcoma are younger than 20. This disease occurs more often in men than in women.

  5. Where does synovial sarcoma develop?
  6. About 50 percent of synovial sarcomas develop in the legs, especially the knees. The second most common location is the arms. Less frequently, the disease develops in the trunk, head and neck region, or the abdomen. It is common for synovial cancer to recur, usually within the first two years after treatment. Half of the cases of synovial sarcoma metastasize to the lungs, lymph nodes, or bone marrow.

  7. What are the symptoms of synovial sarcoma?
  8. Synovial sarcoma is a slow-growing tumor. Because it grows slowly, a person may not have or notice symptoms for some time, resulting in a delay in diagnosis. The most common symptoms of synovial sarcoma are swelling or a mass that may be tender or painful. The tumor may limit range of motion or press against nerves and cause numbness. The symptoms of synovial sarcoma can be mistaken for those of inflammation of the joints, the bursae, or synovial tissue. These noncancerous conditions are called arthritis, bursitis, and synovitis, respectively.

  9. How is synovial sarcoma diagnosed?

  10. The doctor may use the following procedures and tests to diagnose synovial sarcoma:

  11. How is synovial sarcoma treated?
  12. The type of treatment depends on the age of the patient, the location of the tumor, its size, its grade, and the extent of the disease. The most common treatment is surgery to remove the entire tumor with negative margins. If the first surgery does not obtain negative tissue margins, a second surgery may be needed.

    The patient may also receive radiation therapy before or after surgery to control the tumor or decrease the chance of recurrence. The use of intraoperative radiation therapy and brachytherapy are under study.

    Patients may also receive chemotherapy alone or in combination with radiation therapy.

  13. Are clinical trials available? Where can people get more information about clinical trials?
  14. Yes. Participation in clinical trials is an important treatment option for many people with synovial sarcoma. Studies are in progress to determine the effectiveness of biological therapies, including monoclonal antibodies, and chemotherapy with hyperthermia.

    People interested in taking part in a clinical trial should talk with their doctor. Information about clinical trials is available from the NCI’s Cancer Information Service at 1–800–4–CANCER and in the NCI booklet Taking Part in Clinical Trials: What Cancer Patients Need To Know, which can be found at on the Internet. This booklet describes how research studies are carried out and explains their possible benefits and risks. Further information about clinical trials is available at on the NCI’s Web site. The Web site offers detailed information about specific ongoing studies by linking to PDQ®, the NCI’s cancer information database. The CIS also provides information from PDQ.