What is Synovial Sarcoma?

Synovial sarcoma is a rare cancer that can come from different types of soft tissue, such as muscle or ligaments. It often occurs near large joints, most notably in the arm, leg, or foot. It can also form in soft tissues in the lung or abdomen. Synovial sarcoma may also be called malignant synovioma.

This type of cancer begins as a growth of cells that can multiply quickly and destroy healthy tissue. The first symptom is typically swelling or a lump under the skin that may or may not hurt.

It affects around 1,000 people each year, usually young adults, with one-third of patients being diagnosed under the age of 30. 

The symptoms caused by synovial sarcoma depend on where the tumor forms. It is often first noticed as a painless lump. If it is near a nerve, it might cause pain or numbness as it grows.

Imaging: If you have symptoms of synovial sarcoma, your doctor will use scans such as X-ray, ultrasound, CT scan, and MRI to take pictures of the tumor.

Biopsy: Your doctor will perform a biopsy, taking a small sample of the tumor with a needle. A pathologist will study cells from the sample under the microscope to see what kind of tumor it is. 

Treatment for synovial sarcoma depends on whether it has spread. Given that synovial sarcoma can grow for a while before it is found, there is a greater chance that it will spread to other parts of the body.

Surgery: Surgery is the first choice of treatment for synovial sarcomas. The goal is to remove the cancer and some surrounding healthy tissue to get “clean edges” and may include the removal of an entire muscle group. When all of the tumor is removed and there is no sign of cancer anywhere else in the body, there is a better chance of survival. The success of the surgery depends on the size of the tumor and its location in the body.

Radiation therapy: With the use of powerful energy beams to kill cancer cells, radiation therapy can shrink the cancerous tumor before surgery to make success more likely, or after surgery to ensure there are no cancer cells left. 

Chemotherapy: Chemotherapy uses strong medicines to kill cancer cells. For synovial sarcoma, it may be used before or after surgery. It can be used when the cancer has spread to other parts of the body. 

Clinical trials. Clinical trials are studies of new treatments. These studies provide a chance to try the latest treatment options. The side effects may not be known, and depending on the stage of development a therapeutic dose may not be provided.

The survival rate for synovial sarcoma is difficult to estimate given the rarity of the disease. Location of the tumor, when the first diagnosis is made, as well as when and how treatment is administered all impact the survival rate. While life expectancy post-diagnosis has increased significantly over the past 40 years, it is currently estimated that between 35% to 75% of people treated for synovial sarcoma are still alive five years after diagnosis. Unfortunately, synovial sarcoma can reoccur many years later.

Synovial sarcoma accounts for 5% to 10% of soft-tissue tumors. For every one million people, one to two are diagnosed with synovial sarcoma per year in the US.

The information provided above was sourced from The National Institute of Health (NIH), the Mayo Clinic, and the Cleveland Clinic.