What is Synovial Sarcoma?

Synovial sarcoma is a soft tissue sarcoma that is usually found in the legs or arms but can occur anywhere in the body. Despite the name, it is not always found in the synovial tissue of the joints.

What Causes Synovial Sarcoma?

Experts do not know what causes synovial sarcoma to develop. However, one mutated gene is always present in patients who develop this disease. This mutated gene results when parts of chromosome 18 and chromosome X join abnormally. Researchers do not know why this occurs, but they do think that it is the main cause of this disease.

How Common Is Synovial Sarcoma?

About one to three people in a million are diagnosed with the disease each year. Synovial sarcoma can occur at any age, but is most common in teens and young adults. It is more common in males than females.

What Are the Signs and Symptoms of Synovial Sarcoma?

Symptoms of synovial sarcoma vary depending on the tumor’s size and location.

Symptoms of synovial sarcoma appear near where the tumor is located. They may include:

• Swelling
• A tumor that can be felt, usually deep in the tissue
• Pain that lasts a long period of time

What Are the Stages of Synovial Sarcoma?

Staging of synovial sarcoma is based on the size of the tumor and whether it has spread to lymph nodes or distant sites in the body. If the tumor has not spread, it is considered to be localized. Metastatic synovial sarcoma means the tumor has spread past nearby tissues to lungs or other organs.

How Is Synovial Sarcoma Diagnosed?

The first step in diagnosing synovial sarcoma is for the doctor to take a detailed medical history of the patient and family. Next, the patient has a physical exam and other types of tests, which may include:

• X-rays
• Magnetic resonance imaging (MRI)
• Computed tomography (CT)
• Bone scans
• Positron emission tomography (PET), a test that measures important body functions and also can show whether the cancer has spread
• Blood tests
• A needle biopsy or surgical procedure. A specialist examines the tissue under a microscope to confirm the diagnosis of synovial sarcoma.

These tests allow the doctor to see where the tumor is located, its size and whether it has spread to other parts of the body. The team uses all this information to create a personalized treatment plan.

How Do Doctors Treat Synovial Sarcoma?

Treatment for synovial sarcoma can include surgery, chemotherapy and / or radiation therapy.

Surgery

The patient may have a procedure, called a wide resection with margins, to remove the tumor and some tissue around the tumor. If the doctor is concerned that the cancer has also spread to nearby lymph nodes, they may also be removed.

Radiation Therapy

Patients may have radiation treatment before surgery to make the tumor smaller. After surgery, additional radiation therapy can help kill any tumor cells left in the body.

The doctor will make a plan for radiation based on the treatment goals and the location of the tumor. Two types of radiation are used: regular radiation or proton radiation. Proton radiation has fewer side effects because it kills the tumor but does not hurt organs and healthy tissue. This means fewer short-term side effects and long-term complications from radiation. Cincinnati Children’s is one of the few pediatric hospitals in the country that offer proton therapy.

Chemotherapy

If the tumor cannot be removed, the doctor may recommend chemotherapy or other types of drugs to help kill the cancer cells.

Clinical Research Trials

Synovial sarcoma can be challenging to treat. In some situations, the doctor may recommend participating in a clinical trial at Cincinnati Children's, which may include experimental treatments.

What Is the Long-Term Outlook for People with Synovial Sarcoma?

Many factors affect the long-term outlook for patients with synovial sarcoma, including:

• The size of the tumor
• Location of the tumor
• When it was discovered
• Whether it has spread

Prompt diagnosis and treatment can significantly improve the outcome for patients with synovial sarcoma. It is very important for patients to receive specialized care at a hospital such as Cincinnati Children’s. Our sarcoma team has experience in diagnosing and treating this rare type of cancer.

People who are treated for synovial sarcoma will need regular follow-up care. This can include check-ups with the oncologist, imaging tests, blood work and other measures to evaluate their health and recovery.