Synovial Sarcoma (Most Often Found In Pediatric Patients)

Synovial sarcoma can come from the muscle or ligaments. It’s often found in the arm, leg or foot and near joints such as the wrist or ankle. It can also form in soft tissues in the lungs or abdomen. Synovial sarcoma is also called malignant synovioma.

Types & Stages 

Synovial sarcomas are categorized into two types, based on the appearance of the cells in the tumors:

• Monophasic. These tumors are made of just one type of tumor cell, either spindle cells (a long, narrow cell with pointed ends) or epithelial cells (tightly packed cells that form a physical barrier by lining the cavities of the major organs). The latter are less common.
   
• Biphasic. These tumors include both spindle cells and epithelial cells.

Signs & Symptoms 

Signs and symptoms of synovial sarcoma depend on where the cancer starts. Symptoms may include:

• A lump or bump under the skin that slowly gets bigger
• Joint stiffness
• Pain
• Swelling
• Problems breathing
• Difficulty swallowing
• Changes in the way the voice sounds

Diagnosis 

Tests and procedures used to diagnose synovial sarcoma include:

• Imaging tests. They can show where a synovial sarcoma is, how large it is and if it has spread to other areas of the body. Tests might include:
   
  • X-rays. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film.
     
  • Computerized tomography scan (CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body.  
     
  • Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
     
• Biopsy. A biopsy is a procedure to remove a sample of tissue for testing in a lab. The tissue might be removed using a needle that is put through the skin and into the cancer. Sometimes surgery is needed to get the tissue sample.

Treatment 

Treatment options for synovial sarcoma include:

• Surgery. Limb-sparing surgery is the main treatment for synovial sarcoma. The goal is to remove the cancer and some of the healthy tissue around it. This can sometimes mean the removal of an entire muscle or muscle group. To lower the chances of the cancer returning, radiation therapy or chemotherapy might be used as well.
   
• Radiation therapy. Radiation therapy treats cancer with powerful energy beams. During radiation therapy, you lie on a table while a machine moves around you. The machine directs radiation to precise points on the body.
   
• Chemotherapy. Chemotherapy treats cancer with strong medicines. For synovial sarcoma, chemotherapy might be used before or after surgery. It also may be used when cancer has spread to other parts of the body.
   
• Targeted therapy. Targeted therapy uses medicines that attack specific chemicals in the cancer cells. This can cause cancer cells to die or stop growing. Targeted therapy medicines are being studied for advanced synovial sarcoma.
   
• Cell therapy. Cell therapy helps the immune system find and stop the cancer cells. This treatment involves taking some of your immune system cells and making them better at recognizing the cancer cells. Then the cells are put back in your body. This treatment can take months to set up. It might be an option for treating advanced synovial sarcoma that hasn't been helped by chemotherapy.

Causes & Risk Factors 

Risk factors for synovial sarcoma include:  

• Young age. Most cases are diagnosed before age 35.  
• Radiation therapy for a previous cancer  
• Frequent exposure to certain chemicals, including vinyl chloride, arsenic and thorium dioxide
• Long-term swelling. Chronic lymphedema in the arms or legs.

Screening  

There is no specific screening for synovial sarcoma.