How serious is synovial sarcoma?

Very: Synovial sarcomas are serious cancers of the joints. Surgery can be curative, and chemotherapy may also be recommended to decrease the risk for a recurrence. The size of the tumor, and invasion of structures in and around the joint are predictive of cure or recurrence.

It's a cancer.: Synovial sarcoma is a rare cancer that arises near joints. Despite the name synovial, referring to the lining of joints, it almost never arises within a joint. Surgical removal is the mainstay of treatment. Radiation is often added to lower risk of it growing back. It is controversial if chemotherapy helps. While the majority of people are cured, it can be a deadly disease.