Synovial sarcoma is a malignant tumor of the soft tissues, usually around joints. Under the microscope, the tumor resembles synovial tissue (the lining tissue of joints). Synovial tissue is found around the tendons (bands of fiber that connect muscle to bone) and can form a bursa (fluid-filled cushioning pouches or sacs found in spaces between tendons, ligaments, and bones) in the joints.
- Synovial sarcoma most often begins in the head, neck, bladder, vagina, arms, legs, and trunk.
- The tumor may also originate in places where skeletal muscles are absent or very small, such as the prostate, middle ear, or bile duct system.
- Although synovial sarcoma is the most common childhood soft-tissue sarcoma, only about 250 children are diagnosed with this type of cancer in the United States each year.
- There are two main types of synovial sarcoma:
- Embryonal synovial sarcoma (ERMS): It is the most common form of synovial sarcoma. It usually occurs in children under six years of age.
- Alveolar synovial sarcoma (ARMS): It is found more frequently in older children and accounts for about 20 percent of all cases.
We care for children with synovial sarcoma at the Dana-Farber/Boston Children's Cancer and Blood Disorders Center. Our Bone & Soft Tissues Treatment Program features urology, gynecology, head and neck, and surgical specialists who treat these types of tumors in children.
Causes and Symptoms of Synovial Sarcoma
As a parent, you undoubtedly want to know what may have caused your child's tumor. In most cases, doctors don't know what leads to synovial sarcoma. Synovial sarcoma is not associated with environmental factors. There is nothing you could have done or avoided doing that would have prevented the tumor from developing.
Some synovial sarcoma tumors may begin in the fetus, where rhabdomyoblast cells develop in the initial fetal development stages. These cells will mature and develop into muscles. Synovial sarcomas usually have some chromosome abnormality or genetic mutation in the cells of the tumor.
Your child may not experience synovial sarcoma symptoms until the tumor is very large, especially if it is located deep in the muscles or stomach.
If symptoms do appear, they may include:
- A mass that can be seen or felt and may or may not be painful.
- Bleeding from the nose, vagina, rectum or throat (if the tumor is in these areas).
- Tingling, numbness or pain if the tumor compresses a nerve in the affected area.
- Protrusion of the eye or drooping of the eyelid, which may indicate a tumor behind the eye.
Synovial sarcoma symptoms may resemble other, more common conditions or medical problems. If your child has concerning symptoms, consult your child's physician.
How We Diagnose Childhood Synovial Sarcoma
We use several diagnostic tests to determine the type of tumor and whether it has spread. Your child's doctor will start with a complete medical and physical examination. From there, your child's doctor may also order several different tests, such as advanced imaging studies, biopsy, bone scan, and lumbar puncture.
How We Treat Childhood Synovial Sarcoma
Our team of highly trained specialists, including pediatric oncologists, surgeons, and radiation therapists, works closely when treating synovial sarcoma in children. We determine the best treatment options based mainly on the tumor's location.
If a sarcoma is in the arms or legs muscles, we typically remove it surgically and follow-up with chemotherapy and sometimes radiation therapy. However, a tumor in the bladder or prostate requires chemotherapy before surgery or radiation. Tumors around the eye respond well to chemotherapy and radiation, so they rarely need surgery.
Your child's treatment may include:
- Surgery: Surgery is often the first step, allowing doctors to complete the tumor type and provide information on the disease stage. Complete surgical removal of synovial sarcoma is usually not possible.
- Radiation therapy: This treatment can help stop the abnormal cells' growth in specific areas of the body. Radiation therapy uses high-energy rays from a specialized machine to damage or destroy abnormal cells.
- Chemotherapy: These medicines can help stop the growth of abnormal cells throughout the body. Chemotherapy is a systemic treatment, meaning it is introduced into the bloodstream and travels throughout the body to destroy or slow targeted cells' growth. Different groups of chemotherapy drugs work in different ways. Patients can receive chemotherapy in various ways, including orally or intravenously. While chemotherapy can be quite effective in treating certain cancers, the agents don't completely differentiate normal healthy cells from abnormal cells. Because of this, your child could have adverse side effects during treatment.
Children treated for cancer require ongoing, specialized cancer survivorship care to monitor the late effects of treatment. Patients visit a survivorship clinic annually to manage disease complications and screen for early recurrence of cancer. Our pediatric cancer survivorship programs also include patient and family education, psychosocial assessment, genetic counseling, and opportunities to speak with other childhood cancer survivors.
Childhood Synovial Sarcoma Research and Clinical Trials
At Dana-Farber/Boston Children's, we play an active role in the Intergroup Synovial Sarcoma Study (IRS), now a part of the Children's Oncology Group, that outlined the treatment of synovial sarcoma.
Our scientists are conducting numerous research studies to help doctors better understand and treat soft-tissue sarcomas. We're currently evaluating the use of using angiogenesis inhibitors and biologic therapies to fight pediatric cancers.
Long-term Outcomes for Children with Synovial Sarcoma
Over 70 percent of children with synovial sarcoma will survive five years after diagnosis if they have localized disease and receive combination therapy. After five years of disease-free survival, relapses are rare.
Your child's outcome will likely depend on many factors, including:
- The extent of the disease
- Size and location of the tumor
- Presence or absence of metastasis
- Tumor's response to therapy
- Age and overall health of the child
- Child's tolerance of specific medications, procedures, or therapies
- New developments in treatment
Unfortunately, about 40 percent of children treated for synovial sarcoma will experience a relapse or disease return. Our pediatric oncologists and surgeons have experience treating relapsed synovial sarcoma. We offer the highest standard of care for children with relapsed synovial sarcoma, including additional surgery and chemotherapy and access to the latest treatments in clinical trials.
Childhood Synovial Sarcoma Treatment Team
The Dana-Farber/Boston Children's solid tumor treatment team includes childhood soft tissue sarcoma specialists who understand how to care for children with synovial sarcoma. We will work together to diagnose and treat your child with the latest, most effective options possible.
See a complete list of the specialists in our Childhood Solid Tumor Center.