Pediatric Soft Tissue Sarcoma

Medical experts do not know exactly what causes soft tissue sarcomas. Some factors that may increase your child’s risk include:

• Inherited genetic disorders such as neurofibromatosis and Li-Fraumeni syndrome
• Prenatal genetic changes caused by certain chromosome abnormalities
• Previous radiation therapy treatment
• Exposure to certain chemicals, such as vinyl chloride
• AIDS and Epstein-Barr viral (EBV) infections

There are many different types of soft tissue sarcomas. Some examples of soft tissue sarcomas and the type of tissue where they started growing include:

• Rhabdomyosarcoma, in skeletal muscles (the most common sarcoma in children)
• Fibrosarcoma, in fibrous tissues such as tendons and ligaments
• Leiomyosarcoma, in smooth muscle such as the stomach and bladder
• Malignant peripheral nerve sheath tumor, in the protective covering of nerves
• Liposarcoma, in fat cells (rare)

Soft tissue tumors may show no symptoms in early stages. The most common sign is a painless lump or swelling under the skin. As sarcomas grow larger, they may press on nearby muscles, nerves, organs and blood vessels and cause:

• Pain, tingling or numbness
• Weakness
• Trouble breathing

Because these symptoms also appear in other childhood conditions, they may or may not be a sign of soft tissue sarcoma. Your pediatrician will need to thoroughly examine your child to determine the cause of these symptoms.

Children’s National Hospital has advanced imaging equipment available for diagnosis, staging, treatment and follow-up for all bone and soft tissue sarcomas in children, adolescents and young adults. In addition, the Children’s National Sarcoma Program is one of the few in the United States where patients can see a pediatric oncologist, orthopaedic oncologist, biologist and physical therapist in one truly comprehensive visit.

In addition to a physical exam, your pediatrician may recommend one or more of the following tests to look for soft tissue sarcoma:

• Blood and urine tests to measure organ function and evaluate their possible involvement
• Diagnostic imaging, including CT, MRI, ultrasound, X-ray and bone scans, to look for tumors
• Biopsy, a tissue sample of the tumor that a lab pathologist can study to determine whether the growth is cancerous

There are several treatment options for children with soft tissue sarcomas, including:

• Cancer surgery to remove the entire tumor and nearby tissue, if needed
• Radiation therapy, including:
  • External beam using a machine to focus high-powered X-rays on the tumor
  • Brachytherapy (internal radiation) using tiny implants to deliver radiation directly into or very near the tumor
• Chemotherapy with drugs that are delivered by mouth or vein
• Targeted therapy with drugs that focus on cancer cells without damaging normal cells

Children who have soft tissue sarcomas often respond better to treatment than adults and have a better prognosis.

Learn more about our comprehensive Solid Tumor Program at Children’s National.