Pediatric Sarcoma

October 15, 2025

This page was reviewed under our medical and editorial policy by Janet Yoon, M.D., clinical professor, medical director of the Pediatric Musculoskeletal Tumor Program, Department of Pediatrics, City of Hope^® Cancer Center Duarte.

Cancers known as sarcomas may occur in bone or soft tissue like muscle, fat or nerves. Overall, sarcomas are rare, accounting for 1% of adult cancers and approximately 15% of childhood cancers diagnosed in the United States.

What Is Pediatric Sarcoma?

Pediatric sarcoma refers to a group of cancers that develops in bone or soft tissue. The connective tissue between body parts and organs is present in muscles, tendons, fat, bone, cartilage and blood and lymph vessels.

Sarcoma may form anywhere in the body, but is most often found in the arms, legs, chest or abdomen when it occurs in children. It may sometimes spread to other parts of the body.

Pediatric Sarcoma Types

There are two main types of pediatric sarcoma: soft tissue sarcoma (STS) and bone cancer. While there are numerous disease subtypes within pediatric STS and bone cancer, the most common types are:

• Rhabdomyosarcoma
• Osteosarcoma
• Ewing sarcoma

Pediatric Soft Tissue Sarcomas

Rhabdomyosarcomas are malignant tumors in skeletal muscle, a type of muscle that enables movement. According to the American Cancer Society, pediatric rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children 14 years and younger, accounting for 3% of childhood cancers.

Though rhabdomyosarcoma may begin in locations throughout the body, including the head and neck, abdomen, pelvis, groin, arm or leg, RMS typically originates in muscles attached to bones.

The three main subtypes of rhabdomyosarcoma are listed below.

Embryonal rhabdomyosarcoma (ERMS): This cancer typically occurs in the head and neck area or in the genital or urinary organs and affects children up to age 5.

Alveolar rhabdomyosarcoma (ARMS): This frequently occurs in large muscles of the arms, legs or trunk and affects older children and teens.

Anaplastic rhabdomyosarcoma: Also called pleomorphic rhabdomyosarcoma, this cancer is exceedingly rare in children and tends to grow quickly.

Pediatric Bone Cancers

Primary pediatric bone cancers, or cancers originating in the bones, typically occur in older children and teens. But they may develop at any age, in any bone, but usually form in the leg, arm, pelvis or rib.

Osteosarcoma and Ewing sarcoma, detailed below, are the main types of primary pediatric bone cancer and are extremely rare.

Osteosarcoma: This is the most common type of pediatric bone tumor, affecting about 500 children in the United States each year and accounting for 2% of childhood cancer. It is most common in teens and occurs more frequently in males than females. Osteosarcoma often develops in areas where the bone is growing quickly, such as bones of the arms and legs.

Ewing sarcoma: This cancer affects about 200 children per year. It is more likely to affect children’s ribs, pelvis or legs and may also involve soft tissues around the tumor. It is even rarer, making up just 1% of childhood cancers. Ewing sarcoma is more common in males than females and typically occurs in children and young adults between the ages of 10 and 20.

Causes and Risk Factors

The specific cause of childhood sarcomas is not clear. However, through ongoing research and treatment, the medical community has identified factors that may increase the risk for developing these rare diseases, such as:

• Inherited genetic disorders, such as Li-Fraumeni syndrome, neurofibromatosis type 1 (NF1) and Beckwith-Wiedemann syndrome
• Previous radiation therapy treatment
• Prenatal genetic changes caused by certain chromosome abnormalities
• Rapid bone growth
• Exposure to chemicals like vinyl chloride

Symptoms and Signs

Sarcomas often exhibit few symptoms. Initially, they may easily go unnoticed but may increase or worsen as the tumor grows. Common pediatric sarcoma symptoms include:

• A painless lump or mass
• Swelling under the skin
• Redness, tingling or numbness
• Unexplained fever
• Bone pain or unexpected fracture
• Unexpected weight loss
• Weakness or trouble breathing

Tests for Diagnosing

With pediatric sarcoma, a speedy, accurate diagnosis is critical. Often, these tumors are “high grade” because they are malignant, may metastasize rapidly and may recur after treatment.

Common diagnostic tests include:

• Medical history and comprehensive physical exam
• Laboratory tests
• Imaging tests, such as an X-ray, CT (computed tomography) scan, MRI (magnetic resonance imaging), PET (positron emission tomography) scan and bone scan
• Tumor biopsy to confirm a diagnosis

It’s important that a sarcoma specialist performs the biopsy to help prevent future complications, for example, spreading cancer cells beyond the tumor.

Treatment

Specialization and experience matter when treating children — who are still growing and developing — for sarcoma.

Treatment for pediatric sarcoma depends on disease type, size, grade, location, spread and other factors and generally involves a combination of surgery and chemotherapy, and in some cases radiation — though some sarcomas may be completely removed by surgery. Following are the most common treatment options:

• Surgery to remove the tumor and nearby tissue
• Chemotherapy to destroy cancer cells via anticancer drugs
• Radiation therapy to kill cancer cell via high-intensity X-rays

Who Treats Sarcomas in Children?

Pediatric sarcomas are rare and often complex. That’s why a multidisciplinary team approach at a comprehensive cancer center is optimal, with specialists including:

• Medical or pediatric oncologists, who treat cancer with chemotherapy and other drugs
• Surgical oncologists, who diagnose and treat cancer with surgery
• Orthopedic surgeons, who specialize in treating bone tumors
• Radiation oncologists, who use radiation therapy to destroy cancerous tissue
• Pathologists, who examine tissue samples for diagnostic purposes to help determine a treatment plan
• Radiologists, who utilize imaging tools and interventional techniques to diagnose and treat cancer
• Supportive care providers, who focus on cancer- and treatment-related side effects and symptom management

Prognosis

The prognosis, or chance of recovery, for children and adolescents with sarcoma depends on disease type, location and stage as well as the patient’s age, size, stage of development and general health.

According to the National Cancer Institute, the five-year relative survival rate for pediatric soft tissue tumors is 75%. The five-year relative survival rate for pediatric bone tumors is 71.7%.

The five-year relative survival rate is the estimated percentage of patients expected to survive their cancer for five years or more, compared to people without that type of cancer. It’s important to speak with the care team to get an accurate prognosis that’s personalized to each person’s sarcoma subtype, stage, grade and other factors.

Pediatric Sarcoma Treatment at City of Hope

At City of Hope^®, members of the care team work with patients and their families to develop personalized sarcoma treatment plans for pediatric patients. Our multidisciplinary team of oncologists, pathologists, rehabilitation experts, radiologists, behavioral health experts, social workers and child life specialists work together to help achieve the best possible outcomes for patients.