Rhabdomyosarcoma in children is a rare cancer but is the most common type of soft tissue sarcoma (a tumor that is malignant, or that spreads). Soft tissues include muscles, tendons, fibrous tissues, nerves, blood vessels, fat and synovial tissues (which surround joints).
Rhabdomyosarcomas are comprised of muscle cells. The most common sites are the structures of the head and neck, the urogenital tract, and the arms and legs.
Most rhabdomyosarcoma cases are diagnosed in the first 10 years of life. Some children with certain inherited conditions are at increased risk for the disease, and some families have a gene mutation that increases risk, but the majority of children do not have any known risk factors.
The cause of most cases of rhabdomyosarcoma is unknown. In rare cases, rhabdomyosarcoma has been linked to a genetic mutation that affects cell formation during fetal development. Scientists continue to explore the cause of this soft tissue sarcoma.
Symptoms of rhabdomyosarcoma vary depending on the location of the tumor. For example, tumors in muscle may appear as a painful lump and may be mistaken for an injury. Tumors in the nose or throat may cause bleeding, swallowing problems or congestion. Tumors in the vagina may visibly protrude. Bladder and vaginal tumors may cause urinary or bowel obstruction.
Diagnosis is often delayed either because of a lack of clear-cut symptoms or symptoms that mimic injuries. Early diagnosis is important, however, because rhabdomyosarcoma can spread quickly.
Diagnosing rhabdomyosarcoma requires a careful and complete medical workup and examination of your child.
At Children’s Hospital of Philadelphia (CHOP), clinicians use a variety of diagnostic tests to correctly identify rhabdomyosarcoma in your child, including:
- Magnetic resonance imaging (MRI), which uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs, soft tissues, muscles, ligaments and other structures within the body. Your child is exposed to no radiation during an MRI.
- Needle biopsy, which is a procedure where a doctor places a small needle through the skin and into the lesion to withdraw a small sample of the abnormal tissue. The tissue is analyzed to confirm any findings.
- Computed tomography (CT) scan, which uses a combination of X-rays and computer technology to produce cross-sectional images ("slices") of the body.
- Bone marrow biopsy, which is a procedure where a doctor places a small needle into the bone and withdraws a small sample of tissue. The tissue is analyzed to determine if the cancer has spread.
- Positron emission tomography (PET) scan, which uses radioactive sugar injected into a vein and a scanner to make detailed, computerized pictures of areas of the body.
- Spinal tap (lumbar puncture), which is a procedure where a doctor places a small needle into the spinal cord in the lower back and withdraws a small sample of tissue. The tissue is analyzed to determine if the cancer has spread to the brain.
There are many treatment options available for soft tissue tumors like rhabdomyosarcoma, and some children will need a combination of these therapies. At CHOP, experts at the Bone and Soft Tissue Tumor Program take a team approach to treatment. Orthopaedic, cancer and other specialists collaborate to provide your child with individualized care and the best possible outcomes.
Our program is led by Kristy L. Weber, MD, and Alexandre Arkader, MD, nationally renowned surgeons who specialize in treating bone and soft tissues tumors, limb-sparing surgery and reconstructive surgery.
Surgery is usually necessary for rhabdomyosarcoma in children. Our surgeons will remove the cancer using the most advanced surgical techniques available.
The goals of surgery are twofold:
- To remove the tumor
- To restore function at the site of the tumor
More than 90 percent of children with rhabdomyosarcoma can be treated with limb-sparing (also known as limb-salvage) and reconstructive surgery. CHOP surgeons regularly perform these complex surgeries and are constantly working to improve outcomes for children with the most difficult-to-treat tumors.
Limb-sparing surgery is performed under general anesthesia. It involves cutting out the tumor and a margin of health tissue surrounding it. Depending on the size and location of the tumor, as well as your child’s age and stage of growth, orthopaedic and plastic surgeons may use a variety of reconstructive methods to restore your child’s body function. Reconstructive surgery, if necessary, will occur on the same day the tumor is removed.
Reconstruction may include:
- Skin graft, in which a doctor removes skin from the child’s own thigh or buttocks to use it to cover and protect the area where the tumor was removed
- Rotational muscle or fasciocutaneous flap, in which a doctor uses a child’s own muscle or skin near the surgery site, and rotates it to fill the area where the tumor was removed to provide a soft-tissue reconstruction
- Free muscle or fasciocutaneous flap, in which a doctor uses muscle or skin from the child’s own body, relocates it, and then reconnects the blood vessels to the tissue that was moved in the area where the tumor was removed
- A free bone flap, in which a piece of bone from a donor site is moved, based on its blood supply, to reconstruct the bony defect
In extremely rare cases — because of the size or location of the tumor — rhabdomyosarcoma cannot be removed with limb-sparing surgery. In these rare situations, it may be necessary to perform an amputation of the affected limb.
After surgery for rhabdomyosarcoma, your child should expect to stay two to five days in the Hospital.
Though surgery for malignant tumors is highly effective, we understand that any surgery can be a stressful experience for children and families. At CHOP, we offer a wealth of resources about how to prepare your child for surgery and what to expect during surgery.
Additionally, we employ numerous best practices before, during and after surgery to decrease the risk of infection and increase positive outcomes. For more details about safety protocols at Children's Hospital of Philadelphia, see safety in surgery.
Radiation and chemotherapy
Proton Therapy for Rhabdomyosarcoma
Radiation therapy, which uses high-energy X-rays to kill cancer cells and shrink tumors, may be used instead of — or in addition to — surgery. In most cases, clinicians will use protons to deliver radiation to treat rhabdomyosarcoma. Proton therapy can more accurately target the specific area of the tumor and avoid affecting surrounding normal tissues.
Chemotherapy (cancer medicine) is used in all patients with rhabdomyosarcoma.
Bone marrow transplant
Bone marrow transplantation is another type of treatment that is being studied for widespread rhabdomyosarcoma in children. Sometimes very high doses of chemotherapy are necessary to wipe out rhabdomyosarcoma tumors that have become resistant to standard doses. These high doses of drugs, however, can destroy the bone marrow. Bone marrow harvested from other people can be used to transplant to the patient’s bone marrow.
Your child will be examined by the surgeon about 1 to 2 weeks after surgery, then again at three and six months post-surgery.
Regular monitoring by trained clinicians is strongly encouraged to monitor for possible recurrence of the growth and manage any side effects of treatment. During follow-up visits, diagnostic testing of the tumor site or other areas may be recommended to closely monitor your child’s health and make sure there is no recurrence.
Follow-up care and ongoing support and services are available at our Main Campus and throughout our CHOP Care Network. Our team is committed to partnering with parents and referring physicians to provide the most current, comprehensive and specialized care possible for your child.
If your child needs continued monitoring into adulthood, he can continue to see some of the same doctors who treated him. CHOP’s Bone and Soft Tissue Tumor Program works closely with Penn Medicine. For families who live farther away and need continued monitoring, our clinical professionals will help your child transition to adult care near home.
Some children treated for pediatric cancer develop complications years later. Our Cancer Survivorship Program provides information about the potential long-term effects of the specific treatment your child received, including ways of monitoring and treating these effects.