ConditionCancer
Rhabdomyosarcoma (RMS)
Rhabdomyosarcoma (RMS) is a cancer that develops from cells that normally become skeletal muscle. It is the most common soft tissue sarcoma in children and teens, though it can occur in adults. It can arise almost anywhere, most often in the head and neck, the bladder, prostate or genital area, and the arms and legs. It usually appears as a painless, growing lump or causes symptoms from pressure on nearby structures. Treatment combines chemotherapy with surgery and/or radiation, and many children are cured.
Also called: RMS, soft tissue sarcoma of muscle, embryonal rhabdomyosarcoma, alveolar rhabdomyosarcoma
At a glance
- What it is
- A malignant tumor of developing skeletal muscle cells.
- Who
- Mostly children under 10 and teens. Rare in adults.
- Main types
- Embryonal (most common, younger children) and alveolar (often teens, limbs, more aggressive).
- Common sites
- Head and neck, genitourinary tract, arms and legs, trunk.
- Treatment
- Chemotherapy plus surgery and/or radiation, guided by risk group.
When to get help
Call 911 or go to the ER
- Difficulty breathing or swallowing from a neck or throat mass
- Inability to pass urine, or heavy bleeding
See a doctor within a day or two
- A lump that is growing over weeks, firm and painless, anywhere in the body
- A bulging eye, drooping eyelid or double vision in a child
- Blood in the urine, a mass protruding from the vagina, or a swollen scrotum in a child
- Persistent nosebleeds, ear discharge or nasal blockage on one side with a mass
Book a routine appointment
- A lump that has not gone away after 2 to 4 weeks
- A known cancer predisposition syndrome in the family, such as Li-Fraumeni syndrome
Types of rhabdomyosarcoma
| Type | Who | Common sites | Features |
|---|---|---|---|
| Embryonal | Young children, under 10 | Head and neck, genitourinary tract | Most common, usually better outlook. Botryoid subtype grows in grape-like clusters in hollow organs |
| Alveolar | Older children and teens | Arms, legs, trunk, perineum | Often has a PAX3 or PAX7-FOXO1 gene fusion, more aggressive |
| Spindle cell/sclerosing | Children and adults | Variable | Behavior depends on genetic features |
| Pleomorphic | Adults | Limbs | Rare, aggressive |
Symptoms by location
Symptoms depend on where the tumor grows:
- arms, legs or trunk: a firm, growing lump that may or may not hurt
- around the eye (orbit): a bulging eye, swelling, drooping eyelid, double vision
- nose, sinuses and throat: blocked nose, nosebleeds, sinus infections, swallowing problems
- middle ear: ear pain, discharge or a mass in the ear canal
- near the skull base (parameningeal): headaches, facial weakness, cranial nerve problems
- bladder or prostate: blood in the urine, difficulty urinating
- vagina: a grape-like mass, bleeding or discharge
- testis area: painless swelling in the scrotum
- bile ducts: jaundice, rarely
General symptoms such as weight loss, fever and fatigue are more common with spread to the bone marrow or lungs.
Causes and risk factors
Most cases occur with no known cause. Inherited conditions raise the risk:
- Li-Fraumeni syndrome (TP53 gene)
- neurofibromatosis type 1
- Noonan syndrome, Costello syndrome and other RASopathies
- Beckwith-Wiedemann syndrome
- DICER1 syndrome
Children with RMS may be offered genetic counseling and testing.
Diagnosis
- imaging of the primary tumor: MRI or CT
- biopsy: essential to confirm the diagnosis and type, including testing for FOXO1 gene fusions
- staging tests: chest CT, PET-CT or bone scan, and bone marrow sampling, to look for spread
- lumbar puncture for tumors near the skull base
- lymph node assessment for some sites
Patients are assigned a risk group (low, intermediate or high) based on the tumor site, size, how much can be removed, spread, and fusion status. This guides treatment intensity.
Treatment
Treatment is planned by a pediatric oncology team, often within clinical trials.
- Chemotherapy: given to all patients, usually vincristine, actinomycin D and cyclophosphamide (VAC) or related combinations, for about 6 months to a year, sometimes followed by maintenance therapy.
- Surgery: to remove the tumor when this can be done without major loss of function or appearance.
- Radiation therapy: for tumors that cannot be completely removed or have high-risk features. Proton therapy may be used to spare nearby growing tissues.
Supportive care includes infection prevention, nutrition, fertility preservation discussions, and psychological and school support.
Outlook
Outcomes depend on risk group:
- low-risk RMS: about 90% of children survive long-term
- intermediate-risk: roughly 65% to 75%
- high-risk or metastatic: about 20% to 30%, and research is focused on improving these results
Embryonal type, favorable sites (such as the orbit and some genitourinary sites), younger age, small size and complete removal are linked to better outcomes. Survivors need long-term follow-up for late effects of treatment, such as fertility problems, growth changes, heart effects and second cancers.
Frequently asked questions
What is rhabdomyosarcoma?
Rhabdomyosarcoma is a cancer of cells that would normally develop into skeletal muscle. It is the most common soft tissue sarcoma in children and can occur in many parts of the body, including the head and neck, bladder, genital area, arms and legs.
What are the first signs of rhabdomyosarcoma?
The first sign is often a painless, growing lump. Depending on location, there may be a bulging eye, nasal blockage or nosebleeds, ear discharge, blood in the urine, difficulty urinating, a vaginal mass or scrotal swelling.
What causes rhabdomyosarcoma?
Most cases have no known cause. Some children have inherited conditions that raise the risk, including Li-Fraumeni syndrome, neurofibromatosis type 1, Noonan syndrome, Costello syndrome, Beckwith-Wiedemann syndrome and DICER1 syndrome.
How is rhabdomyosarcoma treated?
All patients receive chemotherapy, combined with surgery to remove the tumor and/or radiation therapy. Treatment intensity depends on the risk group, which is based on tumor type, location, size and spread. Care is provided by specialist pediatric cancer teams.
What is the survival rate for rhabdomyosarcoma?
It depends on the risk group. Children with low-risk disease have survival rates around 90%, intermediate-risk around 65% to 75%, and high-risk or metastatic disease around 20% to 30%. The care team can explain the outlook for a specific child.
Sources
This guide was written from current patient and clinical guidance, including:
- National Cancer Institute: Childhood rhabdomyosarcoma treatment (PDQ)
- American Cancer Society: Rhabdomyosarcoma
- Children's Oncology Group: Rhabdomyosarcoma
- American Society of Clinical Oncology (Cancer.Net): Rhabdomyosarcoma - childhood
- St. Jude Children's Research Hospital: Rhabdomyosarcoma