Rhabdomyosarcoma is a fast-growing cancerous tumor that is found most in the head and neck, particularly around the eyes. This tumor begins from the rhabdomyoblast, a type of muscle cell, and is part of a larger group of tumors known as soft tissue sarcomas. Rhabdomyosarcomas are most common in children.
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What Is Rhabdomyosarcoma?
Rhabdomyosarcoma (RMS) is a fast-growing cancerous tumor that is part of a larger group of tumors called soft tissue sarcomas. Sarcomas are cancers made up of cells that would normally develop into the skeletal muscles we use to move our bodies voluntarily.
RMS tumors are made up of muscle cells called rhabdomyoblasts that form before birth. These cells, which one day become skeletal muscles, can later develop into RMS. A cancer of early muscle cells, RMS is more common in children, but can rarely occur in adults.
Although they can occur anywhere on the body, RMS tumors are most often found:
- In the head and neck, particularly around the eyes.
- In the extremities – the arms or legs.
- Near the urinary tract, including the bladder.
- Near reproductive organs, including the prostate or vagina.
Less common primary sites for RMS tumors include:
- Abdomen, including the retroperitoneum and biliary tract.
- Chest wall.
- Perianal region.
- Trunk.
Symptoms of rhabdomyosarcoma may not always be apparent when the sarcoma is small but, as the tumor grows, it can include neurological problems such as headaches.
What are the types of rhabdomyosarcoma?
Rhabdomyosarcoma is classified into subtypes based on their microscopic structure:
- Alveolar rhabdomyosarcoma (ARMS)—Named for its appearance resembling the small alveoli (air sacs) in the lungs, ARMS occurs equally in both males and females and constitutes 23% of RMS tumors.
- Embryonal (ERMS) – Affects predominantly males with about a 4 in 1 million children incidence rate between the ages of newborn and 4, and a 1.5 in 1 million incidence rate in adolescents. The most commonly occurring subtype — roughly 57% of all RMS tumors are embryonal — ERMS has the best prognosis of the RMS subtypes.
- Mixed-type RMS – Rare tumor containing two histologically different subtypes of RMS, commonly found in the testicles.
- Pleomorphic rhabdomyosarcoma – Rare high-grade pleomorphic sarcoma seen in adults. Childhood cases are considered rhabdomyosarcoma with diffuse anaplasia, which is also very rare.
- Spindle cell/sclerosing rhabdomyosarcoma: Spindle cell and sclerosing RMS are uncommon variants, accounting for up to 10% of all RMS tumors.
What causes rhabdomyosarcoma?
The cause is largely unknown. Most RMS cases are sporadic, meaning they occur without pattern, although there may be an association with inherited syndromes within families.
Rhabdomyosarcoma risk factors
Risk of developing RMS increases with:
- High birth weight and babies larger than gestational age (LGA).
- History of congenital defects.
- History of genetic syndromes, including Li-Fraumeni cancer susceptibility syndrome, DICER1 syndrome, neurofibromatosis type I (NF1), Costello syndrome, Beckwith-Wiedemann syndrome (commonly associated with Wilms tumor and hepatoblastoma), and Noonan syndrome.
- Family history of RMS in a first-degree relative.
- Fetal exposure to radiation.
- Fertility drug use.
- Parental drug use.
- Preterm birth.
Complications of rhabdomyosarcoma
If rhabdomyosarcoma (RMS) goes untreated, it can lead to serious and potentially life-threatening consequences due to its aggressive nature and tendency to spread quickly.
Potential outcomes include:
- Physical and emotional challenges that can severely impact quality of life.
- Progressive life-threatening organ damage and loss of function.
- Reduced long-term survival rates or death.
How common is rhabdomyosarcoma?
Rhabdomyosarcoma (RMS) is rare. It makes up 3% of all pediatric cancers, but it is the most common soft tissue sarcoma in children and teens, comprising 50% of soft tissue sarcomas in people under 20. Roughly 350 people are newly diagnosed each year. In contrast, RMS in adults accounts for about 1% of solid tumors.
What Are the Signs and Symptoms of Rhabdomyosarcoma?
In the early stages, rhabdomyosarcoma cancers are small and do not produce symptoms. As the tumor grows, it may push aside normal head and neck structures, causing neurological symptoms.
The most common symptom of rhabdomyosarcoma is a lump or swelling that may or may not be painful.
Your doctor will perform a physical exam and ask you about any symptoms you may be experiencing.
When should I see a doctor about my rhabdomyosarcoma symptoms?
You should call your doctor right away if you have any rhabdomyosarcoma symptoms, including:
- A lump or swelling that may or may not be painful in an arm or leg, or in the head, neck, or abdomen.
- Blood in urine or difficulty urinating.
- Constipation or vomiting.
- Earache or ear discharge.
- Eye bulging or swelling.
- Mass or lump in the groin.
- Nosebleeds or sinus blockages.
Many conditions may cause similar symptoms to RMS, so you should be seen by a health care provider to be sure.
How Do You Diagnose Rhabdomyosarcoma?
Your doctor will conduct a physical examination and may order imaging tests if a rhabdomyosarcoma cancer is suspected. However, the only way to confirm a rhabdomyosarcoma diagnosis is with a biopsy.
Imaging studies
Doctors usually start with MRI scans of the area because of they allow better visualization of musculoskeletal tumors. CT or PET scans may also be ordered if metastasis (spread) is suspected.
Biopsy
Doctors need to understand the structure of the cancer on a microscopic and molecular level to effectively treat it. A biopsy allows a sample of tumor tissue to be taken for testing in the pathology lab. The tissue sample usually will be taken through an excisional or core needle biopsy. Genetic testing of the tissue will identify and confirm the RMS subtype.
How Do You Treat Rhabdomyosarcoma?
UPMC's neurosurgical team may recommend a combination of surgical and nonsurgical approaches for rhabdomyosarcoma treatment.
Surgery for rhabdomyosarcoma
Surgery is one of the most common methods for treating rhabdomyosarcoma. The goal of surgery is to remove the cancerous tumor and nearby tissue to get a clean margin.
At UPMC, rhabdomyosarcoma and other skull base cancers often are approached directly using the Endoscopic Endonasal Approach (EEA). This state-of-the-art, minimally invasive approach — developed and refined at UPMC — allows surgeons to access tumors through the natural corridor of the nose, without making an open incision. Surgeons then remove the tumor through the nose and nasal cavities.
EEA offers the benefits of no incisions to heal, no disfigurement or scarring, and a faster recovery time.
People who receive EEA surgery may be able to begin chemotherapy or radiation therapy soon after surgery.
Chemotherapy and radiation therapy for rhabdomyosarcoma
Chemotherapy is typically used for rhabdomyosarcomas because it can help ensure that the tumor will not come back. Adding radiation will significantly reduce the chances of cancer recurring.
In some cases, radiation therapy and chemotherapy may be done prior to surgery.
How effective is treatment?
In children whose RMS has not spread, more than 70% are alive five years after diagnosis and combined-modality (surgery, chemo, and/or radiation) treatment. Relapses are uncommon in these patients, with a 10-year recurrence rate of under 9%. Relapses are more likely in people whose tumors were in unfavorable sites, were unable to be removed, or had already spread at the time of diagnosis.
Why Choose UPMC for Rhabdomyosarcoma Care?
UPMC surgeons were the first in the world to perform a number of procedures using the Endonasal Endoscopic Approach (EEA), and UPMC is one of the busiest centers in the world for endoscopic treatment of pituitary tumors and tumors of the cranial base.
UPMC surgeons performed our 5,000th EEA procedure in 2025.
In addition to its successful use in adults, EEA has proven safe and effective in children. More than 100 children have been treated by UPMC surgeons using EEA — more than at any other neurosurgery center in the world.
