Rhabdomyosarcoma

Written by Nechama F. Sammet Moring
Medically Reviewed by Zilpah Sheikh, MD on March 04, 2025
8 min read

Rhabdomyosarcoma (RMS) is a rare form of cancer that develops in the soft tissues of your body, often in the muscles. It mostly affects children.

Rhabdomyosarcoma can grow almost anywhere in your body, says Anand Patel, MD, a pediatric oncologist at St. Jude Children’s Research Hospital. But it often affects the arms, legs, head, neck, reproductive organs, and urinary system.

Rhabdomyosarcoma is thought to arise in immature cells that normally develop into the skeletal muscles we use to move parts of our body. These cells, called rhabdomyoblasts, start to form when a human embryo is just a few weeks old.

Only about 400-500 people are diagnosed with rhabdomyosarcoma every year in the U.S. More than half of them are kids under 10. It’s rare for RMS to be diagnosed in adults, but it can happen.

There are four main types of rhabdomyosarcoma, says Bhuvana Setty, MD, a pediatric hematologist/oncologist at Nationwide Children’s Hospital in Columbus, Ohio. They are:

Embryonal rhabdomyosarcoma. This is the most common type, affecting about 6 out of 10 people with RMS. It’s most often found in children under 5. These tumors often grow in the head and neck area or around the bladder and genitals. People with this kind of RMS usually do well with treatment. 

Alveolar rhabdomyosarcoma. About 20% of people with RMS have this type, which is most common in teens. It’s usually found in muscles of the trunk, arms, legs, genitals, or anus. The tumors tend to grow faster than the embryonal type and may require more intense treatment.

Spindle cell/sclerosing rhabdomyosarcoma. This type is rare and has several subtypes. Spindle cell RMS mostly grows in male genitals. Another subtype in this category affects the torso area, most commonly in babies. A third, often faster-growing subtype is found in the head and neck and affects people of all ages.

Anaplastic/pleomorphic rhabdomyosarcoma. This type usually affects adults. Its tumors grow in the arms and legs. It tends to be more aggressive than other types of RMS.

Your doctor will do tests to figure out what type of rhabdomyosarcoma you or your child have. They’ll also check whether the cancer is low, intermediate, or high risk. This depends on where in your body the cancer is, whether it has spread, and what its cells look like under a microscope.

Rhabdomyosarcoma happens when rhabdomyoblast cells develop differently or start behaving in unusual ways. This might start before you’re born. But doctors don’t know why it happens.

“We’re still learning a lot about this disease,” says Patel. “But we know there’s nothing you can do to predict this disease in advance.”

People who have certain genetic medical conditions may be at a higher risk for RMS. These include:

  • Neurofibromatosis type 1 (NF1), a condition that raises the risk for nerve sheath tumors
  • Beckwith-Wiedemann syndrome, which causes babies to be larger than usual
  • Noonan syndrome, which causes short stature, distinctive facial features, and other symptoms

The symptoms of rhabdomyosarcoma depend on where the tumor is:

  • Tumors in the muscles behind the eye can cause eye bulging, drooping eyelids, and vision problems.
  • Tumors in the ear or nasal  cavity can cause earaches, headaches, congestion, or nosebleeds.
  • Tumors in the urinary tract can make it hard to pee or cause blood in the pee.
  • Tumors in the vagina can cause bloody discharge.
  • Tumors in the belly area can cause vomiting, pain, or constipation.
  • Tumors in the neck, chest, arms, legs, back, or groin can cause lumps or swelling. These lumps could grow from the size of a mosquito bite to the size of a lime in just a few weeks.

Many of these symptoms can be caused by other, less serious conditions. But getting an early diagnosis of rhabdomyosarcoma can make it easier to treat. So, if you or your child has one of these symptoms that can’t be explained — such as a bump that doesn’t go away or gets bigger — get it checked by a doctor.

If a doctor thinks you or your child may have RMS, they’ll do a physical exam and ask about symptoms and health history. They may order imaging tests such as:

X-rays. Electromagnetic waves are used to show images of bones and other tissues.

MRI. Powerful magnets and radio waves are used to create detailed pictures.

CT scan. Several X-rays taken from different angles are put together to collect more information.

Ultrasound. Sound waves are used to make images of the body.

Bone scan. A very small amount of radioactive material is put into a vein to show areas where there may be cancer.

If doctors see anything on the imaging tests, they’ll do a biopsy of the affected area. They’ll make a small cut or use a needle to collect a tiny tissue sample. The sample is sent to a lab for testing to check whether cancer is present.

If they find rhabdomyosarcoma, they’ll do further tests to learn more about your specific cancer. Doctors group RMS into risk groups based on details about your tumor, whether the cancer has spread, and whether they see certain changes in the cells under the microscope.

Knowing whether your rhabdomyosarcoma is in the low-risk, intermediate-risk, or high-risk group will help your doctor decide which treatments might work best for you.

There are two main ways doctors treat rhabdomyosarcoma. Some treatments are meant to get rid of as much of the tumor as possible. This could mean doing surgery to take the tumor out, giving you radiation treatments to shrink the tumor, or both. Other treatments, such as chemotherapy, aim to kill cancer cells or stop them from growing.

Your medical team will talk with you about your treatment options. What they recommend will depend on your risk group, the size of the tumor, whether it’s in a place where doctors can fully remove it through surgery, and other factors.

Doctors usually treat RMS with some combination of these treatments:

Surgery. Depending on where the tumor is, doctors might do surgery to take it out. They might be able to get all of it or just some of it. How complicated the operation is can depend on how big the tumor is and other factors.

If the tumor is in a hard-to-reach spot or overlaps with important organs, it’s more difficult for doctors to take out all the cancer cells without damaging healthy tissue. If surgery seems too difficult or risky, you may have chemotherapy or radiation first to try to shrink the tumor. This can make it easier for surgeons to go in later to remove it.

Chemotherapy. Chemotherapy medications are used to kill cancer cells. For RMS, chemotherapy drugs are usually given for six months to a year — once a week at first, then less often.

These drugs are very good at killing cancer cells, but they also can kill healthy cells. They can cause hair loss, nausea and vomiting, fatigue, and other unpleasant reactions. Most of these side effects are temporary, and children tend to handle chemotherapy better than adults. Talk to your doctor about how to ease chemotherapy side effects. 

Radiation. Radiation uses powerful X-rays to kill cancer cells. It can shrink or even destroy tumors. It’s usually given five days a week over several weeks.

Radiation can also cause side effects, both right away and years later. Discuss these risks with your doctor before radiation begins. 

During treatment, you may get support from several different care team members. For example, a nutritionist can help manage nausea and find foods you can eat, while a social worker can help you deal with the stress of the illness and its treatments. A good support network of family and friends is helpful, too. 

Clinical trials

Clinical trials are studies that test new and innovative treatment options, such as targeted therapy and immunotherapy. They help doctors learn things that could help other patients in the future. 

Talk to your doctor if you’re interested in being in a clinical trial. You can take part in a clinical trial before, during, or after having other rhabdomyosarcoma treatments.

It’s easier to treat rhabdomyosarcoma if it’s caught early, before it has a chance to grow or spread much.

Most people with rhabdomyosarcoma in the low- and intermediate-risk groups survive. But treatment can also work for people in the high-risk group. Children between 1 and 10 years old are especially likely to have a good outcome.

But sometimes, the cancer can come back. When it does, it usually happens in the first few years after treatment. For this reason, your doctors will keep a close eye on you after your treatment ends. You might see the doctor every few months at first, then have regular follow-up appointments.

Rhabdomyosarcoma is a rare form of cancer that starts in the soft tissues of your body and most often affects children. It can have a variety of symptoms, depending on where in the body the tumor is. Treatments include surgery, chemotherapy, and radiation.

Is rhabdomyosarcoma an aggressive cancer?

The kind of rhabdomyosarcoma you have affects how aggressive it is. In general, the most common type, embryonal rhabdomyosarcoma, is easier to treat. Alveolar, spindle cell/sclerosing, and pleomorphic rhabdomyosarcomas can be more aggressive. But there are treatment options for all types of rhabdomyosarcoma.

Is rhabdomyosarcoma curable?

Rhabdomyosarcoma can be curable. Doctors say it’s in remission, which means you have no signs of the cancer. Treatment is most likely to be effective if you’re diagnosed before RMS has a chance to spread. Other things that affect your outlook include where the tumor is, its size, and what kind of RMS you have. Kids who are diagnosed when they’re between 1 to 10 years old are most likely to have remission.

What is the difference between sarcoma and rhabdomyosarcoma?

Rhabdomyosarcoma is a type of sarcoma. Sarcomas are cancers that grow in the bones and soft tissues, such as muscles, fat, and nerves.

What are rhabdomyosarcoma risk groups?

Doctors divide people with rhabdomyosarcoma into low-, intermediate-, and high-risk groups, based on things like how far the cancer has spread and where it’s located. This helps them figure out what kind of treatment you need. People in the low-risk group might only need surgery, followed by regular monitoring. Those in the intermediate- and high-risk groups usually need more treatment.