Rhabdomyosarcoma

January 22, 2026

This page was reviewed under our medical and editorial policy by Lee Cranmer, M.D., Ph.D., professor, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte.

Rhabdomyosarcoma (RMS) is a rare soft tissue sarcoma (STS) composed of cells that normally develop into skeletal muscles, which are voluntary muscles that we control for movement.

According to the American Cancer Society, 400 to 500 new cases of rhabdomyosarcoma occur annually in the United States. Primarily affecting children and teens, RMS is the most common soft tissue sarcoma diagnosed in children and accounts for 3% of all childhood cancers. Though more common in younger patients, RMS may affect those of any age.

What Is Rhabdomyosarcoma?

Rhabdomyoblasts are cells that eventually form skeletal muscles. When these cells mutate, or change, and grow out of control, they may cause RMS.

RMS may develop anywhere in the body, but typically affects muscles in the arms, legs, head and neck, abdomen and urinary and reproductive organs. It may sometimes spread to other parts of the body. Scientists know that spread to the other parts of the body may occur very early, and may not be detectable by imaging studies initially.

Types of Rhabdomyosarcoma

Rhabdomyosarcoma takes multiple forms, including the types listed below.

Embryonal

Embryonal rhabdomyosarcoma (ERMS) is the most common type of rhabdomyosarcoma. It typically occurs in the head and neck area or in the genital or urinary organs and affects children up to age 5.

Spindle Cell

Spindle cell rhabdomyosarcoma, a subtype of ERMS, forms in the area around a child’s testicles.

Alveolar

Alveolar rhabdomyosarcoma (ARMS) frequently occurs in large muscles of the arms, legs or trunk and affects all age groups equally. It is aggressive, growing quickly after it develops, and often demands more intense treatment.

Pleomorphic

Anaplastic rhabdomyosarcoma, also called pleomorphic rhabdomyosarcoma, tends to grow quickly and mostly affects the legs, though it may develop anywhere in the body. It usually affects adults ages 50 and older.

Causes and Risk Factors

The cause of most rhabdomyosarcoma cases is not clear, but there are few recognized risk factors.

A small population with RMS has inherited gene mutations, or gene changes inherited from a parent. These differ from acquired gene mutations, which develop at some point during a person's lifetime.

Some rare inherited genetic disorders may increase the risk of developing RMS:

• Li-Fraumeni syndrome
• Neurofibromatosis type 1 (NF1)
• Beckwith-Wiedemann syndrome
• Costello syndrome
• Noonan syndrome
• Dicer1 syndrome

Rhabdomyosarcoma Symptoms

Symptoms of rhabdomyosarcoma vary depending on the tumor’s location, size and spread. The most common symptoms by tumor site include those listed below.

Neck, chest, back, arm, leg or groin: Mass, lump, swelling or redness.

Eyes: Bulging or swelling eyes.

Abdomen or pelvis: Pain, constipation or vomiting.

Ear or nasal sinuses: Nosebleed, sinus congestion, earache or headache.

Bladder or prostate: Blood in urine or difficulty urinating.

Vagina: Vaginal bleeding or difficulty urinating.

Testicles: Fast-growing mass or lump around testicles.

Though RMS symptoms may appear like less serious health conditions, it’s important to see a doctor if they do not go away or worsen.

Tests for Diagnosing

A speedy, accurate diagnosis is critical with diseases as rare and complex as rhabdomyosarcoma. Common diagnostic tests for rhabdomyosarcoma include:

• A complete medical history and comprehensive physical exam to look for signs of RMS or other health issues
• One or more imaging tests — such as an X-ray, computed tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography (PET) scan, bone scan or ultrasound — which use X-rays, magnetic fields, radioactive substances or sound waves to generate pictures of parts of the body
• A biopsy, which removes a tumor sample for laboratory examination and testing, to confirm a rhabdomyosarcoma diagnosis.

It is important that the advice of a sarcoma specialist be obtained prior to biopsy to prevent future complications.

Stages

Staging is the process by which the extent of a cancer is determined. This then allows decisions to be made regarding appropriate treatment. For example, if cancer is identified in only one location within a patient’s body, surgery would often be considered the main treatment in an attempt to cure the patient of that cancer. In contrast, if the cancer has metastasized, it is in different parts of the body and surgery may not be useful to treat the condition. In those circumstances, other treatments, such as chemotherapy, may be the primary treatment. Determining the extent or stage of the cancer may help guide this decision making. This is true for rhabdomyosarcoma, as it is for other types of cancer.

Staging of rhabdomyosarcoma begins with the three key factors that help establish the RMS risk group classification detailed below.

TNM stage: For this classification, T stands for main tumor size and location, N stands for cancer spreading to the lymph nodes and M stands for metastasis to other parts of the body. Stages 1, 2, 3 and 4 are assigned based on TNM factors.

Clinical group: This classification represents the outcomes of biopsies or initial surgeries. Groups I, II, III, and IV are assigned based on whether the cancer has spread and status of removal by surgery.

Gene changes: Pathologists determine the presence of the fusion gene PAX/FOX01 in cancer cells. This gene produces a protein that is made up of parts of two other proteins. This gene and the resulting protein are only present in the cancer cells and are thought to be very important in causing the disease in those with this alteration.

Following the staging and grouping process, oncologists classify risk groups as low-risk, intermediate-risk or high-risk, which helps guide a patient’s sarcoma treatment plan, likelihood of tumor recurrence and prognosis.

Rhabdomyosarcoma Treatment

Factors like tumor location and risk group classification influence personalized treatment plans, but typically rhabdomyosarcoma is treated with surgery and/or radiation therapy in combination with chemotherapy.

Rhabdomyosarcoma is a rare disease. Whether diagnosed with adult or childhood RMS, it’s important to seek specialized care from experts who are equipped with the latest treatments and therapies.

Surgery

Surgery is an important part of the treatment plan in those with RMS. If the disease has metastasized to other parts of the body, surgery may be used less often, but still may be important. The goal is to completely remove the main tumor and nearby tissue.

Most patients will undergo two types of surgery:

• The biopsy to diagnose the cancer
• The surgical procedure to remove the cancer

If surgery is not initially possible, chemotherapy and/or radiation therapy may be used initially to shrink the tumor.

Chemotherapy

When used to treat RMS, two or more chemotherapy drugs are given to destroy cancer cells. Even if the tumor appears to have been removed surgically, all patients with RMS need chemotherapy to help prevent recurrence. This is because scientists have learned that RMS may spread to distant parts of the body very early. This may be the case even if the care team cannot see the disease by imaging studies. Chemotherapy attempts to eradicate disease that has already spread, but which cannot yet be seen. It is very important in working toward a cure of this condition.

The combination of chemotherapy drugs depends on risk group classification. People with higher risk of RMS tend to receive more aggressive treatment.

Radiation Therapy

Radiation, which uses high-intensity X-rays to kill cancer cells. When tumors cannot be removed with surgery, radiation therapy may be used as an alternative treatment to surgery. In some cases, radiation therapy is used to try to cure the patient, in conjunction with chemotherapy. In other settings, radiation therapy may be able to relieve symptoms like pain and swelling.

Who Treats Rhabdomyosarcoma?

Whether the patient is an adult or child, finding the right cancer center and experts who specialize in diagnosing and treating rhabdomyosarcoma is critical. RMS in children presents unique situations and complexities. That’s why a multidisciplinary team approach at a pediatric cancer center or program is recommended throughout the care journey and even years after treatment, with specialists including:

• Pediatric or medical 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

Rhabdomyosarcoma Survival Rate

Survival rates for rhabdomyosarcoma vary significantly and depend on many factors, including the disease type, stage and risk group; surgery results; treatment effectiveness and patient’s general health.

Based on risk group, following are general overall five-year survival statistics for children with RMS.

Low-risk group: Overall, the survival rate ranges from about 70% to over 90%. Most of these patients will be cured.

Intermediate-risk group: The survival rate ranges from about 50% to about 70%, with children aged 1 to 9 years faring better than others.

High-risk group: The survival rate is generally lower, around 20% to 30%, but it’s important to remember that other factors may influence these numbers. For instance, children with embryonal rhabdomyosarcoma and limited spread have a higher five-year survival rate.