Rhabdomyosarcoma is a rare cancer seen in children more than adults. In about two-thirds of cases, rhabdomyosarcoma occurs in a child younger than 10. It is a soft tissue tumor that typically appears in one of three locations: the head and neck region (35% to 40% of cases), the urinary tract and reproductive organs (25% of cases), or the arms and legs (10% of cases). It also can occur on the trunk. Doctors classify this cancer based on the way the cells appear under a microscope; most are either embryonal (60% of cases) or alveolar (20% of cases).

• Embryonal. Tumors tend to develop at the back of the throat, in the ear canal or in the urinary or reproductive tracts. In general, this is a limited, localized cancer that responds well to treatment and rarely spreads (metastasizes).



• Alveolar. Tumors tend to be aggressive and hard to treat. They often begin in the arms and legs, especially in older children and teenagers.
• There are two other varieties known as anaplastic rhabdomyosarcoma and undifferentiated sarcoma that are quite rare.

Rhabdomyosarcoma is often associated with specific genetic abnormalities. Certain people may be prone to developing this type of cancer, as part of an increased susceptibility to developing multiple cancers.

In the United States, rhabdomyosarcoma strikes approximately 5 in every 1 million children each year. Children are more likely to develop rhabdomyosarcoma if they already have Li-Fraumeni syndrome or neurofibromatosis (type I), or if they have an older relative who has been diagnosed with early-onset breast cancer or adrenal cancer. Rhabdomyosarcoma is more common in children whose parents have used recreational drugs, especially marijuana or cocaine, and whose fathers smoke, but this association needs further study. Likewise, children of mothers who were exposed to multiple courses of antibiotics during pregnancy have also been associated with a high incidence of rhabdomyosarcomas.

Symptoms depend on where the tumor develops:

• Head and neck. When rhabdomyosarcoma affects the eye or eyelid, it can cause a bulging eye, a swollen eyelid or paralysis of the eye muscles. In the sinuses, rhabdomyosarcoma can cause a stuffy nose, and sometimes a nasal discharge that contains pus or blood. In other locations in the head and neck, the most common symptom of a rhabdomyosarcoma near the surface is a painless lump or swelling that gradually gets larger. A rhabdomyosarcoma deep in the skull can erode the bones that protect the brain, triggering headache and nausea as the tumor gradually grows toward the brain's surface.



• Genitourinary tract. Rhabdomyosarcomas can develop in the bladder, prostate, vagina, uterus, scrotum and testes. Depending on the exact location, these tumors can cause difficulty in urination, blood in the urine (hematuria), constipation, a lump or mass inside the vagina, vaginal discharge that contains blood and mucus, or a painless enlargement of one side of the scrotum.



• Arms and legs. Rhabdomyosarcoma appears as a lump or swelling in the arms or legs, with or without pain, tenderness and redness. In physically active children, the swelling is sometimes mistaken for an injury related to sports or childhood play.

After reviewing your child's symptoms, your doctor will examine your child. Depending on the results of this exam, your doctor may order a regular X-ray as the first test. Computed tomography (CT) scans and magnetic resonance imaging (MRI) might also be needed. If a tumor is found on any of these studies, small piece of tissue is removed and examined in a laboratory (biopsy).

If the lab tests show signs of a cancerous (malignant) tumor, your doctor will refer you to a medical center that has the facilities, personnel and experience to treat childhood cancer. There your child will have more tests, which probably will include a chest X-ray, a chest CT scan, a radionuclide bone scan, a bone marrow biopsy and other tests to check whether the cancer has spread to the lungs, bones or elsewhere.

Rhabdomyosarcomas are rare, and they can cause symptoms similar to more common conditions, such as bladder infections, sinusitis or sports injuries. For this reason, your doctor may not suspect cancer at first. In fact, in many cases, several months pass before the correct diagnosis is made.

A rhabdomyosarcoma will continue to grow until it is treated. Without proper treatment, this cancer eventually may spread to the lungs, bone marrow, bones or lymph nodes.

There is no way to prevent most cases of rhabdomyosarcoma. However, anyone who hopes to conceive a healthy child should avoid using recreational drugs and smoking tobacco. These dangerous chemicals could increase the risk of rhabdomyosarcoma or other medical conditions in the child, either at birth or later in life.

The treatment of rhabdomyosarcoma is determined by two factors:

• Tumor stage. A tumor's stage is determined by its location, size and how far it has spread (metastasized) to nearby lymph nodes or to distant organs.



• Tumor group. This is established after a surgeon has removed as much of the tumor as possible. Sometimes, a second surgery is needed to remove traces of cancer that remain after the first surgery. In group 1 tumors, the cancer is completely removed surgically. In group 2 tumors, all the visible cancer is removed surgically, but some microscopic cancer remains. In group 3, surgery could not remove all visible tumor, but the cancer had not spread. In group 4, the cancer had spread at the time of diagnosis.

Except for tumors located in the eye or genitourinary tract, the first step in treating most rhabdomyosarcoma is surgery. Surgery is followed by chemotherapy and radiation. For very large tumors, chemotherapy and radiation are given before surgery to shrink the tumor, so that the surgery will be less disfiguring.

Surgery can be used after chemotherapy if there are residual amounts of tumor tissue left behind or abnormalities that are still persisting on X-ray examinations.

In the eye, rhabdomyosarcoma usually is treated with radiation and chemotherapy, without surgery. For rhabdomyosarcoma in the bladder or female reproductive tract, chemotherapy and radiation are used to shrink the tumor before surgery. This allows the surgeon to preserve as much of the organ as possible.

Call your doctor promptly if your child develops a persistent lump or swelling anywhere in the body, especially around the eye, on the face or neck, on an arm or leg, in the vagina or near a testicle. Also, call your doctor if your child has bloody urine, difficulty urinating, pain during urination or a persistent unexplained discharge from the nose, ear or vagina.

The outlook depends on the tumor group. With treatment, more than 80% of children with group 1 rhabdomyosarcoma survive disease-free. This percentage drops to about 50% for children in groups 2 and 3, and drops to less than 20% for children in group 4. In general, children with the embryonal variety of rhabdomyosarcoma respond better to treatment than those with the alveolar type. If rhabdomyosarcoma does not respond well to treatment, the child will die of the disease. It is important that the child visit a pediatric oncologist who can help coordinate the multiple treatments involved in managing this disease.

National Cancer Institute (NCI)
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American Cancer Society (ACS)
Toll-Free: 1-800-227-2345
TTY: 1-866-228-4327
http://www.cancer.org/

American Academy of Pediatrics (AAP)
141 Northwest Point Blvd.
Elk Grove Village, IL 60007-1098
Phone: 847-434-4000
Fax: 847-434-8000
Email: kidsdocs@aap.org
http://www.aap.org/

American Society of Clinical Oncology
2318 Mill Road
Suite 800
Alexandria, VA 22314
Phone: 571-483-1300
Email: asco@asco.org
http://www.asco.org/