Rhabdomyosarcoma is a cancerous (malignant) tumor of the muscles that are attached to the bones.

It can occur in many places in the body. The most common sites are the structures of the head and neck, the urogenital tract, and the arms or legs.

Rhabdomyosarcoma is the most common soft tissue tumor in children.

Soft tissue sarcoma; Alveolar rhabdomyosarcoma; Embryonal rhabdomyosarcoma; Sarcoma botryoides

The cause of rhabdomyosarcoma is unknown. It is a rare tumor with only several hundred new cases per year throughout the United States.

Some children with certain birth defects are at an increased risk, and some families have a gene mutation that elevates risk. However, the great majority of children with rhabdomyosarcoma do not have any known risk factors.

The most common symptom is a mass that may or may not be painful.

Other symptoms vary depending on location of the tumor.

• Tumors in the nose or throat may cause bleeding, congestion, swallowing problems, or neurological problems if they extend into the brain.
• Tumors around the eyes may cause bulging of the eye, problems with vision, swelling around the eye, or pain.
• Tumors in the ears, may cause pain, hearing loss, or swelling.
• Tumors in the vagina may be visibly protruding from the opening of the vagina.
• Bladder and vaginal tumors may cause lead to trouble starting to urinate or having a bowel movement, or poor control of urine.
• Muscle tumors may lead to a painful lump and are often thought to be an injury.

Diagnosis of rhabdomyosarcoma is often delayed because of lack of symptoms, and because the tumor may appear at the same time as a recent injury. Early diagnosis is important because rhabdomyosarcoma is an aggressive tumor that spreads quickly.

A complete physical exam should be done. Tests done to diagnose this condition may include:

• Biopsy of the tumor
• CT scan of the chest to look for spread of the tumor
• CT scan of the tumor site
• Bone marrow biopsy (may show the cancer has spread)
• Bone scan to look for spread of the tumor
• MRI scan of the tumor site
• Spinal tap (lumbar puncture)

The precise treatment depends on the site and type of rhabdomyosarcoma. Because of its rarity, this tumor is best treated at a center with experience treating many patients with rhabdomyosarcoma.

Either radiation or chemotherapy, or both, will be used before or after surgery. In general, surgery and radiation therapy are used to treat the primary site of the tumor. Chemotherapy is used to treat disease at all sites in the body.

Chemotherapy is an essential part of treatment to prevent further spread of the cancer. Many different chemotherapy drugs are active against rhabdomyosarcoma. Some of these drugs include:

• Dacarbazine
• Doxorubicin
• Epirubicin
• Gemcitabine
• Ifosfamide

The stress of illness can often be helped by joining a support group where members share common experiences and problems. See cancer - support group.

While aggressive treatment is usually necessary, most children with rhabdomyosarcoma will achieve long-term survival. Cure depends on the specific type of tumor, its location, and the amount that has spread.

• Complications from chemotherapy
• Location in which surgery is not possible
• Metastasis

Call your health care provider if your child has symptoms of rhabdomyosarcoma.

Arndt CAS. Soft Tissue Sarcomas. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics.18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 500.

National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology: Soft Tissue Sarcoma. National Comprehensive Cancer Network; 2009. Version 2.2009.