Rhabdomyosarcoma is a type of soft tissue cancer that is most often found in children. This cancer will usually present itself as a noticeable lump. Since this is a cancer made up of cells that normally develop into skeletal muscles, the lump can appear in different locations of the body. Although most of our skeletal muscles are in our limbs and truck, it is usually found elsewhere.

The most common sites that rhabdomyosarcoma tumors are found:
Head and Neck (30%-40%)
Urinary and Reproductive Organs (20%-25%)
Arms and Legs (18%-20%)
Truck (7%)

There are two main types of rhabdomyosarcomas that occur in children, embryonal rhabdomyosarcoma and alveolar rhabdomyosarcoma. The embryonal type (ERMS) is the most common type and usually occurs in infants and young children. The alveolar type (ARMS) usually effects older children and teenagers. Embryonal has a better prognosis than alveolar, which is a more aggressive tumor type.


About 3 percent of childhood cancers are diagnosed as rhabdomyosarcoma. In the United States about 350 new cases arise each year. It is the most common type of sarcoma occurring in the soft tissues, which is tissue that lies between the skin and the bone. It is the sixth most common cancer in children.

The researchers say there are no known environmental risk factors that cause rhabdomyosarcoma. There are some inherited conditions that can increase the risk of developing rhabdomyosarcoma but these are only a small fraction of those diagnosed. L-Fraumeni syndrome, Beckwith-Wiedemann syndrome, neurofibromatosis and Costello syndrome are inherited conditions that are known to lead to different forms of cancer. This information gives the researchers of this disease some key knowledge in understanding the disease and points them in the direction of a genetic cause for this type of cancer.