Sarcomas are cancers that develop from connective tissues in the body, such as muscles, fat, bones, the linings of joints, or blood vessels. There are many types of sarcomas. Rhabdomyosarcoma (RMS) is a cancer made up of cells that normally develop into skeletal muscles. The body has 3 main types of muscles.

Common sites of RMS include:

• Head and neck (such as near the eye, inside the nasal sinuses or throat, or near the spine in the neck)
• Urinary and reproductive organs (bladder, prostate gland, or any of the female organs)
• Arms and legs
• Trunk (chest and abdomen)