Childhood rhabdomyosarcoma is a disease in which malignant (cancer) cells form in muscle tissue. Rhabdomyosarcoma is a type of sarcoma. Sarcoma is cancer of soft tissue (such as muscle), connective tissue (such as tendon or cartilage), or bone. Rhabdomyosarcoma usually begins in muscles that are attached to bones and that help the body move. Rhabdomyosarcoma is the most common type of soft tissue sarcoma in children.  It can begin in many places in the body.  There are three main types of rhabdomyosarcoma:

Embryonal: This type occurs most often in the head and neck area or in the genital or urinaryorgans. It is the most common type.

Alveolar: This type occurs most often in the arms or legs, chest, abdomen, genital organs, or analarea. It usually occurs during the teen years.

Anaplastic: This type rarely occurs in children.