Cancers involving muscle, bone, blood vessels and other supporting tissues in the body are termed sarcomas. They are different than carcinomas, which are malignancies of the tissues lining or covering the body's internal organs and passageways. Of all the cancers of solid tissues, children most frequently have sarcomas. Carcinomas are much more frequent in adults.
Types Rhabdomyosarcoma of muscle is the most common soft tissue sarcoma in children, accounting for slightly more than half of all soft tissue sarcomas. Many different tissue types account for the rest. They may be located in nerves or their covering sheaths, blood vessel walls, joint linings, fatty tissues or muscles.
Other sarcomas in children occur in or around bone. The most common is osteogenic sarcoma, which is a cancer of the bone tissue itself. The second most common is Ewing's sarcoma and the closely related primitive neuroectodermal tumors. Although they occur in or around bone, these tumors probably originate from the nerve tissue in these locations.
In the United States, an estimated 500 to 700 children under 18 are diagnosed with rhabdomyosarcoma each year. Osteosarcoma strikes 450 to 600 young people, Ewing's sarcoma affects 350 to 400, and fewer develop primitive neuroectodermal tumors.
