A sarcoma is a type of cancer that develops from certain tissues, like bone or muscle. – American Cancer Society

Sarcomas are an unusual group of cancers that arise from connective tissues, including bone, cartilage, fat, blood vessels, tendons, muscles and nerve. Over 90% of all sarcomas arise in patients with no known predisposing conditions. A very high percentage of bone sarcomas are discovered in young adults.” – Provided By UCI Medical Center

Soft tissue sarcomas constitute a wide group of malignant solid tumors arising from primitive mesenchymal cells, which are scattered throughout the body. Mesenchymal cells normally develop into supportive tissues, such as fibrous tissue, muscle, cartilage and bone. In the development of sarcoma, however, complete differentiation into mature structures, is not achieved.

Despite the diversity of their apparent tissue of origin, the soft tissue sarcomas share many morphologic and behavioral characteristic as a reflection of their common descent from primitive mesenchyme . In general, they are highly invasive and have a propensity for local recurrence. When they metastasize, it is usually via the bloodstream, and less commonly, via lymphatics .

Soft tissue sarcomas account for approximately 6.5% of all malignant neplasms in children in the United States . Soft tissue sarcomas are the 6 th most common form of cancer in childhood, following acute leukemia, central nervous system tumors, lymphoma, neuroblastoma and Wilms tumor.

There are many different kinds of soft tissue sarcomas, some examples of which include rhabdomyosarcoma , extraosseous Ewing ‘s sarcoma, synovial cell sarcoma and rarely, Desmoplastic small round cell tumor. Rhabdomyosarcoma is the most common soft tissue sarcoma in persons less than 21 years of age. Prognosis and treatment generally depends on the type of tumor as well as stage of the disease.
Provided by Dr. L. Torno – CHOC Hospital