Ewing sarcoma is a rare bone tumor that occurs most often in adolescents. It can also arise outside of the bone in soft tissue (extraosseous Ewing sarcoma). Ewing sarcoma is related to another type of tumor known as primitive neuroectodermal tumor (PNET). Researchers have learned that these tumors are associated with the same chromosomal abnormality (balanced reciprocal translocation) and share many physiological characteristics. Consequently, these tumors are sometimes collectively classified as the Ewing family of tumors (EFT). This general term encompasses Ewing sarcoma of bone, extraosseous Ewing sarcoma, primitive neuroectodermal tumor, and Askin’s tumor (a tumor of the chest wall). Ewing sarcoma of bone accounts for approximately 70 percent of the tumors in this family. Generally, the term Ewing sarcoma is preferred because, despite the different names, it is one tumor, molecularly. Ewing sarcoma of bone most often affects the long bone of the legs (femur) and flat bones such as those found in the pelvis and chest well. Ewing sarcoma is an aggressive cancer that may spread (metastasize) to the lungs, other bones, and bone marrow potentially causing life-threatening complications. The exact cause of these tumors is unknown.
Ewing sarcoma was first described in the medical literature in 1921 by Dr. James Ewing. Ewing sarcoma is the second most common primary bone tumor in children and accounts for approximately 2% of all childhood cancer diagnoses.
NORD’s report on Ewing sarcoma is a detailed summary of the main aspects of this rare disorder. The National Cancer Institute offers comprehensive, in-depth information on this disorder, which is available at,
For patients: http://www.cancer.gov/cancertopics/pdq/treatment/ewings/Patient
For healthcare professionals: http://www.cancer.gov/cancertopics/pdq/treatment/ewings/HealthProfessional