What is it?

Ewing Sarcoma is a rare tumor of the bones and soft tissue around the bones such as cartilage or nerves. The typical bones for growth of the tumor are the leg and pelvis but it can occur in any bone. This condition is more common in children and adolescents, and in Europeans. The cause of Ewing sarcoma is still unknown, and it does seem to be genetic or familial. Environmental factors were not found to be linked with Ewing sarcoma.Ewing sarcoma may spread, most often to other bones and the lungs. Recently, there had been a division of Ewing sarcoma to four types of cancer:
Ewing's sarcoma of bone, Ewing's sarcoma of soft tissue, primitive neuroectodermal tumor (PNET) which may occur in both bone and soft tissue, and Askin's tumor, a PNET that occurs in the bones of the chest.