Ewing's sarcoma or Ewing sarcoma is a malignant small, round, blue cell tumor. It is a rare disease in which cancer cells are found in the bone or in soft tissue. The most common areas in which it occurs are the pelvis, the femur, the humerus, the ribs and clavicle (collar bone). Because a common genetic locus is responsible for a large percentage of Ewing's sarcoma and primitive neuroectodermal tumors, these are sometimes grouped together in a category known as the Ewing family of tumors.
Primary bone cancer is cancer that originates in bone cells. The other way cancer can occur in bones is after spreading there from another part of the body through a process called metastasis. When it does, it's called secondary bone cancer. Secondary bone cancer is the same type of cancer that exists in the tissue or organ where it first occurred. For instance, breast cancer that spreads to the bones is still made up of breast cancer cells. Researchers think that Ewing's sarcoma begins in a certain kind of primitive cell.
There are approximately 200 new cases of Ewing's sarcoma diagnosed in the United States annually. Ewing’s sarcoma primarily involves children older than age 10, teens and adolescents, and young adults, usually up to the age of 30. Slightly more boys than girls are prone to get the disease. For unknown reasons, it occurs most often in whites and is extremely rare in African-Americans or Asian-Americans. Compared to adult cancers, risks of most childhood cancers, including Ewing's sarcoma, cannot be affected by making lifestyle changes.