• A malignant neoplasm of the bone, or the soft tissue adjacent to bone, that is comprised of primitive neuroectodermal cells.
  NICHD Pediatric Terminology
  U.S. National Cancer Institute, 2021
• A small round cell tumor that lacks morphologic, immunohistochemical, and electron microscopic evidence of neuroectodermal differentiation. It represents one of the two ends of the spectrum called Ewing sarcoma/peripheral neuroectodermal tumor. It affects mostly males under age 20, and it can occur in soft tissue or bone. Pain and the presence of a mass are the most common clinical symptoms.
  NCI
  U.S. National Cancer Institute, 2021
• A type of cancer that forms in bone or soft tissue.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• (ewing's tumor) Malignant tumor of bones which always arises in medullary tissue, occurring more often in cylindrical bones, with pain, fever, and leukocytosis.
  CRISP Thesaurus
  National Institutes of Health, 2006
• (sarcoma, ewing) A malignant tumor of the bone which always arises in the medullary tissue, occurring more often in cylindrical bones. The tumor occurs usually before the age of 20, about twice as frequently in males as in females.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• Ewing sarcoma tumors include Ewing sarcoma, Askin tumor, and peripheral primitive neuroectodermal tumors. These tumors have a similar cellular physiology, as well as a shared chromosomal translocation.
  Medscape
  WebMD, 2025
• Ewing (YOO-ing) sarcoma is a rare type of cancer that occurs in bones or in the soft tissue around the bones.
  Mayo Clinic
  Mayo Foundation for Medical Education and Research, 2025
• Ewing sarcoma is a type of cancerous tumor that mainly affects children and young adults. Ewing sarcoma usually occurs in the long bones of the arms and legs, pelvis, or chest. Symptoms may include swelling over the location of the tumor, and pain which gets worse over time. Other symptoms may depend on the size and location of the...
  NIH Genetic and Rare Diseases
  National Center for Advancing Translational Sciences