Ewing sarcoma--current opinion]

Ewing tumor family consists of Ewing tumor of bone, extraosseous Ewing tumor, primitive neurectodermal tumor and Askin tumor. All of them share genetic abnormality, reciprocal translocation (11; 22) (q24; q12), and originate from the same primordial stem cell. Ewing tumor is the most common form, found in 60% of cases. It is the second primary malignant bone tumor. Localized lesion is found in nearly 80% and metastatic disease in 20% of cases. Patients present mostly due to pain and palpable tumefaction, and pathological fracture as the initial problem develops in long bones. Ewing tumor can develop in virtually any bone of the body and in extraosseous localizations as well, while localization in the extremities occurs in 50% of patients. Head or neck localizations are extremely rare. Paraspinal, retroperitoneal or deep pelvic tumor localization is manifested by back pain. Systemic symptoms are also present, commonly fever or weight loss, which often indicates the presence of metastatic disease with predominant invasion of lung, bone and bone marrow. Multimodal chemotherapy with local radiation and/or surgical resection is the best way of modern treatment. Distal parts of extremities and axial skeleton are good prognostic features, while proximal parts, pelvic girdle, metastatic disease and low index of postchemotherapeutic necrosis are associated with poor outcome.