Abstract
Background: Clinical data and data on outcome of extra-osseous Ewing tumors are scarce. Procedure: After a search for Ewing tumors in the database of a single institution over a period of 20 years, 16 out of 192 cases were found to have extra-osseous primary tumors. Results: Ages at initial diagnosis ranged from 2.5 to 17 years. Follow-up period ranged from 4 months to 24.8 years (mean 8.4 years). Eleven patients were treated according to protocols for Ewing tumors, while in 4 cases soft tissue protocols were used. In a single patient only surgery was done. Two patients had progressive disease despite chemotherapy; a third patient had only tumor response on the initial 2 chemotherapy courses. All 3 patients with initially metastatic disease died. One patient developed a second malignancy. Overall survival at 5 years was 75%. Event-free survival (EFS) at 5 years was 68%; for nonmetastatic patients 5-year EFS was 83%. Conclusion: The authors conclude that nonmetastasized extra-osseous Ewing tumors have a prognosis at least similar to that of osseous Ewing tumors.
Keywords: