Ewing Sarcoma




CLINICAL SUMMARY


Ewing sarcoma is approximately half as common as osteosarcoma. It arises from bone marrow and almost always presents with a large soft tissue mass. Compared to osteosarcoma, it is more common in the flat bones, such as the pelvis, although still more prevalent in the extremities overall. Treatment and prognosis are largely analogous to osteosarcoma, with chemotherapy similarly being given before and after wide resection.




DIAGNOSTIC FEATURES





















History


  • 50% between ages 10 and 19 years; rare after age 40



  • Deep bone pain, late swelling



  • Symptoms can be present up to 6 months before diagnosis



  • Sometimes systemic symptoms such as fever, fatigue, malaise

Location


  • Metadiaphyseal (59%) or diaphyseal (35%) when in long bones



  • Distribution: lower extremity long bones, 28%; pelvis, 25%

Margins


  • Lytic portions may demonstrate motheaten or permeative bone destruction, although bone destruction is not always apparent on radiographs



  • Large soft tissue mass is almost always present (90%)



  • Rapid growth produces lamellated and discontinuous (“onion-skin”) periosteal reaction

Matrix


  • No matrix mineralization



  • Intraosseous component can demonstrate subtle reactive sclerosis






IMAGING

























  • Ewing sarcoma in the metadiaphyseal femur is visible as an aggressive, destructive process. This is reflected by the permeative lysis and wide zone of transition, demonstrated on radiographs ( left and right ).





Get Clinical Tree app for offline access