Extraskeletal Ewing sarcoma of the abdominal wall

Ewing sarcoma is most commonly a bone tumour which has usually extended into the soft tissues at the time of diagnosis. Exceptionally, this tumour can have an extraskeletal origin. Clinical or imaging findings, are non-specific and diagnosis is based on histology. We report a case of an extraskeletal Ewing sarcoma developed in the soft tissues of the abdominal wall in a 35-year-old woman who presented a painful abdominal wall tumefaction. Ultrasongraphy and computed tomography showed a large, well-defined soft tissue mass developed in the left anterolateral muscle group of the abdominal wall. Surgical biopsy was performed and an extraskeletal Ewing sarcoma was identified histologically. © 2008 International Cancer Imaging Society.