[Ewing's tumor].

Ewing's tumour is an undifferentiated round-cell sarcoma of children and adolescents arising from the skeleton. The translocation (11; 22) (q24; q12) is specific and could serve as a diagnostic marker. It has also enabled this tumour to be classified in the group of primary neuro-ectodermal tumours. Concerning treatment, intensive chemotherapy alternating with local therapy has improved the prognosis of localized Ewing's sarcoma of the limbs and, to a lesser degree, of the axial skeleton.