[Current considerations on pathology in Ewing's sarcoma].

The authors make a review of the correlation between the clinical and pathological data in Ewing's sarcoma. The morphological lesions are generally wider than those given by the radiographic record. The microscopic picture is the same for both osseous and extraosseous cases. The different cell types of Ewing's sarcoma are indicated, all of them giving rise to a similar clinical picture. The histogenesis of the disease is still discussed, the most favored hypothesis being that it originates in the non-differentiated mesenchyma of the primitive bone marrow.