RESUMO
The diagnosis of 17 small-cell round tumors of the bone and soft tissue, which were histologically similar to Ewing's sarcoma (EWS), was verified on paraffin sections, by using tissue microarray (TMA) technology, immunohistochemistry, cytogenetic (FISH) and molecular biological (RT-PCR) methods. Classical EWS was found to be in 8 patients, large-cell EWS in 1 patient; atypical EWS in 1, and endothelial ESW in 1. Two patients were diagnosed as having primitive neuroectodermal tumor (PNET), synovial sarcoma was present in 1 patient, embryonic rhabdomyosarcoma in 1, high-grade undifferentiated sarcoma in 1 and diffuse B-cell large-cell lymphoma in 1. TMA makes it possible to perform a number of diagnostic procedures on the same block containing a copious number of tumor samples and to assess the results of their use. It is emphasized that the diagnosis of small-cell round tumors requires the use of a package of the currently available methods providing the qualitative characteristics of each neoplasm.