Case Report
Angela Tamburini, Giovanni Bel
Abstract
Ewing's sarcoma (ES) is an uncommon malignancy of childhood and adults that constitutes 6%-8% of all primary malignant tumors and the third-most common tumor after osteosarcoma and chondrosarcoma. This article presents a case of localized ES iliac wing in a 12-year-old male patient, treated in accord to the ISG-EW1 protocol, showing extensive percentage of circulating tumor cells if compared with other non-metastatic patients, which is not a frequent presentation. Histopathological needle biopsy from the soft tissue extension of the tumor revealed small round-cell tumor with strong CD99 positivity, supporting the diagnosis of Ewing's sarcoma. The diagnosis was confirmed by reciprocal translocation of chromosomes 11 and 22. Analysis of tumor circulating cells revealed a massive percentage of tumor cell in peripheral blood, comparable to the levels that usually were found in metastatic patient.