Occasional involvement of the ovary in Ewing sarcoma

Eight patients aged 13–20 years with EWS participated in the study. Ovarian samples were fixed and prepared for lightmicroscopy, and frozen in liquid nitrogen for RNA extraction followed by RT–PCR. Histological studies, including immunostaining for theadhesion receptor CD99, were used to detect histopathological features. Sensitive molecular methods were used to detect translocationscausing the formation of tumor-specific EWS–Friend leukemia virus integration site 1 fusion gene (EWS-FLI1).