Cytogenetic studies on fine-needle aspiration samples from osteosarcoma and Ewing's sarcoma.

The preoperative multidrug chemotherapy of osteosarcoma and Ewing's sarcoma patients requires a reliable diagnosis. There are several advantages with obtaining the diagnosis by fine-needle aspiration (FNA) and cytologic examination. Although cytologic criteria have been defined, adjunctive methods such as cytogenetic analysis are valuable to support the diagnosis. We have cytogenetically analyzed FNAs from 18 primary bone sarcomas (six osteosarcomas and 12 Ewing's sarcomas). Two of the osteosarcomas showed abnormal, complex karyotypes seen in most highly-malignant osteosarcomas. Seven Ewing's sarcoma aspirates displayed abnormal karyotypes; five of these had the characteristic 11;22 translocation, and in one of these cases molecular genetic analysis revealed the hybrid EWS/FLI1 transcript. Since only two of six osteosarcomas showed clonal changes, chromosomal analysis of FNAs from suspected osteosarcoma seems to be of limited value, but may in some cases support the diagnosis of high-grade malignancy. In Ewing's sarcomas, however, the finding of an 11;22 translocation was valuable and strongly supported the cytologic diagnosis. As shown in one case, the material obtained by FNA is sufficient for cytologic, cytogenetic, and molecular genetic analysis.