Ewing's sarcoma of bone. A correlative cytological and histological study of 14 cases.

A correlative cytological and histological study of 14 cases of Ewing's sarcoma is presented. All smears from the fine needle aspirates were performed during the diagnostic investigation before treatment of the patients. The smears were very cellular with relatively small, round to oval tumour cells which appeared rather uniform. Two cell types could be distinguished, however. There was a predominance of relatively light, so-called principal or chief cells, but smaller and darker cells, so-called dark cells, were also observed. We found that Ewing's sarcoma has a characteristic appearance in smears and that fine needle aspiration cytology can be used in its primary diagnosis. A conclusive diagnosis may be made when the clinical and radiographic findings are also consistent.