Fine needle aspiration cytology of the Ewing's sarcoma family of tumors

OBJECTIVE: To study the cytomorphologic features of the Ewing's sarcoma (ES )family of tumors. STUDY DESIGN: During a period of eight years (1990-1997), 123 soft tissue t umors and 65 bone tumors were evaluated by fine needle aspiration cytology (FNAC); 14 cases were diagnosed as in the ES family of tumors. The ages of the patients ranged front 8 to 30 years. All the cases were histologically confirmed. RESULT: Of 14 cases of the ES family of tumors, 7 were neuroectodermal tumo r (PPNET) and 2 Askin tumor. Cytologically, smears from all the cases showe d round tumor cells with a high nuclear/cytoplasmic ratio. On detailed exam ination, subtle differentiating features were observed. The cells in ES had finer nuclear chromatin in comparison to those of PPNET and Askin tumor, a nd punched-out clear cytoplasmic vacuoles were present. PPNET showed nuclea r molding, unipolar cytoplasmic tags and Homer-Wright rosettes. Histologica lly, all cases of ES and EOE and one case of Askin tumor showed periodic ac id-Schiff-positive inclusions. CONCLUSION: FNAC features coupled with clinical findings enable a rapid dia gnosis of the ES family of tumors, from which treatment modalities can be d etermined.