Fine-needle aspiration cytology and the diagnosis of neoplasms in the pediatric age group.

Sixty-six aspirates obtained from 63 pediatric patients clinically suspected of having small cell malignancies were studied by a variety of techniques to determine the accuracy and utility of fine-needle aspiration (FNA) in the diagnosis of small round-cell neoplasms (SRCN) of childhood. FNA correctly identified all 47 SRCNs as malignant and gave a correct specific diagnosis in 81% of the cases. No false-positive diagnoses of malignancy occurred in this series. Electron microscopy, immunohistochemistry, and cell culture performed on FNA material were found to be useful aids in the differential diagnosis of these tumors. The cytologic appearances and differential diagnoses of these neoplasms are discussed.