Selective use of electron microscopy in fine needle aspiration cytology.

The utility of electron microscopy (EM) applied to fine needle aspiration (FNA) biopsy specimens was analyzed in order to determine the role and the diagnostic contribution of the EM examination. A rapid stain (Diff-Quik) was used to obtain a preliminary diagnostic impression and to assure the adequacy of the EM specimen for problematic cases. Our experience suggests that EM is being relied upon with greater frequency in the study of FNA specimens because it is an accurate and cost-effective diagnostic procedure. The use of a rapid interpretation (Diff-Quik stain) enhances the quality of the EM specimen and, as in surgical pathology, the EM examination increases the accuracy and specificity of the FNA biopsy diagnosis.