Scanning electron microscopy of thyroid cells under fully hydrated conditions--a novel technique for a seasoned procedure: a brief observation.

Technical information for handling fine-needle aspiration samples from thyroid lesions for WETSEM electron microscopy is presented. The use of wet SEM technology maintains cytological features of the thyroid cells, in the atmospheric electronic microscope chamber without the need for solidification. Images are presented from normal and pathological thyroid specimens showing subcellular elements unavailable to the cytopathologist by light microscopy. Of 24 samples, 18 were adequate for clinical evaluation. In 16 of these 18 specimens, we could find features compatible with the final histological or cytological diagnosis (post-hoc). In two cases, the cell features were too unique to be interpretable. Because this procedure is relatively simple, there is potential for the use of this technology as an adjunct to light microscopy in clinical and research settings.