Characterization through scanning electron microscopy and $\mu $Fourier transform infrared spectroscopy of microcalcifications present in fine needle aspiration smears

Abstract

In this contribution, we have characterized for the first time (to the best of our knowledge), microcalcifications present in fine needle aspiration (FNA) smears of thyroid nodules. Abnormal deposits were analysed through $\mu $Fourier Transform Infrared Spectroscopy ($\mu $FTIR) and Field Emission Scanning Electron Microscopy (FE-SEM) in order to obtain their chemical composition as well as their morphology at the micrometer scale. Thirty-one samples coming from 13 patients were investigated comprising five cases of papillary carcinoma, two of Graves’ disease, and six of adenomatous goitre. The smears were also stained for analysis of the cellular characteristics of these lesions for classifying according to the Bethesda classification. Two mineral species, amorphous and nanocrystallised apatite calcium phosphate, have been identified with very different morphologies. Moreover, FE-SEM observations at the micrometer scale underline the presence of different kinds of abnormal deposits.

Keywords

• Thyroid
• Nodule
• Smears
• Infrared spectroscopy
• Scanning electron microscopy