Morphological and Molecular Assessment in Thyroid Cytology Using Cell-Capturing Scaffolds

Abstract

The increased frequency of thyroid nodules is paralleled by the rise of thyroid cancer diagnosis. To define the nature of most thyroid nodules, fine needle aspiration (FNA) followed by cytological evaluation is considered the method of choice. About 20% of FNA biopsies on thyroid nodules, however, show indeterminate cytological features and may require diagnostic surgery. Several immunocytochemical and molecular markers have been proposed to improve classification of thyroid nodules, but these tests require adequate cell amount and cytological paraffin inclusion. Polymeric matrices were recently proposed for the collection of cells for diagnostic purposes. In this study, we evaluated the diagnostic use of a new matrix (CytoMatrix). Morphological, molecular and immunohistochemical investigations were carried out on 23 FNA samples included in CytoMatrix and compared with data obtained from the definitive histology of surgical samples. Our results showed that CytoMatrix is suitable to capture and preserve the cellularity of the samples harvested by FNA and that its paraffin sections mimic the morphology of those obtained from real histological tissue. Immunohistochemistry on CytoMatrix samples was consistent with the immunophenotypical profile of the corresponding histological surgical specimens. Mutational analysis of the BRAF (V600E) gene performed on CytoMatrix inclusions and paired surgical tissue matched in all but one cases while matrix immunohistochemistry identified 91.6% of BRAF mutated samples. In conclusion, we suggest that CytoMatrix could be a reliable tool to overcome the current limits of traditional collection methods for the study of thyroid cytology, thereby improving their reliability for a conclusive diagnostic interpretation.

Improvement of the Collection, Maintenance, and Analysis of Neoplastic Cells from Urine Specimens with the Use of CytoMatrix

“…The CytoMatrix is a matrix based on chitosan, a natural non-synthetic polymer. The CytoMatrix porosity and ionic strength makes it perfect for attracting and maintaining cells [ 23 , 24 , 25 , 26 ]. After the loading of cells from urine, the fixation, processing, and paraffin embedding of the complex CytoMatrix-sample, we cut on microtome the first 3 µm section from FFPE-CytoMatrix block and we used it for H&E staining.…”

“…In order to improve the collection, maintenance, and analysis of neoplastic cells from urine specimens, we used an innovative synthetic matrix called CytoMatrix which has the property of capturing and storing biological material, as cells and micro-macro cellular aggregates, within its three-dimensional structure from various type of samples, as fine-needle aspiration and other biologic fluids [ 23 , 24 , 25 , 26 ]. The use of the CytoMatrix is simple and reliable; it involves the transfer of cellular material into the CytoMatrix, the fixation in buffered formalin, the standard processing and paraffin embedding of the complex CytoMatrix-sample, and the application on the obtained inclusion of ancillary tests.…”