Inside the Matrix: Integrated Cytology and Molecular Testing of Thyroid FNAC Samples Using a Commercial Synthetic 3D...

Accurate preoperative assessment of thyroid nodules remains challenging, particularly in indeterminate cytological categories. Integrating molecular testing into cytology could improve diagnostic precision, enable timely intervention, and support better risk stratification and patient management. This proof-of-concept study evaluated the feasibility of performing molecular testing on fine-needle aspiration cytology (FNAC) samples processed on CytoMatrix, a three-dimensional synthetic scaffold designed to capture and preserve cellular material. Thirty-three thyroid FNAC specimens were processed on CytoMatrix, and cytological diagnoses were mirrored to the 2023 Bethesda System for Reporting Thyroid Cytopathology and correlated with final histopathology. DNA was extracted from paraffin-embedded CytoMatrix sections and analyzed for the BRAF V600E mutation. Adequate DNA for molecular testing was obtained in 30 of 33 cases (90%), and BRAF V600E mutations were detected in three papillary thyroid carcinoma samples. DNA adequacy and yield were consistent across Bethesda III-V categories, with insufficiency limited to low-cellularity Bethesda III cases. CytoMatrix enables reliable DNA recovery and targeted molecular testing without compromising cytological evaluation. This integrated cytomolecular workflow provides a feasible approach for combining cytological and molecular data in thyroid FNAC, supporting personalized and timely diagnostic management.