GENETIC OF THYROID CANCER MOLECULAR ANALYSIS OF FINE NEEDLE ASPIRATION SAMPLES TO REFINE THE DIAGNOSIS OF THYROID CANCER

Fine Needle Aspiration Cytology (FNAC) is the gold standard for the differential diagnosis of thyroid nodules, but has the limitation of inadequate sampling or indeterminate lesions. Our Unit of Endocrinology was involved in a pilot study aimed to verify whether search of thyroid cancer-associated proto-oncogene mutations in cytological samples may improve the diagnostic accuracy of FNAC. Our results demonstrated that the presence of mutations at cytology was associated with cancer 91.1% of the times and with follicular adenoma 8.9% of the times. BRAF or RET/PTC mutations were always associated with cancer, while RAS mutations were mainly associated with cancer (74%) but also with follicular adenoma (26%). The diagnostic performance of molecular analysis was superior to that of traditional cytology, with better sensitivity and specificity, and the combination of the two techniques further contributed to improve the total. At the moment, we have introduced the search for the most common mutations (BRAF, 3 RAS isoforms and RET/PTC rearrangements) in the clinical practice especially in those FNAC which resulted indeterminate at the first cytological analysis.