PREDICTIVE VALUE OF SOMATIC MUTATIONS FOR THE DEVELOPMENT OF MALIGNANCY IN THYROID NODULES BY CYTOPATHOLOGY

Objective: The purpose of our prospective longitudinal study was to evaluate the predictive efficacy of genetic testing for malignancies in fine-needle aspiration biopsy samples that are cytologically benign at the time of biopsy. Methods: A total of 779 aspirated cytological samples collected from thyroid nodules of 626 patients were included in a 3-year follow-up study. Consecutive patients with cytologically benign thyroid nodules by the Bethesda System for Reporting Thyroid Cytopathology were enrolled in the study. At enrollment, somatic 1-point nucleotide polymorphisms of BRAF and RAS family genes were tested by melting-point analysis, while RET/PTC and PAX8/PPAR-gamma rearrangements were examined by real-time polymerase chain reaction. The genetic test was considered to be positive if a somatic mutation was found. Malignant cytopathologic diagnoses were confirmed by histopathology. Results: In samples collected from 779 thyroid nodules, there were 39 BRAF, 33 RAS mutations, and 1 RET/PTC rearrangeme...