Analysis of mutation in thyroid nodular hyperplasia and follicular neoplasm in a Korean population.

BACKGROUND

To investigate the difference in frequency of mutations between nodular hyperplasia (NH), follicular thyroid adenomas (FTAs) and follicular thyroid carcinomas (FTCs) in a Korean population.

METHODS

mutations in 50 NH, 57 FTAs and 39 FTCs between January 2002 and May 2015 were analysed by pyrosequencing.

RESULTS

Nine nodules of 50 NHs (18%), 18 nodules of 39 FTCs (46.2%) and 19 nodules of 57 FTAs (33.3%) harboured mutations. Three FTCs and three FTAs showed two point mutations simultaneously. codon 61 (n=6 of 9, 66.7%) and codon 61 (n=3 of 9, 33.3%) were found in NHs. codons 12-13, codon 61, codons 12-13 and codons 12-13 were not found in NHs. codon 61 (n=7 of 21, 33.3%), codons 12-13 (n=6 of 21, 28.6%), codon 61 (n=4 of 21, 19.0%), codon 61 (n=3 of 21, 14.3%) and codons 12-13 (n=1 of 21, 4.7%) were found in FTCs, and codon 61 (n=10 of 22, 45.5%), codons 12-13 (n=5 of 22, 22.7%), codon 61 (n=5 of 22, 22.7%), codon 61 (n=1 of 22, 4.5%) and codons 12-13 (n=1 of 22, 4.5%) were observed in FTAs.

CONCLUSIONS

The frequencies of RAS mutations among our Korean population were 18% in NHs, 46.2% in FTC and 33.3% in FTAs. N-RAS codon 61 was the most frequent mutation in NHs, FTCs and FTAs, and the frequency was not significantly different among the three groups. K-RAS codons 12-13 were the second most commonly involved site in FTCs and FTAs, whereas no mutation was detected at this site in NHs.