Ras mutations are rare in solitary cold and toxic thyroid nodules

Abstract

Our study suggests that ras mutations are rare in solitary cold and toxic thyroid nodules and that the frequent monoclonal origin of these tumours implies somatic mutations in genes other than H-, K- and N-ras.

Molecular analysis of thyroid tumors

“…52 A lower incidence has been reported in oncocytic tumors, in which only 0-4% of adenomas and 15-25% of carcinomas appeared to be affected. 54,57,58 RAS mutations have also been detected in few cold adenomatous nodules and goiter nodules, 45,54,59 although it is likely that these lesions are true neoplasms and therefore should be designated as follicular adenomas, despite their frequent macrofollicular colloid-rich histology.…”

Dissecting Molecular Events in Thyroid Neoplasia Provides Evidence for Distinct Evolution of Follicular Thyroid Adenoma and Carcinoma

“…Compared with the published literature, this finding seems surprising but may be partially related to the small sample size. A low prevalence of RAS mutations has previously been reported by Krohn et al 27 in benign CTNs, including FA. Furthermore, in a previous study we did not find PAX8/PPAR␥ rearrangements in an independent cohort of FTC.…”

Molecular pathogenesis of nodular goiter

“…In contrast, focal hyperplasia is not very well explained on the molecular level and has been discussed in detail elsewhere as the cause of thyroid tumors [65,66]. A monoclonal origin has been detected for the majority of cold thyroid nodules which implies nodular development from a single mutated thyroid cell [67]. With reference to their functional status (i.e., reduced iodine uptake) failure in the iodide transport system or failure of the organic binding of iodide have been detected as functional aberrations of cold thyroid nodules long before the molecular components of the iodine metabolism were known.…”

“…However, mutations in the TPO gene have not been detected [76]. A study of 40 cold thyroid adenomas and adenomatous nodules detected ras mutations in only a single case [67]. Moreover, in the same set of CTNs, no point mutations in the mutational hot spots of the BRAF gene were detected [77].…”