The aim of this study was to estimate the diagnostic value of BRAFV600E mutation status combined with cytomorphological features for diagnosis of papillary thyroid cancer (PTC) in cytologically indeterminate thyroid nodules.
The analysis of exons 11 and 15 of BRAF gene revealed the T1796A (V599E) mutation in 32% of cases, and this alteration is significantly associated with PTC tall cell variant.
Papillary thyroid carcinomas (PTC) are the most common type of thyroid malignancy with one of the two mutations, RET/PTC rearrangement or BRAF mutation.
H4-PTEN were detected in 9.6% of PTC and the frequency of the occurrence of BRAF mutation and/or RET/PTC in H4-PTEN positive tumors was extremely high (75%).
Our present aim was to investigate the association between the percentage of BRAF c.1799T > A (p.Val600Glu) alleles and clinicopathological parameters in PTC.
However, several works published in the latest years have provided new evidence, in partial conflict with the previous knowledge, suggesting the need of reconsidering the meaning of the BRAFV600E mutation in PTC.
Twelve thyroid carcinoma cell lines derived from anaplastic, follicular and papillary thyroid carcinomas with wildtype or mutationally activated BRAF were treated with sorafenib.
TCV and classic PTC with tall cell features comprised 4.9% and 6.0% of all tumors, respectively, and were significantly associated with older age at presentation, larger tumor size, high frequency of extrathyroid extension, and BRAF mutation in comparison with classic PTC.
These findings suggest that the novel BRAF mutation, BRAF(V600delinsYM) , is a gain-of-function mutation and plays an important role in PTC development.
To the best of our knowledge, this case is the first case to report two different BRAF mutations in tissues of a Langerhans cell histiocytosis and a papillary thyroid carcinoma co-existing in the thyroid gland.
These results highlight the importance of infiltrative growth pattern and invasiveness over the presence of BRAF mutation in classic and follicular variant PTC for the development of nodal metastases.