Papillary thyroid cancer with coexisting Hashimoto's thyroiditis presents elevated MHC class I expression, which may be the result of IL-17A secretion.
The results showed that the elevated CK-19 expression, and the presence of BRAF mutations and RET/PTC rearrangements were indicators of multifocal PTC in HT, suggesting the need for total bilateral thyroidectomy.
Because Hashimoto's thyroiditis may influence the diagnostic performance, a subgroup was also analysed that included only lymph nodes from PTC without Hashimoto's thyroiditis.
The association between Hashimoto thyroiditis (HT) and papillary thyroid carcinoma (PTC) has been originally suggested by retrospective pathological studies and has recently been re-evaluated and proposed on the basis of several fine-needle aspiration cytology (FNAC) studies.
One hundred five cases composed of 34 follicular nodular disease (FND), 31 Hashimoto's thyroiditis (HT), and 40 papillary thyroid carcinoma (PTC) were compiled retrospectively.
It remains unknown whether the coexistence of RTH with papillary thyroid carcinoma (PTC) and Hashimoto thyroiditis (HT) is incidental or whether it possesses a genetic or pathophysiological association.
For immunohistochemistry, a tissue microarray was generated that contained the following tissues: classic PTC (n = 20), follicular variant of PTC (n = 9), normal thyroid (n = 19), Hashimoto thyroiditis (n = 11), follicular adenoma (n = 15), and follicular carcinoma (n = 14).
We also observed similarities in the E-cadherin expression profiles of Hashimoto thyroiditis and ret/PTC-1-positive papillary thyroid carcinomas and have hypothesized that ret/PTC-1 activation might cause not only the structural and nuclear peculiarities of PTC but also an immune reaction to thyroid epithelium.