Comparative Analysis of Papillary Thyroid Carcinoma and Benign lesions; Immunohistochemical Diagnostic Markers and Their Gene Expression Correlation.

Abstract

     Background: Papillary thyroid carcinoma (PTC) incidence has increased globally, but it is unclear if this was because of an improvement in the patient’s knowledge or if the tumor was incidentally discovered. The microscopical features of the nuclei are the gold standard for diagnosing PTC. Many Immunohistochemical markers have been used to accurately diagnose PTC, such as CK-19, TTF-1, HBME-1, ret, and S-100. Objectives: To assess the incidence of PTC in the Al-Qadisiyah governorate and examine the expression of several markers by immunohistochemistry in thyroid tissue biopsies. Materials and Methods: Two hundred and twenty surgically resected Thyroid glands were implanted in paraffin tissues after being treated in formalin. Then we use hematoxylin and an eosin stain, and immunohistochemical staining by TTF-1 and CK-19. Results: Although benign lesions did not show TTF-1 and CK-19 staining, papillary thyroid carcinoma showed diffuse, strong staining. Furthermore, we used a free gene dataset to assess the genetic expression of genes encoding for TTF-1 and CK-19, TTF-1, and KRT-19 genes, respectively. Results showed that the TTF-1 gene is overexpressed in PTC cases as compared to benign lesions, while KRT-1 gene expression was not changed, which may indicate post-transcriptional KRT-19 gene regulation. Conclusion: The immunohistochemical TTF-1 and CK19 staining could offer a helpful and objective means for confirming the diagnosis of challenging thyroid nodules. In addition, we identified that the TTF-1 protein upregulation is due to genetic overexpression of the TTF-1 gene, in contrast to CK-19, which was most likely post-transcriptionally upregulated.