Endocrine Abstracts

JOINT1410

Background: Hashimoto thyroiditis, which is classified as an autoimmune disorder affecting the thyroid gland, has been considered as a lesion preceding and predisposing to papillary thyroid carcinoma (PTC) by several authors. In contrast, the other clinical type of thyroid autoimmune disease - the Riedel’s thyroiditis has not been evidenced to be a pre-cancer lesion.

Materials and Methods: This hypothesis encouraged us to undertake the morphological and immunohistochemical comparative assessment of these two types of thyroiditis (RT and HT) utilizing the diagnostic value p63 immunohistochemistry in thyroid pathology. The surgical specimens of the thyroid gland, obtained from 36 patients were studied in total, including Riedel’s thyroiditis (n = 5), Hashimoto’s thyroiditis (n = 24) and papillary thyroid carcinoma (n = 7) as a control group.

Results and Discussion: Obtained results showed that autoimmune thyroiditis types are characterized by histological and immunohistochemical heterogeneity, however, pathological alterations in both processes (RT, HT) specifically demonstrated progressive involution of glandular tissue and replacement with rigid tissue, sometimes, scar fibrosis. Positive p63 expression were highly specific for papillary carcinoma in the setting of HT, which was not characteristic for the Riedel’s thyroiditis specimens.

Conclusion: According to biomolecular research data, we could not exclude dysplastic and neoplastic transformation in progenitor cells within the parenchyma of Hashimoto’s thyroiditis vs Riedel’s autoimmune thyroiditis.