The issues of Riedels Thyroiditis etiology are controversial: There are two different topical pathogenic theories: Riedels Thyroiditis as an autoimmune disease or as independent, primary fibroplastic process. Problem is to determine the possibility of malignisation in thyroid parenchym during the autoimmune thyroiditis - Hashimoto and Riedels. Just due this questions, In parallel to the routine histological research, has been studied follow markers: 1. Highly sensitive CD56, which is expressed in the normal, non-neoplastic thyroid follicular cells, but its expression decreases in the thyroid neoplasm, especially during the thyroid gland papillary carcinoma (PTC) and 2. Tumor protein p63 (TP63), a member of p53 transcription factors, a stem/progenitor cell regulator, which is determine as precancerous precursor cells. Observation was carried out on operative materials (total number of cases 32) females, with average age ≈37. Riedels n=10, Hashimoto n=22. Riedels and Hashimotos comparative study has shown the following results. During Hashimotos thyroiditis CD56 negative or weak positive reaction was detected, indicating the existence of probable malignant potential in the tested case. As seen from the results, while the CD56 adhesive factor shows a high affinity in the colloid and in fact a negative receptor response to glandular cells. Especially remarquable is the CD56 negative answer to the displatic districts. In case of PTC (as positive control) CD56 receptor-positive area only found in the colloid and p63 - was positive in the apoptotic nuclei. In the case of Riedels thyroiditis in the active fibroplasia transformation of thyroid gland parenchyma, the weak reaction of p63 was shown. Certainly, in Riedels thyroiditis p63 protein as the cancer stem cells marker receptors do not appear in the thyroid parenchyma, therefore we purpose that Riedels type of autoimmune thyroiditis displays minimal malignisation potential. Riedels parenchyma, unlike Hashimotos thyroiditis, revealed CD56 positive reaction in the colloid, as well as in the papillary carcinoma, and in the follicular cells the expression was not detected. We can conclude, that Riedels thyroiditis is characterized by acellular fibrosis and residual follicles background, CD56 negative glandular cells, the negative p63s receptiveness. The data, obtained by two specific factors, indicates that in Riedels thyroiditis, unlike Hashimotos thyroiditis, malignant potential and cells transmutation not developes, which indicates at the real prognostic differences between this two major types of autoimmune Thyroid disease.
18 - 21 May 2019
European Society of Endocrinology