Cytomorphological features of papillary thyroid carcinomas with the development of radioiodine-resistance

Abstract

Background. The problem of diagnosis and treatment of papillary thyroid cancer (PTC) are radioiodine resistant metastases (RIRM). An urgent issue is the possibility of their early prediction and diagnosis based on the detection of cytomorphological features of the PTC and its metastases, which correlate with the development of radioiodine (RI) resistance. Purpose – detection of cytomorphological features of primary PTC and its metastases in patients who subsequently showed resistance to 131I therapy, compared with the control group of patients who achieved a positive effect of 131I therapy. Materials and Methods. A comparative analysis of morphological features in histological conclusions and the study of cytological characteristics in the fine-needle aspiration (FNA) smears of primary PTC and their primary metastases, as well RIRM оf experimental and control groups of patients were conducted. The experimental group consisted of 152 patients who showed resistance to RI therapy, the control group – 161 patients who achieved a positive effect of RI therapy. Statistical processing was done in Statistica 12. Results and discussion. It is shown that the frequency of follicular structures in the material of primary PTC of patients with a positive effect of 131I therapy is significantly higher, and the frequency of necrotic changes is significantly lower than in patients with the development of RIRM (p <0.05 by criterion χ2). The frequency of follicular structures in the histological material and FNA smears of primary metastases of patients with a positive effect of 131I therapy is significantly higher, and oxyphilic changes are significantly lower than in patients with the development of RIRM (p <0.05 by criterion χ2). Oxyphilic changes were observed significantly more often in the RIRM compared with primary metastases of the control group (p = 0.03). It was proved that cystic changes are significantly more common in FNA smears and histological material of RIRM in comparison with primary metastases of experimental and control groups of patients (p <0.05). Conclusions. TThe use of the presence of oxyphilic and cystic changes in the FNA smears and histological material of metastases of the PTC as prognostic factors of RI resistance is proposed. The presence of follicular structures in the materials of primary PTC and metastases can be a prognostic factor of effective RI therapy.