Diagnostic effectiveness of intraoperative express histological examination as a tool to take decisions on the extent of surgery for papillary thyroid cancer

Abstract

Background. In case of the screening use of high-resolution ultrasound, the level of detecting thyroid neoplasms is about 25 % in the population. Ultrasound criteria are not enough to detect carcinoma. The following methods are used for the differential diagnosis of malignant thyroid neoplasms: ultrasound scans, computed tomography, fine-needle aspiration (FNA) biopsy, intraoperative express histological and histopathological examination. Some authors consider FNA to be the standard method for primary morphological diagnosis of thyroid nodes. It is not always possible to conduct FNA safely. Also, FNA cannot be a method of 100% morphological identification of a primary tumor. In such cases, the extent of the surgery will depend on the data obtained from the intraoperative express histological examination. Analysis of the diagnostic effectiveness of the express histological examination will help to take a decision on the need for it when choosing the extent of a surgery on the thyroid gland. Aim of the study: to evaluate the diagnostic efficiency of the intraoperative express histological method in the detection of papillary thyroid cancer on solitary nodes (Bethesda IV, V) and metastases of papillary thyroid cancer during surgery. Materials and methods. The results of intraoperative express histological and pathohistological examinations performed at the Ukrainian Scientific and Practical Center for Endocrine Surgery, Transplantation of Endocrine Organs and Tissues from 2018 to 2021 were analyzed. The sample included materials of surgeries on the thyroid gland in case of papillary cancer T1ab-2N0–1 and solitary nodes (Bethesda IV and Bethesda V) according to data obtained using FNA. The sample size in the study of regional metastasis included 220 examinations, 845 examinations in the “gray zone” (Bethesda IV — 465, Bethesda V — 380). Cases of discrepancy between the results of intraoperative express histological and final histopathological examinations were considered. The data was processed using the EZR v. 3.4.1 statistical analysis program. Results. The sensitivity of the express histological examination in case of detecting metastases of thyroid cancer is 72.2 % with the method specificity of 99.9 %. The diagnostic efficiency in detecting metastases of thyroid cancer is 89.1 %. When the express histological examination is used for Bethesda IV nodes, the sensitivity of the method is 8 % with a specificity of almost 100 %. The diagnostic efficiency of the express histological examination is even higher in case of Bethesda V: sensitivity of 47 % with the method specificity of almost 100 %. The values obtained correlate with international data. This testifies to the need for further improvement of the of intraoperative diagnosis method. Conclusions. The diagnostic efficiency of the intraoperative express histological examination for detecting metastases of papillary thyroid cancer in the selected group is 89.1 % with sensitivity of 72.2 % and specificity of 99.9 %. The diagnostic efficiency of intraoperative express histological examination for verification of thyroid cancer in case of Bethesda IV nodes is 63.9 % with sensitivity of 8.2 % and specificity of 99.6 %. The diagnostic efficiency of intraoperative express histological examination for verification of thyroid cancer in Bethesda V nodes is 63.4 % with sensitivity of 47.3 % and specificity of 99.2 %. The intraoperative express histological examination method makes it possible to take decisions on surgical tactics during surgery within the determined limits, so we believe it reasonable to further use and improve it.