Malignancy Predictors, Bethesda and TI-RADS Scores Correlated With Final Histopathology in Thyroid Diseases

Correlation of Malignancy Predictors, Bethesda (I-VI) and TI-RADS Scores (I-V) With Final Histopathology in Patients Undergoing Total Thyroidectomy 34 Years After Chernobyl Disaster: Multi-centric Trial

In the last decades, thyroid cancer incidence has continuously increased all over the world, almost exclusively due to a sharp rise in the incidence of the papillary histologic subtype, which has the highest incidence of multifocality. Furthermore, Black Sea and Eastern European regions are both endemic and known to have been under the influence of Chernobyl nuclear explosion. Although overscreening might have a role in certain parts of the world, the predictors of malignancy such as family history, genetical disorders, previous radiation exposure, low iodine intake, diabetes and obesity, should also be taken into consideration in determining the extent of surgery.

High-frequency ultrasound (US) is increasingly used to help distinguish malignancy in patients with solitary or multiple nodules, and US-guided fine needle aspiration (FNA) has become the gold standard test for detecting thyroid cancer. Moreover, a further US-based risk stratification of thyroid nodules with Thyroid Imaging Reporting and Data System (TI-RADS) has been currently proposed for better and easier decision making. However, the presence of multiple nodules in the thyroid gland may decrease the diagnostic value of these preoperative diagnostic tools. The prevalence of incidental carcinoma identified on the final histological examination of the patients who underwent surgery for presumably benign thyroid diseases was previously reported to be roughly around 5 to 10%. Most of the previous studies also showed a lower risk of carcinoma in multinodular goitre (MNG) compared to solitary thyroid nodule (STN). However, some recent surgical series have reported that the risk of thyroid carcinoma in benign thyroid diseases is significantly higher than previously reported.

The purpose of the present study is to detect the accuracy of preoperative cytology and US-findings (TI-RADS) and the prevalence of thyroid carcinoma in patients operated for thyroid diseases and to discuss all malignancy risk factors in detail along with final histopathological report. Cytology-histology discrepant cases will also be further evaluated for sampling and interpretation errors, and possible solutions to increase the accuracy of preop testing are going to be proposed. The accuracy of the preference of total thyroidectomy procedure will be evaluated considering the prevalence of incidental carcinomas diagnosed postoperatively, and whether there are variations in the risk of malignancy with respect to final pathology of patients will also be discussed in detail.

Inclusion Criteria:

• >17 years all patients with benign/malign thyroid disease, total thyroidectomy is indicated/preferred by both primary surgeon and patient (signed informed consent is a must)
• All patients should have a malignancy predictive factors forms filled in
• All patients should have fine needle aspiration cytology (Bethesda category) available
• All patients should have an ultrasound evaluated according to TI-RADS
• All patients should have a final histopathology report

Exclusion Criteria:

• Patients who are prepared for thyroid surgery other than total thyroidectomy procedure
• Age<17 years