The Future of Thyroid Nodule Risk Stratification

The Role of Frozen Section Examination in Thyroid Surgery

In endocrine pathology, frozen section (FS) examination is most commonly used for the intraoperative evaluation of thyroid and parathyroid tumors, as well as cervical lymph nodes. In the past, frozen section was considered a fundamental tool in thyroid surgery. However, with advancements in preoperative ultrasound and fine-needle aspiration biopsy (FNAB), there have been increasing queries about its routine use due to the improved preoperative diagnosis. Nowadays, while the use of FS during thyroidectomy has decreased, it is still used as an additional method for different purposes intraoperatively. FS may not always provide definitive results. If FS will alter the surgical plan or extent, it should be applied. Routine FS is not recommended for evaluating thyroid nodules. But in addition to FNAB, if FS results may change the operation plan or extent, they can be utilized. FS should not be applied for thyroid lesions smaller than 1 cm, and the entire lesion should not be frozen for FS. For the assessment of thyroid nodules, the use of FS is recommended based on the Bethesda categories of FNAB. In Bethesda I category nodules, FS may contribute to distinguishing between malignant and benign lesions and guide surgical treatment. In Bethesda II nodules, where the malignancy rate is low, the performance of FNAB and FS can be compared, but it's not recommended due to the lack of a significant contribution to the surgical strategy. The sensitivity of FS in Bethesda III and IV nodules is low; its contribution to the diagnosis is limited, and it does not provide an apparent benefit to treatment; therefore, it is not recommended. In Bethesda V nodules, FS can effectively confirm the malignancy diagnosis, contribute to the surgical strategy, and reduce the possibility of completion thyroidectomy, and accordingly, it is recommended for use. Nonetheless, in Bethesda V nodules with a benign FS report, the malignancy rate remains high, so it should not be used to rule out malignancy. In Bethesda VI nodules, the performance of FS is lower or comparable to FNAB and does not significantly contribute to the treatment strategy; hence, it is not recommended. Particularly in patients with papillary thyroid cancer, intraoperative FS can be effective in detecting extrathyroidal extension and can assist the surgeon in determining the extent of thyroid surgery and central neck dissection. FS has high sensitivity and specificity in evaluating the lymphatic status of the central region intraoperatively and can be used to determine the extent of central compartment node dissection. During thyroidectomy, FS examination can be used in recognizing parathyroid tissue and distinguishing it from fatty tissue, thymus, thyroid, lymph nodes, especially in differentiating metastatic lymph nodes.

Implementation strategies to support ultrasound thyroid nodule risk stratification: A systematic review

BACKGROUND

Ultrasound risk stratification can improve the care of patients with thyroid nodules by providing a structured and systematic approach for the evaluation of thyroid nodule features and thyroid cancer risk. The optimal strategies to support implementation of high quality thyroid nodule risk stratification are unknown. This study seeks to summarise strategies used to support implementation of thyroid nodule ultrasound risk stratification in practice and their effects on implementation and service outcomes.

METHODS

This is a systematic review of studies evaluating implementation strategies published between January 2000 and June 2022 that were identified on Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane, Scopus, or Web of Science. Screening of eligible studies, data collection and assessment for risk of bias was completed independently and in duplicate. Implementation strategies and their effects on implementation and service outcomes were evaluated and summarised.

RESULTS

We identified 2666 potentially eligible studies of which 8 were included. Most implementation strategies were directed towards radiologists. Common strategies to support the implementation of thyroid nodule risk stratification included: tools to standardise thyroid ultrasound reports, education on thyroid nodule risk stratification and use of templates/forms for reporting, and reminders at the point of care. System based strategies, local consensus or audit were less commonly described. Overall, the use of these strategies supported the implementation process of thyroid nodule risk stratification with variable effects on service outcomes.

CONCLUSIONS

Implementation of thyroid nodule risk stratification can be supported by development of standardised reporting templates, education of users on risk stratification and reminders of use at the point of care. Additional studies evaluating the value of implementation strategies in different contexts are urgently needed.

Management of Thyroid Nodules

Thyroid nodules are common and the prevalence varies between 4 and 7% by palpation and 19-68% by high-resolution USG. Most thyroid nodules are benign, and the malignancy rate varies between 7 and 15% of patients. Thyroid nodules are detected incidentally during clinical examination or, more often, during imaging studies performed for another reason. All detected thyroid nodules should be evaluated clinically. The main test in evaluating thyroid function is thyroid stimulating hormone (TSH). If the serum TSH level is below the normal reference range, a radionuclide thyroid scan should be performed to determine whether the nodule is hyperfunctioning. If the serum TSH level is normal or high, ultrasonography (US) should be performed to evaluate the nodule. US is the most sensitive imaging method in the evaluation of thyroid nodules. Computed tomography (CT) and magnetic resonance imaging are not routinely used in the initial evaluation of thyroid nodules. There are many risk classification systems according to the USG characteristics of thyroid nodules, and the most widely used in clinical practice are the American Thyroid Association guideline and the American College of Radiology Thyroid Imaging Reporting and Data System. Fine needle aspiration biopsy (FNAB) is the gold standard method in the evaluation of nodules with indication according to USG risk class. In the cytological evaluation of FNAB, the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is the most frequently applied cytological classification. TBSRTC is a simplified, 6-category reporting system and was updated in 2023. The application of molecular tests to FNAB specimens, especially those diagnosed with Bethesda III and IV, is increasing to reduce the need for diagnostic surgery. Especially in Bethesda III and IV nodules, different methods are applied in the treatment of nodules according to the malignancy risk of each category, these are follow-up, surgical treatment, radioactive iodine treatment, and non-surgical ablation methods.

[Sociodemographic, clinical and ultrasound characterization of thyroid nodule pathology and its association with malignancy in a Colombian high-complexity center]

BACKGROUND AND OBJECTIVE

Thyroid nodules are among the most frequent conditions, with a 10% risk of malignancy. The objective is to describe the frequency of demographic, clinical, and ultrasonographic characteristics of thyroid nodule pathology in adults and to explore the relationship with tumor malignancy.

METHODS

An analytical, retrospective cross-sectional study in adults with thyroid nodules and nodular fine-needle aspiration performed in adult patients from a Colombian reference center between 2009-2019. Data were obtained from the clinical history, descriptive measures of the patient's demographic, clinical, and ultrasound variables were estimated, and their relationship with the malignancy of the tumor was explored.

RESULTS

A total of 445 patients and 515 nodules were included. The median age was 55 years (IQR 44-64), 86.8% of women, and 54.8% had a single lesion. Percentages of 80.2 and 19.8 were benign and malignant nodules, with a median of 15.7mm (IQR 11-25) and 12.7mm (IQR 8.5-18.3), respectively (p<0.001). Hypothyroidism and levothyroxine consumption were higher in those with malignant nodules (p<0.001). The echographic characteristics were statistically different between the nodules. In the malignant ones, there was a higher frequency of solid composition, hypoechogenicity, and irregular margins. In contrast, in the benign ones, the absence of echogenic focus stood out (p<0.001).

CONCLUSION

The ultrasound characteristics are essential to define the risk of malignancy of a thyroid nodule. Therefore, considering the most frequent ones can help in the most appropriate approach to primary care.

Distribution of ABO blood groups and Rh factor in benign and malign thyroid nodules

Aim: Many factors affect the diagnostic value of the fine-needle aspiration biopsy applied for these thyroid nodules. I aimed to investigate whether one of these factors would be ABO blood groups and Rh factor and examine the relationship of these factors with the Bethesda categorization. Additionally, I aimed to evaluate ABO blood groups and Rh factors in patients with thyroid cancer. Material and Method: This study was planned in a cross-sectional retrospective design. The data of the patients were obtained from the hospital data bank. In the analysis of 801 patients following the acceptance criteria, 412 patient data were obtained. Patients were divided into 4 (O, A, B, and AB groups) according to their blood groups and analyzed for nodules (solitary/ multinodular). Nodules were divided into malignant and benign, according to histopathological diagnosis, and all were analyzed. Results: There was no difference in analyzing the demographic data according to the blood groups. The rates of the FNAB history were 51 (32.3%), 39 (24.2%), 14 (26.4%), and 13 (32.5%) in the same order of blood groups (p=0.393). In the analysis of the nodule type, multinodular did not differ from solitary nodules among the blood groups [O: 141 (89.2%); A:140(87%), B: 46(86.8%), and AB: 35(87.5%)]. Thyroid function status (euthyroid, hypothyroid, or hyperthyroid) was similar for all the blood groups (p=0.815). The O-group had 1 (0.6%) patient with Bethesda score-6, and the A-group had 2 (1.2%) patients with Bethesda score-6. For Bethesda score-5, per blood group had 2 patients. The histopathological distribution of malign nodules (p=0.782) is as follows: O-groups: 6 (33.3%) (Rh+:27%; Rh-:5,5%), A groups: 7(63,6%) (Rh+:54,5%; Rh-:0,9%), B groups: 2(20%)(Rh+:20%; Rh-:0%) and AB groups: 1(33%) (Rh+:33%) Rh-:0%). Conclusion: Malign nodule rate was highest in the A-group and lowest in the B groups, although it did not differ in the overall analysis. No relationship was found between the Bethesda categorization of nodules, their sizes, type of nodules, type of thyroid cancer, and ABO blood groups.