Diagnostic Strategies for Thyroid Nodules Based on Ultrasonographic Findings in Japan

Proposal for Clinical Management of Nodules Diagnosed as Atypia of Undetermined Significance via Thyroid Fine-Needle Aspiration Cytology in the Absence of Molecular Testing

OBJECTIVE

Molecular testing is recommended for risk stratification of atypia of undetermined significance (AUS) nodules in the USA; however, it is not routinely performed in some countries owing to limited availability and affordability. Here, we propose a risk stratification algorithm for AUS nodules when molecular testing is unavailable.

METHODS

We examined 304 (4.3%) AUS nodules among 7073 thyroid fine-needle aspiration cytology specimens examined at Kuma Hospital from January 2020 to December 2020. Clinical data were obtained from the medical records of Kuma Hospital.

RESULTS

AUS with nuclear atypia and AUS-other each accounted for half of the total AUS nodules. The repeat aspiration rate was 19.7%; 61.7% of the nodules were reclassified as benign or malignant upon repeat aspiration. Resection rate and overall risk of malignancy (ROM) were 32.6% and 12.8%, respectively. Architectural atypia showed the lowest (1.1%) overall ROM in the AUS nodules. For AUS with nuclear atypia, nodules ≤ 10 mm in size showed significantly lower overall ROM than those of > 10 mm, and nodules with ultrasonographically low suspicion showed significantly lower overall ROM than those with intermediate to high suspicion. AUS nodules with atypical lymphoid cells, possible medullary thyroid carcinoma, or possible parathyroid lesion were confirmed using flow cytometry, biochemical testing using needle washout fluid or immunocytochemistry, respectively.

CONCLUSIONS

Our proposed clinical management algorithm for each subdivision according to cytological findings, based on repeat aspiration rates, ROM, ultrasound findings and results of ancillary tests except for molecular testing, should be useful for the clinical management of AUS nodules.

Clinicopathological Findings of 220 Pediatric, Adolescent, and Young Adult Patients with Thyroid Cancer in Fukushima Medical University Hospital

Background: Thyroid ultrasound examinations (TUEs), conducted as part of the Fukushima Health Management Survey (FHMS), were initiated to monitor the health status of residents after the Fukushima Daiichi Nuclear Power Plant accident owing to concerns regarding the increased incidence of thyroid cancer among children, as observed after the Chernobyl Nuclear Power Plant accident. This study reported the clinicopathological characteristics of patients with thyroid cancer diagnosed through the FHMS and treated at the Fukushima Medical University Hospital. Methods: Data regarding the clinicopathological characteristics of patients with thyroid cancer were collected and evaluated in this descriptive study. Results: Among the 263 patients diagnosed with thyroid cancer as of September 2021, 220 patients with cytologically diagnosed thyroid cancer were treated as referrals from the FHMS. The median (interquartile range) age at the time of diagnosis was 18.6 (16.2-20.3) years. The median maximum tumor diameter was 13.0 (10.4-18.0) mm. To reduce surgical invasiveness, 199 patients (90.1%) underwent unilateral lobectomy. Pathological findings were suggestive of papillary thyroid carcinomas (PTC) in 216 (98.2%) patients; among them, 205 patients had PTC of the classical type. In addition, 216 (98.2%) patients had stage I disease. Cancer cell extension in the sternothyroid muscle or perithyroidal soft tissues and microscopic lymphovascular invasion were observed in 112 (50.9%) and 123 (55.9%) patients, respectively. No differences were observed between the two age groups (<18.6 years and ≥18.6 years) in terms of the clinical or pathological characteristics of thyroid cancer: risk classification (p = 0.69) and American Thyroid Association pediatric risk level (p = 0.24). Compared with those from previous reports, few surgical complications were observed. Conclusions: Patients with thyroid cancer diagnosed with TUEs underwent safe and minimally invasive operations, and careful postoperative follow-up was provided. The pathological findings of the detected thyroid cancers indicated that the majority were classical papillary carcinomas, and approximately half of the patients had extrathyroidal or lymphovascular invasion. No differences were observed between the two age groups in terms of the clinical or pathological characteristics of thyroid cancer.

Comparison of the value of ultrasound-guided fine needle aspiration biopsy and contrast-enhanced ultrasound in different sizes of thyroid nodules

The purpose of this study was to evaluate the diagnostic value of ultrasound-guided fine needle aspiration biopsy (US-FNAB) and contrast-enhanced ultrasound (CEUS) in the presence of thyroid nodules of different sizes. We retrospectively analyzed 110 patients with surgically operated unimodular thyroid nodules in Yichang City Central Hospital from July 1, 2021, to April 1, 2023, all of whom underwent conventional thyroid ultrasound, CEUS, and US-FNAB, and all of whom were classified according to the size of nodules into <0.5, 0.5 to 1, and ≥1 cm groups. The diagnostic accuracy, sensitivity, and specificity of the 2 methods for benign and malignant nodules were calculated. Among 110 thyroid nodules, 102 were malignant nodules and 8 were benign nodules. In patients with nodule diameters <1 cm the sensitivity of US-FNAB and CEUS was 87.02% and 93.89%, respectively, and the specificity was 100.00% and 66.67%, with an accuracy of 87.31% and 93.28%, respectively. In patients with nodule diameter <0.5 cm, the sensitivities of US-FNAB and CEUS were 74.29% and 100.00%, respectively, and the differences were statistically significant (P < 0.05); in patients with nodule diameter 0.5 to 1 cm, the sensitivities of US-FNAB and CEUS were 79.59% and 95.92%, respectively, and the differences were statistically significant (P < 0.05); among patients with nodule diameters ≥1 cm, the sensitivities of US-FNAB and CEUS were 88.89% and 77.78%, respectively, with no statistically significant difference (P > 0.05). For thyroid nodules ≤1 cm in diameter, the sensitivity of CEUS examination was higher than that of US-FNAB; and CEUS still has good diagnostic accuracy in the diagnosis of benign and malignant thyroid nodules <0.5 cm, CEUS is recommended for thyroid nodules diagnosed negatively by US-FNAB with a diameter of <1 cm; and CEUS should be preferred for thyroid nodules with a diameter of <0.5 cm. CEUS should be preferred for thyroid nodules <0.5 cm in diameter.

Active surveillance of papillary thyroid carcinoma in Latin America: a scoping review

Thyroid nodules are a very common finding and have a malignancy rate of 7%-15%. Some malignant nodules have an indolent behavior and may not affect mortality if left untreated. Active surveillance (AS) is a strategy to prevent overtreatment in patients with papillary thyroid microcarcinomas (PTMCs). This review was conducted to evaluate the status of AS for low-risk PTMC in Latin America, including cultural and logistical challenges, disease progression data, and financial viability. We searched PubMed (MEDLINE), SciELO, LILACS, and Web of Science for articles published after 2014 and enrolling adult Latin American patients. Articles cited in the selected studies were also retrieved. We analyzed the AS protocols, technical or logistical challenges, patient adherence, reasons for AS interruption, surgical conversion rates, duration of AS, and disease progression during AS in our region. Three articles were included in the analysis, all of which considered AS a viable option and reported tumor progression and outcomes similar to those reported in other countries. Neck ultrasound and serum levels of thyroglobulin, thyroid-stimulating hormone (TSH), thyroxine (T4), and antithyroglobulin antibodies were included in the follow-up. No cases of new distant metastases were reported, and the outcomes were favorable when surgery was required. Anxiety was the main reason for AS interruption. We conclude that AS can be an acceptable approach and is safe and effective in Latin America, although more prospective studies are needed to consolidate this strategy in our region. Adequate infrastructure, follow-up, and patient education, as well as multidisciplinary healthcare teams trained in conducting AS must be ensured for successful results.

Washout CYFRA 21-1: A tool to improve diagnostic accuracy of fine needle aspiration in the diagnosis of metastatic lymph nodes in papillary thyroid cancer

Thyroid carcinoma has an increasing incidence of endocrine system cancers. Fine needle aspiration cytology (FNAC) and thyroglobulin (Tg) are the primary diagnostic modalities employed for assessing metastatic lymph nodes (LNs) in thyroid cancer. Due to the limited accuracy, rare patients benefited from these procedures. In this research, we aimed to discover a dependable biomarker that could increase the accuracy of FNAC's ability to diagnose metastatic LNs among patients suffering from papillary thyroid cancer (PTC). From March 2021 to July 2023, 99 LNs from PTC patients who had thyroid ultrasonography suspicions of metastases were examined. All patients underwent FNAC, washout Tg and CYFRA 21-1 measurements. Surgical histology and a subsequent FNAC were utilized to validate the outcomes of LNs. In our study, the optimal cut-off value for CYFRA 21-1 washout fluid was 1.145 ng/mL, with a specificity of 94.00 % (slightly lower than Tg and FNAC at 98 %). However, CYFRA 21-1 demonstrated significantly higher diagnostic sensitivity (85.71 %) and accuracy (86.41 %) compared to Tg (71.43 %, 81.55 %) and FNAC (69.39 %, 80.58 %). Furthermore, FNAC plus washout CYFRA 21-1 performed better in diagnosing the metastatic LNs in PTC than FNAC plus Tg, which may indicate a novel solution for metastatic LNs diagnosis in PTC.

PAFAH1B3 Regulates Papillary Thyroid Carcinoma Cell Proliferation and Metastasis by Affecting the EMT

INTRODUCTION

Thyroid carcinoma (TC) is currently the prevalent type of endocrine malignancy worldwide, having an incidence of around 15.5 per 100,000 people. However, the underlying mechanisms of TC tumorigenesis remain to be further elucidated.

METHODS

Performing the database analyses, Platelet-activating factor acetylhydrolase 1B3 (PAFAH1B3) was found to be dysregulated in several carcinomas and might trigger tumor occurrence as well as the progression of TC. Clinicopathological information of patients from our local validated cohort and The Cancer Genome Atlas (TCGA) cohort also confirmed this hypothesis.

RESULTS

Our present research showed that elevated expression of PAFAH1B3 has a close association with worse behavior in papillary thyroid carcinoma (PTC). We utilized the small interfering RNA to obtain the PAFAH1B3-transfected PTC cell lines, including BCPAP, FTC-133, and TPC-1, and then further examined their biological function in vitro. Furthermore, gene set enrichment analysis suggested that PAFAH1B3 is implicated with epithelial-mesenchymal transition (EMT). Afterward, the western blotting assays aimed at EMT-related proteins were performed.

CONCLUSION

In short, our results revealed that silencing PAFAH1B3 could hinder the capabilities of proliferation, migration, and invasion of PTC cells. Increasing expression of PAFAH1B3 might be of quintessence with lymph node metastasis by triggering EMT in PTC patients.

Confounding factors and biases involved in regional differences in the detection rate of thyroid cancer in the second-round Thyroid Ultrasound Examination: the Fukushima Health Management Survey

In response to concerns about health due to radiation exposure, the Fukushima Prefecture launched the Thyroid Ultrasound Examination program for residents aged 0-18 years at the time of the earthquake. Herein, we considered the confounding factors involved in the regional differences in the development of thyroid cancer. In this study, the 242 065 individuals who participated in both first- and second-round surveys were classified into four groups by address according to their air radiation dose. The number of participants diagnosed as malignant or suspicious for malignancy by cytological examination were 17, 38, 10 and 4 with detection rates of 53.8, 27.8, 21.7 and 14.5 per 100 000 participants in Regions 1, 2, 3 and 4, respectively. Sex (P = 0.0400), age at the time of the primary examination (P < 0.0001) and interval between the first- and second-round surveys (P < 0.0001) were significantly different among the four regions, and these were suspected to be confounding factors affecting regional differences in malignant nodule detection rates. In addition, significant regional differences were observed in the participation rate in the confirmatory examination (P = 0.0037) and the fine needle aspiration cytology implementation rate (P = 0.0037), which could be potential biases. No significant regional differences in the detection of malignant nodules were found in the multivariate logistic regression analysis after adjusting for the survey interval alone or for sex, age and survey interval. The confounding factors and biases identified in this study that may have important impacts on thyroid cancer detection rate should be fully considered in future studies.

BRAF p.V600E genetic testing based on ultrasound-guided fine-needle biopsy improves the malignancy rate in thyroid surgery: our single-center experience in the past 10 years

PURPOSE

Ultrasound-guided fine-needle aspiration biopsy (UG-FNAB) was implemented in Qilu Hospital of Shandong University in 2015 as a preoperative diagnostic method for thyroid surgery. BRAF p.V600E genetic testing was implemented in 2019. This study evaluated the impact of these two tests on the malignancy rate in patients undergoing thyroidectomy.

METHODS

A total of 19,496 patients were included in the study. We retrospectively collected data from patients undergoing thyroid surgery in the Hospital Information System (HIS) of Qilu Hospital of Shandong University from January 2012 to December 2021. Meanwhile, data of FNAB, UG-FNAB, and BRAF p.V600E genetic testing were collected. Differences in means among groups were analyzed via one-way ANOVA, and differences in frequencies were analyzed via Pearson's chi-squared test.

RESULTS

In this study, the 10-year period was divided into three stages, with the implementation of UG-FNAB in 2015 and that of BRAF p.V600E genetic testing in 2019 as dividing lines. The malignancy rate in thyroid surgery increased significantly during these three stages (48.06% vs. 73.47% vs. 88.17%; P < 0.001). In the same period (May 2019 to December 2021), the malignancy rate in thyroid surgery was significantly different between the Non-FNAB, UG-FNAB, and UG-FNAB-BRAF groups (78.87% vs. 95.63% vs. 98.32%; P < 0.001).

CONCLUSIONS

The successful implementation of UG-FNAB and BRAF p.V600E genetic testing improved the malignancy rate in thyroid surgery and reduced unnecessary diagnostic surgery for benign and marginal lesions. It can, therefore, provide a clinical reference for other hospitals.

Active surveillance of low-risk papillary thyroid microcarcinoma

Recently, the incidence of thyroid carcinoma has been increasing rapidly worldwide. This is interpreted as an increase in the incidental detection of small papillary thyroid carcinomas by the widespread use of high-resolution imaging techniques such as ultrasonography. However, the mortality rates of thyroid carcinoma have not changed, suggesting that small papillary thyroid carcinomas may be overdiagnosed and overtreated. Active surveillance management has been introduced from Japan since the 1990s, as one of the measures to prevent overtreatment of low-risk papillary thyroid microcarcinoma. Based on the favorable outcomes, active surveillance has been gradually adopted worldwide as an alternative to immediate surgery. The management should be carried out with strict eligibility criteria and close monitoring for cancer progression, under a multidisciplinary team. In addition, an adequate shared decision-making is mandatory for individual patients. Papillary thyroid microcarcinomas with clinically apparent lymph node metastasis, distant metastasis, or invasion to adjacent organs should have surgery.

Multiparametric Sonographic Imaging of Thyroid Lesions: Chances of B-Mode, Elastography and CEUS in Relation to Preoperative Histopathology

Simple Summary

As the incidence of thyroid lesions in Europe is rising, more and more people affected by thyroid pathologies seek treatment in a clinic. Every suspicious thyroid nodule needs to be confirmed as benign or malignant in order to be treated correctly. Unnecessary invasive diagnostics and thyroid surgery should be avoided. The aim of this retrospective study was to improve the distinction between benign and malignant nodules by using new high-performance multiparametric ultrasound examination techniques. By analyzing 122 thyroid nodules we created a score-based system combining B-mode, shear-wave elastography and contrast-enhanced ultrasound malignancy criteria. This system allows for a quite accurate detection of thyroid carcinomas with a sensitivity of 95% and specificity of 75.49%. Shear-wave elastography and contrast-enhanced ultrasound can detect unique malignancy features, which cannot be found in B-mode. Therefore, these criteria would present a relevant addition to the B-mode TI-RADS classification.

Abstract

Background: The aim was to improve preoperative diagnostics of solid non-cystic thyroid lesions by using new high-performance multiparametric ultrasound examination techniques. Methods: Multiparametric ultrasound consists of B-mode, shear-wave elastography and contrast enhanced ultrasound (CEUS) including Time-Intensity-Curve (TIC) analysis. A bolus of 1–2.4 mL Sulfur Hexafluorid microbubbles was injected for CEUS. Postoperative histopathology was the diagnostic gold standard. Results: 116 patients were included in this study. 102 benign thyroid nodules were diagnosed as well as 20 carcinomas. Suspicious B-mode findings like microcalcifications, a blurry edge and no homogeneous sonomorphological structure were detected in 60, 75 and 80% of all carcinomas but only in 13.7, 36.3 and 46.1% of all benign lesions. The average shear-wave elastography measurements of malignant lesions (4.6 m/s or 69.8 kPa centrally and 4.2 m/s or 60.1 kPa marginally) exceed the values of benign nodules. Suspicious CEUS findings like a not-homogeneous wash-in and a wash-out were detected almost twice as often in carcinomas. Conclusion: Multiparametric ultrasound offers new possibilities for the preoperative distinction between benign and malignant thyroid nodules. A score based system of B-mode, shear-wave and CEUS malignancy criteria shows promising results in the detection of thyroid carcinomas. It reaches a sensitivity of 95% and specificity of 75.49%.

Molecular Testing for Thyroid Nodules: The Experience at McGill University Teaching Hospitals in Canada

In the past few decades, molecular characterization of thyroid cancer has made significant progress and is able to identify thyroid-cancer-related molecular markers that can then be applied clinically for improved decision making. The aim of this review is to provide a general overview about the molecular markers (mutations and alterations) of thyroid cancers, present several molecular tests, and discuss the clinical applications of identifying these markers supported by the clinical experience of several high-volume thyroid cancer specialists at the McGill university hospitals in Montreal, Canada. Our group experience showed that molecular testing can reclassify more than half of the patients with indeterminate thyroid nodules (Bethesda III and IV) into benign and spare these patients from unnecessary diagnostic surgery. Furthermore, it can help optimize the initial management in thyroid cancers with no evidence of high risk of recurrence of disease preoperatively. While routine molecular testing is not firmly established for thyroid FNA specimens that are suspicious or positive for malignancy (Bethesda V and VI), knowledge of a thyroid nodule’s molecular risk group profile in such cases, together with its clinical and radiologic features, can help select the optimal surgical options (lobectomy versus upfront total thyroidectomy and central neck dissection), as demonstrated by our studies.

A Comprehensive Review of the Progress and Evaluation of the Thyroid Ultrasound Examination Program, the Fukushima Health Management Survey

The Great East Japan Earthquake on March 11, 2011, and the subsequent tsunami caused an accident at the Fukushima Daiichi Nuclear Power Plant, in which extensive damage to the nuclear power reactors resulted in massive radioactive contamination. Fukushima Prefecture implemented the Thyroid Ultrasound Examination (TUE) program as part of the Fukushima Health Management Survey project in response to residents' anxieties about health risks due to radiation exposure for residents aged 0-18 years at the time of the nuclear accident. This program consisted of the primary examination and the confirmatory examination. In the primary examination, thyroid nodules and cysts were examined using portable ultrasound apparatuses. The confirmatory examination was performed to have clinical or cytological diagnosis. As of June 30, 2021, 116, 71, 31, 36, and 9 examinees in the first, second, third, and fourth round of surveys, and the survey at age 25 years, respectively, were determined to have nodules cytologically diagnosed as malignant or suspicious for malignancy. The confirmatory examination of the fourth-round survey and the primary and confirmatory examination of fifth-round survey are currently in progress. Together with the low thyroid absorbed radiation dose estimated in the United Nations Scientific Committee on the Effects of Atomic Radiation 2020 report, our results suggested that the increased incidence of childhood thyroid cancer in Fukushima Prefecture was not caused by radiation exposure, but rather by the highly sensitive detection method. As detailed in this review, there were ongoing challenges in our program, such as actions against the risk of overdiagnosis and psychological support for participants and their families.