Ultrasonography and the American Thyroid Association Ultrasound-Based Risk Stratification Tool: Utility in Pediatric and Adolescent Thyroid Nodules

Diagnostic performance of adult-based thyroid imaging reporting and data systems in pediatric thyroid carcinoma: a retrospective study

BACKGROUND

Thyroid nodules diagnosed in children pose a greater risk of malignancy compared to those in adults. However, there is no ultrasound thyroid nodule evaluation system aimed at children. The objective of this research is to assess the diagnostic performance of the adult-based American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS) and Chinese Thyroid Imaging Reporting and Data System (C-TIRADS) in pediatric thyroid carcinoma.

METHODS

The preoperative ultrasound images of 177 thyroid lesions in 136 pediatric patients aged 18 or younger who underwent thyroid surgery or fine needle aspiration (FNA) at our center from July 2017 to July 2022 were reviewed. The sonographic characteristics of pediatric thyroid carcinoma were compared and analyzed in contrast to benign nodules. All the nodules were evaluated by the ACR-TIRADS and the C-TIRADS respectively.

RESULTS

Ultrasound features such as solid composition (94.8%), hypoechogenicity or marked hypoechogenicity (94.8-95.7%) and microcalcification (78.3-84.3%) were more common in pediatric malignant nodules (P-values < 0.05). The areas under receiver operating characteristic curves (AUC) of the ACR-TIRADS and the C-TIRADS in diagnosing pediatric thyroid carcinoma were 0.903-0.906, 0.907-0.909 (P-value > 0.05). The interobserver agreement of both the ACR-TIRADS and the C-TIRADS was strong (weighted Kappa > 0.90).

CONCLUSIONS

Both the C-TIRADS and the ACR-TIRADS owned great diagnostic performance and strong interobserver agreement in diagnosing pediatric thyroid carcinoma. However, a more complete and specific ultrasound evaluation system for pediatric thyroid nodules is still needed.

Insights into Ultrasound Features and Risk Stratification Systems in Pediatric Patients with Thyroid Nodules

Thyroid nodules in pediatric patients are less common than in adults but show a higher malignancy rate. Accordingly, the management of thyroid nodules in pediatric patients is more complex the younger the patient is, needing careful evaluation by physicians. In adult patients, specific ultrasound (US) features have been associated with an increased risk of malignancy (ROM) in thyroid nodules. Moreover, several US risk stratification systems (RSSs) combining the US features of the nodule were built to define the ROM. RSSs are developed for the adult population and their use has not been fully validated in pediatric patients. This study aimed to evaluate the available data about US features of thyroid nodules in pediatric patients and to provide a summary of the evidence regarding the performance of RSS in predicting malignancy. Moreover, insights into the management of thyroid nodules in pediatric patients will be provided.

Application value of multi-gene mutation detection in the clinical management of pediatric papillary thyroid carcinoma: a preliminary exploration

Objectives

Thyroid cancer rarely occurs in children and adolescents. Molecular markers such as BRAF, RAS, and RET/PTC have been widely used in adult PTC. It is currently unclear whether these molecular markers have equivalent potential for application in pediatric patients. This study aims to explore the potential utility of a multi-gene conjoint analysis based on next-generation targeted sequencing for pediatric papillary thyroid carcinoma (PTC).

Materials and methods

The patients diagnosed with PTC (aged 18 years or younger) in the pediatrics department of Lishui District Hospital of Traditional Chinese Medicine were retrospectively screened. A targeted enrichment and sequencing analysis of 116 genes associated with thyroid cancer was performed on paraffin-embedded tumor tissues and paired paracancerous tissue of fifteen children (average age 14.60) and nine adults (average age 49.33) PTC patients. Demographic information, clinical indicators, ultrasonic imaging information and pathological data were collected. The Kendall correlation test was used to establish a correlation between molecular variations and clinical characteristics in pediatric patients.

Results

A sample of 15 pediatric PTCs revealed a detection rate of 73.33% (11/15) for driver gene mutations BRAF V600E and RET fusion. Compared to adult PTCs, the genetic mutation landscape of pediatric PTCs was more complex. Six mutant genes overlap between the two groups, and an additional seventeen unique mutant genes were identified only in pediatric PTCs. There was only one unique mutant gene in adult PTCs. The tumor diameter of pediatric PTCs tended to be less than 4cm (p<0.001), and the number of lymph node metastases was more than five (p<0.001). Mutations in specific genes unique to pediatric PTCs may contribute to the onset and progression of the disease by adversely affecting hormone synthesis, secretion, and action mechanisms, as well as the functioning of thyroid hormone signaling pathways. But, additional experiments are required to validate this hypothesis.

Conclusion

BRAF V600E mutation and RET fusion are involved in the occurrence and development of adolescent PTC. For pediatric thyroid nodules that cannot be determined as benign or malignant by fine needle aspiration biopsy, multiple gene combination testing can provide a reference for personalized diagnosis and treatment by clinical physicians.

Thyroid Ultrasound Screening in Childhood Cancer Survivors following Radiotherapy

INTRODUCTION

Childhood cancer survivors (CCS) are at risk for radiotherapy (RT) late effects, including second malignancies. Optimal screening for differentiated thyroid cancer (DTC) in CCS post-RT remains controversial. We assessed the outcome of thyroid ultrasound (US) surveillance in CCS exposed to RT.

METHODS

306 CCS were surveilled with thyroid US between 2002-2021. Surveillance was dependent on age at the time of primary diagnosis, interval from receipt of RT, and individual provider. Thyroid US, clinicopathologic features, and outcomes were described. Cutpoints of CCS RT age associated with varying risk of nodule presentation were explored. The selected cutpoints were used to define age categories, which were then used to compare thyroid nodule-related outcomes. Risk factors for thyroid nodule(s) were evaluated using multivariate logistic regression (odds ratio [OR] [95% confidence interval]).

RESULTS

The most common CCS diagnoses were leukemia (32%), CNS tumor (26%), and neuroblastoma (18%). Patients received TBI (45%) and/or RT to craniospinal (44%), chest (11%), and neck regions (6%). About 49% (n = 150) of patients had thyroid nodule(s). Forty-four patients underwent surgery, and 28 had DTC: 19 with American Thyroid Association (ATA) low-risk classification, 2 with ATA intermediate-risk, and 7 with ATA high-risk disease. Age cutpoint analyses identified cutpoints 3 and 10; hence, ≤3, >3 to ≤10, and >10 years were used. Of the 9 patients with intermediate- or high-risk disease, 8 were ≤10 years and 1 was >10 years at the time of RT. Female sex (OR = 1.62 [1.13-2.12] p = 0.054) and greater interval between RT and first US (OR = 1.10 [1.04-1.16] p = 0.001) were independent risk factors for nodule presentation.

CONCLUSIONS

Thyroid US surveillance may be beneficial for CCS exposed to RT at younger ages (≤10 years) for earlier detection of DTC, prior to developing advanced metastatic disease.

Performance of ACR TI-RADS and the Bethesda System in Predicting Risk of Malignancy in Thyroid Nodules at a Large Children's Hospital and a Comprehensive Review of the Pediatric Literature

While thyroid nodules are less common in children than in adults, they are more frequently malignant. However, pediatric data are scarce regarding the performance characteristics of imaging and cytopathology classification systems validated to predict the risk of malignancy (ROM) in adults and select those patients who require fine-needle aspiration (FNA) and possibly surgical resection. We retrospectively reviewed the electronic medical records of all patients 18 years of age or younger who underwent thyroid FNA at our institution from 1 July 2015 to 31 May 2022. Based on surgical follow-up from 74 of the 208 FNA cases, we determined the ROM for the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) ultrasound risk stratification system and The Bethesda System for Reporting Thyroid Cytopathology and added our results to those of pediatric cohorts from other institutions already published in the literature. We found the following ROMs for 1458 cases using ACR TI-RADS (TR): TR1. Benign: 2.2%, TR2. Not Suspicious: 9.3%, TR3. Mildly Suspicious: 16.6%, TR4. Moderately Suspicious: 27.0%, and TR5. Highly Suspicious 76.5%; and for 5911 cases using the Bethesda system: Bethesda I. Unsatisfactory: 16.8%, Bethesda II. Benign: 7.2%, Bethesda III: Atypia of Undetermined Significance: 29.6%, Bethesda IV. Follicular Neoplasm: 42.3%, Bethesda V. Suspicious for Malignancy: 90.8%, and Bethesda VI. Malignant: 98.8%. We conclude that ACR TI-RADS levels imply higher ROMs for the pediatric population than the corresponding suggested ROMs for adults, and, in order to avoid missing malignancies, we should consider modifying or altogether abandoning size cutoffs for recommending FNA in children and adolescents whose thyroid glands are smaller than those of adults. The Bethesda categories also imply higher ROMs for pediatric patients compared to adults.

What is this bump in my neck? Ultrasonographic evaluation of pediatric neck masses

Neck masses are common in pediatric patients, with benign etiologies such as congenital or inflammatory lesions accounting most of these masses. Anatomic location (most important), clinical history, and the appearance in ultrasonography (US) are helpful clues to narrow down differential diagnosis. Because of widespread availability, lack of ionizing radiation, and no need for sedation or contrast administration, US is the preferred initial modality for the evaluation. Further evaluation with cross-sectional imagings is needed for more extensive lesions with trans-spatial extension or suspicion of intrathoracic or retropharyngeal extension. This review will focus on US appearance and clinical presentation of masses of the neck in children, to enable radiologist to arrive at a reasonable differential diagnosis. We also briefly discuss more complex pathologies that need to be evaluated with cross-sectional modalities such as CT scan and magnetic resonance imaging.

Imaging of pediatric thyroid tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Pediatric thyroid cancer is rare in children; however, incidence is increasing. Papillary thyroid cancer and follicular thyroid cancer are the most common subtypes, comprising about 90% and 10% of cases, respectively. This paper provides consensus imaging recommendations for evaluation of pediatric patients with thyroid cancer at diagnosis and during follow-up.

Diagnostic performance of adult-based ultrasound risk stratification systems in pediatric thyroid nodules: a systematic review and meta-analysis

Purpose

Ultrasound (US) is the first choice in the detection of thyroid nodules in pediatric and adult patients. The purpose of this study was to evaluate the diagnostic performance of adult-based US risk stratification systems (RSSs) when applied to the pediatric population.

Methods

Medline, Embase, and Cochrane Library (CENTRAL) were searched up to 5 March 2023 for studies about the diagnostic performance of adult-based US RSS in pediatric patients. The pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR, and diagnostic odds ratio (DOR) were calculated. The summary receiver operating characteristic (SROC) curves and area under the curve (AUC) were also analyzed.

Results

The sensitivity was highest in American College of Radiology-Thyroid Imaging Reporting and Data System (ACR-TIRADS) category 4-5 and American Thyroid Association RSS high-intermediate risk (ATA), which was 0.84 [0.79, 0.88] and 0.84 [0.75, 0.90], respectively. The specificity was highest in ACR-TIRADS category 5 and Europe-TIRADS (EU-TIRADS) category 5, which was 0.93 [0.83, 0.97] and 0.93 [0.88, 0.98], respectively. The ACR-TIRADS, ATA, and EU-TIRADS showed moderate diagnostic performance in pediatric thyroid nodule patients. For Korea-TIRADS (K-TRADS) category 5, the summary sensitivity and specificity with a 95% CI were 0.64 [0.40, 0.83] and 0.84 [0.38, 0.99], respectively.

Conclusions

In conclusion, the ACR-TIRADS, ATA, and EU-TIRADS have moderate diagnostic performance in pediatric thyroid nodule patients. The diagnostic efficacy of the K-TIRADS was not as high as expected. However, the diagnostic performance of Kwak-TIRADS was uncertain because of the small sample size and small number of studies included. More studies are needed to evaluate these adult-based RSSs in pediatric patients with thyroid nodules. RSSs specific for pediatric thyroid nodules and thyroid malignancies were necessary.

Autoimmune Thyroiditis and Risk of Malignancy in Children with Thyroid Nodules

Background: It is uncertain whether the presence of autoimmune thyroiditis (AIT) increases the risk of thyroid cancer in children with thyroid nodules. This study evaluated the association between AIT and thyroid cancer in pediatric patients with thyroid nodules. Methods: A cross-sectional study was performed of pediatric patients (<19 years old) with a thyroid nodule (≥1 cm) who underwent fine-needle aspiration in an academic pediatric thyroid center. AIT was defined by the presence of thyroid autoantibodies or diffusely heterogeneous sonographic echotexture. The primary outcome was diagnosis of thyroid cancer. The association of AIT with thyroid cancer was evaluated with univariable and multivariable logistic regression. Associations of AIT with subject and nodule characteristics were also assessed. Results: Four hundred fifty-eight thyroid nodules in 385 patients (81% female) were evaluated at a median age of 15.5 years (interquartile range 13.5-17.0). Thyroid cancer was present in 108 nodules (24%). AIT was present in 95 subjects (25%) and was independently associated with an increased risk of thyroid cancer (multivariable odds ratio [OR] 2.19, 95% confidence interval [CI] 1.32-3.62). Thyroid cancer was also independently associated with younger age, nodule size, and solitary nodules, but was not associated with serum thyrotropin concentration. AIT was not associated with the likelihood of subjects undergoing thyroid surgery (p = 0.17). AIT was less commonly associated with follicular thyroid carcinoma than with papillary thyroid carcinoma (OR 0.22, CI 0.05-1.06). Among papillary thyroid carcinomas, AIT was strongly associated with the diffuse sclerosing variant (OR 4.74, CI 1.33-16.9). AIT was not associated with the extent of local, regional, or distant disease at thyroid cancer diagnosis. Conclusions: AIT is independently associated with an increased risk of thyroid cancer in children with thyroid nodules. These findings suggest that the evaluation of thyroid autoantibodies and thyroid echotexture may inform thyroid cancer risk assessment and surgical decision-making in children with thyroid nodules.

Assessment of diagnostic capacity and decision-making based on the 2015 American Thyroid Association ultrasound classification system

BACKGROUND

This study evaluates the American Thyroid Association (ATA) ultrasound (US) classification system for the initial assessment of thyroid nodules to determine if it indeed facilitates clinical decision-making.

AIM

To perform a systematic review and meta-analysis of the diagnostic value of the ATA US classification system for the initial assessment of thyroid nodules.

METHODS

In accordance with the PRISMA statement for diagnostic test accuracy, we selected articles that evaluated the 2015 ATA US pattern guidelines using a diagnostic gold standard. We analyzed these cases using traditional diagnostic parameters, as well as the threshold approach to clinical decision-making and decision curve analysis.

RESULTS

We reviewed 13 articles with 8445 thyroid nodules, which were classified according to 2015 ATA patterns. Of these, 46.62% were malignant. No cancer was found in any of the ATA benign pattern nodules. The Bayesian analysis post-test probability for cancer in each classification was: (1) Very-low suspicion, 0.85%; (2) Low, 2.6%; (3) Intermediate, 6.7%; and (4) High, 40.9%. The net benefit (NB), expressed as avoided interventions, indicated that the highest capacity to avoid unnecessary fine needle aspiration biopsy (FNAB) in the patterns that we studied was 42, 31, 35, and 43 of every 100 FNABs. The NB calculation for a probability threshold of 11% for each of the ATA suspicion patterns studied is less than that of performing FNAB on all nodules.

CONCLUSION

These three types of analysis have shown that only the ATA high-suspicion diagnostic pattern is clinically useful, in which case, FNAB should be performed. However, the curve decision analysis has demonstrated that using the ATA US risk patterns to decide which patients need FNAB does not provide a greater benefit than performing FNAB on all thyroid nodules. Therefore, it is likely that a better way to approach the assessment of thyroid nodules would be to perform FNAB on all non-cystic nodules, as the present analysis has shown the ATA risk patterns do not provide an adequate clinical decision-making framework.

Suspected Malignant Thyroid Nodules in Children and Adolescents According to Ultrasound Elastography and Ultrasound-Based Risk Stratification Systems-Experience from One Center

The risk of malignancy in thyroid nodules correlates with the presence of ultrasonographic features. In adults, ultrasound risk-classification systems have been proposed to indicate the need for further invasive diagnosis. Furthermore, elastography has been shown to support differential diagnosis of thyroid nodules. The purpose of our study was to assess the application of the American Thyroid Association (ATA), British Thyroid Association (BTA) ultrasound risk-classification systems and strain elastography in the management of thyroid nodules in children and adolescents from one center. Seventeen nodules with Bethesda III, IV, V and VI were selected from 165 focal lesions in children. All patients underwent ultrasonography and elastography followed by fine needle aspiration biopsy. Ultrasonographic features according to the ATA and BTA stratification systems were assessed retrospectively. The strain ratio in the group of thyroid nodules diagnosed as malignant was significantly higher than in benign nodules (6.07 vs. 3.09, p = 0.036). According to the ATA guidelines, 100% of malignant nodules were classified as high suspicion and 73% of benign nodules were assessed as low suspicion. Using the BTA U-score classification, 80% of malignant nodules were classified as cancerous (U5) and 20% as suspicious for malignancy (U4). Among benign nodules, 82% were classified as indeterminate or equivocal (U3) and 9% as benign (U2). Our results suggest that application of the ATA or BTA stratification system and elastography may be a suitable method for assessing the level of suspected malignancy in thyroid nodules in children and help make a clinical decision about the need for further invasive diagnosis of thyroid nodules in children.

Pediatric Thyroid Nodules: Ultrasound Characteristics as Indicators of Malignancy

Objective

Pediatric thyroid nodules are uncommon but carry a 25% malignancy risk. Adult patients have well-established ultrasound characteristics that are predictive of malignancy, but these are not clearly defined in pediatric patients. We reviewed a case series of pediatric thyroid nodules.

Study Design

Retrospective chart review.

Setting

Tertiary children’s hospital.

Method

Institutional review board approval was obtained. This case series with chart review includes all pediatric thyroid nodules with ultrasounds from 2006 to 2016 at 2 pediatric tertiary care centers.

Results

An overall 112 pediatric thyroid nodules were analyzed. The mean patient age was 14.3 years; there was a female:male ratio of 4:1; and 94% were Caucasian. Seventeen percent (20/112) of nodules were malignant. In patients with malignant nodules, the average presenting age was 15.5 years, with a female:male ratio of 5.6:1. Seventy percent of malignant nodules had accompanying microcalcifications, 55% had abnormal lymph nodes, and 45% had irregular margins. In the benign nodules, 11% had microcalcifications, 12% had abnormal lymph nodes, and 26% had irregular margins. The presence of microcalcifications (odds ratio, 19.1 [95% CI, 6.0-61.0]; P < .0001), abnormal lymph nodes (odds ratio, 9.0 [95% CI, 3.0-26.6]; P = .0001), and size >3.5 cm (odds ratio, 5.8 [95% CI, 1.5-22.5]; P = .01) was associated with thyroid cancer. Irregular margins were not statistically significant (odds ratio, 2.3 [95% CI, 0.86-6.3]; P = .9).

Conclusions

Our data suggest that abnormal lymph nodes, microcalcifications, and size >3.5 cm could be predictors of malignancy in the pediatric population and influence clinical decision making.

Ultrasound criteria (EU-TIRADS) to identify thyroid nodule malignancy risk in adolescents. Correlation with cyto-histological findings

INTRODUCTION

Thyroid nodule (TN) harbouring a thyroid carcinoma are more common in paediatric than adult patients. In paediatric population, the evaluation of a TN should require specific paediatric tools for its diagnostic and therapeutic management. High-resolution ultrasonography and cytological evaluation after fine-needle aspiration biopsy (FNAB) remain the cornerstones of evaluation of TN.

OBJECTIVES

To evaluate in paediatric TN for the first time the usefulness and precision of the ultrasound criteria defined by the "Thyroid Imaging Reporting and Data System (EU-TIRADS) 2017 in adults" to establish the ultrasound indication for the practice of FNAB and stratify the risk of malignancy.

PATIENTS AND METHODS

24 paediatric patients under age 18 years with thyroid nodules were attended in the last 15 years, 24 of them (31 nodules; age: 15.2 ± 2.2 years; 18 women) met the inclusion criteria: FNAB with Bethesda classification and ultrasound with EU-TIRADS score. EU-TIRADS score were evaluated retrospectively. Fourteen patients underwent surgery and the definitive histological diagnosis was obtained, this allowed the calculations of sensitivity, specificity and positive and negative predictive values of the EU-TIRADS and Bethesda classification. Data on the largest diameters of the nodules were collected.

RESULTS

Of the overall 31 nodules, the distribution by EU-TIRADS (T) category was: T1 (3.2%), T2: 2 (6.4%), T3: 7 (22.6%), T4: 16 (51.6%) and T5: 5 (16.1%). All malignant nodules were included in EU-TIRADS category 4 or 5. By the other hand, 13 of the 25 benign nodules were also included in the EU-TIRADS 4 category, and one in the 5. The distribution by categories of Bethesda's classification (B): BI: 6 (19.4%), BII: 14 (45.2%), BIII: 5 (16.1%), BIV: 2 (6.5%), BV: 0 and BVI: 4 (12.9%). The pathological diagnosis of the 14 patients who underwent surgery was: 6 papillary carcinomas and 8 with benign lesions: 6 nodular hyperplasia and 2 follicular adenoma. The percentage of malignancy was 42%. The sensitivity of the EU-TIRADS classification to detect malignant nodules was 100%, the specificity was 25%, PPV 44% and NPV 100%. The sensitivity of the Bethesda classification to detect malignant nodules was 86%, the specificity was 75%, PPV 67% and NPV 90%. The analysis of the largest diameter of the nodules did not show statistically significant differences between benign and malignant lesions.

CONCLUSIONS

EU-TIRADS for ultrasonographic criteria classification in combination with the clinical history is an adequate and reproducible method to estimate suspicion of malignancy of paediatric TN. It is also a reliable diagnostic tool to decide which nodules will be candidates for FNAB.

Thyroid Cancer Risk Factors in Children with Thyroid Nodules: A One-Center Study

Thyroid nodules are common in the adult population (13%), but in childhood, they are relatively rarely diagnosed (0.2–5%). The risk factors and diagnostic and therapeutic algorithms are well-known and effectively used in adults, but no clear procedures supported by scientific research are available in the pediatric population. Our aim in this study was to identify predictive factors for thyroid cancer in a pediatric population. We retrospectively analyzed 112 children (80 girls and 32 boys, aged 0.6–18 years, with an average group age of 13.4 ± 4.5 years) with thyroid nodules who presented or were referred between 2010 and 2021. A total of 37 children qualified for partial or total thyroidectomy. After histopathological nodule examination, the most common cases were benign lesions in 23 patients (57.5%) and malignant lesions in 14 children (32.5%). Solitary benign thyroid nodules were found in 16 children (40%). Malignancy risk was higher in children with increased nodule diameter (greater than 7 mm; p = 0.018) or hypoechogenic lesions in ultrasound (p = 0.010), with no correlation between increased blood flow in the vessels and tumor diagnosis. The relative risk of developing thyroid cancer for class III was found to be higher in comparison to adults and 11.1 times higher than for classes I and II combined.

Facing Thyroid Nodules in Paediatric Patients Previously Treated with Radiotherapy for Non-Thyroidal Cancers: Are Adult Ultrasound Risk Stratification Systems Reliable?

Simple Summary

The risk of thyroid nodules harbouring cancer has been evaluated, in adults, using specific ultrasound criteria. However, it is unclear whether such evaluation can be translated in paediatric patients. In this study, we tested the effectiveness of three known risk evaluation systems in children with thyroid nodules and with a history of radiation exposure. We found that these systems are reliable in confirming or ruling out cancer in most cases, except when evaluating very small nodules (<1 cm). For these reasons, these risk criteria should be adopted to account for the reduced size of malignant lesions when evaluating paediatric subjects.

Abstract

Thyroid nodule ultrasound-based risk stratification systems (US-RSSs) have been successfully used in adults to predict the likelihood of malignancies. However, their applicability to the paediatric population is unclear, especially in children with a history of radiation exposure, who are at a higher cancer risk. We tested the efficacy of three US-RSSs in this setting by retrospectively applying three classification systems (ACR-TIRADS, ATA and EU-TIRADS) to all paediatric patients referred for thyroid nodules and with a radiation exposure history. We compared the results with a reference standard (pathology or 36-month follow-up); sensitivity, specificity, positive and negative predictive values (PPV and NPV) and accuracy were calculated. A total of 52 patients were included; fourteen of them (27%) had papillary thyroid cancer (PTC) at the final histology. No significant differences across the US-RSSs were detected; specificity (range 95–97%) and NPV (range 88–93%) were particularly elevated. However, ACR-TIRADS, ATA and EU-TIRADS did not indicate the need for a biopsy in six (42.8%), seven (50%) and eight (57%) cases of PTC; in five cases, this lack of indication was due to a small (<1 cm) nodule size. In conclusion, US-RSSs show a high NPV and specificity in paediatric patients, whereas the cytology indication could be improved by reconsidering the dimensional criterion.

Ultrasound criteria (EU-TIRADS) to identify thyroid nodule malignancy risk in adolescents. Correlation with cyto-histological findings

INTRODUCTION

Thyroid nodule (TN) harboring a thyroid carcinoma are more common in pediatric than adult patients. In pediatric population, the evaluation of a TN should require specific pediatric tools for its diagnostic and therapeutic management. High-resolution ultrasonography and cytological evaluation after fine-needle aspiration biopsy (FNAB) remain the cornerstones of evaluation of TN.

OBJECTIVES

To evaluate in pediatric TN for the first time the usefulness and precision of the ultrasound criteria defined by the"Thyroid Imaging Reporting and Data System (EU-TIRADS) 2017 in adults" to establish the ultrasound indication for the practice of FNAB and stratify the risk of malignancy.

PATIENTS AND METHODS

24 pediatric patients under age 18 years with thyroid nodules were attended in the last 15 years, 24 of them (31 nodules; age: 15.2 ± 2.2 years; 18 women) met the inclusion criteria: FNAB with Bethesda classification and ultrasound with EU-TIRADS score. EU-TIRADS score were evaluated retrospectively. Fourteen patients underwent surgery and the definitive histological diagnosis was obtained, this allowed the calculations of sensitivity, specificity and positive and negative predictive values of the EU-TIRADS and Bethesda classification. Data on the largest diameters of the nodules were collected.

RESULTS

Of the overall 31 nodules, the distribution by EU-TIRADS (T) category was: T1 (3.2%), T2: 2 (6.4%), T3: 7 (22.6%), T4: 16 (51.6%) and T5: 5 (16.1%). All malignant nodules were included in EU-TIRADS category 4 or 5. By the other hand, 13 of the 25 benign nodules were also included in the EU-TIRADS 4 category, and one in the 5. The distribution by categories of Bethesda's classification (B): BI: 6 (19.4%), BII: 14 (45.2%), BIII: 5 (16.1%), BIV: 2 (6.5%), BV: 0 and BVI: 4 (12.9%). The pathological diagnosis of the 14 patients who underwent surgery was: 6 papillary carcinomas and 8 with benign lesions: 6 nodular hyperplasia and 2 follicular adenoma. The percentage of malignancy was 42%. The sensitivity of the EU-TIRADS classification to detect malignant nodules was 100%, the specificity was 25%, PPV 44% and NPV 100%. The sensitivity of the Bethesda classification to detect malignant nodules was 86%, the specificity was 75%, PPV 67% and NPV 90%. The analysis of the largest diameter of the nodules did not show statistically significant differences between benign and malignant lesions.

CONCLUSIONS

EU-TIRADS for ultrasonographic criteria classification in combination with the clinical history is an adequate and reproducible method to estimate suspicion of malignancy of pediatric TN. It is also a reliable diagnostic tool to decide which nodules will be candidates for FNAB.

Diagnostic performance of adult-based ATA and ACR-TIRADS ultrasound risk stratification systems in pediatric thyroid nodules: a systematic review and meta-analysis

OBJECTIVES

To evaluate the diagnostic performance of adult-based "American College of Radiology- Thyroid Imaging Reporting And Data System" (ACR-TIRADS) and "American Thyroid Association" (ATA) in the pediatric population.

METHODS

MEDLINE/PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched for articles investigating the diagnostic performance of each stratification system (ACR-TIRADS or ATA) and evaluated them according to three aspects: (a) the risk of malignancy in each category; (b) diagnostic performance using the classic indicators (sensitivity, specificity); and (c) diagnostic performance regarding fine needle aspiration/biopsy recommendation. In addition to pathologic diagnosis, we allowed imaging follow-up as the reference standard for benign nodules.

RESULTS

Eight articles (1036 thyroid nodules) were included. For ACR-TIRADS, the pooled risk of malignancy in category was as follows: category 5 (59.3%); 4 (20.7%); 3 (11.0%); 2 (6.0%), and 1 (5.5%). For nodules of high suspicion of malignancy (category 4 or 5), the pooled sensitivity and specificity were 0.84 and 0.64. For ATA, the pooled risk of malignancy was as follows: category 5 (55.4%); 4 (34.2%); 3 (12.2%); and 2 (7.5%). For nodules of high suspicion of malignancy (category 4 or 5), the pooled sensitivity and specificity were 0.90 and 0.50. For category 5 nodules, the pooled specificity was significantly higher in ACR-TIRADS (p = 0.02). For ACR-TIRADS, the missed malignancy rate was 21.7% and the unnecessary biopsy rate was 62.7%. Information was not sufficient for this calculation with ATA.

CONCLUSIONS

The diagnostic performance of ACR-TIRADS and ATA in the pediatric population was somewhat modest. Large studies are mandatory for further validation and future amendments.

KEY POINTS

• The pooled sensitivity and specificity for highly suspicious nodules (category 4 or 5) for ACR-TIRADS were 0.84 and 0.64, and for ATA were 0.90 and 0.50, respectively. • When applying ACR-TIRADS for children, the pooled missed malignancy rate (21.7%) and unnecessary biopsy rates (62.7%) are still reasonably high. Insufficient information was available to perform these calculations for the ATA system. • Current risk stratification systems, especially ACR-TIRADS, require modification by focusing more on increasing the sensitivity and decreasing the missed malignancy rate. Lowering size cut-off for biopsy would be a reasonable option.

Ultrasound measurement of thyroid volume in euthyroid children under 3 years of age

Objective

To establish ultrasound reference values for thyroid volumes in children up to 3 years of age, given that ultrasound of the thyroid is an essential examination in the diagnosis of childhood thyroid disease.

Materials and Methods

This was a prospective study conducted in an iodine-sufficient city in southeastern Brazil. A total of 100 healthy children underwent clinical evaluation, anthropometric examination, and cervical ultrasound in accordance with conventional protocols. We evaluated characteristics such as echotexture, thyroid lobe volume, and total thyroid volume. The children were divided into five groups, by age: < 2 months; 2-12 months; 12-18 months; 18-24 months; and 24-36 months.

Results

The mean thyroid volume was lower in the < 2 month age group than in the other groups (0.4 mL vs. 0.18-0.70 mL; p < 0.001). For the subjects between 2 and 36 months of age, the mean volume was 1.0 mL (range, 0.30-2.0 mL). No other significant differences were observed between groups, thyroid lobes, or gender. However, body mass index correlated significantly with total thyroid volume (r = 0.347; p = 0.001).

Conclusion

The mean thyroid dimensions were smallest in the < 2 month age group (0.35 ± 0.16 mL). For the subjects between 2 and 36 months of age, a reference value of 0.85 ± 0.42 mL can be used. Our data could guide the diagnostic investigation of thyroid disease, especially congenital hypothyroidism, in childhood.

Genetic Landscape of Papillary Thyroid Carcinoma and Nuclear Architecture: An Overview Comparing Pediatric and Adult Populations

Thyroid cancer is a rare malignancy in the pediatric population that is highly associated with disease aggressiveness and advanced disease stages when compared to adult population. The biological and molecular features underlying pediatric and adult thyroid cancer pathogenesis could be responsible for differences in the clinical presentation and prognosis. Despite this, the clinical assessment and treatments used in pediatric thyroid cancer are the same as those implemented for adults and specific personalized target treatments are not used in clinical practice. In this review, we focus on papillary thyroid carcinoma (PTC), which represents 80-90% of all differentiated thyroid carcinomas. PTC has a high rate of gene fusions and mutations, which can influence the histologic subtypes in both children and adults. This review also highlights telomere-related genomic instability and changes in nuclear organization as novel biomarkers for thyroid cancers.

Pediatric thyroid ultrasound: a radiologist's checklist

Ultrasonography (US) is the imaging method of choice for evaluating the pediatric thyroid gland, complemented by scintigraphy and thyroid function tests, especially when evaluating children with suspected congenital hypothyroidism, goiter, infectious or autoimmune diseases, or neoplasm. Diagnostic considerations in newborns with congenital hypothyroidism mainly include dysgenesis, dyshormonogenesis, transient hypothyroidism and central (hypophyseal) hypothyroidism. The midline of the neck should be scrutinized for thyroid tissue from the floor of the mouth to the thoracic inlet. Cystic and echogenic ultimobranchial remnants should not be misinterpreted as orthotopic thyroid tissue. Diffuse thyroid diseases affect older children; these comprise Hashimoto and Graves diseases and infectious thyroiditis and exhibit features similar to those in adults. It is important to note that the diffuse sclerosing variant of papillary thyroid cancer can complicate thyroiditis and should not be confused with Hashimoto disease. In children with solid nodules the threshold for fine-needle aspiration biopsy or surgery should be lower compared to adults because of a higher likelihood of malignancy compared with adults. Biopsy should be considered in nodules with suspicious ultrasonographic features, even when smaller than 1 cm. Adult classification systems of thyroid nodules, although useful, are not sufficient to safely discriminate the nodules' likelihood of malignancy in children. We describe key sonographic findings and suggest a standard checklist that might be considered while performing and interpreting thyroid US in neonates and children.

Adolescents with thyroid nodules: retrospective analysis of factors predicting malignancy

Thyroid nodules are less common in children than in adults. However, pediatric thyroid nodules have a higher rate of malignancy compared to those in adults, and increased risk of metastasis and recurrence. In the present study, we analyzed the clinical features as well as laboratory and thyroid ultrasound (US) findings of children and adolescents with thyroid nodules to identify predictive factors of thyroid cancer. We retrospectively analyzed 275 patients with thyroid nodules under 18 years of age who visited Severance Children's Hospital between January 2005 and May 2017. Among them, 141 patients who underwent ultrasonography-guided fine needle aspiration biopsy (FNAB), and four patients without FNAB who underwent surgical resection, were included in this study. The remaining 125 patients without FNAB and five patients with follow-up loss after FNAB were excluded. Clinical, laboratory, and US data were evaluated in 145 patients to establish the potential predictive factors of thyroid cancer. Thyroid malignancies were observed in 101 patients. Grade 2 goiters were seen more often in benign nodule group. Hypoechoic nodules, nodules with microcalcifications, abnormal lymph nodes, and irregular margins were findings significantly associated with thyroid cancer. The findings of hypoechoic nodule, nodule with microcalcifications, and abnormal lymph nodes showed statistical significance in predicting thyroid cancer.Conclusion: Hypoechoic nodules, nodules with microcalcifications, and abnormal lymph nodes are predictive factors for thyroid cancer in children. Therefore, further diagnostic evaluations, including FNAB, should be considered in patients with such findings.What is Known:• Thyroid nodules are less common in children than in adults, but pediatric thyroid nodules have a higher rate of malignancy, and also have increased risk of metastasis and recurrence.• Research on ways to predict thyroid cancer have mostly been accomplished in adult patients, and the application of risk stratification system has not been fully satisfactory in children, which requires further studies in pediatric thyroid nodules.What is New:• Hypoechoic nodules, nodules with microcalcifications, and abnormal lymph nodes are predictive factors for thyroid cancer in Korean children.

Thyroid nodules in children and adolescents

PURPOSE OF REVIEW

Compared with adults, there is a two-fold to three-fold increased risk of malignancy for a pediatric patient undergoing evaluation of a thyroid nodule. In 2015, the American Thyroid Association published guidelines on the evaluation and management of pediatric patients with thyroid nodules and differentiated thyroid cancer. The goal of this clinical update is to review recent additions to the literature and propose opportunities how to best incorporate these findings into clinical practice.

RECENT FINDINGS

Recent additions to the literature include assessment of ultrasound-based scoring systems to improve selection of patients for fine needle aspiration, defining the pediatric-specific risk of malignancy within The Bethesda System for Reporting Thyroid Cytopathology, and broadening our knowledge of the oncogene landscape that supports incorporation of adjunct oncogene testing to rule-in malignancy of nodules with indeterminate cytology.

SUMMARY

There have been significant additions to the literature on the evaluation and management of children and adolescents with thyroid nodules since publication of the 2015 American Thyroid Association guidelines. Incorporating these changes into clinical care, within the setting of multidisciplinary, pediatric-specific, regional centers, will maximize ongoing efforts to improve the care of children and adolescents with thyroid nodules.

Thyroid Cancer in the Pediatric Population

Thyroid cancer is rare in the pediatric population, but thyroid carcinomas occurring in children carry a unique set of clinical, pathologic, and molecular characteristics. In comparison to adults, children more often present with aggressive, advanced stage disease. This is at least in part due to the underlying biologic and molecular differences between pediatric and adult thyroid cancer. Specifically, papillary thyroid carcinoma (which accounts for approximately 90% of pediatric thyroid cancer) has a high rate of gene fusions which influence the histologic subtypes encountered in pediatric thyroid tumors, are associated with more extensive extrathyroidal disease, and offer unique options for targeted medical therapies. Differences are also seen in pediatric follicular thyroid cancer, although there are few studies of non-papillary pediatric thyroid tumors published in the literature due to their rarity, and in medullary carcinoma, which is most frequently diagnosed in the pediatric population in the setting of prophylactic thyroidectomies for known multiple endocrine neoplasia syndromes. The overall shift in the spectrum of histotypes and underlying molecular alterations common in pediatric thyroid cancer is important to recognize as it may directly influence diagnostic test selection and therapeutic recommendations.

Ultrasound imaging classifications of thyroid nodules for malignancy risk stratification and clinical management: state of the art

Assessing the risk of malignancy in the thyroid with ultrasound (US) is crucial in patients with nodules, as it can aid in selecting those who should have a fine-needle aspiration (FNA) biopsy performed. Many studies have examined whether the US characteristics of thyroid nodules are useful indicators of histological malignancy. Overall, these investigations have identified a few US features that are significantly more frequent in malignant thyroid nodules which can be coalesced into a defining set to be used as an indicator of a higher risk of malignancy. Despite these efforts, none of these classifications have been widely adopted worldwide, and there are still conflicting recommendations from different institutions. Understanding the role and appropriate utilization of these systems could facilitate the effective interpretation and communication of thyroid US findings among referring physicians and radiologists. In this comprehensive review, we outline the major US classification systems of thyroid nodules published in the last few years.

Diagnostic accuracy of the McGill thyroid nodule score in paediatric patients

INTRODUCTION

Thyroid cancer is the most common paediatric endocrine cancer; accurate diagnosis and prompt management of paediatric thyroid nodules is critical. The McGill Thyroid Nodule Score (MTNS), based upon clinical, ultrasound (US) and cytology criteria, has recently been modified and studied in a pilot paediatric group with good results. We aim to describe the diagnostic accuracy of the paediatric modified MTNS (PMTNS) in a large paediatric cohort.

METHODS

We utilized an established retrospective cohort between 1996 and 2015 of 99 patients ≤21 years old with 131 thyroid nodules. Two experienced paediatric radiologists, blinded to pathology and radiology reports, reviewed US features. We abstracted cytology, histology and laboratory results, assigning each nodule a PMTNS. PMTNS performance was compared to FNA and histology.

RESULTS

Approximately 33% of nodules were malignant. The cohort was predominantly adolescent (mean age 15.4 ± 3.8 years). The average PMTNS for malignant and benign nodules, based on final histology, was 12.7 ± 4.3 and 1.7 ± 2.9, respectively. A PMTNS ≥8 resulted in a 93.2% sensitivity and 93.1% specificity for detecting malignancy, while a PMTNS ≥9 resulted in a 90.9% sensitivity and 96.6% specificity. However, Bethesda cytology category ≥4 independently had a 97.7% sensitivity and 94.0% specificity for detecting malignancy. The PMTNS had diminishing diagnostic accuracy in younger children compared with older children.

CONCLUSION

Paediatric modified McGill Thyroid Nodule Score predicts malignancy, perhaps due to the score's emphasis on cytology results; however, the score is less accurate in younger patients. While cytology results remain reliable, further work is needed to develop a non-invasive scoring system to predict malignancy in children.