Diagnostic utility of fine needle aspiration cytology in pediatric thyroid nodules based on Bethesda Classification

Diagnostic value of ultrasound-guided fine-needle aspiration cytology in the pathological natures of thyroid nodules: A retrospective study

Objective

Thyroid nodules, a clinical disease with high incidence, include benign and malignant types. This study aims to evaluate the diagnostic value of ultrasound-guided fine-needle aspiration cytology (US-FNAC) in determining the pathological nature of thyroid nodules and to conduct an in-depth analysis of its diagnostic efficacy across nodules of varying sizes.

Material and Methods

This retrospective study identified 116 patients undergoing thyroidectomy in Zibo Central hospital from January 2022 to March 2023, with 98 meeting the study's inclusion criteria. All patients received ultrasound and US-FNAC examinations before surgery to analyze the ultrasonic features of thyroid nodules. The diagnosis results of pathological natures obtained by US-FNAC were analyzed with the result of post-operative pathological examination as the gold standard. The patients were divided into four groups according to the median and quartile of nodular diameters to explore the diagnostic efficacy of US-FNAC for the pathological natures of thyroid nodules with various diameters and comprehensively evaluate its application value. The evaluation tool of diagnostic efficacy was the receiver operator characteristic (ROC) curve.

Results

A total of 98 puncture nodules were evaluated, with a diameter of 0.8-5.2 cm. Post-operative pathological examination showed 10 (10.20%) benign and 88 (89.80%) malignant lesions. The ultrasound examination showed 14 (14.29%) benign and 84 (85.71%) suspected malignant lesions. The US-FNAC results showed 2 cases (2.04%) of type I, 9 cases (9.18%) of type II, 3 cases (3.06%) of type III, 29 cases (29.59%) of type IV, 39 cases (39.80%) of type V, and 16 cases (16.33%) of type VI, including 9 (9.18%) benign and 84 (85.72%) malignant lesions and 5 (5.10%) uncertain pathological natures. According to the median and quartile of nodular diameters, specifically, 1.90 (1.60, 2.30) cm, 93 nodules with decided pathological natures were divided into groups Q1 (n = 24, ≤1.6 cm), Q2 (n = 26, 1.7-1.9 cm), Q3 (n = 24, 2.0-2.3 cm), and Q4 (n = 19, >2.3 cm). The results of ROC analysis showed that the area under the curve (AUC), sensitivity, and specificity of US-FNAC diagnosis were 0.894, 98.80%, and 80.00%, respectively. The AUCs of US-FNAC in groups Q1, Q2, Q3, and Q4 were 0.978, 1.000, 0.977, and 0.971. The AUCs of Q1 group, Q2 group, Q3 group and Q4 group were all > 0.9, and US-FNAC had high diagnostic efficiency for the pathological properties of thyroid nodules with different diameters.

Conclusion

US-FNAC has a high diagnostic efficiency for the pathological properties of thyroid nodules. Whether the nodule diameter has an effect on the accuracy of this method requires more clinical evidence.

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.

The Complex Cyto-Molecular Landscape of Thyroid Nodules in Pediatrics

Thyroid fine-needle aspiration (FNA) is a commonly used diagnostic cytological procedure in pediatric patients for the evaluation of thyroid nodules, triaging them for the detection of thyroid cancer. In recent years, greater attention has been paid to thyroid FNA in this setting, including the use of updated ultrasound score algorithms to improve accuracy and yield, especially considering the theoretically higher risk of malignancy of these lesions compared with the adult population, as well as to minimize patient discomfort. Moreover, molecular genetic testing for thyroid disease is an expanding field of research that could aid in distinguishing benign from cancerous nodules and assist in determining their clinical management. Finally, artificial intelligence tools can help in this task by performing a comprehensive analysis of all the obtained data. These advancements have led to greater reliance on FNA as a first-line diagnostic tool for pediatric thyroid disease. This review article provides an overview of these recent developments and their impact on the diagnosis and management of thyroid nodules in children.

Cytological evaluation of thyroid nodules in children and young adults: a multi-institutional experience

PURPOSE

The utility of the Bethesda system for reporting thyroid cytopathology is debatable in determining the risk of malignancy in pediatric patients. Moreover, the upper age limit for defining the pediatric group has varied across different studies. The aim of this study is to compare the risk of malignancy (ROM) and risk of neoplasia (RON) across different Bethesda categories between the pediatric, young adult, and adult patients.

METHODS

This is a retrospective multi-institutional study performed in three Indian hospitals. ROM was calculated and compared across Bethesda categories in adult (>18 years) and pediatric age groups (≤18 years), with a subgroup analysis in young adults (19-21 years).

RESULTS

Thyroid nodules from a total of 5958 patients were subjected to fine needle aspiration. Of these 199 were pediatric (3.3%) and follow-up histology was available in 2276. The ROM and RON rates, including overall ROM/RON, were significantly higher in pediatric age group as compared to adults. Overall ROM of suspicious for malignancy and malignant categories was higher in children as compared to adults. The overall surgical resection rates were also higher in pediatric patients (45.2% vs. 35.7%; p < 0.01). The similar trend of increased ROM, RON and resection rates was seen among young adults as compared to adult age group.

CONCLUSION

Thyroid nodules presenting in children are more likely to be malignant than those in adults. Importantly, the young adult group behaved in a similar manner with regard to surgical resection rates, ROM and RON to pediatric.

Differences in the management of thyroid nodules in children and adolescents as compared to adults

PURPOSE OF REVIEW

To describe recent advances in the diagnosis and management of thyroid nodules in both children and adults, highlighting differences between the two groups.

RECENT FINDINGS

Thyroid nodules are less common in children than adults but the risk of malignancy is higher. Screening recommendations for patients with certain genetic syndromes or specific risk factors for thyroid nodules and cancer continue to evolve ultrasound is the most appropriate imaging modality for evaluating thyroid nodules in all patients, but radiographic risk stratification systems validated in adults have not been extensively studied in children. Criteria for proceeding to fine needle aspiration (FNA) biopsy differ some between children and adults, with nodule size being less of a consideration in young patients. Molecular testing continues to improve the diagnostic capabilities of FNA for all age groups, but options for pediatric thyroid nodules are currently limited. In children, only oncogene panels are validated and their exact utility, along with miRNA classifiers, is an evolving area of study. For adults, data support selection of a specific molecular test based on ultrasound characteristics and pretest probability of malignancy. Multiple series have shown that fusion mutations are more common in pediatric thyroid nodules, while point mutations are seen more often in adult thyroid nodules. Molecular data help guide management recommendations regarding the need for surgery when FNA is indeterminate, but clinical use is still being refined. Radiofrequency ablation is a nonoperative approach that has gained significant traction for the treatment of symptomatic benign nodules in adults, but data are currently extremely limited in children.

SUMMARY

There are difference in the diagnosis and treatment of thyroid nodules in adults and children, the nuances of which are important for clinical management.

Performance of the Bethesda System for Reporting Thyroid Cytology in Multi-Institutional Large Cohort of Pediatric Thyroid Nodules: A Detailed Analysis

Background: To evaluate the performance of TBSRTC through multi-institutional experience in the paediatric population and questioning the management recommendation of ATA Guidelines Task Force on Paediatric Thyroid Cancer; Methods: A retrospective search was conducted in 4 institutions to identify consecutive thyroid FNAC cases in paediatric population between 2000 and 2018. Following the 2nd TBSRTC, the risk of malignancy ratios (ROMs) was given in ranges and calculated by 2 different ways. Sensitivity, specificity, PPV, NPV and DA ratios were calculated using histologic diagnosis as the gold standard; Results: Among a total of 405 specimens, the distribution of cases for each category was, 44 (11%) for ND, 204 (50%) for B category, 40 (10%) for AUS/FLUS, 36 (9%) for FN/SFN, 24 (6%) for SFM and 57 (14%) for M categories. 153 cases have a histological diagnosis. The ratio of surgery was 23% in ND, 16% in the B, 45% for AUS/FLUS, 75% for SFN/FN and 92% for SFM and 75% in M categories; Conclusions: The data underlines the high ROM values in paediatric population which might be clinically meaningful. The high rate of malignancy of the cohort of operated patients (50%) also underlines the need of better preoperative indicators for stratification. Considering that more than half of the nodules in AUS/FLUS category were benign, direct surgery recommendation could be questionable as proposed in ATA 2015 guidelines.