Fine-needle aspiration biopsy in the diagnosis and follow-up of thyroid nodules in childhood

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.

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.

Paediatric differentiated thyroid carcinoma: a UK National Clinical Practice Consensus Guideline

This guideline is written as a reference document for clinicians presented with the challenge of managing paediatric patients with differentiated thyroid carcinoma up to the age of 19 years. Care of paediatric patients with differentiated thyroid carcinoma differs in key aspects from that of adults, and there have been several recent developments in the care pathways for this condition; this guideline has sought to identify and attend to these areas. It addresses the presentation, clinical assessment, diagnosis, management (both surgical and medical), genetic counselling, follow-up and prognosis of affected patients. The guideline development group formed of a multi-disciplinary panel of sub-speciality experts carried out a systematic primary literature review and Delphi Consensus exercise. The guideline was developed in accordance with The Appraisal of Guidelines Research and Evaluation Instrument II criteria, with input from stakeholders including charities and patient groups. Based on scientific evidence and expert opinion, 58 recommendations have been collected to produce a clear, pragmatic set of management guidelines. It is intended as an evidence base for future optimal management and to improve the quality of clinical care of paediatric patients with differentiated thyroid carcinoma.

Evaluation of Children and Adolescents with Thyroid Nodules: A Single Center Experience

OBJECTIVE

We aimed to evaluate the clinical, radiological and pathological findings of children and adolescents with thyroid nodules.

METHODS

Data of 121 children and adolescent with thyroid nodules and had fine needle aspiration (FNA) were examined retrospectively. Concomitant thyroid disease, ultrasonography (US) features of the nodule, FNA and histopathological results were recorded. FNA results were assessed according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC).

RESULTS

Median (range) age of the cases was 14 (3-18) years and 81% were female. FNA results of patients were: insufficient in 1 (0.8%); benign in 68 (56.2%); indeterminate in 44 (36.4%); and malignant in 8 (6.6%) patients. Among 39 patients who underwent surgery, 10 (25.6%) had differentiated thyroid cancer (DTC) and the overall malignancy rate was 10.0% (10/100). Follow-up FNA results showed progress based on TBSRTC in 18.7% of benign results and 4/75 patients had DTC on surgical excision. Two of 22 patients with atypia of undetermined significance (AUS) who continued follow-up was diagnosed with DTC. Male gender, presence of Hashimoto thyroiditis and US findings of uninodularity, hypoechogenicity, increased blood flow, irregular margins, solid structure, microcalcification and presence of abnormal cervical lymph nodes were associated with malignancy.

CONCLUSION

In this study 10% of thyroid nodules were malignant in children and adolescents. Patients with AUS have a 9% potential for malignancy. Patients with initially benign FNA result may have changes on repeat FNA when assessed with TBSTRC indicating a 5.3% false negative rate.

The Use of the Bethesda System for Reporting Thyroid Cytopathology in Pediatric Thyroid Nodules: A Meta-Analysis

Background: Little is known about the application of the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) in pediatric thyroid nodules. This meta-analysis was aimed to investigate the use of TBSRTC in the pediatric population. Methods: Relevant articles were searched in PubMed and Web of Science. Meta-analysis of proportion and its 95% confidence interval (CI) were computed utilizing the random-effect model. We used subgroup analyses and meta-regression to explore the sources of heterogeneities. Egger's regression test and funnel plot visualization were used to examine publication bias. Results: We included 17 articles comprising of 3687 pediatric thyroid nodules for meta-analyses. TBSRTC outputs including frequency and risk of malignancy (ROM) for the majority of categories were not statistically different from recently published meta-analysis of 145,066 thyroid nodules in adult patients. The resection rate (RR) in the pediatric group was significantly higher in most of the categories compared with published adult data: benign, 23.2% [CI = 18.6-27.9] vs. 13.0% [CI = 9.5-16.5]; atypia of undetermined significance/follicular lesion of undetermined significance, 62.6% [CI = 50.3-74.9] vs. 36.2% [CI = 29.9-42.5]; follicular neoplasm/suspicious for follicular neoplasm, 84.3% [CI = 75.2-93.4] vs. 60.5% [CI = 54.5-66.5]; and suspicious for malignancy, 93.8% [CI = 90.1-97.6] vs. 69.7% [CI = 64.0-75.5]. Conclusion: TBSRTC is a valuable tool to make clinical decisions for pediatric patients with thyroid nodules. Pediatric patients with benign and indeterminate thyroid nodules had a higher RR than adult counterpart, but ROM of these categories in adults and children was not statistically different suggesting a potential risk of overtreatment in pediatric patients. Determining the best treatment guidelines and additional tools for risk stratification must be a top priority to precisely identify the target patient groups for surgical intervention.

Improving our departmental reporting of thyroid cytology specimens against national guidelines: A two-cycle retrospective audit

INTRODUCTION

In the UK, guidelines from the Royal College of Pathologists (RCPath) facilitate consistent and reproducible reporting and classification of fine needle aspiration cytology (FNAC) thyroid specimens. The aim was to audit our department against RCPath guidelines to refine and improve our reporting process.

METHODS

Two-cycle retrospective observational audit of all patients undergoing thyroid FNAC over a 2-year period (1 year for each cycle). Final histology was correlated. The positive predictive value (PPV) for malignant neoplastic lesions was calculated; for Thy1, Thy1c, Thy2 and Thy2c all cases without final histology were assumed to be benign, while for Thy3a, Thy3f, Thy4 and Thy5 samples the PPV calculation was based only on those cytology samples with corresponding histology. False positive and false negative cases were reviewed.

RESULTS

In total, 288 cytology samples were included in the first cycle; 96 (33.3%) had corresponding histology. There were 287 samples included in the second cycle; 119 (41.5%) had follow-up histology. The rate of non-diagnostic samples (Thy1/1c) decreased from 39.6% to 30.0%. The PPV for malignant neoplastic lesions was Thy1/1c 2.6%, Thy2/2c 0.0%, Thy3a 40.0%, Thy3f 19.4%, Thy4 75.0%, Thy5 100.0% (first cycle); Thy1/1c 4.7%, Thy2/2c 0.7%, Thy3a 13.3%, Thy3f, 7.7%, Thy4, 50.0%, Thy5 100.0% (second cycle).

CONCLUSIONS

Our department was able to reduce the rate of non-diagnostic FNAC samples and improve the diagnostic accuracy of FNAC. Auditing local outcomes helps refine and improve the reporting process. Review of false positive and false negative cases helps examine potential pitfalls of cytology.

THE ROLE OF THYROID FINE-NEEDLE ASPIRATION CYTOLOGY IN THE TREATMENT AND FOLLOW-UP OF THYROID NODULES IN THE PEDIATRIC POPULATION

Objective

Thyroid fine-needle aspiration (FNA) and cytology is a reliable diagnostic method used in the assessment of malignancy when evaluating thyroid nodules, in conjunction with clinical and ultrasonographic findings. The aim of this study is to compare clinical, ultrasonographic, cytological and histopathological findings in children who underwent thyroid FNA.

Methods

Subjects comprised 80 patients (52 female) aged 13.7±2.8 years at the time of FNA who where evaluated for thyroid nodules. Clinical, ultrasonographic and cytological findings of patients were evaluated retrospectively.

Results

Autoimmune thyroiditis was present in 30% and history of radiotherapy to the head or neck in 10%. The cytological diagnosis of patients included: inadequate or hemorrhagic sample in 10%; benign in 42.5%; atypia or follicular lesion of undetermined significance (AUS/FLUS) in 15%; suspicion of follicular neoplasia (SFN) in 7.5%; suspicion of malignancy (SM) in 8.8%; and malignant in 16.3%. Thirty-seven patients underwent thyroidectomy. Malignancy rates for histopathologic follow-up were 75%, 85.7% and 100% for SFN, SM and malignant categories, respectively. Only one benign and two AUS/FLUS FNAs were found to be malignant on histopathological examination. Among patients who had received radioiodinetherapy, 87.5% had malignancy. In this study, the sensitivity of FNA was 96%, specificity 50%, positive predictive value 90.9%, negative predictive value 75%, and diagnostic value of FNA was 89.2%.

Conclusion

Thyroid FNA results were highly compatible with histopathological examination. Sensitivity, positive predictive value and diagnostic value of FNA were high.

Management of Childhood Thyroid Nodules: Surgical and Endocrinological Findings in a Large Group of Cases

OBJECTIVE

The management of childhood thyroid nodules is still a big challenge for clinicians. In this study, we aimed to present our surgical and endocrinological experience in more than one hundred pediatric cases.

METHODS

A retrospective analysis of patients admitted with a thyroid nodule between 2006 and 2014 was performed. Detailed ultrasonography and fine-needle aspiration biopsy (FNAB) were the cornerstones of the diagnostic approach.

RESULTS

One hundred-three children (72 female, 31 male) with a mean age of 13.1±3.6 years (3-18 years) were admitted to our center. Management strategy was surgery in 58 patients and follow-up in 45 patients. Mean nodule size was 17±12.7 mm (2-45 mm). The diagnoses were listed as benign solitary nodule (48 patients), thyroid carcinoma (26 patients), multinodular goiter (23 patients), Hashimoto thyroiditis (4 patients), and Graves' disease (2 patients). Surgical procedures were nodulectomy/lobectomy (32 patients), total thyroidectomy (TT) (13 patients), or TT+ neck dissection (13 patients). The rate of malignancy was 25% in the total group and 44% in the surgery group. The malignancy rate was higher in patients younger than 12 years compared to older children (41% vs. 17%, p=0.040). Metastasis was seen in 38% of the malignant nodules. Postoperative complications were transient hypocalcemia (8%), permanent hypocalcemia (1.7%), and unilateral vocal cord paralysis (1.7%). Recurrence or mortality was not encountered in the 5.4±1.2-year follow-up period.

CONCLUSION

Thyroid nodule in a child requires an aggressive diagnostic approach due to increased risk of malignancy and metastasis. Intraoperative frozen section examination must be done as a useful adjunct to determine the surgical strategy. Incidence of complications is small in thyroid surgery when performed by experienced surgeons.

Diagnostic accuracy of fine needle aspiration biopsy for detection of malignancy in pediatric thyroid nodules: protocol for a systematic review and meta-analysis

BACKGROUND

Fine needle aspiration biopsy (FNAB) is an accurate test commonly used to determine whether thyroid nodules are malignant in adults. However, less is known about its diagnostic accuracy for this purpose in children, where conduct of FNAB is less frequent, more technically challenging, and pre-test probabilities of malignancy are often higher. The purpose of this systematic review is to evaluate the diagnostic accuracy of FNAB for the detection of malignancy in pediatric thyroid nodules.

METHODS

We will search electronic bibliographic databases (MEDLINE, EMBASE, the Cochrane Library, and Evidence-Based Medicine) from their date of inception, reference lists of included articles, proceedings from relevant conferences, and the table of contents of the Journal of Pediatric Surgery (January 2007-present). Two reviewers will independently screen titles and abstracts and identify diagnostic accuracy studies involving FNAB of the thyroid in children. We will include studies comparing FNAB to a reference standard of surgical histopathology or clinical follow-up for detection of malignancy in pediatric thyroid nodules. Two investigators will independently extract data and assess risk of bias using the Quality of Diagnostic Accuracy Studies-II tool. Pooled estimates of sensitivity, specificity, and positive and negative likelihood ratios will be calculated using bivariate random-effects and hierarchical summary receiver operating characteristic models. In the presence of between-study heterogeneity, we will conduct stratified meta-analyses and meta-regression to determine whether diagnostic accuracy estimates vary by country of origin, use of ultrasound guidance during FNAB, qualifications of the individuals performing/interpreting FNAB, adherence to the Bethesda criteria for cytology classification, length of clinical follow-up, timing of data collection, patient selection methods, and presence of verification bias.

DISCUSSION

This meta-analysis will determine the diagnostic accuracy of FNAB for detection of malignancy in pediatric thyroid nodules and explore whether heterogeneity observed across studies may be explained by variations in patient population, FNAB technique or interpretation, and/or study-level risks of bias. This will be the first study to determine the accuracy of Bethesda cytological classification levels of FNAB (benign, atypical, follicular, suspicious, malignant). We expect that our results will help in guiding clinical decision-making in children with thyroid nodules.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO No. CRD42014007140.

The Bethesda System for Reporting Thyroid Cytopathology is applicable to frozen section diagnosis in children

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) offers standardized and widely understood diagnostic categories for reporting thyroid cytology diagnoses. We compared the utility of TBSRTC categories in pediatric cytology diagnoses and pediatric intraoperative frozen section diagnoses. We examined the experience of our primary and referral care center over a 20-year period. This included 182 thyroidectomy patients who underwent 64 preoperative fine-needle aspirations and 91 intraoperative frozen section evaluations, including 38 patients evaluated sequentially by each method. All diagnoses were retrospectively reclassified into TBSRTC categories and correlated with the final thyroidectomy diagnoses. For each sampling method, malignant final diagnoses were observed at similar frequencies to rates predicted by TBSRTC. Malignant final diagnoses following fine-needle aspiration or frozen section diagnoses in TBSRTC categories other than malignant or suspicious for malignancy most often resulted from difficulty in detecting papillary carcinoma, including difficulty detecting the nuclear characteristics of papillary carcinoma in frozen sections. The limitations of needle biopsy and frozen section evaluations differ, yet serial utilization of these procedures was rarely informative. Based on the experience of our institution, classification of cytology and frozen section diagnosis by TBSRTC predicts a risk of malignancy similar to the guidance offered by TBSRTC. We recommend including a TBSRTC category when reporting either thyroid cytology or frozen section diagnoses in children.

Irreversible Horner's syndrome diagnosed by aproclonidine test due to benign thyroid nodule

We are reporting an irreversible Horner Syndrome (HS) in a patient with benign thyroid gland nodule in which thyroidectomy was performed for treatment. A 37-year-old female was admitted to our clinic with a swelling in the left lobe of the thyroid gland and ptosis at the left eyelid. The clinical diagnosis of HS was confirmed pharmacologically by aproclonidine. Histopathologic examination of thyroidectomy specimen was reported as benign nodule. To the best of our knowledge, this is a very rare report in terms of thyroid benign nodule associated with irreversible HS due to cervical sympathetic chain compression.

Thyroid nodules in pediatrics: which ones can be left alone, which ones must be investigated, when and how

Thyroid nodules are less frequent in childhood than in adulthood, but are more often malignant. Recent estimates suggest that up to 25% of thyroid nodules in children are malignant, therefore, a more aggressive approach is recommended. In this review, we suggest an approach based on a first-step clinical, laboratory, and sonographic evaluation. A history of irradiation of the neck, cranium or upper thorax, previous thyroid diseases or thyroid neoplasms in the family should alert clinicians as being associated with a greater likelihood of malignant nodules. Signs or symptoms of hyperthyroidism and dysmorphic features should be carefully considered during the physical examination. Palpable firm lymph nodes, found in some 70% of cases, are the most significant clinical finding in children with malignant nodules. Although the routine determination of calcitonin levels is not uniformly practiced, it can help recognize sporadic or familial medullary thyroid neoplasms. Blood thyroid stimulating hormone, free thyroxine, and free triiodothyronine determinations (the latter in case of symptoms of hyperthyroidism) are aimed at identifying the few hyperthyroid patients, for whom the next step should be scintiscan. Hyperthyroid patients usually disclose an increased uptake, and a diagnosis of toxic adenoma is commonly made. Cases with normal thyroid function or hypothyroidism (which is usually subclinical) should be evaluated by fine-needle aspiration biopsy (FNAB). In eu/hypo-thyroid patients, scintiscan provides poor diagnostic information and should not be routinely employed. Thyroid ultrasonography is used to select cases for FNAB. Although ultrasound cannot reliably discriminate between benign and malignant lesions, it does provide an index of suspicion. Sonographic features that increase the likelihood of malignancy are microcalcifications, lymph node alterations, nodule growth under levothyroxine treatment, and increased intranodular vascularization demonstrated by color Doppler. There is growing evidence that elastography may provide further information on nodule characteristics. FNAB is indicated in all cases with a likelihood of malignancy. FNAB has a diagnostic accuracy of approximately 90% and is used in selection of patients which require surgery. Recently, histological markers and elastography have been introduced to increase the specificity of FNAB and ultrasound, respectively. The pitfall in FNAB cytology is the follicular cytology, in which it is not possible to distinguish between adenoma and carcinoma and therefore thyroidectomy is advised.

Evolution of pediatric thyroid surgery at a tertiary medical center

BACKGROUND

Thyroidectomy in the pediatric population is often avoided due to perceived risks in children. With growing subspecialization and establishment of high volume endocrine surgery centers, the indications for thyroid surgery and extent of resection continue to change. We examined the evolution of pediatric thyroid surgery at a high volume tertiary medical center.

METHODS

From our prospectively collected database, we reviewed medical records of individuals younger than 19 y who underwent thyroidectomy at our institution from 1994 to 2009. Patients were divided into two groups: (1) before establishment of our endocrine surgery center (1994-2001) and (2) since establishment of the center (2002-2009).

RESULTS

We identified 78 operations performed on 74 patients with a median age of 15 (range 3-18) y. We found that the number of patients doubled in the later time period, with 26 operations in group 1 and 52 in group 2. The age of patients and percentage of females were similar between groups. After establishment of the endocrine surgery center, there was a significant increase in total thyroidectomies for all indications, including significantly more for benign disease. Overall, 9% of the patient population experienced transient complications, with no permanent complications or long-term sequelae.

CONCLUSIONS

Pediatric thyroid surgery is extremely safe, especially when performed at a high volume endocrine surgery center. We more often select surgical treatment for benign disease and choose total thyroidectomy over limited resection. This may reflect increasing confidence in the safety and efficacy of surgery and reliability of thyroid hormone replacement.

Cytomorphological and molecular genetic findings in pediatric thyroid fine-needle aspiration

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology is largely based on data from adult studies. Although thyroid nodules in children are rare, the rate of malignancy is high. The authors' aim was to analyze the cytomorphology and mutational profiles in pediatric thyroid fine-needle aspirations (FNAs).

METHODS

Thyroid FNAs from patients 21 years old or younger were identified from the authors' pathology archive, categorized using the Bethesda System for Reporting Thyroid Cytopathology, and correlated with histological and molecular follow-up.

RESULTS

A total of 179 samples from 142 patients were identified, including 96 cases (54%) with histological follow-up and 66 cases (37%) with molecular data. The diagnoses included 21 (12%) unsatisfactory, 82 (46%) negative, 43 (24%) atypia or follicular lesion of undetermined significance, 19 (11%) suspicious for follicular neoplasm, 6 (3%) suspicious for malignancy, and 8 (4%) positive for malignancy. The rate of malignancy in each category was 0%, 7%, 28%, 58%, 100%, and 100%, respectively. Of the 66 FNAs with molecular data, there were 11 (17%) positive for mutations. All mutation-positive FNAs were papillary thyroid carcinomas (PTCs) on resection. The overall sensitivity and specificity in this population were 80% and 100%, respectively.

CONCLUSIONS

This study demonstrates that thyroid FNA in children is a sensitive and highly specific tool. There was a 17% positivity rate for a genetic mutation, which correlated with malignancy in all cases. In comparison to adults, there was a higher prevalence of RET/PTC mutations and lower prevalence of BRAF mutations, which may in part explain the less aggressive nature of PTCs reported in children.