Cytopathologic analysis of thyroid lesions in the pediatric population

Radiation Dose Does Not Affect the Predictive Value of Thyroid Biopsy for Diagnosing Papillary Thyroid Cancer in a Belarusian Cohort Exposed to Chernobyl Fallout

INTRODUCTION

The Chernobyl nuclear accident exposed residents of contaminated territories to substantial quantities of radioiodines and was followed by an increase in thyroid cancer, primarily papillary thyroid cancer (PTC), among exposed children and adolescents. Although thyroid biopsy is an essential component of screening programs following accidental exposure to radioiodines, it is unknown whether the predictive value of biopsy is affected by different levels of environmental exposure.

METHODS

A cohort of 11,732 Belarusians aged ≤18 years at the time of the Chernobyl accident with individual thyroid radiation dose estimates was screened at least once 11-22 years later. Paired cytologic conclusions and histopathologic diagnoses were possible for 258 thyroid nodules from 238 cohort members. Cytologic conclusions were divided into five reporting categories, with all follicular lesion aspirates combined into a single indeterminate category. Standard performance indicators, risk of malignancy (ROM), and odds ratios for a correct cytologic conclusion were calculated, both overall and according to quintile of thyroid radiation dose.

RESULTS

The arithmetic mean thyroid dose estimate for the study group was 1.73 Gy (range: 0.00-23.64 Gy). The final histopathologic diagnosis was cancer for 136 of 258 biopsies (52.7%; 135 papillary and 1 follicular). The overall ROM was 96.7% for cytologies definite for PTC, 83.7% for suspicious for PTC, 33.0% for indeterminate, 8.1% for benign, and 31.0% for non-diagnostic. The ROM showed little change according to level of radiation exposure. Overall, there was no association between thyroid radiation dose and the odds ratio for a correct cytologic conclusion (p = 0.24). When analyzed according to dose quintile, the odds ratio for a correct conclusion increased two-fold at 0.10-0.29 Gy compared to a dose of 0.00-0.09 Gy and decreased at doses of 0.3-24 Gy (p value for linear trend = 0.99).

CONCLUSIONS

At radiation doses received by a cohort of young Belarusians exposed to radioiodines by the Chernobyl accident, the predictive value of thyroid biopsy for diagnosing PTC was not significantly affected by level of radiation exposure.

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.

Thyroid FNAC: Causes of false-positive results

In this paper, we aim to focus on false positive results in the evaluation of thyroid aspirations, covering cystic, inflammatory, follicular and oncocytic lesions, papillary carcinoma, and medullary carcinoma of thyroid. The recently described entity noninvasive follicular thyroid neoplasm with papillary-like nuclear features is also discussed detailing the impact of its introduction on the sensitivity and specificity of thyroid FNA, as well as the use of molecular tests for diagnostics. Medicolegal issues in relation to current practice in English law are also described.

Efficacy and Pitfalls of FNAC of Thyroid Lesions in Children and Adolescents

BACKGROUND AND OBJECTIVES

Fine-needle aspiration has proven safe and efficacious in the evaluation of nodular diseases in the adults. It has been used extensively to select patients for surgical exploration with a high degree of reliability. The purpose of this study was to assess the extent of its applicability in thyroid lesions in children and adolescents, as well as to determine distribution of thyroid lesions in pediatric and adolescent patients in whom the prevalence of thyroid nodules and probability of malignancy are different.

METHODOLOGY

This is a four-year study undertaken between January 2009 and December 2012, during which, 284 fine-needle aspiration cytology were performed for palpable thyroid lesions in children and adolescents and analysed. Out of these 11, 52, 82 and 116 aspirates belonged to the age group between 7-<12 years, 12 -<16 years, 16 -<19 years, 19-21 years respectively. There were 261 (91.9%) satisfactory aspirates and 23 unsatisfactory aspirates (8.1%). These 261 satisfactory aspirates with adequate cellular material were taken up for interpretation and analysed. Thirty one patients underwent thyroidectomy. There were 4 true positives, 24 true negatives, 2 false positives and one false negative case in this study. Sensitivity, Specificity, Accuracy, Positive predictive value and Negative predictive value were calculated.

RESULTS

Benign cytology was reported in 89 cases (34.2%) where 11 cases (4.2%) were males. Thyroiditis was observed in 154 cases (59%) and 8 cases (3.1%) were males. Suspicious cytology was reported in 12 cases and comprised of 2 cases with a suspicion of Papillary Carcinoma and 10 cases (3.8%), with a suspicion of a Follicular lesion. Papillary Carcinoma was detected on 6 cases where all were females. The Sensitivity was 96%, Specificity was 66% and the Accuracy was 90%, Positive predictive value was 66%, Negative predictive value was 96%.

CONCLUSION

Fine-needle aspiration cytology of palpable thyroid lesions in children and adolescents is a good screening test because of its high sensitivity. Majority of the nodules in this age-group are benign and fine-needle aspiration cytology helps prevent unnecessary surgery.

Indeterminate pediatric thyroid fine needle aspirations: a study of 68 cases

OBJECTIVE

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) provides a reporting scheme for thyroid fine needle aspiration (FNA) and includes three indeterminate categories with different management strategies. This study analyzes indeterminate thyroid FNAs in children, and correlates these findings with the histological features.

METHODS

A total of 179 thyroid FNA specimens were retrieved from children. Cases were categorized by TBSRTC. Only cases diagnosed as atypia (AUS)/follicular lesion of undetermined significance (FLUS), suspicious for follicular or oncocytic neoplasm (SFON), or suspicious for malignancy (SM) were selected and correlated with the nodule size and histological follow-up.

RESULTS

Sixty-eight cases were identified, including 43 (63%) AUS/FLUS diagnoses, 19 (28%) SFON, and 6 (9%) SM. On follow-up, 48% were malignant, including 28% AUS/FLUS cases, 58% SFON, and 100% SM. The average size of the malignant lesions diagnosed preoperatively as AUS/FLUS was 1.5 cm (range 0.7-4.5), compared to 3.3 cm (range 1.2-6.6) in SFON and 2.8 cm (range 0.7-3.8) in SM. Malignancies included 92% papillary thyroid carcinoma (PTC), 77% of which were the follicular variant of PTC (FVPTC) and 8% follicular carcinomas. The AUS/FLUS cases were largely due to compromised specimens (49%) and the highest malignancy rate occurred in those with cytological atypia (50%).

CONCLUSIONS

This study shows an incremental risk of malignancy within the indeterminate categories using TBSRTC in children. Malignant nodules with a preoperative AUS/FLUS diagnosis tended to be smaller than those with a SFON or SM diagnosis, and the vast majority of malignancies were PTC, with a high proportion being FVPTC.

Sensitivity of fine-needle biopsy in detecting pediatric differentiated thyroid carcinoma

BACKGROUND

Differentiated thyroid carcinomas (DTC) are uncommon in children. Since the frequency of malignancy is assumed to be high in pediatric symptomatic thyroid nodules, carcinomas should be ruled out reliably. The objective of this study was to assess the sensitivity of fine-needle biopsy (FNB) in diagnosing children with DTC.

PROCEDURE

We retrospectively analyzed 15 years of data from the GPOH-MET registry, a database by the German Society for Pediatric Oncology and Hematology (GPOH) with a focus on malignant endocrine tumors (MET). We reviewed data on pediatric patients with DTC who had undergone FNB. FNB results were classified according to well-established guidelines.

RESULTS

During the study period, 206 children with a histological diagnosis of DTC were entered into the GPOH-MET database. Fifty of those patients aged 3.6-17.3 years (mean, 12.3 years) had undergone FNB preoperatively. Forty-one were diagnosed with papillary thyroid carcinoma (PTC), seven with follicular thyroid carcinoma (FTC), and two had DTC not otherwise specified. Of the first FNB performed on each patient, the cytological specimens were diagnosed as benign in 13 cases, malignant in 14, suspicious in 9, follicular neoplasms in 6, and unsatisfactory in 8. The sensitivity of FNB in detecting DTC was 69.0%.

CONCLUSIONS

Our results reflect the current practice of pediatric thyroid FNB in Germany. In order to improve its usefulness, FNB should always be performed by experienced physicians. Furthermore, a central review of all specimens is necessary to ascertain the validity of the cytological diagnosis and to introduce immunocytological and molecular methods.

Image cytometry of fine needle aspiration of thyroid epithelial lesions

Fine needle aspiration (FNA) biopsy has been documented as a reliable, cost-effective test, diagnosing different thyroid lesions. However, its sensitivity declines much in some settings. This study aimed to investigate the value of computerized morphometry and DNA ploidy in differential diagnosis of different thyroid epithelial follicular lesions diagnosed on FNA smears. In this study, 68 cases of thyroid FNA were cytologically examined, and classified according to their postthyroidectomy histopathologic diagnosis as follow: 10 cases of nodular goiter, 14 cases of adenomas, 10 cases of follicular carcinoma, 20 cases of papillary carcinoma, 10 cases of anaplastic carcinoma, and 4 cases of poorly differentiated carcinoma. Using Leica Qwin 500 image analysis system, nuclear area as a morphologic variable, and the DNA ploidy, DNA index, and proliferation indices were measured for each case. Sensitivity of FNA in the studied cases was optimum (100%) in papillary carcinomas and anaplastic carcinomas. However, the sensitivity declined sharply in discriminating nodular goiter and follicular adenoma from well-differentiated follicular carcinoma, thus, most of these cases were diagnosed as follicular lesions. A significant difference in mean values of nuclear area was found between benign and malignant lesions, with no statistical differences within the benign group. Aneuploidy was significantly associated with malignancy. Therefore, image analysis may become an important ancillary test in the initial evaluation of patients with thyroid epithelial lesions.

Circulating thyrotropin receptor messenger RNA for evaluation of thyroid nodules and surveillance of thyroid cancer in children

PURPOSE

The aim of this study was to determine the role of thyrotropin receptor messenger RNA as a novel blood test for evaluation of thyroid nodules and cancer in children.

METHODS

We reviewed thyroid disease management of patients younger than 18 years with thyrotropin receptor messenger RNA measurements identified from a prospective, institutional review board-approved registry during 2008 to 2010.

RESULTS

Thirty-nine thyrotropin receptor messenger RNA measurements were made in 21 female patients (12-17 years old; median, 16 years). Four patients with fine-needle aspiration only had benign thyroid cytology, and 3 of 4 had undetectable thyrotropin receptor messenger RNA. Seventeen patients underwent 22 thyroid operations. Preoperative thyrotropin receptor messenger RNA was measured in 9 patients: 3 of 4 with thyroid cancer had elevated levels and 3 of 5 with goiters undetectable. Postthyroidectomy surveillance (median, 16 months; range, 6-24) of 11 thyroid cancer patients (8 papillary, 3 follicular) showed that thyrotropin receptor messenger RNA was concordant with thyroglobulin in 14 (73%) of 19 measurements. In 3 (16%) of 19 measurements, thyrotropin receptor messenger RNA was the only blood test useful for disease assessment because of elevated antithyroglobulin antibodies. Overall, to predict thyroid cancer, thyrotropin receptor messenger RNA demonstrated 73% sensitivity, 82% specificity, 62% positive predictive value, 88% negative predictive value, and 79% accuracy.

CONCLUSION

Thyrotropin receptor messenger RNA provides complementary evaluation to thyroglobulin and fine-needle aspiration for pediatric thyroid nodule management.

Diagnostic utility of fine-needle aspiration cytology in pediatric differentiated thyroid cancer

BACKGROUND

Pediatric patients present with thyroid nodules less often than adults, but the rate of malignancy is much higher. This study was designed to determine the ability of fine-needle aspiration cytology (FNA) to diagnose accurately and facilitate management of thyroid neoplasms in pediatric patients.

METHODS

A retrospective study revealed 110 patients <19 years old who had undergone thyroid surgery and FNA biopsy at two academic institutions over the last 28 years. FNA sensitivity for diagnosing papillary thyroid cancer (PC) and follicular neoplasm (FN) was investigated.

RESULTS

Of 110 patients who presented for surgery, 27 had PC and 33 had a FN: 4 follicular carcinomas (FCs) and 29 follicular adenomas (FAs). Among the PCs patients, the FNA results were as follows: 1 (4%) nondiagnostic, 6 (22%) atypical, 2 (7%) benign, and 18 (67%) malignant lesions. The sensitivity of a malignant FNA was 90% for diagnosing a PC. Sensitivity of an atypical FNA was 75% for FCs and 69% for FAs, giving an overall FN sensitivity of 70%. Of the atypical FNA readings, 60% had confirmed histological atypical features, and 19% were malignant. In 95% of the malignant FNA reports, final histology confirmed PC, resulting in a positive predictive value of 95%.

CONCLUSIONS

FNA biopsy can reliably diagnose malignancy in pediatric thyroid patients and should be used as a standard technique to indicate surgical treatment. Atypical or suspicious FNA results do not predict cancer effectively, confirming the current accepted practice for adults that diagnostic excision is required to exclude malignancy in pediatric patients.

Thyroid fine needle aspiration biopsies in children: study of cytological-histological correlation and immunostaining with thyroid peroxidase monoclonal antibodies

Context. There is limited data comparing results of fine needle aspiration biopsies (FNABs) to histological diagnosis in children. Design. FNABs were performed in 707 children and cytological results were compared to histology in 165 cases. The usefulness of immunostaining with anti-TPO monoclonal antibodies (MoAb47) on FNAB samples was examined in 54 operated patients. Results. Among unsatisfactory, benign, suspicious, and malignant FNAB, the histological diagnoses were benign in 12/12 (100%), 69/70 (98.5%), 40/50 (80.0%), and 0/33 (0%), respectively. After surgery, malignancy was established in 44/165 (26.6%) cases. The sensitivity, specificity, and positive and negative predictive values were 95.4%, 55.8%, 61.7%, and 95% with standard FNAB; and 100%, 75%, 73.3, and 100% with MoAb47. Among suspicious FNAB, positive MoAb47 staining was a reliable marker for exclusion of malignancy. Conclusion. Benign and malignant FNAB accurately predict histological diagnosis. In suspicious FNAB, MoAb47 immunostaining may be a useful adjunct to standard cytology.

Pediatric thyroid fine-needle aspiration cytology: a meta-analysis

BACKGROUND

There is conflicting evidence in the current literature regarding the use of fine-needle aspiration (FNA) biopsy in the diagnosis of a thyroid nodule in the pediatric population. There are numerous studies that look at the sensitivity and specificity of this test with varying results. A meta-analysis will provide further insight into this topic.

PURPOSE

Our objective was to investigate the diagnostic parameters of FNA biopsy in the diagnosis of a thyroid nodule in the pediatric population, specifically, to determine the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the test in differentiating malignant vs benign tumors.

MATERIAL AND METHODS

We performed a literature search of Medline, Embase, and evidence based medicine (EBM) reviews for English studies that looked at FNA biopsy in thyroid nodules in the pediatric population, in which diagnostic values were present or could be calculated and where FNA results were compared to an acceptable reference standard. Two reviewers independently selected all abstracts, and from these, studies to review. Two reviewers also independently checked diagnostic values in the studies or calculated them from data available. A meta-analysis was performed, and pooled diagnostic test values were calculated using a random-effects, bivariate meta-regression model. Studies were also assessed for quality using the quality assessment for diagnostic accuracy studies tool.

RESULTS

Twelve studies were included for review. The quality of the studies in general was good. The pooled estimate of sensitivity and specificity were 94% (95% confidence interval [CI], 86%-100%) and 81% (95% CI, 72%-91%), respectively. Assuming 20% of nodules are malignant, the accuracy, PPV, and NPV were 83.6%, 55.3%, and 98.2%, respectively.

CONCLUSION

This meta-analysis provides good evidence that FNA biopsy of thyroid nodules is a sensitive test in the pediatric population and may be a useful tool for excluding malignancy in young patients. Future prospective studies are needed to evaluate this further.

Ultrasound-guided fine-needle aspiration in the management of thyroid nodules in children and adolescents

BACKGROUND

The reported incidence of thyroid nodules in children and adolescents is estimated to be between 1% and 2%. However, this incidence may be increasing because diagnostic radiological procedures are detecting incidental thyroid nodules in children. The objective of this study was to assess the diagnostic accuracy, sensitivity, and specificity of ultrasound-guided fine-needle aspiration (US-FNA) of thyroid nodules in children and adolescents.

METHODS

Forty-two children (mean age, 14.75 years) underwent US-FNA of 52 thyroid nodules. The specificity, sensitivity, diagnostic accuracy, and unsatisfactory rates were compared to other similar studies.

RESULTS

Six patients had a cytological diagnosis of papillary thyroid cancer, which was confirmed at surgery. There were no false-negative specimens, and cytological diagnostic accuracy was 93.7%. The inadequate rate was only 1.9%.

CONCLUSIONS

US-FNA of thyroid nodules in children and adolescents is highly accurate in experienced hands and is associated with a very low inadequate rate.

Palpable pediatric thyroid abnormalities - diagnostic pitfalls necessitate a high index of clinical suspicion: a case report

A 12-year-old girl presented with a 4 year history of an enlarged, firm thyroid gland. On exam, her thyroid was firm and fixed and an enlarged cervical lymph node was palpable as well. Though a thyroid ultrasound prior to referral was read as thyroiditis, clinical suspicion for thyroid carcinoma mandated continued investigation. The diagnosis of papillary thyroid cancer was established and her workup revealed lymph node metastases as well as a tremendous burden of pulmonary metastases. Pediatric thyroid cancer is extremely rare, but often presents with aggressive disease. Palpable thyroid abnormalities in an individual under 20-years-old should be viewed with suspicion and should be thoroughly investigated to rule out malignancy even in the face of negative diagnostic procedures. Though pediatric papillary thyroid cancer often presents with loco-regional and even distant metastatic disease, mortality rates in follow-up for as long as 20 years are very favorable.