Nondiagnostic fine-needle aspirations of the thyroid: is the risk of malignancy higher?

The Evaluation of Malignancy Rates of Nondiagnostic Cases in Thyroid Fine-Needle Aspirations

Aim: In this study, it was aimed to investigate the malignancy rates of nondiagnostic (ND) thyroid fine-needle aspiration cytology (FNAC) material by evaluating either the result of the second FNAC or resection/biopsy materials.Method: Among the 1165 thyroid FNAC cases evaluated in the Pathology Department of Başakşehir Çam and Sakura City Hospital within 9 months (October 2020-June 2021), 102 cases (8,7%) diagnosed with ND were included in the study. At the end of the 6-15 months follow-up period after the diagnosis of ND, the results of the second FNAC or resection (thyroidectomy, lobectomy)/biopsy of the cases were evaluated. Diameter and sonographic features of thyroid nodules (solid, cystic, mixed) were also noted.Results: 49% of the cases (n:50) had a second FNAC. Resection/biopsy was performed in only 12 (11,8%) cases. Of these 62 cases, 39 were diagnosed by second FNAC and 7 by resection/biopsy as benign (74,1%), and 5 cases were diagnosed as malignant by resection/biopsy. 7 cases were diagnosed as nondiagnostic again after the second FNAC. Final diagnosis (by resection) of the case whose second FNAC result was reported as suspicious for malignancy was papillary microcarcinoma. This case was included in the group ‘diagnosed as malignant only by resection/biopsy. In other words, malignancy was detected in 5 of 62 patients who underwent a second FNAC or resection/biopsy. The risk of malignancy was found to be 8% in the patient population included in the study with the diagnosis of ND.Conclusion: A low rate of NE results were found in this ultrasound-guided thyroid series (8,7%). After the second FNAC or resection, malignancy rates was found to be 8%. Although this result is compatible with the results of some studies, it is considerably lower than others. It would be appropriate to follow up on ND nodules with their clinical/sonographic features. Additional studies with large series will be more helpful in determining the malignancy rates of the ND group.

Ultrasound-based computer-aided diagnosis for cytologically indeterminate thyroid nodules with different radiologists

PURPOSE

To evaluate a computer-aided diagnosis (CAD) technique in predicting malignancy for cytologically indeterminate thyroid nodules (TNs) as compared with different experienced radiologists.

METHOD

436 patients with 436 cytologically indeterminate TNs on fine-needle aspiration cytology (FNAC) were included and all were confirmed by surgical pathology. They were retrospectively analyzed with respect to ultrasound (US) characteristics using a commercially available CAD system (AmCAD-UT; AmCad BioMed, Taiwan, China) and reviewed by one junior and one senior radiologists.The CAD system and different experienced radiologists stratified the risk of malignancy using ACR TI-RADS category. The diagnostic performance by different experienced radiologists independently and after consulting the CAD (different experienced radiologists + CAD) and by the CAD alone were compared.

RESULTS

The different experienced radiologists showed significantly higher specificities than the CAD system alone. The combination of radiologist and CAD system showed improved diagnostic performance with an AUC (Area under the curve) of 0.740 in the senior radiologist and 0.677 in the junior radiologist, as compared with CAD (AUC: 0.585) alone (all P < 0.05). The combination of senior radiologist and CAD system had the highest diagnostic performance (AUC: 0.740) and specificity (68.9%) compared to the others (all P < 0.05).

CONCLUSION

The CAD system may play the potential role as a decision-making assistant alongside radiologists for differential diagnosis of TNs with indeterminate cytology.

The Italian Consensus for the Classification and Reporting of Thyroid Cytology: Cytohistologic and molecular correlations on 37,371 nodules from a single institution

BACKGROUND

The Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC) includes six diagnostic categories (TIR 1/1C, TIR 2, TIR 3A, TIR 3B, TIR 4, and TIR 5), each indicating a different risk of malignancy. The objective of this monocentric retrospective study was to evaluate the distribution of the ICCRTC classes at the authors' institution and assess their cytohistologic correlations.

METHODS

The authors retrospectively collected 37,371 consecutive cytologic reports of thyroid nodules and described the clinical-pathologic features of the different cytologic categories. The cytologic diagnoses also were compared with histologic outcomes in a subset of patients.

RESULTS

The cytologic classes were distributed as follows: nondiagnostic, 15.6%; benign, 66.5%; low-risk indeterminate, 10% (TIR 3A); high-risk indeterminate, 3.5% (TIR 3B); suspicious, 1.7%; and malignant, 2.6%. According to histology, the risk of malignancy was very high in the nondiagnostic category (29.8%), with young male patients more exposed to malignancy, and it was relatively high among benign (7.8%) and indeterminate nodules (32.5% in TIR 3A; 52.1% in TIR 3B), mainly because of the high prevalence of follicular architecture in malignant tumors. On histology, the malignancy rates were 92.4% and 99.3% for the suspicious and malignant categories, respectively; aggressive variants of papillary thyroid carcinoma were mostly diagnosed in these categories.

CONCLUSIONS

In this series, nondiagnostic nodules showed high prevalence and, surprisingly, high malignancy rates. Malignant tumors with follicular architecture represented a diagnostic pitfall in benign and indeterminate nodules. The suspicious and malignant categories had high specificity for malignancy. Importantly, the ICCRTC had high reliability for identifying preoperatively aggressive histotypes of thyroid carcinoma.

Standardization of thyroid fine needle aspiration procedure and outcomes within an endocrine surgery department

Background

Fine needle aspiration (FNA) biopsy is an essential procedure for thyroid nodules. Although, the efficacy of surgeon-performed thyroid FNA biopsies has been demonstrated in the literature, there are insufficient data regarding how to establish an efficient program with a low insufficiency rate within a group practice.

Methods

An endocrine surgery thyroid FNA biopsy program was established in 2000 by one surgeon, with training of additional partners during fellowship and upon recruitment. The results within 18 years were analyzed. The FNA biopsies were performed by endocrine surgeons under ultrasound guidance without on-site pathologist review.

Results

A total of 5,469 FNA biopsies were performed by 7 surgeons. The total number of FNA biopsies performed by each surgeon varied between 291-1,378. FNA biopsies were performed in 2 passes using 22-gauge needles under constant suction. The overall insufficiency rate was 4.3%, with individual surgeon rates ranging between 2.7% and 7.2%. The insufficiency rate for the whole team ranged between 3.3% and 5% when examined in 5-year blocks.

Conclusions

This study shows that an establishment of a highly efficient thyroid FNA biopsy program within a group practice is possible with a structured endocrine surgical training and adoption of a standard technique.

Nondiagnostic Fine-Needle Aspiration Biopsy of Thyroid Nodules: Outcomes and Determinants

Background: Nondiagnostic results are common following fine-needle aspiration biopsy (FNAB) of thyroid nodules, but recommendations for the management of these patients vary. We sought to determine the outcomes and predictors of nondiagnostic FNABs in a single-center cohort of patients undergoing thyroid nodule evaluation. Methodology: We identified all first time ultrasound-guided FNABs performed between May 2007 and June 2013 at the Beth Israel Deaconess Medical Center Thyroid Nodule Clinic and examined demographic data, follow-up ultrasounds, repeated FNABs, and histopathologic findings. We examined the likelihood of diagnostic findings and of cancer with increasing numbers of nondiagnostic evaluations with their exact binomial confidence intervals [CIs] and potential predictors of nondiagnostic status using generalized estimating equations. Results: During the six-year period, 2234 unique individuals underwent ultrasound-guided FNAB of a thyroid nodule. The probability of obtaining a diagnostic biopsy declined from 84.4% [95% CI 82.8-85.8%] for initial FNABs to 57.6% [CI 50.8-64.2%] for the first re-FNAB and further to 42.4% [CI 25.5-60.8%] for second re-FNABs. Adjusted risk of nondiagnostic FNAB strongly increased with increasing numbers of previous biopsies and was also higher among whites. The overall rate of diagnosis of malignancy after a nondiagnostic FNAB was 8.1% [CI 4.2-13.7%] and was similar regardless of the number of previous nondiagnostic aspirations. Conclusion: Following an initial nondiagnostic FNAB, the probability of yielding a diagnostic result declines with each sequential repeat FNAB. Nonetheless, a tangible possibility of malignancy remains even after repeated nondiagnostic FNABs.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

Metabolomics as a potential method for predicting thyroid malignancy in children and adolescents

PURPOSE

To identify potential metabolic biomarkers for distinguishing malignant and benign thyroid nodules in children and adolescents using a metabolomics approach.

METHODS

A total of 96 consecutive patients (median age 14.29 ± 2.31 years, range 9-18 years) who underwent thyroidectomy and 40 healthy controls were enrolled. Patients were assigned to the papillary thyroid carcinoma and benign thyroid adenoma groups according to postoperative pathologic biopsy. Plasma samples were preoperatively collected, and multivariate analysis was performed to identify differential metabolites.

RESULTS

Papillary thyroid carcinoma could be distinguished not only from healthy serum but also from benign thyroid adenoma according to the metabolic profiles. A total of 17 metabolites were identified. Compared with those from benign thyroid adenoma patients and healthy controls, the metabolites from papillary thyroid carcinoma patients, including leucine, lactate, alanine, glycine, acetate, lysine and choline, were increased, while glucose was decreased.

CONCLUSION

The metabolomics method based on proton nuclear magnetic resonance has great potential for identifying papillary thyroid carcinoma in children and adolescents. Lactate and glycine may be used as potential serum markers for the diagnosis of papillary thyroid carcinoma.

Evaluation of malignancy with thyroid imaging reporting and data system (TI-RADS) in thyroid nodules with persistent nondiagnostic cytology

Background/aim

We aimed to evaluate the utility of thyroid imaging reporting and data system (TI-RADS) in prediction of malignancy in thyroid nodules with persistent nondiagnostic (ND) cytology.

Materials and methods

A total of 246 thyroid nodules which were surgically removed and had at least two fine-needle aspirations (FNAs) with ND cytology were included in this study. Ultrasonography features and TI-RADS scores were recorded.

Results

Of 246 nodules, 218 (88.6%) had benign and 28 (11.4%) had malignant final histopathology. Frequencies of taller than wide shape, solidity, hypoechogenicity, microcalcifications, and presence of irregular borders were similar between benign and malignant nodules (P > 0.05). The number of nodules categorized as TI-RADS 3, 4a, 4b, and 4c were 12 (4.9%), 53 (21.5%), 104 (42.3%), and 77 (31.3%), respectively. There was not any nodule in TI-RADS 5 category. Malignancy rates of categories 3, 4a, 4b, and 4c were 0%, 13.2%, 9.6%, 14.3%, respectively. No significant differences were detected in TI-RADS categories between benign and malignant nodules (P > 0.05).

Conclusion

In this study, we did not demonstrate any suspicious ultrasound (US) finding predictive for malignancy in thyroid nodules with persistent ND cytology and did not determine any difference between malignant and benign nodules regarding TI-RADS scores. Whereas, we found that thyroid nodules in 4a, 4b, and 4c TI-RADS categories had higher malignancy rates than those previously reported in ND cytology. We think that TI-RADS categories in thyroid nodules with persistent ND cytology can be helpful in treatment decision.

Incidence and malignancy rates classified by The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) - An 8-year tertiary center experience in Thailand

Incidence and Malignancy Rates Classified by The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) – An 8-year Tertiary Center experience in Thailand.

Background

Fine-needle aspiration (FNA) of the thyroid is considered the best diagnostic tool for preoperative evaluation of thyroid nodules. The introduction of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) in 2010 provided the opportunity to establish worldwide standard for reporting and terminology guidelines for diagnostic categories. It is recommended that every institution evaluates the risk of malignancy (ROM) in each category for quality improvement process.

Aim

To assess the effectiveness of TBSRTC method at our institution using cyto-histological correlation.

Method

A retrospective 8-year (2010–2017) audit of thyroid FNA done by thyroid specialists at Theptarin hospital. The FNA results were classified according to TBSRTC. Histopathology reports for operated cases were used to correlate cytology and final histopathology.

Results

A total of 2735 thyroid FNA from 2115 patients (mean age 45.7 ± 13.1 years, female 89.8%) were examined. The rates of non-diagnostic, benign, atypia of undetermined significance (AUS), follicular neoplasm, suspected for malignancy, and malignant cases were 21.1%, 66.6%, 4.7%, 2.4%, 1.8%, and 3.3% respectively. There were 188 patients (9%) who underwent surgical resection with available histopathology. Malignancy rates in operated thyroid nodules were 20.0%, 4.2%, 9.4%, 23.5%, 57.1%, and 90.3% for categories 1 to 6, respectively. The sensitivity, specificity, negative predictive value, and positive predictive value were 96.6%, 88.5%, 95.8%, and 90.3, respectively.

Conclusions

Preoperative diagnosis of thyroid nodules using TBSRTC in our hospital was comparable with other studies. The uniform diagnostic criteria of the Bethesda System help avoid misinterpretation while sharing local experience with international benchmarks.

Controversy regarding when clinically suspicious thyroid nodules should be subjected to surgery: Review of current guidelines

BACKGROUND

The work-up of a thyroid nodule to diagnose malignancy is not always straightforward. There are various international thyroid societies each with their own guidelines on the approach to a thyroid nodule. The aim is therefore to determine whether a clinically suspicious thyroid nodule should be subjected to surgery.

METHOD

A review of various international thyroid society guidelines on their approach to a suspicious thyroid nodule.

RESULTS

Sixty-two relevant articles were identified of which 4 current international thyroid guidelines, consisting of 6 different international societies, were reviewed. The commonalities of each of the thyroid society guidelines are imaging, with ultrasound, and cytopathology as the main diagnostic investigations. The description and the size of the nodule are the 2 most important factors on ultrasound; however, the guidelines vary in their recommendations whether to biopsy a suspicious thyroid nodule. An indeterminate group exists whereby thyroid nodules cannot be confirmed as malignant even with fine needle aspiration cytology (FNA). Although further investigations (Technetium-99m -sestamethoxyisobutylisonitryl scan, 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan, and molecular testing) may assist in the diagnosis, there are limitations. There are differences in the guidelines whether suspicious nodules should be subjected to surgery.

CONCLUSION

Ultrasound and cytopathology are the 2 most appropriate investigations to diagnose whether a suspicious thyroid nodule is benign or malignant. The clinician needs to be aware of the differences between the guidelines from the various international thyroid societies, specifically concerning the indeterminate group of patients where a definitive diagnosis cannot be made. Management decisions should be discussed with a thyroid multidisciplinary team for a consensus decision whether or not to subject a patient with a suspicious thyroid nodule to surgery.

Non-diagnostic thyroid nodules after application of the Bethesda system: a study evaluating the interval for repeat aspiration for non-diagnostic results

Background The non-diagnostic category of the Bethesda system has a low malignancy rate; nevertheless, repeat ultrasonography-guided fine needle aspiration (US-FNA) is recommended with no consensus for follow-up intervals. Purpose To investigate whether a six-month time interval for repeat US-FNA is appropriate for non-diagnostic thyroid nodules after applying the Bethesda system. Material and Methods From January 2010 to January 2014, 322 thyroid nodules ≥10 mm with non-diagnostic results on initial US-FNA with any follow-up with US or US-FNA were included (mean age = 52.2 years ± 12.4). Clinical and US features were compared according to size change (increase, no change, decrease) and follow-up interval (<6 months and ≥6 months after initial US-FNA), and the minimal time interval observed in nodules with size increase on follow-up. The outcome of non-diagnostic nodules according to follow-up interval and size change were evaluated. Results Of the 322 nodules, 13 (4.0%) were malignant and 309 (96.0%) were benign. None of the 82 nodules with decreased size were malignant and 90.2% nodules with decreased size were found after six months. Of 175 nodules with repeat US-FNA, repeat cytology results did not differ significantly between the groups with follow-up US-FNA before and after six months ( P = 0.337). No significant differences were seen in size or extrathyroidal extension among the 13 malignant nodules according to the six-month interval (all P > 0.05), and no lateral lymph node metastasis was present. Conclusion Repeat US-FNA for initially non-diagnostic thyroid nodules can be performed at a six-month interval after initial procedure without tumor progression.

Thyroid Nodules With Nondiagnostic Cytologic Results: Follow-Up Management Using Ultrasound Patterns Based on the 2015 American Thyroid Association Guidelines

OBJECTIVE

The purpose of this study was to evaluate the malignancy rate of nodules with nondiagnostic cytologic results based on the American Thyroid Association (ATA) ultrasound (US) patterns and to suggest management guidelines for these nodules.

MATERIALS AND METHODS

From January 2013 to December 2014, 441 nodules (≥ 1 cm) were found in 437 patients with nondiagnostic results of ultrasound (US)-guided fine-needle aspiration biopsy (nondiagnostic nodules). A total of 191 nodules that were cytopathologically confirmed or were smaller (> 3 mm) at follow-up US were enrolled. The US findings of each nodule were reviewed. One radiologist classified the nodules into the following five categories according to the 2015 ATA guidelines: high, intermediate, low, and very low suspicion for malignancy and benign. The reference standard was histopathologic confirmation. Nodules that were smaller at follow-up US were considered benign. The malignancy rate of each category was calculated.

RESULTS

Among a total 191 nodules, 20 (10.5%) were malignant. Solid composition, marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, and taller-than-wide shape were more frequently seen in malignant nodules (all p < 0.001). The malignancy rate of nodules with very low suspicion of malignancy was 0% (0/58); low, 0% (0/45); intermediate, 10.3% (6/58); and high, 46.7% (14/30) (p < 0.001).

CONCLUSION

When US findings of thyroid nodules are assessed according to the 2015 ATA guidelines, nondiagnostic thyroid nodules with very-low- or low-suspicion US patterns can be followed up with US. Nondiagnostic nodules with intermediate or highly suspicious US patterns should be evaluated with repeat US-guided fine-needle aspiration biopsy.

Repeated nondiagnostic result of thyroid fine-needle aspiration biopsy

Aim of the study

Fine-needle aspiration biopsy (FNAB) is the most accurate and cost-effective method to evaluate the risk of malignancy of thyroid nodules, but approximately 1–24% of FNABs generate a nondiagnostic result (ND-FNAB). The aim of this study was to determine the predictive factors of a repeated nondiagnostic result of FNAB.

Material and methods

A total of 4018 FNABs performed in a territorial referral centre were analysed, of which 288 (7.17%) were nondiagnostic. Medical records were available for 245 biopsies performed in 228 patients. The retrospective analysis of factors that may influence a repeat ND-FNAB, including demographic, clinical and ultrasound characteristics, was performed.

Results

A repeat FNAB was performed in 159 nodules giving a diagnostic result in 79.2% of cases. The time between the biopsies ranged from 1 to 611 days (mean 154.4, median 119). The timing of a repeat FNAB did not significantly alter the diagnostic output (p = 0.29). In the univariate analysis, significant predictors of a repeat ND-FNAB were older patient age (p = 0.02), L-thyroxine supplementation (p = 0.05), and a history of ¹³¹I therapy (p < 0.0001). In the multivariate analysis, only a history of ¹³¹I therapy was a statistically significant risk factor for a repeat ND-FNAB (p = 0.002).

Conclusions

Patients with a history of ¹³¹I therapy and ND-FNAB should undergo periodic ultrasonographic assessment rather than a repeat biopsy. The interval between repeated FNABs recommended by guidelines does not affect the diagnostic output.

Risk of Malignancy in Thyroid Nodules with Non-Diagnostic Fine-Needle Aspiration: A Retrospective Cohort Study

BACKGROUND

Fine-needle aspiration (FNA) of thyroid nodules is commonly performed, and despite the use of ultrasound (US) guidance, the rate of non-diagnostic FNAs is still significant. The risk of malignancy of thyroid nodules with a non-diagnostic FNA is not clearly defined. However, most studies exclude the majority of patients without a repeat biopsy or surgery, thus increasing the likelihood of selection bias. The aims of this study were to determine the malignancy risk in nodules with an initial non-diagnostic FNA, and to identify the factors associated with malignancy.

METHODS

This was a retrospective cohort study of patients with thyroid nodules who underwent US-guided FNA between 2004 and 2010 and had a non-diagnostic result. Patients were followed until confirmatory diagnosis of the nature of the nodule was made. The outcome of malignant or benign disease was based on one of the following: (i) final surgical pathology following thyroidectomy; (ii) repeat biopsy; (iii) clinically, based on repeat ultrasound performed at least three years following biopsy; or (iv) report of thyroid status for patients without follow-up visits contacted by mail.

RESULTS

There were 699 nodules from 665 patients included. The mean age was 59 ± 15 years, and 71.7% were women. There was complete follow-up of 495 nodules. After a median follow-up of 2.7 years, thyroid cancer was found in 15 nodules. The prevalence of malignancy was 3% (15/495). The presence of nodular calcifications was the strongest predictor of thyroid malignancy (odds ratio 5.03 [confidence interval 1.8-14.7]). Initial nodule size was inversely associated with malignancy (odds ratio 0.55 [confidence interval 0.28-0.93]). However, the 193 patients without follow-up had smaller nodules compared with those included in the analysis. None of the patients with repeatedly non-diagnostic results were diagnosed with thyroid cancer at follow-up.

CONCLUSION

The prevalence of thyroid cancer in nodules with non-diagnostic results is lower than the malignancy rate in thyroid nodules in general, but not negligible. They should be followed as per guidelines with heightened suspicion for nodules containing calcifications. Nodules with repeatedly non-diagnostic FNA results especially in the absence of calcifications have a low risk of malignancy and may be observed.

Evaluation the Relationship Between Thyroid Nodule Size with Malignancy and Accuracy of Fine Needle Aspiration Biopsy (FNAB)

INTRODUCTION

Some studies have shown largest thyroid nodule size, especially ≥4cm that can predict malignancy and reduce fine needle aspiration biopsy (FNAB) accuracy. Therefore, this study is designed to evaluate relationship between thyroid nodule sizes with malignancy and its effect on FNBA accuracy.

MATERIALS AND METHODS

a retrospective analytical study design aims to investigate all patients with thyroid nodules who referred to surgery department of Imam-Khomeini Hospital of Mazandaran University of Medical Sciences in Sari from 20 March 2008 to 22 March 2014. We collected patient's demographic data, nodules size, FNAB reports and final pathology (after surgery) reports from their medical records. All data were analyses performed by SPSS18.

RESULTS

167 patients (153 women) with mean age of 41.56±13.24 years old were enrolled for this study. In final pathology; 38 patients (22.8%) had malignant nodules. The mean age of patients with or without malignant nodules were 34.93±11.86 and 42.37±12.26 years old, respectively (P=0.002). The mean size of benign and malignant nodules were 2.91±1.29 cm and 3.38±1.86 cm, respectively (P=0.15). 25.2% of <4 cm nodules and 17.9% of ≥4 cm nodules were diagnosed as a malignant (P=0.29). FNAB was done on 95 patients that reported benign in 60 patients (63.2%), malignant in 18 patients (18.9%) and suspicious in 17 patients (17.9%). Positive and negative results of FNAB in all nodules were 3.5% and 6.3%, in <4cm nodules were 5.8% and 6.2% and in ≥4cm nodules were zero and 6.7%, respectively. The sensitivity, specificity, Positive predict value (PPV), negative predict value (NPV) and overall accuracy (OA) of FNAB in all nodules were 76.19%, 96.49%, 88.88%, 91.66% and 91.02%, and in <4cm nodules were 78.57%, 94.11%, 84.61%, 91.42% and 89.58%, and in ≥4cm nodules were 71.4%, 100%, 100%, 92% and 93.33%, respectively.

CONCLUSION

the results of this study revealed that the size of the thyroid nodules is not reliable at predicting malignancy and should not be applied in medical decision making. FNAB showed good specificity but the sensitivity was low in our study. In ≥4cm nodules; FNAB sensitivity was decreased and accompanied by higher false-negative results. Furthermore, FNABs with suspicious results were associated with high probability of malignancy.

Bethesda classification is a valuable guide for fine needle aspiration reports and highly predictive especially for diagnosing aggressive variants of papillary thyroid carcinoma

BACKGROUND

A fine needle aspiration biopsy (FNAB) is the most valuable diagnostic procedure for pre-operative discrimination of benign and malignant nodules. The Bethesda System for Reporting Thyroid Cytopathology provides standardised reporting and cytomorphological criteria in aspiration smears. The aim of the present study was to determine malignancy rates in nodules with different cytology results and evaluate the diagnostic value of Bethesda for variants of papillary thyroid carcinoma (PTC).

MATERIALS AND METHODS

A retrospective analysis of 2534 cases with 5784 thyroid nodules, who underwent FNAB followed by surgery, were included in this study. FNAB was performed with ultrasonography guidance. Cytological diagnoses were classified as: non-diagnostic (ND), benign, atypia of undetermined significance/follicular lesions of undetermined significance (AUS/FLUS), follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), suspicious for malignancy (SUS) and malignant. Histopathological diagnoses were classified into four groups: benign, PTC, follicular thyroid cancer and other types of thyroid cancer (including medullary thyroid cancer, undifferentiated thyroid cancer and thyroid tumours of uncertain malignant potential). Cases with PTC were further divided into four categories: conventional variant, follicular variant, aggressive variants (tall cell, diffuse sclerosing and columnar variant) and other variants (oncocytic, solid/trabecular and warthin-like variants). FNAB results were compared with histopathological results.

RESULTS

Malignancy rates were 6.3%, 3.2%, 20.7%, 33.3%, 74.2% and 95.6% in the nodules with ND, benign, AUS/FLUS, FN/SFN, SUS and malignant cytology results, respectively. Pre-operative cytology was malignant or SUS in 56.6% of conventional, 24.3% of follicular, 92% of aggressive and 41.7% of other variants of histopathologically confirmed PTC. The difference between the groups was significant (P < 0.001).

CONCLUSION

The Bethesda classification is a reliable indicator of malignancy in nodules with different cytology results and seems to be very effective in predicting the malignancy for the nodules diagnosed with aggressive variant PTC on the final histological examination.

Current status and diagnostic values of the Bethesda system for reporting thyroid cytopathology in a papillary thyroid carcinoma-prevalent area

BACKGROUND

Most studies validating the Bethesda system for reporting thyroid cytopathology (TBSRTC) have been conducted in Western countries. We explored the current status of TBSRTC in an area where most thyroid malignancies are papillary carcinomas.

METHODS

Fine-needle aspirations (FNAs) of thyroid nodules performed in 2013 were retrospectively analyzed and the results were compared to final pathology on resection.

RESULTS

Of 1947 FNAs, 1925 (98.9%) were reported using TBSRTC. Among 381 resected lesions, 27.3% of nondiagnostic, 19.6% of benign, 56.0% of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 33.3% of follicular neoplasm/suspicious for a follicular neoplasm (FN/SFN), 97.7% of suspicious for malignancy, and 100.0% of malignant lesions were malignant on pathology. The sensitivity and specificity of FNA using TBSRTC were 96.7% and 84.1%, respectively.

CONCLUSION

TBSRTC works well in an area in which papillary thyroid cancer is prevalent; however, it may underestimate malignancy rates in AUS/FLUS, benign, and nondiagnostic categories. © 2016 Wiley Periodicals, Inc. Head Neck 39: 269-274, 2017.

Fine-Needle Aspiration Biopsy as a Preoperative Procedure in Patients with Malignancy in Solitary and Multiple Thyroid Nodules

BACKGROUND

Fine-needle aspiration biopsy (FNAB) is a recognized technique for the basic, preoperative cytological diagnosis of thyroid nodules.

AIM OF THE STUDY

To analyze the accuracy of FNAB in the diagnosis of thyroid cancer in patients with solitary and multiple thyroid nodules and to compare the demographic, clinical and pathological characteristics of patients with thyroid carcinoma in solitary and multiple tumors.

MATERIALS AND METHODS

The case records of 2,403 patients with solitary and multiple thyroid tumors treated consecutively between 2008 and 2013 were analyzed retrospectively. We selected 1,645 for further analysis. A solitary thyroid nodule was observed in 493 patients, and multiple nodules were detected in 1,152 patients. Further classification of the patients in these two groups was performed on the basis of the FNAB results, type of surgery performed and histopathology. TC was histopathologically confirmed in 166 patients, and benign disease was found in 1,479. The TC patients were assigned to the study group, and those with benign thyroid disease were placed into the control group. The study group was divided into two subgroups according to the presence of cancer in a single thyroid nodule or in multiple nodules. Malignancy in a solitary thyroid nodule was diagnosed in 98 (59.0%) patients, and cancer in multiple nodules was diagnosed in 68 (41.0%). Comparative analyses of the demographic, clinical and histopathological characteristics were performed for both subgroups. The following statistical analyses were performed: comparative characteristic of subgroups, ROC analysis for study group and subgroup of patients, and multivariable logistic regression analysis for study group.

RESULTS

The rate of prediction of TC by FNAB was three times higher in the patients with a solitary thyroid nodule compared with those with multiple thyroid nodules and it was statistically significant (p<0.001). The rate of total thyroid resection and lack of necessity for reoperation were also significantly higher in the TC patients with a solitary nodule. The histopathological results showed that significantly more patients with a solitary nodule had advanced-stage TC (stage III or IV) and tumor progression (pT3 or pT4) (p = 0.002 for both). ROC analysis demonstrated that the overall accuracy of FNAB as a predictor of thyroid cancer presence was high, especially for the subgroup of patients with a solitary thyroid nodule (AUC = 0.958, p<0.0001). Multivariable logistic regression analysis confirmed that a positive FNAB result was the sole predictor of the performance of total resection in the TC study group (p<0.0001), while a negative FNAB result and the presence of a papillary cancer type were independent predictors of the risk of reoperation (p<0.0001 and p = 0.002, respectively).

CONCLUSIONS

FNAB often produces false-negative results in patients with multiple malignant thyroid tumors, which results in reoperation in many cases. False-negative FNAB results are rare in patients with a solitary tumor. Because of the low predictive capacity of FNAB for thyroid cancer in patients with multiple thyroid tumors, total thyroid excision should be considered in most cases despite a "negative" (no malignant) FNAB result.

Applying Ultrasound-Guided Core Needle Biopsy for Diagnosis of Thyroid Masses: Preliminary Results From a Single Institution

OBJECTIVES

The purpose of this study was to investigate the level of conclusive results obtained with ultrasound (US)-guided core needle biopsy (CNB) and how this method should be applied for diagnosis of thyroid nodules.

METHODS

From January 2013 to November 2014, US-guided CNB was performed in 84 thyroid lesions of 83 patients. Based on CNB pathologic reports, thyroid nodules were divided into 2 categories: conclusive (nodules reaching a definite pathologic diagnosis suggesting benignity or malignancy) and inconclusive (nodules that were not able to reach a definite diagnosis because of ambiguous results). Medical records and US examinations were reviewed and compared.

RESULTS

The mean age of the 83 patients ± SD was 49.7 ± 14.1 years. Of the 84 thyroid nodules, 73 (86.9%) were diagnosed as benign or malignant and 11 (13.1%) as inconclusive by CNB pathologic analysis. Among the 11 nodules with inconclusive results, the possibility of a follicular neoplasm was suggested in 8 nodules (72.7%). No significant difference was seen in tumor size and US features when comparing the nodules with conclusive and inconclusive results (all P >.05).

CONCLUSIONS

Ultrasound-guided CNB may have supplemental roles in addition to US-guided fine-needle aspiration for diagnosis of selected cases. A considerable proportion of inconclusive results are seen on US-guided CNB, especially for diagnosis of follicular lesions, which must be considered when using this method for diagnosis of thyroid nodules.

Thyroid Nodules: Nondiagnostic Cytologic Results according to Thyroid Imaging Reporting and Data System before and after Application of the Bethesda System

PURPOSE

To compare the malignancy rates and the effectiveness of the Thyroid Imaging Reporting and Data System (TIRADS) for risk stratification of nodules with nondiagnostic results classified before and after application of the Bethesda System for Reporting Thyroid Cytopathology.

MATERIALS AND METHODS

This retrospective study was approved by an institutional review board, with waiver of informed consent. A total of 763 patients with 790 thyroid nodules and nondiagnostic cytologic results were included (mean age ± standard deviation, 52.3 years ± 11.5), 485 nodules from the pre-Bethesda period (from March 2007 to December 2008) and 305 nodules from the post-Bethesda period (from May 2011 to May 2012). A TIRADS category was assigned to each thyroid nodule on the basis of the number of features that appeared suspicious for cancer at ultrasonography (US). Malignancy rates and TIRADS categories during the two periods were compared. Correlation between TIRADS category and malignancy risk between the two periods was evaluated and compared.

RESULTS

The malignancy rates of nodules with nondiagnostic cytologic results were not significantly different between the two periods (P = .148). Malignancy risk of TIRADS category 3, 4a, 4b, 4c, and 5 was 1.8%, 5.7%, 4.1%, 29.8%, and 16.7%, for the pre-Bethesda period, and 1.6%, 3.0%, 7.1%, 16.3%, and 25.0% for the post-Bethesda period, respectively. Near-perfect correlation was seen between the TIRADS category and malignancy risk in the post-Bethesda period (r = 0.961, P = .009), while no significant correlation was found in the pre-Bethesda period (r = 0.731, P = .161).

CONCLUSION

Malignancy risk stratification with TIRADS was more effective for nodules with nondiagnostic cytologic results classified according to the Bethesda System. When these Bethesda-classified nodules with nondiagnostic results are evaluated as TIRADS category 3 or 4a, they may be treated conservatively with follow-up US, but when other cytologic classifications are applied, follow-up US and fine- needle aspiration must be considered for nodules showing one or more features suspicious for cancer at US.

Predictors of non-diagnostic cytology in surgeon-performed ultrasound guided fine needle aspiration of thyroid nodules

BACKGROUND

Fine needle aspiration (FNA) is the standard of care for the diagnostic work-up of thyroid nodules but despite its proven utility, the non-diagnostic rate for thyroid FNA ranges from 6-36%. A non-diagnostic FNA is problematic for the clinician and patient because it can result in repeated procedures, multiple physician visits, and a delay in definitive treatment. Surgeon-performed FNA has been shown to be safe, cost-effective, as accurate as those performed by other clinicians, and has the added benefit of decreasing wait times to surgery. Several studies have examined rates and factors that may be predictive of a non-diagnostic cytology in non-surgeon FNA, but none have evaluated this in surgeon-performed thyroid FNA. If these factors are unique in surgeon-performed vs. non-surgeon performed thyroid FNA, then patients may be more appropriately triaged to FNA by alternate clinicians.

OBJECTIVES

The purpose of this study was to determine the rate and factors predictive of a non-diagnostic FNA in surgeon performed ultrasound-guided FNA of thyroid nodules.

METHODS

We conducted a retrospective review of all adult patients who underwent thyroid FNA by a staff, fellow, or resident Otolaryngologist at the University of Alberta between January 2011 and June 2013. Factors analyzed included patient factors, thyroid characteristics, nodule characteristics, and surgeon level of training and experience. Univariate and multivariate binary logistic regression analysis were performed.

RESULTS

131 patients (180 nodules) were reviewed. The non-diagnostic rate was 23%. Nodules with predominant cystic component, those less than 1 cm, and resident-performed FNA were associated with non-diagnostic cytology (p = 0.001, p = 0.02, p = 0.04 respectively). A cystic nodule was the only independent predictor of non-diagnostic FNA on multivariate analysis (OR = 4.441, 95% CI [1.785-11.045], p = 0.001).

CONCLUSIONS

The rate of non-diagnostic thyroid FNA performed by a surgeon with ultrasound guidance is similar to other clinicians. A cystic nodule is a strong independent predictor of non-diagnostic cytology. Non-cystic nodules may particularly benefit from surgeon-performed thyroid FNA due to the high diagnostic rate and potential for earlier definitive management.

[Repeated fine-needle aspiration cytology for the diagnosis and follow-up of thyroid nodules]

INTRODUCTION

The recently-proposed Bethesda reporting system has offered clinical recommendations for each category of reported thyroid cytology, including repeated fine-needle aspiration (FNA) for non-diagnostic and atypia/follicular lesions of undetermined significance, but there are no sound indications for repeated examination after an initial benign exam.

OBJECTIVE

To investigate the clinical validity of repeated FNA in the management of patients with thyroid nodules.

METHOD

The present study evaluated 412 consecutive patients who had repeated aspiration biopsies of thyroid nodules after an initial non-diagnostic, atypia/follicular lesion of undetermined significance, or benign cytology.

RESULTS

The majority of patients were female (93.5%) ranging from 13 to 83 years. Non-diagnostic cytology was the most common indication for a repeated examination in 237 patients (57.5%), followed by benign (36.8%), and A/FLUS (5.6%) cytology. A repeated examination altered the initial diagnosis in 70.5% and 78.3% of the non-diagnostic and A/FLUS patients, respectively, whereas only 28.9% of patients with a benign cytology presented with a different diagnosis on a sequential FNA.

CONCLUSIONS

Repeat FNA is a valuable procedure in cases with initial non-diagnostic or A/FLUS cytology, but its routine use for patients with an initial benign examination appears to not increase the expected likelihood of a malignant finding.

Differential expression of transforming growth factor-beta in benign vs. papillary thyroid cancer nodules; a potential diagnostic tool?

Background

Thyroid nodules are common, but only 5% of nodules are found to be malignant. In North America, the incidence of thyroid cancer is increasing. Fine needle aspirate (FNA) biopsy is the diagnostic test of choice. Unfortunately, up to 20% of FNAs are non-diagnostic. A specific molecular marker for thyroid cancer is desirable. Evidence suggests that cell signaling through transforming growth factor beta (TGF- β) is important in the development of thyroid cancer. We sought to compare the expression of TGF- β in malignant and benign thyroid nodules.

Methods

From 2008-present, thyroid nodule tissue from thyroidectomy specimens was prospectively collected and stored at −80°C. RNA extraction and reverse transcription was performed on 47 samples (24 papillary thyroid cancer and 23 benign nodules). Quantitative PCR using SYBR green was performed to detect TGF-β-1 and −2. Resulting C_T values were normalized against β-actin. Gene expression was calculated using the 2^-ΔC_T method.

Results

A significantly greater expression of TGF- β1 (p < 0.0001) was detected in the group of malignant thyroid nodules compared to benign nodules. There was no difference in the expression of TGF- β2 (p = 0.4735) between the two groups.

Conclusions

In this study, we demonstrated that expression of TGF- β1 but not TGF- β2 is significantly increased in papillary thyroid cancer compared to benign thyroid nodules. This may serve as a potential diagnostic marker for papillary thyroid cancer.

Analysis of nondiagnostic results in a large series of thyroid fine-needle aspiration cytology performed over 9 years in a single center

OBJECTIVE

Thyroid fine-needle aspiration cytology (FNAC) is the most valuable, cost-effective and accurate method for the evaluation of patients with thyroid nodules. One of its limitations is that up to 20% of results are nondiagnostic or unsatisfactory. The aim of this study was to analyze the number of thyroid FNAC specimens with nondiagnostic results obtained on an outpatient basis and how many of these had to be repeated according to their results.

STUDY DESIGN

This was a retrospective analysis of diagnostic reports of nondiagnostic thyroid FNAC specimens obtained between 1 January 2004 and 31 December 2012 which were retrieved by means of a computerized search. The FNAC results and the age and sex of the patients were collected.

RESULTS

From a total of 15,292 thyroid FNAC specimens, 6.8% (n = 1,033) corresponded to nondiagnostic cases. Eligible diagnostic reports for analysis included 877 cases (106 were repetitions of previous nondiagnostic FNAC). After an initial nondiagnostic finding for 771 FNAC smears, 29.5% (n = 225) were repeated with the following results: 43.6% insufficient, 49.3% benign, 6.2% follicular neoplasm, 0.4% suspicious for malignancy and 0.4% malignant. Twenty-two patients underwent a second repeated FNAC. Here the findings were: 36.4% insufficient, 59.1% benign, 4.5% follicular neoplasm, 0.0% suspicious for malignancy and 0.0% malignant.

CONCLUSIONS

There was a low rate of repeated FNAC among the group of nondiagnostic cases. With repeated FNAC, the rate of nondiagnostic cases and the number of results that potentially demand surgery diminish.