Prevalence of malignancy in thyroid nodules with an initial nondiagnostic result after ultrasound guided fine needle aspiration

Factors for second non-diagnostic ultrasound-guided fine-needle aspiration cytology in thyroid nodules

INTRODUCTION

Results in fine-needle aspiration cytology (FNAC) of thyroid nodules may be non-diagnostic (ND). In these cases, it is recommended to repeat the FNAC. The aim of our study was to evaluate the influence of demographic, clinical and ultrasound (US) characteristics in the recurrence of an ND result in thyroid nodule FNAC.

METHODS

A retrospective study of ND thyroid nodule FNAC was performed for the period 2017-2020. Demographic and clinical data (age, gender, cervical radiotherapy, presence of Hashimoto's thyroiditis, and TSH value) and US characteristics (nodule size, echogenicity, composition and microcalcifications) were collected at first ND FNAC.

RESULTS

Out of 230 nodules with first ND FNAC (83% women; mean age 60.2±14.1 years), 195 (84.8%) underwent a second FNAC: 121 benign, 63 non-diagnostic, 9 indeterminate and 2 malignant. Nine (3.9%) underwent surgery, only 1 of which showed malignant histology and 26 (11.3%) remained under US monitoring. Demographically, patients with second ND FNAC were older (63.4±14 vs. 59±14 years; P=0.032). Females had lower risk of second ND FNAC (OR, 0.4, 0.2-0.9; P=0.016); risk of second ND FNAC was higher in patients treated with anticoagulant/antiplatelet drugs (OR, 2.2, 1.1-4.7; P=0.03). Previous cervical radiotherapy, family history of thyroid cancer, Hashimoto's thyroiditis and TSH value did not influence the risk of second ND FNAC. On US, nodule echogenicity differed significantly between the ND and diagnostic FNAC, with greater risk of an ND result in hypoechogenic nodules. Microcalcification increased the risk of ND FNAC (OR 2.2, 1.1-4.5; P=0.03). Nodule composition and size did not significantly differ according to ND or diagnostic second FNAC.

CONCLUSION

Male gender, advanced age, anticoagulant/antiplatelet drug therapy, hypoechogenic nodules and microcalcified nodules are likely factors for second ND FNAC. Nodules with two ND FNACs were rarely malignant, and a more conservative approach in these cases is not unsafe.

Not All Bethesda 1 Thyroid Nodules Were Created Equal: Different B1 Subgroups

OBJECTIVE

The Bethesda System for Reporting Thyroid Cytopathology is a uniform method used worldwide to report thyroid fine-needle aspiration (FNA) outcomes. This study focuses on the Nondiagnostic/Unsatisfactory category, designated as Bethesda1 (B1). The documented risk of malignancy for B1 nodules can vary significantly, implying this category is not homogenous and might be composed of different subtypes. Our hypothesis was that B1 subgroups (blood only, insufficient thyrocytes, cyst content) will vary in their malignancy rate.

METHODS

The study design was observational and retrospective. The study population included 154 patients in the Galilee Medical Center who underwent FNA examination of the thyroid gland from 2013-2018 and had a B1 result. We looked at the final diagnosis of malignant or benign for patients who underwent surgery and calculated the malignancy rate for each subgroup.

RESULTS

Malignancy rates were higher in the Blood subgroup than in the other subgroups, and higher in the Thyrocytes subgroup than in the Cyst subgroup (P < .05). All malignancies were papillary thyroid carcinomas. There was no significant difference in the malignancy rate when we further divided the B1 samples into 2 groups based on the presence of epithelial cells. Many repeat FNA tests resulted in a different B1 subgroup.

CONCLUSION

The different malignancy rates suggest that individual management approaches should be considered for each B1 subgroup.

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.

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.

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.

The impact of repeat FNA in non-diagnostic and indeterminate thyroid nodules: A 5-year single-centre experience

INTRODUCTION

FNA is a well-established method for the preoperative diagnosis of thyroid nodules, but limitations still reside among non-diagnostic and indeterminate samples. The objective of the present study was to assess the impact of repeat FNA in thyroid nodules primarily classified as non-diagnostic and indeterminate, with the evaluation of the diagnostic resolution rate after the reassessment of the nodule.

METHODS

We retrospectively collected all cases of thyroid FNA at our institution in the last 5 years that had one or more repeat aspirations of the same nodule, calculating the percentage of samples with change in the diagnostic category. Additional collected data included sex, age and interval between the repeat aspirations.

RESULTS

One hundred and seventy-eight specimens from 167 patients (140 female, 27 male) with a median age of 56 years (range 11-90) were included in the study. Among the 86 cases primarily classified as non-diagnostic, 25 (29.1%) remained in the same category after the first reassessment and only 18 (20.9%) after the second repeat aspiration. Among the 40 indeterminate cases, only 10 (25%) retained their status after the second aspiration, with no change after the third assessment.

CONCLUSION

Repeat aspiration of non-diagnostic and indeterminate thyroid nodules had a positive impact in both groups, with diagnostic resolution rates of 80% and 75%, respectively. The present study therefore endorses the use of such strategy for the initial follow-up of nodules with no definite diagnosis, especially in low-resource centres with limited access to modern molecular technologies.

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.

Impact of Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Features on Adequacy Criteria and Risk of Malignancy of Thyroid Fine-Needle Aspiration

OBJECTIVES

The impact of noninvasive follicular thyroid neoplasm with papillary-like features (NIFTP) on nondiagnostic and benign diagnoses is not well characterized.

METHODS

The results of all thyroid fine-needle aspirates (FNAs) performed from 1997 to June 2016 with corresponding resections were reviewed.

RESULTS

From 12,764 aspirates, there were 8,106 (64%) benign diagnoses with 412 (5%) resections and 1,888 (14.8%) nondiagnostic diagnoses with 329 (17%) resections. Before the use of NIFTP, there were 18 (4.3%) malignancies in the benign aspirates and 39 (11.9%) malignancies in the nondiagnostic aspirates. There were 12 NIFTP cases on review. After reclassification using NIFTP, there were 10 of 412 (2.4%) malignancies in the benign aspirates. When cases with 10 to 60 benign follicle cells without atypia or Hürthle cell change were reclassified as benign rather than nondiagnostic, the malignancy rate for a benign aspirate decreased (12/506, 2.3%; P = 1.0) when NIFTP cases were recognized.

CONCLUSIONS

With NIFTP, reducing the threshold for adequacy from 60 to 10 cells led to nonsignificant decrease in the risk of malignancy of a benign diagnosis (2.4% to 2.3%). Thyroid fine-needle aspirates with 10 to 60 benign cells without atypia or Hürthle cell change should be diagnosed as benign.

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.

First-Line Use of Core Needle Biopsy for High-Yield Preliminary Diagnosis of Thyroid Nodules

BACKGROUND AND PURPOSE

Although core needle biopsy was introduced as a diagnostic alternative to fine-needle aspiration, the utility and safety of core needle biopsy for thyroid nodules in a large population has yet to be studied comprehensively. We evaluate core needle biopsy yields on a large-scale basis to investigate its potential in the preliminary diagnosis of thyroid nodules.

MATERIALS AND METHODS

Between March 2005 and December 2013, 2448 initially detected thyroid nodules from 2120 consecutive patients who underwent core needle biopsy were retrospectively evaluated. Of these, 72 thyroid nodules from 63 patients were excluded due to prior fine-needle aspiration attempts. The inconclusive and conclusive result rates, diagnostic accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and unnecessary surgery rate of core needle biopsy were evaluated.

RESULTS

With core needle biopsy as the first-line method, the inconclusive result rate was 11.9% (283/2376) and the conclusive result rate was 88.1% (2093/2376). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of core needle biopsy for the diagnosis of malignancy were 96.7% (1160/1200), 89.7% (347/387), 100% (813/813), 100% (347/347), and 95.3% (813/853), respectively. There were no major complications and 12 minor complications.

CONCLUSIONS

We have demonstrated that first-line use of core needle biopsy may well improve diagnostic accuracy in thyroid nodules, reducing inconclusive or false-negative results and unnecessary operations. Such benefits underscore the promising role of core needle biopsy in managing thyroid nodules and optimizing related surgical decision-making.

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.

Core Needle Biopsy Is a More Conclusive Follow-up Method Than Repeat Fine Needle Aspiration for Thyroid Nodules with Initially Inconclusive Results: A Systematic Review and Meta-Analysis

Background:

This study investigated the appropriate management of thyroid nodules with prior non-diagnostic or atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) through a systematic review and meta-analysis.

Methods:

This study included 4,235 thyroid nodules from 26 eligible studies. We investigated the conclusive rate of follow-up core needle biopsy (CNB) or repeat fine needle aspiration (rFNA) after initial fine needle aspiration (FNA) with non-diagnostic or AUS/FLUS results. A diagnostic test accuracy (DTA) review was performed to determine the diagnostic role of the follow-up CNB and to calculate the area under the curve (AUC) on the summary receiver operating characteristic (SROC) curve.

Results:

The conclusive rates of follow-up CNB and rFNA after initial FNA were 0.879 (95% confidence interval [CI], 0.801 to 0.929) and 0.684 (95% CI, 0.627 to 0.736), respectively. In comparison of the odds ratios of CNB and rFNA, CNB had more frequent conclusive results than rFNA (odds ratio, 5.707; 95% CI, 2.530 to 12.875). Upon subgroup analysis, follow-up CNB showed a higher conclusive rate than rFNA in both initial non-diagnostic and AUS/FLUS subgroups. In DTA review of followup CNB, the pooled sensitivity and specificity were 0.94 (95% CI, 0.88 to 0.97) and 0.88 (95% CI, 0.84 to 0.91), respectively. The AUC for the SROC curve was 0.981, nearing 1.

Conclusions:

Our results show that CNB has a higher conclusive rate than rFNA when the initial FNA produced inconclusive results. Further prospective studies with more detailed criteria are necessary before follow-up CNB can be applied in daily practice.

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.

Thyroid nodules with initially non-diagnostic, fine-needle aspiration results: comparison of core-needle biopsy and repeated fine-needle aspiration

OBJECTIVE

To evaluate the role of core-needle biopsy (CNB) by comparing the results of CNB and repeated fine-needle aspiration (FNA) for thyroid nodules with initially non-diagnostic FNA results.

METHODS

From October 2008 to December 2011, 360 nodules - 180 consecutive repeated FNAs and 180 consecutive CNBs -- from 360 patients (83 men, 277 women; mean age, 54.4 years) with initially non-diagnostic FNA results were analyzed retrospectively. The incidence of non-diagnostic results, inconclusive results, diagnostic surgery, and diagnostic performance of repeated FNA and CNB were assessed, and factors affecting second non-diagnostic results were evaluated.

RESULTS

CNB achieved a significantly lower non-diagnostic and inconclusive rate than repeated FNA (1.1 % versus 40.0 %, P < 0.001; 7.2 % versus 72.0 %, P < 0.001). All diagnostic performances with CNB were higher than repeated FNA. The diagnostic surgery rate was lower with CNB than with repeated FNA (3.6 % versus 16.7 %, P = 0.047). Multivariate logistic regression analysis showed that repeated FNA was the most important factor for second non-diagnostic results (OR = 56.06, P < 0.001), followed by nodules with rim calcification (OR = 7.46, P = 0.003).

CONCLUSIONS

CNB is more useful than repeated FNA for reducing the number of non-diagnostic and inconclusive results and for preventing unnecessary diagnostic surgery for thyroid nodules with initially non-diagnostic FNA results.

KEY POINTS

• Core-needle biopsy achieved a lower number of non-diagnostic and inconclusive results. • Core-needle biopsy achieved better diagnostic performance. • Use of core-needle biopsy could prevent unnecessary diagnostic surgery. • Repeated fine-needle aspiration was significantly associated with a second non-diagnosis.

Core needle biopsy can minimise the non-diagnostic results and need for diagnostic surgery in patients with calcified thyroid nodules

PURPOSE

To evaluate the role of core needle biopsy (CNB) for calcified thyroid nodules.

METHODS

Between October 2008 and July 2011, 264 patients underwent ultrasound-guided CNB for 272 calcified thyroid nodules at our institution. We retrospectively evaluated the incidence of technical failure, non-diagnostic readings, and the diagnostic performance of CNB, and analysed the relationship between the types of calcification and the CNB results. Finally, the incidence of diagnostic surgery was calculated.

RESULTS

The incidence of technical failure was 1.1 % (3/275) and that of non-diagnostic results was 0.7 % (2/272). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CNB were 94.7 %, 89.5 %, 100 %, 100 %, and 90.2 %, respectively. There were no significant differences according to the calcification subtype for either the non-diagnostic results or the incidence of technical failure (P > 0.99 and P > 0.99). CNB could prevent diagnostic surgery for 92.9 % (13/14) of the patients who showed more than two non-diagnostic results in previous FNA.

CONCLUSIONS

CNB can minimise the non-diagnostic results as well as diagnostic surgery in patients with calcified thyroid nodules. Therefore, CNB may be used as a first-line diagnostic tool for calcified thyroid nodules rather than FNA.

KEY POINTS

CNB results show the low incidence of technical failure (1.1 %, 3/275). • CNB results show the low non-diagnostic rate (0.7 %, 2/272). There were no significant differences according to the calcification subtype. CNB can prevent unnecessary diagnostic surgery in 92.9 % (13/14).

Clinical outcomes in patients with non-diagnostic thyroid fine needle aspiration cytology: usefulness of the thyroid core needle biopsy

BACKGROUND

Patients with non-diagnostic thyroid fine needle aspiration cytology (FNAC) results undergo repeat FNAC or core needle biopsy (CNB) for definite diagnosis or surgical resection, or are followed up by clinical and ultrasound surveillance. We aimed at evaluating the risk of malignancy in patients with non-diagnostic FNACs and their clinical outcomes according to the follow-up modality.

METHODS

We retrospectively reviewed 1,496 (8.8 %) cases with a non-diagnostic result on a first aspiration among 17,045 thyroid FNACs performed between October 2008 and August 2012. Of the non-diagnostic FNACs, 389 patients underwent a second FNAC; 125, CNB; and 89, thyroidectomy by clinical indication. The remaining patients were clinically followed up.

RESULTS

The rate of a second non-diagnostic result was significantly higher on repeat FNAC than on CNB (33.2 vs. 2.4 %; p < 0.001). There was no significant difference in the malignancy risk among patients initially non-diagnostic, twice non-diagnostic, and thrice or more non-diagnostic, nor did this differ from the rate following CNB. No further malignancy was found in cases with ≥2 non-diagnostic CNBs. The malignancy risk was 51 % in those who underwent thyroidectomy. The sensitivity for detecting malignancy was 65 and 70 % for repeat FNACs and first CNBs, respectively, with no false positives seen in either test.

CONCLUSIONS

Approximately one-third of repeat FNACs after an initial non-diagnostic aspirate are non-diagnostic on repeat examination, and the malignancy risk may not reduce following repetitively non-diagnostic FNACs. However, a single CNB may be enough to exclude malignancy risk for patients with a non-diagnostic aspirate.

Thyroid nodules with initially nondiagnostic cytologic results: the role of core-needle biopsy

PURPOSE

To evaluate the role of core-needle biopsy (CNB) in thyroid nodules with nondiagnostic results at previous fine-needle aspiration (FNA).

MATERIALS AND METHODS

From October 2008 to July 2011, 155 nodules from 155 patients (37 men, 118 women) with a mean age of 51.8 years (age range, 22-76 years) with nondiagnostic results at previous FNA were reviewed retrospectively. The Bethesda system for reporting thyroid cytopathologic results was used to assign FNA and CNB findings. Malignant nodules (n = 37) were diagnosed after surgery. Benign nodules (n = 79) were diagnosed either after surgery, with benign findings after FNA and/or CNB that had been repeated at least twice, or after benign cytology findings at FNA or CNB with a stable size at follow-up. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ultrasonographically guided CNB were evaluated.

RESULTS

At CNB, two nodules (1.3%) showed nondiagnostic results, and 135 nodules (87.1%) had conclusive diagnoses. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of core biopsies for the detection of malignancy were 94.6% (35 of 37), 100% (79 of 79), 100% (35 of 35), 97.5% (79 of 81), and 98.3% (114 of 116), respectively. For 28 nodules, nondiagnostic results were found after two or more FNA procedures; however, diagnostic surgery was performed in only one patient.

CONCLUSION

CNB of the thyroid nodule demonstrates high rates of conclusive and accurate diagnoses in patients for whom previous FNA results were nondiagnostic, thereby reducing the need for unnecessary diagnostic surgery.

Fine-Needle Aspiration, Touch Imprint, and Crush Preparation Cytology for Diagnosing Thyroid Malignancies in Thyroid Nodules

Several methods are used to evaluate the thyroid nodules. The aim of this study was to determine the sensitivity, specificity, false positive and negative rates, positive predictive value (PPV), and negative predictive value (NPV) of touch imprint, crush preparation, and fine-needle aspiration (FNA) methods. This cross-sectional study was done in Shohada-ye Ashayer University Hospital in Khorramabad. All the patients who underwent thyroid surgery due to thyroid nodules in this hospital between March and September 2011 were evaluated. The thyroid nodules of all the patients were evaluated by touch imprint, crush preparation, FNA, and permanent pathology methods. Finally, the results of the first three methods were compared with the result of permanent pathology method. The mean age of 104 patients who underwent thyroid surgery was 42.6 ± 11.9 years old. Based on permanent pathology, touch imprint, crush preparation, and FNA methods, 15.3, 6.25, 6.25, and 4.4 % of thyroid nodules were malignant, respectively. Sensitivity, specificity, false positive rate, false negative rate, PPV, and NPV of FNA biopsy were 62.5, 100, 0, 37.5, 100, and 95.3 %, respectively. Also, sensitivity, specificity, false positive rate, false negative rate, PPV, and NPV of touch imprint and crush preparation were equal and were 80, 100, 0, 20, 100, and 96.7 %, respectively. Using touch imprint and crush preparation in evaluation of thyroid nodules for rapid evaluation of these nodules in operating rooms seems to be logical, and it can prevent further surgeries.