Errors in Thyroid Gland Fine-Needle Aspiration

Consistency in the Distribution of Bethesda System for Reporting Thyroid Cytology Categories Over 9 Years: A Single Institute, Retrospective Study

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) has evolved since it was first introduced in 2009 to become a worldwide accepted cytologic analysis reference, due to its simplicity and reproducibility. To date, the consistency of BSRTC throughout time has yet to be investigated.

METHODS

Retrospective single institution case series with chart review of all patients who underwent fine-needle aspirations for a thyroid nodule in our institution between the years 2010 and 2018 with a documented BSRTC classification. Data collection included demographics, risk factors, sonographic evaluation, nodule size, and final pathology when feasible. The main outcome is the difference in the rates of BSRTC categories benign, atypia of undetermined significance (AUS), follicular neoplasm, suspicious for malignancy, and malignant (BSRTC II-VI, respectively) between the study years.

RESULTS

A total of 2830 thyroid nodules were included. BSRTC II-VI distribution was 83.9% (2373), 8.2%, (232), 2.7% (75), 3.3% (93), and 2.0% (57), respectively. There was no significant change in the overall trend of each BSRTC category distribution throughout the study. There was a significant increase in the benign cytology rate (BSRTC II) in 2011 compared to 2015 and 2018 (76.4% compared to 88.7% and 87.6%, respectively. P < .005) alongside a significant decline in the AUS category rate (BSRTC III) between the same years (13.0% compared to 4.8% and 5.5%, respectively. P < .005).

CONCLUSION

BSRTC showed consistency throughout the study across all observed categories. An overlap between AUS and benign may exist, possibly due to the heterogenic definition of AUS as reflected in the 2023 BSRTC subclassification for AUS.

Core Needle Biopsy in the Diagnosis of Thyroid Nodules

BACKGROUND

Core needle biopsy (CNB) is a relatively new technique for the diagnosis of thyroid nodules, and there are currently no large clinical series available. CNB results from 3000 cases are presented in this article.

METHODS

A spring-loaded 20-gauge needle was used for CNB under local anesthesia and ultrasonography guidance for 3000 patients with nodular goiter (584 males, 2416 females, mean age: 48.5). One physician performed all biopsy procedures without conducting on-site pathological examinations.

RESULTS

There were non-diagnostic 22 (.7%), benign 2620 (87.4%), atypia of undetermined significance and/or, follicular lesion of undetermined significance 90 (3%), follicular neoplasms and/or suspicious for follicular neoplasm 53 (1.7%), suspicious for malignancy 160 (5.4%), and malignant 55 (1.8%) cases. The CNB procedure was repeated in 19 non-diagnostic cases, and 17 of these patients were benign and two had malignancy. Thyroidectomy was performed on patients who had malign CNB results. All final pathology reports, except for one, were malignant for the patients who had malignant CNB results. The specificity and the sensitivity of CNB were found to be 99.9% and 100%, respectively. There were no serious complications.

CONCLUSION

In thyroid nodules, core needle biopsy is a highly sensitive, specific, and reliable method that could be performed by a single physician. It does not require on-site pathological analysis and has a low incidence of complications and non-diagnostic rates.

Elastography and Doppler May Bring a New Perspective to TIRADS, Altering Conventional Ultrasonography Dominance

RATIONALE AND OBJECTIVES

The main aim of ultrasonography (US) examining thyroid nodules is to differentiate malignant nodules from benign nodules. Several professional societies and groups of investigators have defined guidelines such as Thyroid Imaging Reporting and Data System (TIRADS) to provide the standardized language and approach to thyroid nodules. This study is aimed to investigate the compatibility of such classification systems with the pathological diagnosis of nodules and evaluate the contribution of the Shear-wave elastography (SWE) and Doppler ultrasonography (DUS) findings.

MATERIALS AND METHODS

This is a prospective study. Patients with thyroid US exams between December 2017 and April 2019 were included. In the study, eligible 210 nodules from 210 patients were enrolled. For stratification, the conventional B-mode US, SWE and DUS were performed. According to Kwak, American College of Radiology (ACR), and European (EU)-TIRADS, Nodules were classified separately, and a new scoring system whose the criteria was put defined in the study has developed.

RESULTS

For SWE; Emean cut-off value was 33 kPa with a sensitivity and specificity of 95,6% (95% CI: 0,85-0,98) and 95% (95% CI:0,90-0,97) respectively (p <0.001). For spectral DUS; resistivity index (RI) cut-off value was 0.64 with a sensitivity and specificity of 73,3% (95% CI:0,59-0,83) and 80% (95% CI:0,73-0,85) respectively (p <0.001). Kwak TIRADS, American College of Radiology TIRADS, EU-TIRADS, and new system were compared by ROC curve analysis. The new system has the highest sensitivity, specificity, PPV, NPV, accuracy, and AUC compared to others.

CONCLUSIONS

The new scoring system has shown that SWE and DUS findings may alter the categorization in TIRADS and increase sensitivity and specificity.

Is Diagnostic Performance of Quantitative 2D-Shear Wave Elastography Optimal for Clinical Classification of Benign and Malignant Thyroid Nodules?: A Systematic Review and Meta-analysis

RATIONALE AND OBJECTIVE

This study is a dedicated 2D-shear wave elastography (2D-SWE) review aimed at systematically eliciting up-to-date evidence of its clinical value in differential diagnosis of benign and malignant thyroid nodules.

METHODS

PubMed, Web of Science, and Scopus databases were searched for studies assessing the diagnostic value of 2D-SWE for thyroid malignancy risk stratification published until December 2016. The retrieved titles and abstracts were screened and evaluated according to the predefined inclusion and exclusion criteria. Methodological quality of the studies was assessed using the Quality Assessment of Studies of Diagnostic Accuracy included in Systematic Review 2 (QUADAS-2) tool. Extracted 2D-SWE diagnostic performance data were meta-analyzed to assess the summary sensitivity, specificity, and area under the receiver operating characteristic curve.

RESULTS

After stepwise review, 14 studies in which 2D-SWE was used to evaluate 2851 thyroid nodules (1092 malignant, 1759 benign) from 2139 patients were selected for the current study. Study quality on QUADAS-2 assessment was moderate to high. The summary sensitivity, specificity and area under the receiver operating characteristic curve of 2D-SWE for differential diagnosis of benign and malignant thyroid nodules were 0.66 (95% confidence interval [CI]: 0.64-0.69), 0.78 (CI: 0.76-0.80), and 0.851 (Q* = 0.85), respectively. The pooled diagnostic odds ratio, negative likelihood ratio, and positive likelihood ratio were 12.73 (CI: 8.80-18.43), 0.31 (CI: 0.22-0.44), and 3.87 (CI: 2.83-5.29), respectively.

CONCLUSION

Diagnostic performance of quantitative 2D-SWE for malignancy risk stratification of thyroid nodules is suboptimal with mediocre sensitivity and specificity, contrary to earlier reports of excellence.

Diagnostic Performance of Thyroid Core Needle Biopsy Using the Revised Reporting System: Comparison with Fine Needle Aspiration Cytology

BACKGROUND

We aim to validate the diagnostic performance of thyroid core needle biopsy (CNB) for diagnosing malignancy in clinical settings to align with the changes made in recently updated thyroid CNB guidelines.

METHODS

We retrospectively analyzed 1,381 thyroid CNB and 2,223 fine needle aspiration (FNA) samples. The FNA and CNB slides were interpreted according to the Bethesda System for Reporting Thyroid Cytopathology and updated practice guidelines for thyroid CNB, respectively.

RESULTS

Compared to FNA, CNB showed lower rates of inconclusive results categories I (2.8% vs. 11.2%) and III (1.2% vs. 6.2%), and higher rates of categories II (60.9% vs. 50.4%) and IV (17.5% vs. 2.0%). The upper and lower bounds of the risk of malignancy (ROM) for category IV of CNB were 43.2% and 26.6%, respectively. The CNB subcategory IVb with nuclear atypia had a higher ROM than the subcategory without nuclear atypia (40%-62% vs. 23%-36%). In histologically confirmed cases, there was no significant difference in the diagnostic performance between CNB and FNA for malignancy. However, neoplastic diseases were more frequently detected by CNB than by FNA (88.8% vs. 77.6%, P=0.046). In category IV, there was no difference in unnecessary surgery rate between CNB and FNA (4.7% vs. 6.9%, P=0.6361).

CONCLUSION

Thyroid CNB decreased the rate of inconclusive results and showed a higher category IV diagnostic rate than FNA. The revised guidelines for thyroid CNB proved to be an excellent reporting system for assessing thyroid nodules.

Shear Wave Elastography Combined with Thyroid Imaging Report and Data System for Risk Stratification of Thyroid Nodule Malignant Tumor

Benign and malignant thyroid cancer diagnosis is crucial. Our study intends to evaluate the role of shear wave elastography (SWE) and thyroid imaging report and data system (TI-RADS) in diagnosing the benign and malignant thyroid nodules. 100 thyroid nodules patients were recruited and evaluated by SWE and TI-RADS before fine needle biopsy and/or surgery. The maximum elastic index (Emax), mean elasticity index of thyroid nodules (Emean), minimum elastic index (Emin) and elastic ratio (ER) was measured and compared between different imaging. Ultrasound diagnosis showed solid nodules with significant hypoechoic, unclear boundary, and microcalcification. TI-RADS value was measured based on suspected ultrasound features. Combination of SWE and TI-RADS was performed. Among the 100 nodules, 38 were benign (38.0%), 62 were malignant (62.0%), and malignant nodules had significantly elevated SWE and TI-RADS compared with benign nodules (P < 0.001). The optimal SWE threshold for Emax was 51.95 kPa, with a sensitivity of 81.44% and specificity of 83.19%. There were two methods for combining SWE and TI-RADS. One was sequential detection, with a specificity of 95.80%, positive similarity ratio of 18.16 and PPV of 96.73%; the other was parallel detection method with a sensitivity of 94.85%, negative similarity ratio of 0.07 and PPV of 90.00%. Our results suggest that combination of SWE and TI-RADS might be applied to identify benign and malignant thyroid cancers.

The Value of Negative Diagnosis in Thyroid Fine-Needle Aspiration: a Retrospective Study with Histologic Follow-Up

The Bethesda System for reporting thyroid cytopathology (BSRTC) predicts an incidence of malignancy of less than 5% in thyroid nodules with a benign diagnosis on fine-needle aspiration (FNA). However, recent series have suggested that the true rate of malignancy might be significantly higher in this category of patients. We reviewed our experience by performing a retrospective analysis of patients with benign thyroid FNA results who underwent thyroidectomy between 2008 and 2013 at a large academic center. Information including demographics, ultrasound features, FNA diagnosis, and surgical follow-up information were recorded. Slides were reviewed on cytology-histology discrepant cases, and it was determined whether the discrepancy was due to sampling or interpretation error. A total of 802 FNA cases with a benign diagnosis and surgical follow-up were identified. FNA diagnoses included 738 cases of benign goiter and 64 cases of lymphocytic thyroiditis. On subsequent surgical resection, 144 cases were found to be neoplastic, including 117 malignant cases. False negative, defined as interpretation error and inadequate biopsy of the nodule harboring malignancy, was 6%. When cases of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) were excluded from the analysis, false-negative rate was 5%. When microPTC cases were excluded, false-negative rate was 3% and was slightly less than 3% when both microPTC and NIFTP cases were excluded from the analysis. Retrospective review of neoplastic cases showed that 57% were due to sampling error and 43% were due to interpretation error. Interpretation error was more likely to occur in follicular patterned neoplasms (75%), while sampling error was more common in non-follicular variants of papillary thyroid carcinoma (non-FVPTC) (61%). With the exclusion of microPTC, interpretation errors were still more likely to occur in follicular neoplasms (79%) but there was no significant difference in sampling error between non-FVPTC (37%) and follicular patterned neoplasms (42%). Tumor size was larger in cases with interpretation error (mean = 2.3 cm) compared to cases with sampling error (mean = 1.4 cm). This study shows that the false-negative rate of thyroid FNA at our institution is not significantly above the rate suggested by the BSRTC. Interpretation errors were more likely to occur in follicular patterned neoplasms, while non-FVPTC was more frequently found in false negative cases due to inadequate sampling.

Broadband (550-1350 nm) diffuse optical characterization of thyroid chromophores

Thyroid plays an important role in the endocrine system of the human body. Its characterization by diffuse optics can open new path ways in the non-invasive diagnosis of thyroid pathologies. Yet, the absorption spectra of tyrosine and thyroglobulin–key tissue constituents specific to the thyroid organ–in the visible to near infrared range are not fully available. Here, we present the optical characterization of tyrosine (powder), thyroglobulin (granular form) and iodine (aqueous solution) using a time domain broadband diffuse optical spectrometer in the 550–1350 nm range. Various systematic errors caused by physics of photo migration and sample inherent properties were effectively suppressed by means of advanced time domain diffuse optical methods. A brief comparison with various other known tissue constituents is presented, which reveals key spectral regions for the quantification of the thyroid absorbers in an in vivo scenario.

The role of core needle biopsy in the diagnosis of initially detected thyroid nodules: a systematic review and meta-analysis

OBJECTIVES

To systematically review the published literature and evaluate the efficacy and safety of core needle biopsy (CNB) for initially detected thyroid nodules.

METHODS

The Ovid-MEDLINE and Embase databases were searched for studies evaluating CNB for the diagnosis of initially detected thyroid nodules. A meta-analysis was performed to evaluate non-diagnostic results, inconclusive results and diagnostic accuracy for a diagnosis of malignancy with CNB. To overcome heterogeneity, multiple subgroup analyses were performed. The complication rate was also evaluated.

RESULTS

Thirteen eligible studies, which included a total sample size of 9,166 patients with 13,585 nodules, were included. The pooled proportions were 3.5% (95% CI 2.4-5.1) for non-diagnostic results and 13.8% (95% CI 9.1-20.3) for inconclusive results. Considerable heterogeneity was observed among the studies in terms of the pooled proportions for CNB (I²=92.9%, 97%). With regard to the diagnostic performance for malignancy, the sensitivity was 80% (95% CI 75-85) and the specificity was 100% (95% CI 93-100). Only two major complications of CNB were observed.

CONCLUSIONS

CNB demonstrates a low non-diagnostic result rate and high diagnostic accuracy for initially detected thyroid nodules and a low major complication rate. These findings indicate that CNB may be a feasible diagnostic tool for patients with initially detected thyroid nodules.

KEY POINTS

CNB demonstrates high diagnostic accuracy for initially detected thyroid nodules. CNB demonstrates a low major complication rate. CNB may be a feasible diagnostic tool for patients with initially detected thyroid nodules.

The Bethesda System for Reporting Thyroid Cytopathology Explained for Practitioners: Frequently Asked Questions

BACKGROUND

The recent update of The Bethesda System for Reporting Thyroid Cytology (TBSRTC) is a very important development in the evaluation of thyroid nodules. Clinical experience and scientific literature both show that practitioners performing thyroid fine-needle aspiration are accustomed to basing the clinical management of patients on reports using TBSRTC. Specifically, clinicians are familiar with the percent risk of malignancy corresponding to each TBSRTC diagnostic category (DC), as well as with the respective recommendation for clinical management. However, most clinicians are much less familiar with the specific considerations that lie between a given DC, on the one end, and the respective risk of malignancy and associated management recommendation, on the other end.

SUMMARY

A deeper understanding of the system can enlighten the clinician's thinking about the specific nodule under examination and can guide the decision-making process in a more meaningful way. Such an understanding can only be developed via close two-way communication between cytopathologists and clinicians. Through this type of interaction in the authors' tertiary medical center, recurring issues of particular importance for clinical practice were identified, which are reported here in the form of 16 frequently asked questions posed by the clinician to the cytopathologist.

CONCLUSIONS

For each frequently asked question, an answer is provided based on the literature, the authors' experience, the new version of TBSRTC, and the new World Health Organization classification of tumors of endocrine organs.

The Sensitivity and Specificity of Fine-Needle Aspiration in Thyroid Neoplasia

Objective: To evaluate and demonstrate the accuracy of fine-needle aspiration (FNA) in thyroid lesions in our department and to highlight probable causes of errors leading to unsatisfactory sampling, which may depend on the characteristics of the nodule.

Methods: This is a retrospective study conducted on 319 diagnosed cases of thyroid nodules referred to the Surgery Unit of Puls hospital, Tîrgu Mureș in the January 2014 – December 2015 period, who underwent fine-needle aspiration. Histological examination was considered to be the gold standard; therefore we compared the cytological diagnosis with the histological one.

Results: Of the 319 cases, 289 (90.6%) were female and 30 (9.4%) male patients; 210 cases (69.3%) were interpreted as benign, 46 cases (15.2%) as follicular lesion of undetermined significance, 4 cases (1.3%) as suspect for malignancy, 1 case (0.3%) as malignant sampling, and 42 cases (13.9%) as unsatisfactory. We compared the results of fine-needle aspiration cytology (FNAC) with the corresponding histopathological results (49 in total). FNAC achieved a sensitivity of 76.47%, a specificity of 83.1%, a positive predictive value of 35.1%, a negative predictive value of 96.7%, a false positive rate of 16.9%, a false negative rate of 23%, and an overall accuracy of 82.3%.

Conclusions: The results of our study demonstrate the accuracy of the FNA technique in the first-line diagnosis of thyroid nodules.

The diagnostic ability of core needle biopsy in nodular thyroid disease

INTRODUCTION Non-diagnostic results of fine needle aspiration biopsy (FNAB) remain an important limitation of this technqiue. The aim of our study was to evaluate the results of core needle biopsy (CNB) of thyroid nodules and its effectiveness in non-diagnostic FNAB cases. METHODS CNBs were performed in 1,000 patients (154 male, 846 female; mean age: 50.2 years, range: 18-86 years) with a spring loaded 20G needle. Of these, 143 had initially had FNABs that were insufficient for evaluation. The CNB reports were reviewed. Patients with suspicious or malignant CNB results underwent total thyroidectomy. RESULTS When considering all 1,000 CNBs, the non-diagnostic rate was 1.5% (15/1,000). However, when the first 100 cases were eliminated as a learning curve, this reduced to 0.9% (8/900). Of the 143 cases with initial FNABs that were non-diagnostic, 0.7% (1/143) were also non-diagnostic on CNB. Twelve patients underwent surgery because of malignant CNB reports and all of these cases were confirmed as malignant by the postoperative pathology specimen results (100% accuracy). There were no major complications although three self-limiting minor complications were observed. CONCLUSIONS CNB is a safe and accurate method. It is more diagnostic than FNAB for nodular thyroid disease.

Reproducibility of atypia of undetermined significance/follicular lesion of undetermined significance category using the bethesda system for reporting thyroid cytology when reviewing slides from different institutions: A study of interobserver variability among cytopathologists

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) offers a six-tiered diagnostic scheme for thyroid Fine Needle Aspiration (FNA): Benign, Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance (AUS/FLUS), suspicious for follicular neoplasm, suspicious for malignancy, malignant, and unsatisfactory with an aim to standardize diagnostic criteria. Reported rate of AUS/FLUS category in the literature has varied from 3% to 20.5%.

METHODS

The aim of this study was to assess interobserver variability among cytopathologists to assess reproducibility of the AUS/FLUS category. Seven cytopathologists brought FNA cases (a mixture of atypical and non-atypical FNA diagnosis) diagnosed using TBSRTC from their respective institutions which were reviewed and diagnosed by the participants. The analysis assessed interobserver variability among 7 cytopathologists and determined characteristics on the slides which were associated with concordance to the institutional diagnosis.

RESULTS

Seventy eight of 125 (62.4%) benign cases were classified as benign by the reviewers and 26 (21%) were called AUS/FLUS on review. A third of the AUS/FLUS cases were called benign on review and 28.2% were classified as suspicious for neoplasia/malignancy. Roughly a third each of the suspicious for follicular neoplasm/suspicious for malignancy cases were classified as AUS/FLUS.

DISCUSSION

When pathologists from different institutions shared their slides, concordance was high for specimens with adequate cellularity and those that were clearly benign but thresholds varied for the other indeterminate categories. Most definite categorization of the AUS/FLUS category was seen on review. Diagn. Cytopathol. 2017;45:399-405. © 2017 Wiley Periodicals, Inc.

Cytopathology of Follicular Cell Nodules

The detection of thyroid nodules, consisting of different diseases, represents a common finding in population. Their evaluation and diagnosis are mostly achieved with fine-needle aspiration cytology (FNAC). Even though the majority of thyroid nodules are correctly diagnosed, a total of 25% to 30% of them are classified "indeterminate" comprising lesions with varying risk of malignancy and different types of management. Although the number of thyroid FNACs, including small lesions, is increasing due to the reliance upon sonographic and cytologic interpretations, there are issues concerning cytomorphologic interpretation and interobserver reproducibility. Different classification systems have tried to better define the criteria for inclusion in specific categories and to therefore reduce the rate of indeterminate diagnoses such as atypia of undetermined significance, follicular neoplasms, and suspicious for malignancy. However, the support of ancillary techniques (eg, immunocytochemistry and molecular analysis) are reshaping morphologic diagnoses made on materials obtained from FNAC.

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.

Diagnostic Performance of Shear Wave Elastography Parameters Alone and in Combination with Conventional B-Mode Ultrasound Parameters for the Characterization of Thyroid Nodules: A Prospective, Dual-Center Study

The aims of our study were to determine whether shear wave elastography (SWE) can improve the conventional B-mode differentiation of thyroid lesions, determine the most accurate SWE parameter for differentiation and assess the influence of microcalcifications and chronic autoimmune thyroiditis on SWE values. We examined 119 patients with 169 thyroid nodules who prospectively underwent B-mode ultrasound and SWE using the same ultrasound machine. The parameters assessed using SWE were: mean elasticity within the entire lesion (SWE-whole) and mean (SWE-mean) and maximum (SWE-max) elasticity for a 2-mm-diameter region of interest in the stiffest portion of the lesion, excluding microcalcifications. The discriminant powers of a generalized estimating equation model including B-mode parameters only and a generalized estimation equation model including both B-mode and SWE parameters were assessed and compared using the area under the receiver operating characteristic curve, in association with pathologic verification. In total, 50 and 119 malignant and benign lesions were detected. In generalized estimated equation regression, the B-mode parameters associated with higher odds ratios (ORs) for malignant lesions were microcalcifications (OR = 4.3), hypo-echogenicity (OR = 3.13) and irregular margins (OR = 10.82). SWE-max was the only SWE independent parameter in differentiating between malignant and benign tumors (OR = 2.95). The area under the curve for the B-mode model was 0.85, whereas that for the model combining B-mode and SWE parameters was 0.87. There was no significant difference in mean SWE values between patients with and without chronic autoimmune thyroiditis. The results of the present study suggest that SWE is a valuable tool for the characterization of thyroid nodules, with SWE-max being a significant parameter in differentiating benign and malignant lesions, independent of conventional B-mode parameters. The combination of SWE parameters and conventional B-mode parameters does not significantly improve the diagnosis of malignant thyroid nodules. The presence of microcalcifications can influence the SWE-whole value, whereas the presence of chronic autoimmune thyroiditis may not.

Comparison of the efficacy and safety of ultrasound-guided core needle biopsy versus fine-needle aspiration for evaluating thyroid nodules

OBJECTIVE

Ultrasound-guided core needle biopsy (UG-CNB) is a procedure that is often performed either after repeated inadequate or nondiagnostic ultrasound-guided fine-needle aspiration (UG-FNA) or in combination with UG-FNA in the evaluation of thyroid nodules. The purpose of this study was to compare the efficacy and safety of UG-CNB and UG-FNA for evaluating thyroid nodules.

METHODS

This was a retrospective study of 350 consecutive patients who had thyroid nodules biopsied by UG-CNB or UG-FNA from January 2007 until November 2011 at our institution. Biopsy results were compared to the surgical specimen pathology reports for the 105 patients who subsequently underwent hemi- or total thyroidectomy in order to determine whether UG-CNB has advantages over UG-FNA for diagnosing thyroid malignancy and neoplasia.

RESULTS

Out of 461 thyroid nodules biopsied from 350 patients, 365 (79%) involved UG-CNB and 96 (21%) involved UG-FNA. The UG-FNA biopsy group had a significantly higher rate of inadequate sampling than the UG-CNB group (P<.0001; Fisher's exact test). Out of 365 UG-CNB samples, 6 (2%) were deemed inadequate for histologic diagnosis, whereas 26 (27%) of the 96 UG-FNA samples were considered inadequate for cellularity. Comparison of biopsy results with the surgical specimen pathology reports revealed that the diagnostic accuracy of UG-CNB and UG-FNA for detecting malignancy was similar, at 89 and 94%, respectively (not significant by Fisher's exact test). However, the UG-CNB group had a higher detection rate for benign follicular lesions compared to the UG-FNA group (65% versus 48% for UG-FNA; P = .002). Although UG-FNA detected neoplasia with high sensitivity (100%), the specificity was poor (30%). Neither biopsy group had any significant immediate or delayed procedure-related complications.

CONCLUSION

Our study demonstrated that UG-CNB is safe and is less likely to result in a nondiagnostic biopsy. The accuracy of the UG-CNB technique is similar to that of UG-FNA for detecting thyroid malignancy.

Comparison of diagnostic yield of core-needle and fine-needle aspiration biopsies of thyroid lesions: Systematic review and meta-analysis

Objectives

Thyroid nodular disease is one of the most commonly observed medical conditions. Cytological evaluation of the specimens obtained with fine-needle aspiration biopsy (FNAB) is the most accurate tool for selecting nodules which should be further surgically removed. A major limitation of this method is the high occurrence of non-diagnostic results. This indicates the need for improvement of the thyroid biopsy technique. The aim of this meta-analysis was to compare the diagnostic value of thyroid core-needle biopsies (CNBs) and FNABs.

Materials and methods

PubMed/MEDLINE, Cochrane Library, Scopus, Cinahl, Academic Search Complete, Web of Knowledge, PubMed Central, PubMed Central Canada and Clinical Key databases were searched. Risk ratios (RRs) of non-diagnostic results were meta-analysed using the random-effects model.

Results

Eleven studies were included in the quantitative analysis. CNB yielded significantly more diagnostic results – the pooled risk ratio (RR) of gaining a non-diagnostic result was 0.27 (p<0.0001). For lesions with one previous non-diagnostic FNAB, RR was 0.22 (p<0.0001).

Conclusions

CNB seems to be a valuable diagnostic technique yielding a higher proportion of diagnostic results than conventional FNAB. It is also significantly more effective in case of nodules with a prior non-diagnostic result of FNAB results than repeated FNABs.

Key Points

• Core-needle biopsy yields a higher proportion of diagnostic results than fine-needle biopsy.

• Core-needle biopsies may decrease the amount of unnecessary thyroidectomies.

• Probability of gaining non-diagnostic result using core-needle biopsy is almost four times lower.

Focal Lymphocytic Thyroiditis Nodules Share the Features of Papillary Thyroid Cancer on Ultrasound

PURPOSE

It is often difficult to discriminate focal lymphocytic thyroiditis (FLT) or adenomatous hyperplasia (AH) from thyroid cancer if they both have suspicious ultrasound (US) findings. We aimed to make a predictive model of FLT from papillary thyroid cancer (PTC) in suspicious nodules with benign cytologic results.

MATERIALS AND METHODS

We evaluated 214 patients who had undergone fine-needle aspiration biopsy (FNAB) and had shown thyroid nodules with suspicious US features. PTC was confirmed by surgical pathology. FLT and AH were confirmed through more than two separate FNABs. Clinical and biochemical findings, as well as US features, were evaluated.

RESULTS

Of 214 patients, 100 patients were diagnosed with PTC, 55 patients with FLT, and 59 patients with AH. The proportion of elevated thyrotropin (TSH) levels (p=0.014) and thyroglobulin antibody (Tg-Ab) or thyroid peroxidase antibody (TPO-Ab) positivity (p<0.001) in the FLT group was significantly higher than that in the PTC group. Regarding US features, absence of calcification (p=0.006) and "diffuse thyroid disease" (DTD) pattern on US (p<0.001) were frequently seen in the FLT group. On multivariate analysis, Tg-Ab positivity, presence of a DTD pattern on US, and absence of calcification in nodules were associated with FLT with the best specificity of 99% and positive predictive value of 96%. In contrast, a taller than wide shape of nodules was the only variable significant for differentiating AH from PTC.

CONCLUSION

Suspicious thyroid nodules with cytologic benign results could be followed up with US rather than repeat FNAB, if patients exhibit Tg-Ab positivity, no calcifications in nodules, and a DTD pattern on US.

Digital gene expression profiling of a series of cytologically indeterminate thyroid nodules

BACKGROUND

Fine-needle aspiration cytology (FNAC) has been widely accepted as the most crucial step in the preoperative assessment of thyroid nodules. Testing for the expression of specific genes should improve the accuracy of FNAC diagnosis, especially when it is performed in samples with indeterminate cytology.

METHODS

In total, 69 consecutive FNACs that had both cytologic and histologic diagnoses were collected, and expression levels of 34 genes were determined in RNA extracted from FNAC cells by using a custom digital mRNA counting assay. A supervised k-nearest neighbor (K-nn) learning approach was used to build a 2-class prediction model based on a subset of 27 benign and 26 malignant FNAC samples. Then, the K-nn models were used to classify the 16 indeterminate FNAC samples.

RESULTS

Malignant and benign thyroid nodules had different gene expression profiles. The K-nn approach was able to correctly classify 10 FNAC samples as benign, whereas only 1 sample was grouped in the malignant class. Two malignant FNAC samples were incorrectly classified as benign, and 3 of 16 samples were unclassified.

CONCLUSIONS

Although the current data will require further confirmation in a larger number of cases, the preliminary results indicate that testing for specific gene expression appears to be useful for distinguishing between benign and malignant lesions. The results from this study indicate that, in indeterminate FNAC samples, testing for cancer-specific gene expression signatures, together with mutational analyses, could improve diagnostic accuracy for patients with thyroid nodules.

The Bethesda System for Reporting Thyroid Fine-Needle Aspiration Cytology: A Kuwaiti Experience - A Cytohistopathological Study of 374 Cases

INTRODUCTION

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) identifies 6 diagnostic categories in which the risk of malignancy increases respectively. The aim of our study was to assess TBSRTC reporting in our hospital and to evaluate its specificity based on cytohistological correlation.

METHODS

A histological diagnosis was available in 374 (110 males and 264 females) out of 7,809 thyroid aspirates examined at Mubarak Al-Kabeer Hospital, Kuwait, from 2004 to 2012. The aspirates were classified in accordance with TBSRTC.

RESULTS

Thyroid aspirates were classified as nondiagnostic (n = 18; 4.8%), benign (n = 114; 30.5%); atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS; n = 59; 15.8%), follicular neoplasm/suspicious for follicular neoplasm (FN/SFN; n = 17; 4.5%), suspicious for malignancy (SM; n = 80; 21.4%), or malignant (n = 86; 23.0%). In 75 of 86 malignant cases, a papillary carcinoma was detected. There were 3 (1.6%) false-positive aspirates and the sensitivity, specificity, negative predictive value, and positive predictive value were 91.0, 61.9, 84.2, and 75.3%, respectively.

CONCLUSIONS

Our results are fairly comparable to those of various previous studies in the SM, AUS/FLUS, and SFN categories. The higher rates observed in the nondiagnostic and benign categories were possibly due to limited guided aspirations and a lack of on-site evaluation for all cases.

Molecular characterization of 54 cases of false-negative fine-needle aspiration among 1347 papillary thyroid carcinomas

BACKGROUND

Fine-needle aspiration (FNA) has been widely accepted as the most crucial step in the preoperative assessment of thyroid nodules, but the false-negative rates are generally reported to be between 3.6% and 10.2%. To lower the overall incidence of this false-negative testing, new reporting systems encourage the molecular testing of thyroid nodules. However, to the authors' knowledge, the role of molecular testing in false-negative FNA has not yet been evaluated.

METHODS

In total, 1347 consecutive papillary thyroid carcinomas (PTCs) with both cytological and histological diagnoses were collected from the same center. A blinded revision of the false-negative cases was performed. An analysis of the BRAF and Ras genes in the false-negative cases was then performed.

RESULTS

The false-negative rate at the time of primary FNA diagnosis was 4.8% (65 of 1347 cases). False-negative cases were 15 follicular variant PTCs, 2 classical variant, and 1 solid variant that lacked peculiar PTC cytomorphological features. Adequate cellular material for molecular analysis was available only in 54 of the 65 false-negative cases. Mutations were found in 6 cases (11%), and Ras alterations were present in 16 cases (29.6%). The addition of molecular analysis decreased the false-negative rate to 0.4% (5 of 1347 cases).

CONCLUSIONS

The results of the current study confirm the feasibility of BRAF and Ras analysis in routine FNA. However, when the false-negative FNA rate is low, the cost-benefit analysis of the detection of BRAF and Ras mutations should be carefully evaluated. Consequently, the authors suggest that preoperative molecular assessment could be helpful for benign nodules, but only in the presence of clinical suspicion of malignancy.

Rapid on-site evaluation of fine needle aspiration specimens by cytology scientists: a review of 3032 specimens

OBJECTIVES

To determine: (1) the accuracy of cytology scientists at assessing specimen adequacy by rapid on-site evaluation (ROSE) at fine needle aspiration (FNA) cytology collections; and (2) whether thyroid FNA with ROSE has lower inadequacy rates than non-attended FNAs.

METHODS

The ROSE of adequacy for 3032 specimens from 17 anatomical sites collected over a 20-month period was compared with the final report assessment of adequacy. ROSE was performed by 19 cytology scientists. The report profile for 1545 thyroid nodules with ROSE was compared with that for 1536 consecutive non-ROSE thyroid FNAs reported by the same cytopathologists during the study period.

RESULTS

ROSE was adequate in 75% (2276/3032), inadequate in 12% (366/3032) and in 13% (390/3032) no opinion was rendered. Of the 2276 cases assessed as adequate by ROSE, 2268 (99.6%) were finally reported as adequate for assessment; eight specimens had adequacy downgraded on the final report. Fifty eight per cent of cases with a ROSE assessment of inadequate were reported as adequate (212/366), whereas 93% (363/390) with no opinion rendered were reported as adequate. The overall final report adequacy rate for the 3032 specimens was 94% (2843/3032). Confirmation of a ROSE of adequacy at reporting was uniformly high amongst the 19 scientists, ranging from 98% to 100%. The inadequacy rate for thyroid FNAs with ROSE (6%) was significantly (P < 0.0001) lower than for non-ROSE thyroid FNAs (17%). A significantly (P = 0.02) higher proportion of adequate ROSE thyroid specimens was reported with abnormalities, compared with non-ROSE thyroid collections.

CONCLUSIONS

Cytology scientists are highly accurate at determining specimen adequacy at ROSE for a wide range of body sites. ROSE of thyroid FNAs can significantly reduce inadequate reports.

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.

Comparison of metabolic ratios of urinary estrogens between benign and malignant thyroid tumors in postmenopausal women

Background

Estrogen metabolism may be associated with the pathophysiological development of papillary thyroid carcinoma (PTC).

Methods

To evaluate the differential estrogen metabolism between benign and malignant PTCs, estrogen profiling by gas chromatography–mass spectrometry was applied to urine samples from postmenopausal patients with 9 benign tumors and 18 malignant stage I and III/IV PTCs.

Results

The urinary concentration of 2-methoxyestradiol was significantly lower in the stage I malignant patients (3.5-fold; P < 0.025) than in the benign group. The metabolic ratios of 16α-OH-estrone/estrone and estriol/estradiol, which are responsible for 16α-hydroxylase activity, were increased more than 2.5-fold in the advanced-stage malignant PTC (P < 0.02 each). The more than 6.2-fold decrease in the urinary 2-/16α-hydroxylase ratio in stage III/IV malignant PTC was consistent with the ratio in postmenopausal patients with endocrine gland cancers. In addition, reductive 17β-hydroxysteroid dehydrogenase (17β-HSD; estradiol/estrone or estriol/16α-OH-estrone) was present at significantly higher levels in subjects with stage III/IV malignant PTCs than in benign subjects (>3.5-fold difference; P < 0.002). In particular, the estriol/16α-OH-estrone ratio differentiated between the benign and early-stage malignant patients (P < 0.01).

Conclusions

Increased 16α-hydroxylation and/or a decreased 2-/16α-ratio, as well increased reductive 17β-HSD, with regard to estrogen metabolism could provide potential biomarkers. The devised profiles could be useful for differentiating malignant thyroid carcinomas from benign adenomas in postmenopausal women.

A core needle biopsy provides more malignancy-specific results than fine-needle aspiration biopsy in thyroid nodules suspicious for malignancy

BACKGROUND AND AIMS

The most commonly used diagnostic method for the preoperative diagnosis of thyroid nodules is ultrasound-guided fine-needle aspiration biopsy (FNA), which often yields non-diagnostic or non-definitive results and seldom produces definite malignant diagnoses. To improve upon the malignancy-specific sensitivity, we tested core needle biopsies (CNBs) of thyroid lesions taken from surgical specimens.

MATERIAL AND METHODS

52 consecutive patients with malignant or malignant-suspicious thyroid nodules were referred to Tampere University Hospital between May 2010 and December 2011. Preoperative FNAs were categorised as follicular neoplasm (48%), suspicion for malignancy (46%) or malignancy (6%). Intraoperative FNA and CNB samples were acquired from surgical specimens removed during surgery. The results of the needle biopsies were compared with the final pathological diagnosis.

RESULTS

CNBs had a high definitive sensitivity for malignancy (61%, CI 41% to 78%) whereas the definitive sensitivity for malignancy of FNAs was significantly lower (22%, CI 10% to 42%). CNB was not beneficial in the diagnosis of follicular thyroid lesions. When all suspected follicular tumours were excluded, the definitive sensitivity of CNB rose to 70% (CI 48% to 86%).

CONCLUSIONS

CNB may be beneficial for the diagnosis of papillary thyroid carcinoma and other non-follicular thyroid lesions. CNB may be considered as an additional diagnostic procedure in cases with FNA suspicious for malignancy.

In vivo thyroid vibro-acoustography: a pilot study

Background

The purpose of this study was to evaluate the utility of a noninvasive ultrasound-based method, vibro-acoustography (VA), for thyroid imaging and determine the feasibility and challenges of VA in detecting nodules in thyroid.

Methods

Our study included two parts. First, in an in vitro study, experiments were conducted on a number of excised thyroid specimens randomly taken from autopsy. Three types of images were acquired from most of the specimens: X-ray, B-mode ultrasound, and vibro-acoustography. The second and main part of the study includes results from performing VA and B-mode ultrasound imaging on 24 human subjects with thyroid nodules. The results were evaluated and compared qualitatively.

Results

In vitro vibro-acoustography images displayed soft tissue structures, microcalcifications, cysts and nodules with high contrast and no speckle. In this group, all of US proven nodules and all of X-ray proven calcifications of thyroid tissues were detected by VA. In vivo results showed 100% of US proven calcifications and 91% of the US detected nodules were identified by VA, however, some artifacts were present in some cases.

Conclusions

In vitro and in vivo VA images show promising results for delineating the detailed structure of the thyroid, finding nodules and in particular calcifications with greater clarity compare to US. Our findings suggest that, with further development, VA may be a suitable imaging modality for clinical thyroid imaging.

False negatives in thyroid cytology: impact of large nodule size and follicular variant of papillary carcinoma

OBJECTIVES/HYPOTHESIS

Fine-needle aspiration (FNA) cytology is well established in the diagnosis of thyroid nodules. However, false-negative rates for malignancy of 3% to 10% are reported. The purpose of the present study was to investigate the impact of nodule size and follicular variant of papillary carcinoma (FVPTC) on false-negative FNA rates in thyroid nodules and on malignancy rates in nodules with indeterminate cytology.

STUDY DESIGN

Retrospective study.

METHODS

A total of 765 consecutive ultrasound-guided FNAs were reviewed. Histological correlation was available in 262 cases.

RESULTS

The overall sensitivity of FNA for malignancy was 84%, and the false-negative rate 9.1%. Nodules ≥ 3 cm were significantly more likely to ultimately be diagnosed as cancer by histology than nodules <3 cm (14% vs. 6.8%, P = .006); however, they were also significantly more likely to undergo surgery than smaller nodules (P < .0001). Among the surgical series, the false-negative rate was 10.9% in nodules ≥ 3 cm and 6.1% in nodules <3 cm (P = .71). Most false negatives were due to FVPTC. FVPTC was significantly more likely to be missed by preoperative cytology than conventional or other variants of papillary carcinoma (P < .001). Among cases with indeterminate cytology, nodule size and Thy-3f versus Thy-3a subclassification did not have any significant impact on likelihood of malignancy.

CONCLUSIONS

The sensitivity of FNA for detection of FVPTC is reduced compared to conventional papillary carcinoma. The impact of nodule size is not significant.

LEVEL OF EVIDENCE

4.

Rare tracheal tumors and lesions initially diagnosed as isolated differentiated thyroid cancers

BACKGROUND

Thyroid carcinoma with tracheal invasion is uncommon; however, this is significantly more prevalent than primary tracheal tumors. Rare tracheal tumors at the level of the thyroid can be misinterpreted as invasive thyroid cancer upon initial diagnosis. We present a series of tumors within the tracheal wall that were initially misdiagnosed as isolated, but aggressive, thyroid cancer, and later diagnosed to be different histopathologic entities.

METHODS

The series consisted of four women and five men, all but two age 60 or older, who were initially diagnosed with tracheal invasion from differentiated thyroid carcinoma (DTC). Eight had obstructive airway symptoms and one experienced gagging and choking sensations. Preoperatively, the patients underwent fine-needle aspiration (FNA) and imaging studies. A complete resection of the involved airway in combination with the thyroid gland was performed in all patients.

RESULTS

In this series of patients, the final diagnosis was tracheal stenosis, recurrent laryngeal nerve schwannoma, papillary thyroid carcinoma (PTC) with benign intratracheal thyroid tissue, adenoid cystic carcinoma, and squamous cell carcinoma, each in one patient. Two patients had a tracheal chondrosarcoma, and two patients had collision tumors (PTC with laryngeal squamous cell carcinoma). All patients were misunderstood preoperatively as having isolated DTC with aggressive involvement of the trachea. An accurate diagnosis in these cases was difficult due to misleading FNA readings, thought due to the FNA needle passing through the thyroid before reaching the trachea or a tumor that abuts both structures on imaging. Primary tracheal tumors and a nontumorous lesion, as well as benign thyroidal masses, mimicked invasive thyroid carcinoma in this preoperative setting.

CONCLUSIONS

Various entities other than thyroid cancer can masquerade as invasive thyroid cancer. In patients with an FNA showing thyroid tissue or suggesting PTC, but also have obstructive or other airway symptoms, physician awareness is needed to consider the distinct possibility of a primary tracheal lesion. Obtaining the correct preoperative diagnosis is essential for accurate surgical planning for patients with tracheal tumors.

Directed peer review in surgical pathology

Second pathologist peer review is used in many surgical laboratory quality-assurance programs to detect error. Directed peer review is 1 method of second review and involves the selection of specific case types, such as cases from a particular site of anatomic origin. The benefits of using the directed peer review method are unique and directed peer review detects both errors in diagnostic accuracy and precision and this detection may be used to improve practice. We utilize the Lean quality improvement A3 method of problem solving to investigate these issues. The A3 method defines surgical pathology diagnostic error and describes the current state in surgical pathology, performs root cause analysis, hypothesizes an ideal state, and provides opportunities for improvement in error reduction. Published data indicate that directed peer review practices may be used to prevent active cognitive errors that lead to patient harm. Pathologists also may use directed peer review data to target latent factors that contribute to error and improve diagnostic precision.

Analysis of the bethesda system for reporting thyroid cytopathology and similar precursor thyroid cytopathology reporting schemes

The Bethesda System for Reporting Thyroid Cytopathology is a standardized reporting system for classifying thyroid fine-needle aspiration results comprising of 6 diagnostic categories with unique risks of malignancy and recommendations for clinical management. The majority of thyroid nodules are benign; however, up to 30% of fine-needle aspiration of thyroid nodule results are equivocal. Until 2007, various diagnostic terms were used to classify such cases, including "atypical," "indeterminate," and rule-out or cannot exclude malignancy. A literature review of 13 original studies was conducted to evaluate whether utilization of the Bethesda System for Reporting Thyroid Cytopathology nomenclature represent an improvement over thyroid cytopathology reporting schemes used before 2007 in diagnosing thyroid malignancy. The sensitivity and specificity of thyroid fine-needle aspiration was high in the studies that assessed the measures. However, a selection bias exists and most studies do not include indeterminate diagnosis in their calculations. Although the Bethesda System for Reporting Thyroid Cytopathology recommends a repeat fine-needle aspiration to follow-up nondiagnostic specimens, in the majority of studies, an appreciable number of cases underwent follow-up surgical biopsy or thyroidectomy. The diagnostic category of atypia/follicular lesion of undetermined significance remains heterogenous in terms of usage and clinical outcome. The majority of the studies that utilize the Bethesda System for Reporting Thyroid Cytopathology in this literature review retrospectively reclassified thyroid fine-needle aspiration into the Bethesda System for Reporting Thyroid Cytopathology nomenclature with reported malignancy rates that are similar between cases reclassified as atypia/follicular lesion of undetermined significance and follicular neoplasm/suspicious for follicular neoplasm.

Diagnostic accuracy of fine-needle aspiration versus core-needle biopsy for the diagnosis of thyroid malignancy in a clinical cohort

OBJECTIVES

To retrospectively compare the accuracy of fine-needle aspiration (FNA) and core-needle biopsy (CNB) for the diagnosis of thyroid malignancy

METHODS

We evaluated the results of FNA and CNB in 555 consecutive thyroid nodules with final diagnoses (malignancy 318, benign 237). All patients underwent FNA and CNB simultaneously for each nodule. We assessed the sensitivity, specificity and accuracy of FNA, CNB and FNA/CNB for the diagnosis of thyroid malignancy.

RESULTS

The sensitivity of FNA, CNB and FNA/CNB for thyroid malignancy was 68.6%, 86.8% and 90.6%, specificity 100%, 99.2% and 99.2%, and accuracy 82.0%, 92.1% and 94.2%, respectively. The sensitivity and accuracy of CNB or FNA/CNB for thyroid malignancy were significantly higher than those of FNA (P < 0.001). Compared with CNB alone, FNA/CNB was more accurate for thyroid malignancy only in small nodules less than 1 cm (P < 0.001).

CONCLUSIONS

Our clinical cohort data demonstrated that CNB was more accurate for the diagnosis of thyroid malignancy than FNA, and FNA/CNB was more accurate than CNB alone in small thyroid nodules. CNB will play a complementary role in optimal surgical decision-making and the management of thyroid nodules.

KEY POINTS

• CNB was more accurate for the diagnosis of malignancy than FNA. • Combined FNA/CNB was more accurate than CNB alone in small thyroid nodules. • CNB should play at least a complementary role in managing thyroid nodules.

Prognostic factors and follow-up of patients with differentiated thyroid carcinoma with false negative or nondiagnostic FNAC before surgery. Comparison with a control group

Since the clinical implementation of fine needle aspiration cytology (FNAC) to diagnose thyroid carcinoma, few patients remain misdiagnosed and little is known about their clinical outcomes. An observational retrospective study was carried out to analyse prognostic factors and follow-up of patients with differentiated thyroid carcinoma (DTC) not disclosed by FNAC before surgery, compared to a control group. From October 2003 to July 2010, 308 patients underwent surgery as treatment for nodular goitre and 53 had DTC. Cases were 12 subjects with DTC and benign (n = 7) or nondiagnostic (n = 5) FNAC. Controls were 39 subjects with DTC and suspicious (n = 19) or malignant (n = 20) FNAC. Prognostic factors, recurrence and survival rates were compared. Cases had longer time from FNAC to surgery than the control group (86.8 ± 74.1 vs. 16.4 ± 23.8 weeks; P < 0.001), higher prevalence of follicular carcinoma (33.3 vs. 2.6%; P = 0.009), and of two-time total thyroidectomy (75 vs. 30.8%; P = 0.016). Average follow-up was 42.7 ± 25.3 months (2-86 months). There were no deaths. Disease-free survival for cases was 66.9 ± 5.8 months, and for controls 78.7 ± 3.9 months (P: ns). In patients with DTC, the result of the FNAC performed before surgery was not an independent predictor of recurrences or mortality in the first 7 years of follow-up. Thus, false negative or nondiagnostic FNAC in a patient with DTC does not seem to be a primary prognostic factor, but it may reveal other adverse prognostic factors such as longer time to therapy and higher prevalence of follicular carcinoma that may influence long-term outcomes.

The impact of implementation of the Bethesda System for Reporting Thyroid Cytopathology on the quality of reporting, "risk" of malignancy, surgical rate, and rate of frozen sections requested for thyroid lesions

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has been anticipated to improve communication between pathologists and clinicians and thereby patient outcomes. In the current study, the impact of TBSRTC on various quality and outcome measures was assessed.

METHODS

The current study included all patients who underwent fine-needle aspiration (FNA) of the thyroid between April 2006 and April 2009. Before implementation, the authors used generic diagnostic categories; after implementation, TBSRTC was used. Quality of reporting, diagnostic categories, rate of surgery, rates of frozen section, the "risk" of malignancy after a cytologic diagnosis, and errors before and after implementation of TBSRTC were compared using the chi-square and Fisher exact tests. Multilevel likelihood ratios and the receiver operating characteristic were used to compare the accuracy of FNA before and after implementation.

RESULTS

A total of 1671 FNAs (957 obtained before and 714 obtained after implementation of TBSRTC) were obtained from 1339 patients. Of these, 301 patients (191 before and 110 after implementation) underwent subsequent surgical resection. Before implementation, the reports were more ambiguous (3.7% vs 0.5%; P < .05) and implicit (5.1% vs 2.7%; P < .05) than after implementation. The overall rate of surgery decreased after implementation of TBSRTC (24.5% vs 19.6%; P < .05). The overall risk of malignancy did not appear to be affected by implementation of TBSRTC, but it decreased significantly after a benign FNA diagnosis compared with a diagnosis of an atypical lesion or follicular neoplasm. The rate of frozen section remained unchanged. The diagnostic accuracy was not found to be significantly different before compared with after implementation of TBSRTC.

CONCLUSIONS

Implementation of TBSRTC appears to improve the quality of reporting by lowering the number of ambiguous and implicit diagnoses and decreases the overall surgery rates, particularly for benign lesions, but it does not appear to have any effect on the accuracy of FNA of the thyroid, false-positive rates, or the frequency of intraoperative consultations.

Role of core needle biopsy and ultrasonographic finding in management of indeterminate thyroid nodules

BACKGROUND

Thyroid fine-needle aspiration (FNA) is used as a screening test of choice for evaluation of thyroid nodules. However, approximately 15% to 25% of the cases are classified as indeterminate, posing dilemmas in decision-making. This study was designed to compare the diagnostic performances of second FNA and core needle biopsy of indeterminate nodules by initial FNA.

METHODS

From February 2005 through June 2009, 258 patients who completed scheduled follow-ups were enrolled and the follow-up results were analyzed.

RESULTS

Nondiagnostic results were obtained in 41.8% of the second FNA group and in 1.7% of the core needle biopsy group (p < .001; chi-square). The nodules that show borderline features in preoperative ultrasonography had a malignancy rate of 18.3% and could be identified successfully with core needle biopsy.

CONCLUSION

Core needle biopsy is a better method for evaluating indeterminate nodules by initial FNA than second FNA, especially in patients with ultrasonographic findings of a borderline nodule.

Ultrasonographic characteristics predictive of nondiagnostic results for fine-needle aspiration biopsies of thyroid nodules

The objective of this study was to identify clinical and ultrasonographic (US) characteristics predictive of nondiagnostic results. An experienced radiologist performed an US-guided fine-needle aspiration biopsy (US-FNA) for 1493 thyroid nodules in 1419 patients. Cytological results were classified as nondiagnostic (<6 groups of cells containing more than 10 cells) or diagnostic. The clinical characteristics of patients and the US features of thyroid nodules were compared according to nondiagnostic or diagnostic results. Age and sex were not associated with nondiagnostic results. A cystic portion >50% and hypoechogenicity were independent factors for predicting nondiagnostic results in all nodules (odds ratios [OR] = 2.82 and 1.88, respectively). In 534 nodules with more than 50% of cystic portion, the size of more than 10 mm and in 813 solid nodules, the size of 5 mm or smaller increased the likelihood of nondiagnostic results (ORs = 3.61 and 1.88, respectively).

[Epidemiology, pathophysiology, guideline-adjusted diagnostics, and treatment of thyroid nodules]

BACKGROUND

Clinically relevant thyroid carcinomas can be found in 5-6% of nodular goiters which undergo surgery. Moreover, multinodular goiters fre- quently contain hot areas. Therefore, efficient and rational methods for the differential diagnosis and decision are required to identify those nodules with an increased cancer risk or those which are hot among the many thyroid nodules.

METHODS

Description of a newly revised and further guidelines and consensus statements as well as selected literature search.

RESULTS

Already history, ultrasound and TSH (thyroid-stimulating hormone) determination do allow a first risk assessment for the further diagnostic work-up. Fine-needle biopsy (FNB) offers the best sensitivity and specificity for the distinction between benign and malignant thyroid nodules. The combination of several clinical and ultrasound criteria and laboratory determinations (calcitonin) can help with the selection of thyroid nodules with scintigraphically normal or decreased uptake > 1 cm for FNB. However, the efficiency of FNB requires sufficient training and experience of both the cytopathologist and the person performing FNB.

CONCLUSION

Whereas solitary thyroid nodules with a suspicion for malignancy should be referred to the surgeon, euthyroid thyroid nodules without clinical ultrasound or cytological indicators of malignancy may be followed up - possibly under medication -, if surgery is not indicated by local complaints, tracheal or mediastinal involvement.