Improved preoperative definitive diagnosis of papillary thyroid carcinoma in FNAs prepared with both ThinPrep and conventional smears compared with FNAs prepared with ThinPrep alone

Advances in diagnostic liquid-based cytology

Liquid-based cytology (LBC) has changed the landscape of gynaecological cytology. A growing demand exists for LBC in diagnostic cytology, particularly for ancillary testing, such as immunocytochemistry and molecular testing. Ancillary testing solely based on conventional preparation (CP) methods remains challenging. Recently, the increased demand for specialist testing and minimally invasive techniques, such as endoscopic ultrasonography fine-needle aspiration, to obtain cellular samples has led to an increasing demand for ancillary testing on cytology LBC supernatant, slides and cell block (CB). This facilitates the diagnosis and prognosis in cytology samples enabling personalized treatment. An understanding of the history and future prospects of LBC is crucial for its application in routine diagnostics by cytopathologists and cytotechnologists. In this review, we initiated an internet search using the keyword 'liquid-based cytology', and we conducted a literature review to discuss the usefulness of combined diagnosis of LBC and CP, immunocytochemistry and molecular testing and assessed the quality of nucleic acids in diagnostic LBC. High-quality and cell-rich diagnostic LBC surpassed the CP method alone in terms of reliability and versatility of ancillary testing in cytological diagnosis. Conclusively, diagnostic LBC lends itself to various new technologies and is expected to continue evolving with innovations in the future.

Comparison of Liquid-Based Preparations with Conventional Smears in Thyroid Fine-Needle Aspirates: A Systematic Review and Meta-Analysis

BACKGROUND

To compare conventional smears (CSs) and liquid-based preparations (LBPs) for diagnosing thyroid malignant or suspicious lesions.

METHODS

Studies in the PubMed, SCOPUS, Embase, Web of Science, and Cochrane database published up to December 2023. We reviewed 17 studies, including 15,861 samples.

RESULTS

The diagnostic odds ratio (DOR) for CS was 23.6674. The area under the summary receiver operating characteristic curve (AUC) was 0.879, with sensitivity, specificity, negative predictive value, and positive predictive value of 0.8266, 0.8668, 0.8969, and 0.7841, respectively. The rate of inadequate specimens was 0.1280. For LBP, the DOR was 25.3587, with an AUC of 0.865. The sensitivity, specificity, negative predictive value, and positive predictive value were 0.8190, 0.8833, 0.8515, and 0.8562. The rate of inadequate specimens was 0.1729. For CS plus LBP, the AUC was 0.813, with a lower DOR of 9.4557 compared to individual methods. Diagnostic accuracy did not significantly differ among CS, LBP, and CS plus LBP. Subgroup analysis was used to compare ThinPrep and SurePath. The DORs were 29.1494 and 19.7734. SurePath had a significantly higher AUC.

CONCLUSIONS

There was no significant difference in diagnostic accuracy or proportion of inadequate smears between CS and LBP. SurePath demonstrated higher diagnostic accuracy than ThinPrep. Recommendations for fine-needle aspiration cytology should consider cost, feasibility, and accuracy.

Usefulness of cellblock preparation in fine needle aspiration for the diagnosis of thyroid nodules

BACKGROUND

Thyroid nodules are common in the general population. The current diagnostic method for nodules is the ultrasound guided fine needle aspiration (US-FNA). The aim of the study was to evaluate the usefulness of cellblock preparation in addition to routine US-FNA in the diagnosis of thyroid nodules.

METHODS

A retrospective study of patients with thyroid nodules submitted to US-FNA, with collection of material using both smears and cellblock preparation. Two air-dried smears were prepared for each nodule. After centrifugation, the residual aspirate in the syringe and needle was processed as a standard histology specimen (cellblock). Then a pathologist reviewed the smears and cellblock slides of each case.

RESULTS

A total of 12.360 thyroid nodules were submitted to US-FNA. Cellblock preparation was performed in 153 (1.2%) in addition to smears. Among the satisfactory cellblocks (80.5%, 120), 31.7% (38) provided additional morphological information in comparison with smears alone. No significant differences were found between the smear and the combined smear and cellblock evaluation concerning the number of unsatisfactory (12.1% vs. 11.4%, p = .85) and indeterminate (27.5% vs. 24.2%, p = .52) results. Overall, 10 samples (6.7%) had their diagnosis changed after cellblock evaluation, nine of them due to immunohistochemical studies. Immunohistochemistry confirmed parathyroid origin of the nodule in six cases.

CONCLUSION

Cellblocks did not contribute to increase cellularity of the samples or to reduce indetermined results of FNA of thyroid nodules. Immunohistochemistry was essential to characterize rare cases without follicular histogenesis. Cellblock must only be prepared when considering performing immunohistochemistry.

Subclassification of the Bethesda Category III (AUS/FLUS): A study of thyroid FNA cytology based on ThinPrep slides from the National Cancer Center in China

BACKGROUND

The atypia of an undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) category in the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is a heterogeneous category, which includes various cell patterns. The subclassification of AUS/FLUS was suggested in the 2017 TBSRTC. However, the risk of malignancy (ROM) associated with different subgroups remains unresolved. Herein, AUS/FLUS aspirates were subclassified, from which the ROM of each subgroup was determined.

METHODS

All cases undergoing fine-needle aspiration (FNA) from July 2013 to December 2018 were reviewed. Of 12,913 thyroid FNAs, 1053 (8.2%) were AUS/FLUS. The slides of 222 patients with AUS/FLUS with surgical follow-up were reviewed and subclassified according to the recommendations of the 2017 TBSRTC. There were 195 aspirates consistently diagnosed as AUS/FLUS and subclassified as cytologic atypia 1 (AUS-C1); cytologic atypia 2 (AUS-C2); architectural atypia (AUS-A); cytologic and architectural atypia (AUS-C&A); Hürthle cell aspirates (AUS-H); atypia, not otherwise specified (AUS-NOS); and atypical lymphoid cells, rule out lymphoma (AUS-L).

RESULTS

Malignancy was identified in 83.3% (185 of 222) of the AUS/FLUS nodules. The AUS-C1 group was the most common (62.1%), followed by the AUS-C&A (12.8%), AUS-C2 (10.8%), AUS-H (6.7%), AUS-NOS (5.6%), AUS-L (1.5%), and AUS-A (0.5%) groups. AUS-C1 had the highest ROM (92.6%) among the groups and varied significantly from that of the AUS-C&A (P = .171), AUS-C2 (P = .001), AUS-H (P = .001), and AUS-NOS (P < .001) groups.

CONCLUSIONS

As a heterogeneous category of TBSRTC, the ROM for AUS/FLUS varies greatly among medical centers. Subclassification of AUS/FLUS might be helpful in identifying nodules with a high ROM in this category and improving the management of such nodules.

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.

Computerized Cytological Features for Papillary Thyroid Cancer Diagnosis-Preliminary Report

Fine needle aspiration cytology (FNAC) is the final diagnosis of thyroid nodules before surgery. It is important to further improve the indeterminate FNAC diagnosis results using computerized cytological features. This retrospective cross-sectional study included 240 cases, of whom 110 had histologic diagnosis of papillary thyroid cancers (PTC), 100 had nodular/adenomatous goiters/hyperplasia (benign goiters), 10 had follicular/Hurthle cell carcinomas, and 20 had follicular adenomas. Morphological and chromatic features of FNAC were quantified and analyzed. The result showed that six quantified cytological features were found significantly different between patients with a histologic diagnosis of PTC and patients with histologic diagnosis of benign goiters in multivariate analysis. These cytological features were used to estimate the malignancy risk in nodules with indeterminate FNAC results. The Area Under the Receiver Operating Characteristics (AUROC) of the diagnostic accuracy with a benign or malignant nature was 81.3% (p < 0.001), 78.7% (p = 0.014), and 56.8% (p = 0.52) for nodules with FNAC results of atypia, which is suspicious for malignancy and follicular neoplasm, respectively. In conclusion, quantification of cytological features could be used to develop a computer-aided tool for diagnosing PTC in thyroid nodules with indeterminate FNAC results.

Assessment of The Bethesda System for Reporting Thyroid Cytopathology

OBJECTIVES

Long-term follow-up is important for determining performance characteristics of thyroid fine-needle aspiration (FNA).

METHODS

Histologic or 3 or more years of clinical follow-up was used to calculate performance characteristics of thyroid FNA before and after implementation of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). The impact of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) classification was also investigated.

RESULTS

Follow-up was obtained for 1,277/1,134 and 1,616/1,393 aspirates/patients (median clinical follow-up, 9.9 and 4.4 years, pre- and post-TBSRTC, respectively). Nondiagnostic, suspicious for follicular neoplasm, and suspicious for malignancy (SFM) diagnoses decreased and benign diagnoses increased post-TBSRTC, while atypical rate remained less than 1%. Negative predictive value for benign nodules and positive predictive value (PPV) for SFM increased significantly. Eleven nodules were reclassified as NIFTP, slightly decreasing PPV/risk of malignancy (ROM).

CONCLUSIONS

Appropriate ROM for thyroid FNA can be achieved through application of TBSRTC terminology with minimal use of atypical category.

Is thyroid nodule volume predictive for malignancy?

OBJECTIVE

We aimed to determine the roles of preoperative thyroid nodule diameter and volume in the prediction of malignancy.

SUBJECTS AND METHODS

The medical records of patients who underwent thyroidectomy between January 2007 and December 2014 were reviewed. The nodule diameters were grouped as < 1 cm, 1-1.9 cm, 2-3.9 cm and ≥ 4 cm, and volume was grouped as > 5 cm3, 5-9.9 cm3 and > 10 cm3. ROC (Receiver Operating Characteristic) curve analysis was performed to find the optimal cutoff value of diameter and volume that can predict malignancy.

RESULTS

There were 5561 thyroid nodules in 2463 patients. Five hundred and forty (9.7%) nodules were < 1 cm, 2,413 (43.4%) were 1-1.9 cm, 1,600 (28.8%) were 2-3.9 cm and 1,008 (18.1%) were ≥ 4 cm. Malignancy rates were 25.6%,10.6%, 9.7% and 8.5% in nodules < 1 cm, 1-1.9 cm, 2-3.9 cm and ≥ 4 cm, respectively. When classified according to volume, 3,664 (65.9%) nodules were < 5 cm3, 594 (10.7%) were 5-9.9 cm3 and 1,303 (23.4%) were ≥ 10 cm3. The malignancy rates were 12.7%, 11.4% and 7.8% for the nodules < 5 cm3, 5-9.9 cm3 and ≥ 10 cm3, respectively (p < 0.001). In ROC curve analysis, an optimal cutoff value for diameter or volume that can predict malignancy in all thyroid nodules or nodules ≥ 4 cm could not be determined.

CONCLUSION

In this surgical series, malignancy risk did not increase with increasing nodule diameter or volume. Although the volume of malignant nodules ≥ 4 cm was higher than that of benign nodules ≥ 4 cm, there was no optimal cutoff value. The diameter or volume of the nodule cannot be used to predict malignancy or decide on surgical resection.

Statement and Recommendations on Interventional Ultrasound as a Thyroid Diagnostic and Treatment Procedure

The recently published guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on interventional ultrasound (INVUS)-guided procedures summarize the intended interdisciplinary and multiprofessional approach. Herewith, we report on recommendations for interventional procedures for diagnosis and treatment of the thyroid gland.

Can liquid-based preparation substitute for conventional smear in thyroid fine-needle aspiration? A systematic review based on meta-analysis

OBJECTIVE

Conventional smear (CS) using fine-needle aspiration cytology (FNAC) has been established as the test of choice for diagnosing thyroid lesions, despite low sample adequacy and inter-individual variations. Although a liquid-based preparation (LBP) technique has been recently applied to overcome these limitations, its clinical utility and its accuracy over CS are controversial. This study aimed to determine the true sensitivity and specificity of LBP in thyroid FNAC by meta-analysis.

DESIGN

Systematic review with meta-analysis.

METHODS

We searched major electronic databases (MEDLINE, EMBASE, Cochrane library, Google Scholar) with queries of 'thyroid', 'LBP' and 'liquid-based cytology'. Original articles including cytohistologic correlation data comparing the accuracy of any LBP technique, such as ThinPrep, SurePath and Liqui-Prep, with CS were included for qualitative meta-analysis and preparation of synthesized reporter-operating curves (sROC).

RESULTS

A total of 372 studies were screened and 51 original articles were eligible for full-text review; finally, 24 studies were chosen for the meta-analysis. Average sample inadequacy was significantly lower in two mainstream LBP methods (ThinPrep and SurePath) than CS. Specificity and sensitivity by sROC were similar or slightly superior for LBP vs CS. Various cytomorphologic changes by each method have been reported.

CONCLUSIONS

Although a learning curve is essential for adapting to the cytomorphologic features of the LBP technique, our results support the use of two mainstream LBPs alone in thyroid FNAC that LBP will increase the sample adequacy and reduce the workload with similar accuracy. More data and further evaluation are needed for the other LBP methods.

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Evaluation and management of thyroid nodules in children

PURPOSE OF REVIEW

The review is focused on new information about the presentation and management of thyroid nodules in children and adolescents.

RECENT FINDINGS

Palpable thyroid nodules are uncommon in children but many children have nodules detected by radiologic imaging. How to evaluate them, when to suspect thyroid cancer, and how best to follow apparently benign nodules has become an area of great interest. The American Thyroid Association recently published treatment guidelines for children with thyroid nodules and cancers but much has been learned since that publication.

SUMMARY

Personal and family history, ultrasound features, and fine needle aspiration cytology are used to determine the risk of cancer in thyroid nodules, which are then managed according to cancer risk.

Fine needle aspiration cytology guided by ultrasound in the diagnosis of subcentimetre thyroid nodules

Background

This study aimed to investigate the value of fine needle aspiration biopsy (FNAB) under ultrasound guidance in diagnosis of thyroid nodules. In a retrospective analysis of FNAB in 1050 cases of patients with 1100 nodules, patients were divided according to the maximum diameter of their nodules into two groups: >1.0 and ≤1.0 cm. The ultrasound-guided FNAB cytology results were compared between two groups.

Results

Ultrasound findings showed that among 1100 thyroid nodules, 547 were highly suspicious, 358 were moderately, 175 were low, and 19 were very low. Cytology results showed papillary carcinomas in 453, possible papillary cancer in 126 cases, follicular tumors in 26, suspicious follicular tumors in 6, atypical cells in 7, nodular goiter in 289, colloid in 13, chronic lymphocytic thyroiditis in 175, and undiagnosed specimen in 5. Ultrasound diagnosis of thyroid nodules had an overall sensitivity of 86.0 %, and a specificity of 81.9 %. In nodules larger than 1.0 cm, the sensitivity was 92.8 %, and the specificity 92.3 %. In nodules ≤1.0 cm, the sensitivity was 82.4 %, and the specificity was 81.7 %.

Conclusions

Patients with highly suspicious thyroid nodules on ultrasonography, regardless of nodule sizes, should receive ultrasound-guided FNAB to confirm their natures and direct clinical managements.

Combined use of conventional smear and liquid-based preparation versus conventional smear for thyroid fine-needle aspiration

The purpose of the study was to compare the diagnostic utility of the combined conventional smear (CS) and liquid-based preparation (LBP) compared to CS with respect to the non-diagnostic rate, the atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) rate, and the diagnostic performances for malignancy. This retrospective study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. In our institution, thyroid FNAs were processed with CS before October 2012, and LBP has been used in combination with CS after October 2012. On-site evaluation for the adequacy of CS was not performed. This study included nodules 5 mm or larger with FNAs performed by faculties: 811 nodules in 773 patients for CS, and 926 nodules in 894 patients for combined CS and LBP. Nodules with surgery or either benign or malignancy cytology on initial or repeat FNA were regarded to have the reference standards needed to calculate diagnostic performances. The proportion of Bethesda categories and diagnostic performances were compared between the two groups with z test. The non-diagnostic rate, the AUS or FLUS rate, and the diagnostic performances for malignancy were similar (All P > 0.05). The follicular neoplasm (FN) or suspicious for FN rate decreased from 1.2 to 0.3 % (P = 0.034). The benign rate increased from 51.4 to 57.0 % (P = 0.019). Combined CS and LBP decreased FN or suspicious for FN diagnoses, and increased benign diagnoses compared to CS with comparable non-diagnostic rates and AUS or FLUS rates, and comparable diagnostic performances.

Thyroid nodules with repeat nondiagnostic cytologic results: the role of clinical and ultrasonographic findings

OBJECTIVES

Ultrasound-guided fine-needle aspiration (FNA) is the most valuable procedure in the diagnosis of thyroid nodules. One possible result of FNA of thyroid nodules, however, is "nondiagnostic" cytology. In these cases, consensus guidelines suggest repeating FNA with ultrasound guidance, but the results obtained may continue to be nondiagnostic. These results cause confusion due to the fact that there exist conflicting potential treatment modalities, such as performing diagnostic surgery or recommending follow-up. Hence, the present study aimed to establish a protocol for performing diagnostic operations for thyroid nodules with repeat nondiagnostic cytology.

MATERIALS AND METHODS

This study was performed on patients who underwent ultrasound-guided FNA and molecular testing for BRAF gene mutation. Out of 1,203 patients, 84 had nondiagnostic cytology and were BRAF negative, and ultrasound-guided FNA was repeated on these patients. Out of this group, 54 patients once again had nondiagnostic cytology, and 51 of these underwent diagnostic surgery. We analyzed the characteristics and ultrasonographic findings of the group of patients with repeat nondiagnostic cytology.

RESULTS

On the initial ultrasound-guided FNA, the percentage of patients with nondiagnostic cytology was 6.98 %, and on repeat ultrasound-guided FNA, the percentage of patients with nondiagnostic cytology was 67.5 %. The majority of these patients underwent diagnostic surgery, and 36 (70.6 %) patients were diagnosed as having a malignant thyroid nodule, while15 (29.4 %) patients were diagnosed with a benign nodule. Univariate analysis showed a significant difference in the size of the nodule, hypoechogenicity, and microcalcification in the ultrasonography findings. Multivariate analysis revealed only hypoechogenicity as a factor that showed a significant difference (p value 0.017, 95 % confidence interval 1.494-62.426).The diagnostic accuracy of the ultrasonography was 76.5 %.

CONCLUSIONS

Hypoechogenicity on ultrasonography represents an excellent parameter for the selection of those who should be referred for diagnostic operation among patients with thyroid nodules and repeat nondiagnostic cytology.

Diagnostic value of liquid-based cytology with fine needle aspiration specimens for cervical lymphadenopathy

Background

Cervical lymphadenopathy is a symptom that is frequently seen among outpatients, and it is important to differentiate malignant lesions from reactive lymphoid hyperplasia. Fine needle aspiration (FNA) cytology has been widely used for the diagnosis of cervical lymphadenopathy. However, some limitations of the diagnostic accuracy using conventional smear (CS) cytology have been pointed out. The diagnostic value of liquid‐based cytology (LBC) with FNA specimens has not yet been fully proven.

Methods

Forty‐two patients with cervical lymphadenopathy who underwent FNA with CS cytology from 2007 to 2011 and 123 patients who underwent FNA with LBC utilizing LBCPREP2™ from 2011 to 2015 were studied. Diagnostic values were compared between the CS and the LBC groups.

Results

Of the total 165 patients representing the combined CS and LBC groups, 81 (49.1%) were diagnosed as benign lymph node and 84 (50.9%) were malignant diseases including 37 (22.4%) of metastatic carcinoma except for thyroid carcinoma, 30 (18.2%) of metastatic thyroid carcinoma, and 17 (10.3%) of malignant lymphoma. The overall statistical values including sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the CS were 75%, 100%, 100%, 78.9%, and 87.1%, respectively, whereas those values for LBC were 91.2%, 100%, 100%, 90.7%, and 95.3%, respectively. The sensitivity of LBC for malignant diseases tended to be higher than that of CS cytology (p = 0.081).

Conclusion

LBC with FNA specimens from cervical lymphadenopathy is a useful and reliable method for the diagnosis of malignant diseases, especially of metastatic carcinomas, due to its increased sensitivity compared with CS cytology. Diagn. Cytopathol. 2016;44:169–176. © 2016 Wiley Periodicals, Inc.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

Shear-Wave Elastography for the Preoperative Risk Stratification of Follicular-patterned Lesions of the Thyroid: Diagnostic Accuracy and Optimal Measurement Plane

PURPOSE

To evaluate the diagnostic accuracy of shear-wave elastography (SWE) for the diagnosis of malignancy in follicular lesions and to identify the optimal SWE measurement plane.

MATERIALS AND METHODS

The institutional review board approved this HIPAA-compliant, single-institution, prospective pilot study. Subjects scheduled for surgery after a previous fine-needle aspiration report of "atypia of undetermined significance" or "follicular lesion of undetermined significance," "suspicion for follicular neoplasm," or "suspicion for Hurthle cell neoplasm," were enrolled after obtaining informed consent. Subjects underwent conventional ultrasonography (US), Doppler evaluation, and SWE preoperatively, and their predictive value for thyroid malignancy was evaluated relative to the reference standard of surgical pathologic findings.

RESULTS

Thirty-five patients (12 men, 23 women) with a mean age of 55 years (range, 23-85 years) and a fine-needle aspiration diagnosis of atypia of undetermined significance or follicular lesion of undetermined significance (n = 16), suspicion for follicular neoplasm (n = 14), and suspicion for Hurthle cell neoplasm (n = 5) were enrolled in the study. Male sex was a statistically significant (P = .02) predictor of malignancy, but age was not. No sonographic morphologic parameter, including nodule size, microcalcification, macrocalcification, halo sign, taller than wide dimension, or hypoechogenicity, was associated with malignancy. Similarly, no Doppler feature, including intranodular vascularity, pulsatility index, resistive index, or peak-systolic velocity, was associated with malignancy. Higher median SWE tissue Young modulus estimates from the transverse insonation plane were associated with malignancy, yielding an area under the receiver operating characteristic curve of 0.81 (95% confidence interval: 0.62, 1.00) for differentiation of malignant from benign nodules. At a cutoff value of 22.3 kPa, sensitivity, specificity, positive predictive value, and negative predictive value of 82%, 88%, 75%, and 91%, respectively, were observed.

CONCLUSION

This prospective pilot study indicates that SWE may be a valuable tool in preoperative malignancy risk assessment of follicular-patterned thyroid nodules.

Molecular analysis of residual ThinPrep material from thyroid FNAs increases diagnostic sensitivity

BACKGROUND

Molecular testing for genetic alterations associated with malignancy is a potential triage approach for thyroid fine-needle aspiration (FNA) samples with indeterminate cytology. Because liquid-based FNA material allows for efficient RNA extraction, the authors analyzed residual material for common point mutations and rearrangements.

METHODS

Thyroid FNAs were classified according to The Bethesda System for Reporting Thyroid Cytopathology after routine ThinPrep slide preparation. Residual samples from malignant and indeterminate cases were submitted for molecular analysis, along with a random cohort of nondiagnostic and benign aspirates. Blinded analysis of BRAF and RAS point mutations and RET/PTC and PAX8/PPARγ rearrangements was correlated with subsequent follow-up.

RESULTS

Adequate results were obtained in 402 of 597 cases (67%). Mutations or rearrangements were detected in 24 of 117 cytologically indeterminate specimens (21%) (17 RAS rearrangements, 6 BRAF rearrangements, and 1 PAX8/PPARγ rearrangement). BRAF mutations were preferentially associated with malignant cytologic diagnoses (22 of 42 cases; 52%), with less frequent detection in the suspicious for malignancy category (4 of 27 cases; 15%) and very low detection in all other categories (1%-4%). Surgical follow-up confirmed malignancy in all 21 BRAF-mutated cases, 42% of RAS-mutated cases (10 of 24 cases), and 37% of cases with no detected mutation (39 of 105 cases).

CONCLUSIONS

Molecular analysis is feasible on residual ThinPrep material with the advantage of not requiring additional FNA procedures. The majority of BRAF mutations are identified in cases classified cytologically as malignant, and, to a lesser extent, as suspicious for malignancy. The usefulness of BRAF testing is limited by the low rate of BRAF-positive cases in other categories, thereby highlighting the need to identify other genetic drivers of clinically aggressive thyroid cancers.

Thyroid cytopathology with an emphasis on the 'atypical cells of uncertain significance' category: a 3-year audit with cytohistologic correlation

BACKGROUND

The National Cancer Institute meeting of 2007 resulted in the reporting terminology for thyroid cytopathology. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) aims to standardise thyroid cytopathology reporting for cytology centres and clinicians alike.

STUDY OBJECTIVE

To compare our laboratory's performance against TBSRTC. The second aim was to determine our laboratory's atypia of undetermined significance/follicular cells of undetermined significance (AUS/FLUS) reporting rate and malignant outcomes. Our laboratory subclassifies the AUS/FLUS category into AUS/FLUS not otherwise specified (NOS) and AUS/FLUS cannot exclude malignancy.

MATERIALS

All thyroid reports were retrieved from our computerised database for the period of January 1, 2008 to March 31, 2011. Histologic correlation was obtained where available, and cases were classified according to their original diagnosis into 1 of the 6 categories of TBSRTC.

RESULTS

A total of 1,767 cases were retrieved. The categories were as follows: inadequate (n=415; 23%), benign (n=1,063; 60%), AUS/FLUS (n=141; 8%) [NOS (n=93; 5%) and cannot exclude malignancy (n=48; 3%)] suspicious for follicular/Hürthle cell neoplasm (n=68; 4%), suspicious for malignancy (n=37; 2%) and malignant (n=43; 2%). The malignant rates for the categories were as follows: -6 (26%), 0 (0%), 8 (40%), 9 (38%), 11 (42%), 15 (62.5%), and 15 (94%), respectively.

CONCLUSION

We have shown that the AUS category carries a higher malignant rate than that of the AUS category in TBSRTC of 5-15%. We conclude that subclassifying the AUS/FLUS category into NOS and cannot exclude malignancy helps to better identify patients with an increased risk of malignancy in the AUS/FLUS cannot exclude malignancy category.

Thyroid "atypia of undetermined significance" with nuclear atypia has high rates of malignancy and BRAF mutation

BACKGROUND

"Atypia of undetermined significance" (AUS) in the Bethesda System for Reporting Thyroid Cytopathology is a heterogeneous category for cases that cannot be easily classified into benign, suspicious, or malignant. This study evaluated whether cytomorphology-based subcategorization could better predict the malignancy risk in cases designated as AUS, and how the subcategories correlated with BRAF mutation status in thyroid fine-needle aspirates (FNA).

METHODS

Of 3589 cases of thyroid FNA diagnosed at the authors' institution in Seongnam, Korea, from January 2010 to December 2011, 331 cases of AUS were reviewed and subcategorized based on cytomorphological features, including nuclear atypia (NA), microfollicle formation (MF), Hürthle cell change (HC), and others (O). The malignancy rate of each subcategory was calculated using cases with histologic follow-up. Pyrosequencing was conducted to detect BRAF mutations.

RESULTS

Malignancy was histologically proven in 23.3% (77 of 331) of cases diagnosed as AUS. In cytomorphology-based subcategories, the rate of malignancy was 30.8% (66 of 214) for AUS-NA, 14.5% (8 of 55) for AUS-O, 4.8% (2 of 42) for AUS-MF, and 5% (1 of 20) for AUS-HC. The BRAF V600E mutation was found in 40% (48 of 120) of AUS-NA, 30.8% (4 of 13) of AUS-HC, 6.7% (1 of 15) of AUS-O, and 2.8% (1 of 35) of AUS-MF.

CONCLUSIONS

The AUS-NA subcategory was associated with the highest risk of malignancy and the greatest frequency of BRAF V600E (substitution of valine to glutamic acid at position 600) mutation. These findings suggest that subcategorization of AUS by cytomorphology and BRAF V600E mutation status is important for predicting the risk of malignancy.

Implementation of the Bethesda System for Reporting Thyroid Cytopathology: observations from the 2011 thyroid supplemental questionnaire of the College of American Pathologists

CONTEXT

Although information about the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has been widely disseminated since its inception in 2007, the extent of its implementation and impact on daily practice has not been formally evaluated.

OBJECTIVES

To assess the extent of uptake of TBSRTC across pathology laboratories and to evaluate its impact on daily practice by collating participant responses to the 2011 supplemental thyroid questionnaire of the College of American Pathologists.

DESIGN

A questionnaire was designed to gather information about various aspects of TBSRTC and mailed in June 2011 to 2063 laboratories participating in the College of American Pathologists cytopathology interlaboratory comparison program. The participating laboratories' answers were collated and summarized.

RESULTS

Seven hundred and seventy-seven laboratories (37.6%) returned the survey. Although 60.9% (n = 451) and 17.1% (n = 127) of laboratories reported using TBSRTC or planning to use it in the near future, respectively, 22% (n = 163) had no plans to implement TBSRTC. Of the latter, 32% (n = 70) stated that they were unaware of this classification system. The majority (78.3%, n = 343) of the laboratories used TBSRTC as published in the Thyroid Bethesda System atlas, whereas 21.7% (n = 95) used it with minor modifications. Most reported that the use of TBSRTC had caused either no change (n = 67, 15.2%) or only minor changes (n = 353, 80.2%) in the terminology and diagnostic criteria previously used in their laboratories.

CONCLUSIONS

According to the collected data, TBSRTC is generally well implemented in pathology laboratories. However, because approximately a third of those not using this terminology are not aware of it, additional educational efforts regarding TBSRTC are warranted.

Thyroid Fine-Needle Aspiration Reporting Rates and Outcomes Before and After Bethesda Implementation Within a Combined Academic and Community Hospital System

Context.—The current study compares data from our hospital system before and after the 2008 implementation of the Bethesda System for Reporting Thyroid Cytology (BSRTC).

Objective.—To show the effects the BSRTC has had on the reporting rates and outcomes for thyroid lesions.

Design.—A search for thyroid fine-needle aspiration biopsies (FNABs) was performed for 2002–2005 (before BSRTC) and 2009–2011 (after BSRTC). Diagnostic outcomes were reviewed for cases with available follow-up.

Results.—For 2002–2005, cytology reports for 3302 thyroid FNABs were reviewed, and 309 (9.4%) were classified as suspicious. For 2009–2011, cytology reports for 3432 thyroid FNABs were reviewed; 72 (2.1%) were classified as “atypia of undetermined significance or follicular lesion of undetermined significance” (AUS/FLUS), and 142 (4.1%) were classified as suspicious. Follow-up material was available for 31 AUS/FLUS cases (43.0%), and 6 of these cases (19%) were malignant. Follow-up material was available for 60 cases (42.3%) classified as suspicious, and 23 of these cases (38%) were malignant.

Conclusions.—The AUS/FLUS rate of 2.1% at our institution is at the lower range of the &lt;7% recommended by the BSRTC, and our rate of 19% for risk of malignancy for AUS/FLUS is slightly above the BSRTC recommendation of 5% to 15%. Implementation of the BSRTC did not significantly affect our institution's reporting rates, most likely because an essentially similar classification system was employed before implementation of the BSRTC.

Performance differences between conventional smears and liquid-based preparations of thyroid fine-needle aspiration samples: analysis of 47,076 responses in the College of American Pathologists Interlaboratory Comparison Program in Non-Gynecologic Cytology

CONTEXT

Controversy exists about whether thyroid fine-needle aspirates (FNAs) should be processed with conventional smears or liquid-based preparations (LBPs).

OBJECTIVE

To compare the performance of conventional smears to LBPs for thyroid FNA slides circulated in the College of American Pathologists Interlaboratory Comparison Program in Non-Gynecologic Cytology.

DESIGN

Participant responses for thyroid FNA slides were compared with the reference diagnosis at the level of 3 general diagnostic categories: negative, suspicious (which included only follicular and Hürthle cell neoplasm), and malignant. For specific reference diagnoses of benign/goiter and papillary thyroid carcinoma, the participants' specific diagnoses were analyzed and poorly performing slides were rereviewed.

RESULTS

The 47, 076 thyroid FNA slide responses, between 2001 and 2009, included 44, 478 responses (94%) for conventional smears and 2598 responses (6%) for LBPs. For the general reference category negative, participant responses were discrepant in 14.9% of conventional smears compared with 5.9% for LBPs (P < .001). The specific reference diagnosis of benign/goiter was misdiagnosed as a follicular neoplasm in 7.8% of conventional smears, compared with 1.3% of LBP. For the general reference category of malignant, participant responses were discrepant in 7.3% of conventional smears compared with 14.7% of LBPs (P < .001). The specific reference diagnosis of papillary thyroid carcinoma was misdiagnosed as benign/goiter in 7.2% of LBPs, compared with 4.8% of conventional smears (p <.001).

CONCLUSIONS

LBPs performed worse than conventional smears for cases with a reference diagnosis of papillary thyroid carcinoma. However, LBPs performed better than conventional smears for cases with a benign reference diagnosis. Specific features in thyroid FNAs that may improve the diagnostic accuracy of LBPs and conventional smears are described.

BRAF mutation detection in indeterminate thyroid cytology specimens: underlying cytologic, molecular, and pathologic characteristics of papillary thyroid carcinoma

BACKGROUND

BRAF mutations are highly specific for papillary thyroid carcinoma (PTC) and many cytology specimens with BRAF mutations are expected to demonstrate cytologic features typical of PTC. However, indeterminate thyroid cytology cases are inevitable and understanding the significance of the BRAF mutation within the context of the Bethesda System for Reporting Thyroid Cytopathology would be valuable.

METHODS

Thyroid cytology cases submitted for conventional cytomorphologic evaluation and BRAF mutational analyses were selected from the authors' cytopathology files from April 2007 to October 2011. From this group, the diagnostic usefulness of BRAF mutations in indeterminate and malignant cases was assessed and analyses of cytologic and histopathologic features associated with the mutations in this gene were performed.

RESULTS

A total of 131 cases with a BRAF mutation were identified. Of these, 119 underwent surgical pathology resection follow-up and demonstrated PTC. Approximately 75% of the cases were cytologically diagnosed as being positive for malignancy and these cases were associated with both the classic and tall cell variants of PTC at the time of resection, a greater likelihood of extrathyroidal extension, and the V600E type of BRAF mutation. In contrast, BRAF-mutated cases with diagnoses of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) and follicular neoplasm/suspicious for follicular neoplasm were found to be more strongly associated with the follicular variant of PTC, a K601E BRAF mutation, and a lower likelihood of extrathyroidal extension. However, a subset of AUS/FLUS cases with the V600E BRAF mutation appeared to represent sampling variability of the classic or tall cell variants of PTC.

CONCLUSIONS

Bethesda thyroid diagnoses in the setting of a BRAF mutation reflect differences in PTC subtypes, the nature of cytology specimens, and molecular characteristics.

Atypia of undetermined significance and nondiagnostic rates in The Bethesda System for Reporting Thyroid Cytopathology are inversely related

There is substantial variation in the reported rates of different diagnostic categories in The Bethesda System for Reporting Thyroid Cytopathology (TBS). Specifically, the relationship between the nondiagnostic (ND) and atypia of undetermined significance (AUS) categories has not been closely examined previously. Data from published series in the literature and from 2 separate hospitals with more than 15,000 thyroid aspirates were reviewed. The AUS and ND rates were consistently negatively correlated when analyzed by year, aspirator, and cytologist. The strongest correlation was with cytologists (P < .0003). Absolute ND rates decreased by 1% for every 3.5% increase in AUS, implying the existence of a discrete population of cases that cytologists will classify as ND or AUS. As such, AUS and ND are not independent variables. Awareness of this relationship may be useful for laboratories and individual cytopathologists for refining the use of TBS.

Eliminating the "Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance" category from the Bethesda System for Reporting Thyroid Cytopathology

The "Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance (AUS/FLUS)" category in the Bethesda System for Reporting Thyroid Cytology is heterogeneous and includes both specimens with borderline cellularity/compromised quality and those with genuine atypia. We have used a reporting scheme that is similar to the Bethesda System but does not include an AUS/FLUS category. We retrospectively reviewed all reports on thyroid FNA and thyroidectomy specimens submitted to the Beth Israel Deaconess Medical Center from January 2006 to December 2008. The positive predictive values for various categories and subcategories in this scheme demonstrate that the AUS/FLUS category can be eliminated to provide information for the most appropriate management of patients with thyroid nodules.