COVID-19 pandemic impact on cytopathology practice in the post-lockdown period: An international, multicenter study.

BACKGROUND: In a previous worldwide survey, the authors showed a drastic reduction in the number of cytological specimens processed during the coronavirus disease 2019 "lockdown" period along with an increase in malignancy rates. To assess the continued impact of the pandemic on cytological practices around the world, they undertook a second follow-up worldwide survey collecting data from the post-lockdown period (2020). METHODS: Participants were asked to provide data regarding their cytopathology activity during the first 12 weeks of their respective national post-lockdown period (2020), which ranged from April 4 to October 31. Differences between the post-lockdown period and the corresponding 2019 period were evaluated, and the authors specifically focused on rates of malignant diagnoses. RESULTS: A total of 29 respondents from 17 countries worldwide joined the survey. Overall, a lower number of cytological specimens (n = 236,352) were processed in comparison with the same period in 2019 (n = 321,466) for a relative reduction of 26.5%. The overall malignancy rate showed a statistically significant increase (12,442 [5.26%] vs 12,882 [4.01%]; P < .001) during the same time period. Similar results were obtained if both malignancy and suspicious for malignancy rates were considered together (15,759 [6.58%] vs 16,011 [4.98%]; P < .001). CONCLUSIONS: The data showed a persistent reduction in the cytological specimen volume during the post-lockdown period (2020). However, the relative increase in the cytological workload in the late part of the post-lockdown is a promising finding of a slow return to normality.

Thyroid FNA terminology: The case for a single unified international system for thyroid FNA reporting.

The use of reporting terminologies for thyroid FNA cytology enables standardisation and international alignment of the reporting of thyroid cytology results, which is essential. There are currently three major internationally recognised systems: Bethesda (TBS), UK RCPath (Thy), and Italian (TIR). A fourth terminology system used in Japan has identical categories to TBS but with different nomenclature. The aim of this review is to discuss the strengths and weaknesses of the TBS, UK RCPath, and TIR systems, and to make the case for international terminology harmonisation and standardisation.

The dilemma of 18F-FDG PET/CT thyroid incidentaloma: what we should expect from FNA. A systematic review and meta-analysis.

PURPOSE: 18F-FDG thyroid incidentaloma (TI) occurs in ~2% of PET/CT examinations with a cancer prevalence of up to 35-40%. Guidelines recommend fine-needle aspiration cytology (FNA) if a focal 18F-FDG TI corresponds to a sonographic nodule >1 cm. The aim of this systematic review and meta-analysis was to provide evidence-based data on the diagnostic distribution of 18F-FDG TIs in the six Bethesda systems for reporting thyroid cytopathology (BETHESDA) subcategories. METHODS: Original studies reporting 18F-FDG TIs and cytologically classified according to BETHESDA were included. Six separate meta-analyses were performed to obtain the pooled prevalence (95% confidence interval, 95% CI) of 18F-FDG TIs in the six BETHESDA subcategories. RESULTS: Fifteen studies were finally included. Nine studies were from Asian/Eastern and six from Western countries. FNA data according to BETHESDA was available in 2304 cases. The pooled prevalence of 18F-FDG TIs according to BETHESDA was BETHESDA I 10% (6-14), BETHESDA II 45% (37-53), BETHESDA III 8% (3-13), BETHESDA IV 8% (5-12), BETHESDA V 6% (4-9), BETHESDA VI 19% (13-25). A significantly different prevalence was found in the BETHESDA IV between Asian/Eastern (2%) and Western (19%) studies. CONCLUSION: Two-thirds of focal 18F-FDG TIs undergoing FNA have either malignant (BETHESDA VI) or benign (BETHESDA II) cytology while a minority will have indeterminate (BETHESDA III or IV) FNA results. Significant differences between Asian/Eastern and Western studies are also present in the prevalence of indeterminate FNA results.

Should uncertainty concerning the risk of malignancy be included in diagnostic (nongynecologic) cytopathology reports?

In diagnostic cytology, the known site-specific false positive rates at various anatomical sites for the risk malignancy (ROM) when a confirmed malignant diagnosis is made are comparatively well documented. ROM figures for diagnostic cytology specimens may vary according to the anatomical site of the specimen, the exact nature of the specimen received, the staining method(s) used, and the use of additional laboratory techniques including molecular profiling; furthermore, they often differ to some extent from institution to institution, between differing cytologists within the same institution, and over time. A brief literature review for a selected group of routine diagnostic cytology specimens shows a published ROM for a confirmed malignant diagnosis as follows: bile duct brushings, ~99% (range, 97%-100%); breast fine needle aspiration, 98.5% (range, 92%-100%); serous effusion fluid, 98.9% (range, 90%-100% although lower for squamous cell carcinoma, mesothelioma, and lymphoma), pulmonary endobronchial ultrasound cytology, ~99% (range, 86.6%-100%); thyroid FNA, 98% (range, 97%-99% if NIFTP tumors are excluded), salivary gland FNA, ~90%; (range 57%-100%) and lateral neck cyst FNA, ~99% (range, 95.5%-100%). Because most diagnostic cytology specimens have a small but accepted false-positive rate, this information is vitally important for the clinical management of patients and for shared patient decision making. In our view, the known false-positive rate for a given diagnostic cytology specimen could be included within the cytology report to assist in explaining the limitations of the diagnostic cytology interpretation and help facilitate the clinical decision-making process.

Data set for reporting carcinoma of the thyroid: recommendations from the International Collaboration on Cancer Reporting.

Thyroid cancer therapy is increasingly tailored to patients' risk of recurrence and death, placing renewed importance on pathologic parameters. The International Collaboration on Cancer Reporting (ICCR), an organization promoting evidence-based, internationally agreed-upon standardized pathology data sets, is the ideal conduit for the development of a pathology reporting protocol aimed at improving the care of patients with thyroid carcinomas. An international expert panel reviewed each element of thyroid pathology reporting. Recommendations were made based on the most recent literature and expert opinion.The data set uses the most recent World Health Organization (WHO) classification for the purpose of a more clinically and prognostically relevant nomenclature. One example is the restriction of the term minimally invasive follicular carcinoma to tumors with capsular invasion only. It reinforces the already established criteria for blood vessel invasion adopted by the most recent WHO classification and Armed Forces Institute of Pathology fascicle. It emphasizes the importance of the extent of blood vessel invasion and extrathyroid extension to better stratify patients for appropriate therapy. It is the first data set that requires pathologists to use the more recently recognized prognostically powerful parameters of mitotic activity and tumor necrosis. It highlights the importance of assessing nodal disease volume in predicting the risk of recurrence.The ICCR thyroid data set provides the tools to generate a report that will guide patient treatment in a more rational manner aiming to prevent the undertreatment of threatening malignancies and spare patients with indolent tumors the morbidity of unnecessary therapy. We recommend its routine use internationally for reporting thyroid carcinoma histology.

Hürthle Cells on Fine-Needle Aspiration Cytology Are Important for Risk Assessment of Focally PET/CT FDG Avid Thyroid Nodules.

This study assesses the role of [18F] FDG PET/CT, fine needle aspiration (FNA) cytology and ultrasound in the 1-2% of patients with focally positive thyroid nodules on FDG PET/CT. All FDG PET/CT scans with focally increased thyroid FDG PET/CT uptake performed over 37 months in one institution were matched to patients undergoing thyroid FNA. Diffuse FDG PET/CT uptake patients were excluded. A total of 47 patients showed focally increased thyroid uptake. Consistent with previous studies, 18 (38.2%) patients had malignancy-12 primary thyroid carcinoma, 1 parathyroid carcinoma, 3 metastatic carcinoma to the thyroid and 2 lymphoma. A total of 15 (31.9%) lesions categorized as non-malignant contained Hürthle cells/oncocytes. A total of 14 lesions (29.8%) had focally increased FDG PET/CT uptake with no specific cytological or histopathological cause identified. No focally PET avid Hürthle cell/oncocytic lesions were found to be malignant. Exclusion of oncocytic lesions increased the calculated risk of malignancy (ROM) of focally PET avid nodules from 38% to 68%. It may be useful to exclude focally FDG PET/CT avid Hürthle cell/oncocytic lesions, typically reported as follicular neoplasm or suspicious for a follicular neoplasm, Hürthle cell type (Oncocytic) type, RCPath Thy 3F: Bethesda IV or sometimes Thy 3a: Bethesda III FNAs) from ROM calculations. Oncocytic focally PET/CT FDG avid lesions appear of comparatively lower risk of malignancy and require investigation or operation but these lesions should be readily identified by FNA cytology on diagnostic work up of focally PET avid thyroid nodules.

Litigation in thyroid cytology and histopathology in England: a very brief overview.

This brief review discusses legal issues in thyroid cytology and histopathology in England. The principal risks in thyroid cyto/histopathology are either underdiagnosis of a malignant condition as benign, overdiagnosis of a benign condition as malignant, or the failure to recognise or the overdiagnosis as malignant of a benign or inflammatory condition. There are multiple diagnostic pitfalls in both cytology and histopathology and these are reasonably well documented. The interobserver reproducibility as assessed by kappa statistics of some of the major criteria for malignancy, specifically papillary-type nuclei in the diagnosis of papillary thyroid carcinoma, capsular invasion or vascular invasion are comparatively poor hence diagnoses of well differentiated papillary or follicular carcinoma may often be to some extent subjective. This article reviews the current legal situation in England discussing recent legal case precedents with a suggestion for improving communication and the preoperative consent process for patients.

Global impact of the COVID-19 pandemic on cytopathology practice: Results from an international survey of laboratories in 23 countries.

BACKGROUND: To the authors' knowledge, the impact of the coronavirus disease 2019 (COVID-19) pandemic on cytopathology practices worldwide has not been investigated formally. In the current study, data from 41 respondents from 23 countries were reported. METHODS: Data regarding the activity of each cytopathology laboratory during 4 weeks of COVID-19 lockdown were collected and compared with those obtained during the corresponding period in 2019. The overall number and percentage of exfoliative and fine-needle aspiration cytology samples from each anatomic site were recorded. Differences in the malignancy and suspicious rates between the 2 periods were analyzed using a meta-analytical approach. RESULTS: Overall, the sample volume was lower compared with 2019 (104,319 samples vs 190,225 samples), with an average volume reduction of 45.3% (range, 0.1%-98.0%). The percentage of samples from the cervicovaginal tract, thyroid, and anorectal region was significantly reduced (P < .05). Conversely, the percentage of samples from the urinary tract, serous cavities, breast, lymph nodes, respiratory tract, salivary glands, central nervous system, gastrointestinal tract, pancreas, liver, and biliary tract increased (P < .05). An overall increase of 5.56% (95% CI, 3.77%-7.35%) in the malignancy rate in nongynecological samples during the COVID-19 pandemic was observed. When the suspicious category was included, the overall increase was 6.95% (95% CI, 4.63%-9.27%). CONCLUSIONS: The COVID-19 pandemic resulted in a drastic reduction in the total number of cytology specimens regardless of anatomic site or specimen type. The rate of malignancy increased, reflecting the prioritization of patients with cancer who were considered to be at high risk. Prospective monitoring of the effect of delays in access to health services during the lockdown period is warranted.

A human factor event-based learning assessment tool for assessment of errors and diagnostic accuracy in histopathology and cytopathology.

This review article summarises systems for categorisation of diagnostic errors in pathology and cytology with regard to diagnostic accuracy and the published information on human factors (HFs) in pathology to date. A 12-point event-based checklist for errors of diagnostic accuracy in histopathology and cytopathology is proposed derived from Dupont's 'Dirty Dozen' HF checklist, as used in the aerospace industry for aircraft maintenance. This HF checklist comprises 12 HFs; (1) Failure of communication. (2) Complacency. (3) Lack of knowledge. (4) Distractions. (5) Lack of teamwork. (6) Fatigue. (7) Lack of resources. (8) Pressure. (9) Lack of assertiveness. (10) Stress. (11) Norms. (12) Lack of awareness. The accompanying article explains practical examples of how each of these 12 HFs may cause errors in diagnostic accuracy in pathology. This checklist could be used as a template for analysis of accuracy and risk of diagnostic error in pathology either retrospectively 'after the event' or prospectively at the time of diagnosis. There is a need for further evaluation and validation of this proposed 12-point HF checklist and similar systems for categorisation of diagnostic errors and diagnostic accuracy in pathology based on HF principles.

Measures to reduce diagnostic error and improve clinical decision making in thyroid FNA aspiration cytology: A proposed framework.

Thyroid fine-needle aspiration cytology (FNA) and histopathology can be subjective areas of medical diagnosis and subject to different interpretations. On the basis of the authors' personal experience, 12 recommendations with potential to improve clinical decision making, ensure quality, and reduce diagnostic error in thyroid FNAC and histopathology are presented. 1) use a standardized reporting terminology for thyroid FNAC; 2) understand and explain to service users the limitations of cytology and the standardized thyroid FNAC reporting terminology used; 3) the cytopathologist should review all relevant clinical and ultrasound findings, if feasible; 4) include the risk of malignancy in all FNAC reports if feasible; 5) collect data to calculate the local institutional risk of malignancy for FNAC if feasible; 6) accept that nondiagnostic FNAC will include small numbers of carcinomas; 7) use rapid on-site evaluation and/or educational sessions for aspirators if the nondiagnostic aspiration rate is high; 8) know the diagnostic pitfalls of both cytology and histopathology; 9) use special immunohistochemical and molecular techniques that are evidence-based; 10) make use of second opinions, either in-house or interinstitutional; 11) multidisciplinary discussion of cases before surgery or therapy is invaluable; and, finally, 12) manage patient and clinician expectations of thyroid cytology and histopathology. These 12 recommendations may assist in quality-improvement initiatives and may reduce diagnostic errors in thyroid cytology and histopathology. Thyroid multidisciplinary case discussion remains the principal, overarching method for error reduction and for providing high-quality clinical decision making.

Thyroid FNA: Is cytopathologist review of ultrasound features useful?

Cytopathologist review of thyroid ultrasound (US) has been proposed to be useful in diagnosis and patient triage. This review explores the implications for practicing cytopathologists of integrating US review into the thyroid fine-needle aspiration diagnosis. At present, there is no agreed-upon system for combining cytologic and US features and communicating those results as a single report. If cytologists are performing tasks that require expertise in US interpretation, then they should know and be fully conversant with US interpretation. Whether cytologists performing aspirations require expertise in US interpretation is not clear. Regardless, cytologists should avoid using US results to alter their cytologic interpretations unless they clearly communicate that this is what they are doing. An evidence-based integrated reporting system that would allow cytologists to clearly explain to other physicians exactly how they reached their interpretation might provide value beyond current standard practice.

Rates of Thy 1-non-diagnostic thyroid fine needle aspiration using the UK Royal College of Pathologists Thy Terminology. A systematic review of the literature comparing patients who undergo rapid on-site evaluation and those who do not.

INTRODUCTION: The UK Royal College of Pathologists (RCPath) Thy terminology is an internationally recognised system for reporting thyroid fine needle aspiration. The terminology has been used throughout the UK and Ireland, in some parts of Italy and Switzerland, and elsewhere in the world. There is no systematic review of the literature specifically addressing the use of the non-diagnostic for cytological diagnosis-Thy1/Thy 1c category in the UK RCPath terminology. METHODS: A comprehensive literature search of online databases was conducted in October 2019 specifically examining overall reported rates of Thy1 and Thy1c in aspirates classified according to the UK Thy terminology. RESULTS: Twenty-five articles were identified showing a Thy1 rate of 13.4% (2540/18 920). The studies were then stratified according to whether or not the patients underwent rapid on-site evaluation (ROSE): 6.0% (353/5841; range 3.0%-10.9%) of ROSE aspirates were Thy1 whereas 18.5% (2072/11 204; range 7.9%-43.3%) of non-ROSE patients were Thy1; (P < .05). Three studies from 2016 reported Thy1c rates of 5.4%, 6.5% and 10.6%, respectively, implying Thy1 rates excluding Thy1c aspirates of 20.9%, 8.7% and 12.7%, respectively. CONCLUSION: This systematic review of the literature shows relatively high rates of aspirates non-diagnostic for cytological diagnosis-Thy1 in the peer-reviewed published literature using the UK terminology. Utilisation of ROSE appears to produce lower rates of Thy1 aspirates and ROSE should be considered if rates of non-diagnostic for cytological diagnosis-Thy1/Thy 1c are high.

Risk of malignancy in the various categories of the UK Royal College of Pathologists Thy terminology for thyroid FNA cytology: A systematic review and meta-analysis.

BACKGROUND: The UK Royal College of Pathologists Thy terminology for reporting thyroid fine-needle aspiration cytology (FNAC), first published in 2009 is used throughout the United Kingdom and Ireland, in some parts of Italy and Switzerland and elsewhere. There is no review of the literature or meta-analysis of the risk of malignancy (ROM) in the various categories of the UK Thy terminology. The goal of this study was to establish the published ROM for each Thy category and compare the results with other existing terminology systems for which similar meta-analyses are available. METHODS: A comprehensive literature search of online databases was conducted in May 2019 to examine the ROMs for histologically proven nodules with preoperative FNAC classified according to the UK Thy terminology. RESULTS: Twenty-five articles were identified that showed results of both cytology and histology. Twelve of these articles were excluded to prevent a selection bias because they showed data in just 1 Thy category. In the remaining 13 articles, the pooled ROMs were as follows: Thy1, 12% (95% confidence interval [CI], 5%-22%); Thy2, 5% (95% CI, 3%-9%); Thy3, 22% (95% CI, 18%-26%); Thy3a, 25% (95% CI, 20%-31%); Thy3f, 31% (95% CI, 24%-39%); Thy4, 79% (95% CI, 70%-87%); and Thy5, 98% (95% CI, 97%-99%). CONCLUSIONS: This meta-analysis shows results comparable to those of meta-analyses of other internationally recognized reporting terminologies for the pooled ROMs for surgically excised nodules in the various Thy reporting categories. There is comparatively little difference (only 6%) between the pooled ROMs of Thy3a and Thy3f surgically excised nodules.

A feasibility trial of Acetic acid-targeted Biopsies versus nontargeted quadrantic biopsies during BArrett's surveillance: the ABBA trial.

BACKGROUND: The aims of this study were to compare neoplasia detection rates for nontargeted biopsies (Seattle protocol) versus acetic acid-targeted biopsies (Portsmouth protocol) during Barrett's surveillance and to explore feasibility, patient/clinician experience, acceptance, and barriers/enablers to study participation and implementation of the acetic acid technique. METHODS: This was a mixed-methods feasibility study including a pilot multicenter, randomized, crossover trial with qualitative interviews. Patients under Barrett's surveillance with no history of neoplasia were included. Patients underwent two endoscopies, one with each protocol, 8 weeks apart. Outcomes included recruitment and retention rates, neoplasia yield, and number of biopsies. RESULTS: 200 patients were recruited from 6 centers, and 174 (87.0 %) underwent both procedures. Neoplasia prevalence was 4.7 % (9/192). High grade dysplasia and cancer were detected with both protocols. Five low grade dysplasias were detected (two with acetic acid, four with nontargeted biopsies; one lesion was detected with both techniques). A total of 2139 biopsies were taken in the nontargeted arm and 226 in the acetic acid arm. Both patients and clinicians found the acetic acid technique acceptable. Based on these data, a noninferiority, tandem, crossover trial would require an estimated 2828 patients. CONCLUSIONS: We demonstrated the feasibility of performing a crossover endoscopy trial in Barrett's surveillance. Low neoplasia yield makes this design necessary and qualitative results demonstrated patient and clinician acceptance. The reduced numbers of biopsies suggest that the acetic acid technique could result in cost savings, providing the lack of missed pathology can be proven in a fully powered definitive trial.

An International Interobserver Variability Reporting of the Nuclear Scoring Criteria to Diagnose Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features: a Validation Study.

The aim of the study was to assess interobserver variation in reporting nuclear features of encapsulated follicular variant of papillary thyroid carcinoma, newly reclassified as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), based on a proposed standardized scoring system. An education module was individually reviewed as a pre-evaluation teaching guide of the specific features of classical papillary carcinoma, the specific inclusion and exclusion features for the diagnosis of NIFTP, and a catalog of the standardized scoring system of the nuclear features of papillary carcinoma used to reach this diagnosis. Participants subsequently reviewed 30 cases of thyroid lesions previously scored by members of the Endocrine Pathology Society Working Group for the Re-evaluation of the Encapsulated Follicular Variant of Papillary Thyroid Carcinoma. There was one uninvolved reference image to demonstrate fixation, processing, and cell size and one image from each case for scoring, with results recorded for each participant. The location of training (country and program), years as a practicing pathologist, and approximate number of thyroid gland surgical cases diagnosed per year were recorded. The degree of agreement between participants was assessed by kappa statistics, using the individual criteria and the average composite scores of the Working Group as a point of comparison. Using the Nuclear Standardized Scoring System, the interobserver agreement for final diagnosis score was generally excellent: unweighted and weighted kappa values between individual observers ranging from 0.242 to 0.930 (average 0.626). There was significant agreement between observers in reaching an interpretation of the presence or absence of nuclear features to diagnose NIFTP (score 0-1 versus score of 2-3), with California pathologists, 0.63 (median 0.66, SD 0.15); Japanese pathologists, 0.64 (median 0.66, SD 0.16); and UK pathologists, 0.60 (median 0.57, SD 014) compared to the expert panel, 0.70 (median 0.73, SD 0.19). The use of the nuclear scoring system to evaluate the nuclear features of papillary thyroid carcinoma as applied to reach the diagnosis of NIFTP shows a good to substantial interobserver agreement, suggesting that consensus can be reached in diagnosing the nuclear features required for this newly reclassified neoplasm.

Acetic acid-guided biopsies in Barrett's surveillance for neoplasia detection versus non-targeted biopsies (Seattle protocol): A feasibility study for a randomized tandem endoscopy trial. The ABBA study.

BACKGROUND AND STUDY AIMS: Barrett's esophagus is a potentially pre-cancerous condition, affecting 375,000 people in the UK. Patients receive a 2-yearly endoscopy to detect cancerous changes, as early detection and treatment results in better outcomes. Current treatment requires random mapping biopsies along the length of Barrett's, in addition to biopsy of visible abnormalities. As only 13 % of pre-cancerous changes appear as visible nodules or abnormalities, areas of dysplasia are often missed. Acetic acid chromoendoscopy (AAC) has been shown to improve detection of pre-cancerous and cancerous tissue in observational studies, but no randomized controlled trials (RCTs) have been performed to date. PATIENTS AND METHODS: A "tandem" endoscopy cross-over design. Participants will be randomized to endoscopy using mapping biopsies or AAC, in which dilute acetic acid is sprayed onto the surface of the esophagus, highlighting tissue through an whitening reaction and enhancing visibility of areas with cellular changes for biopsy. After 4 to 10 weeks, participants will undergo a repeat endoscopy, using the second method. Rates of recruitment and retention will be assessed, in addition to the estimated dysplasia detection rate, effectiveness of the endoscopist training program, and rates of adverse events (AEs). Qualitative interviews will explore participant and endoscopist acceptability of study design and delivery, and the acceptability of switching endoscopic techniques for Barrett's surveillance. RESULTS: Endoscopists' ability to diagnose dysplasia in Barrett's esophagus can be improved. AAC may offer a simple, universally applicable, easily-acquired technique to improve detection, affording patients earlier diagnosis and treatment, reducing endoscopy time and pathology costs. The ABBA study will determine whether a crossover "tandem" endoscopy design is feasible and acceptable to patients and clinicians and gather outcome data to power a definitive trial.

Value of cytopathologist review of ultrasound examinations in non-diagnostic/unsatisfactory thyroid FNA.

BACKGROUND: Correlation of cytologic and ultrasound findings is extremely valuable for the cytopathologist in management of thyroid nodules. METHODS: Ultrasound scans (US) of all thyroid FNA taken over a 13 month period and reported by a single cytologist were reviewed at the time of reporting, focusing on aspirates that were non-diagnostic/unsatisfactory, equivalent to Bethesda Class I, UK Royal College of Pathologists Class Thy1 or Thy1c. RESULTS: FNA cases [68 (40.7%)] were classified as Thy1, equivalent to Bethesda Class I. US of 3 Thy1 cases were not available for review. On cytologist US review 9 cases were classified as pure cystic, 28 as mixed cystic/solid, 12 as predominantly solid/focally cystic and 16 as purely solid. 27 (41.5%) of cases on cytological assessment were Thy1 and showed no evidence of a cyst on US, 17 (26.1%) were Thy1/Thy1c showing features suggestive of a possible cyst and 21 (32.3%) were Thy1c showing definite features of a cyst. Fifteen of 16 (93.7%) of pure solid cases on US were Thy1, equivalent to Bethesda Class I and all 9 (100%) of cases that were pure cystic on US were reported as Thy1c-equivalent to Bethesda Category I-cyst fluid only (P < .001). CONCLUSION: Cytopathologist review of thyroid US is extremely useful and can be helpful in triaging patients for further management in cases of solid, mixed cystic and/or solid, and pure cystic thyroid lesions with non-diagnostic/unsatisfactory thyroid FNA.