BRAFV600E mutation analysis of liquid-based preparation–processed fine needle aspiration sample improves the diagnostic rate of papillary thyroid carcinoma

Advances in Molecular Profiling and Their Potential Influence on the Extent of Surgery in Well-Differentiated Thyroid Carcinoma (WDTC)

Thyroid cancer surgery has evolved dramatically with advances in our understanding of the biological behaviour of WDTC. Molecular profiling is shedding light on the subset that may behave aggressively. In an era when thyroid cancer management is becoming increasingly conservative, decision making regarding the extent of surgery must be objectively guided by molecular markers. The aim of the present article is to summarise the current published literature and provide possible practice recommendations. An online search for relevant published articles was performed using several databases. Title, abstract, and full-text screening, along with data extraction, was performed by two independent reviewers after the inclusion and exclusion criteria were defined. A total of 1241 articles were identified, and 82 relevant articles were extracted and scrutinised. BRAF V600E and TERT promoter mutations were found to be associated with an increased risk of disease recurrence and distant metastases. Several other mutations have been identified that enhance disease aggressiveness (such as RET/PTC, PTEN, and TP53). One of the most important determinants of the outcome in WDTC is the extent of surgical resection. The evolution of molecular testing has reached a stage of personalised incorporation into surgical practice. Guidelines for molecular testing and surgery in WDTC will need to be clearly defined, arguably representing the next chapter in the management of the disease.

Molecular testing of cytology specimens: overview of assay selection with focus on lung, salivary gland, and thyroid testing

Ancillary and molecular testing of cytopathology specimens has emerged as a reliable and useful tool to provide diagnostic information and treatment-related biomarker status for the management of cancer patients. The cytology specimens obtained through minimally invasive means have proven suitable testing substrates for a variety of ancillary tests, including immunohistochemistry, fluorescence in situ hybridization, as well as polymerase chain reaction and next generation sequencing molecular techniques. By focusing specifically on the cytology specimen, this review provides an overview of basic testing considerations and assay selection in addition to updates on the ancillary testing of cytologic tumor specimens from the lung, salivary gland, and thyroid.

Thyroid and Molecular Testing. Advances in Thyroid Molecular Cytopathology

Thyroid nodules are a common finding in the adult population including the fact that more than 50% of individuals, over the age of 60, have thyroid nodules. The majority have been mostly detected with ultrasonography and 10% by palpation. The majority of these nodules are benign, whereas 5–15% of them are malignant. The pre-operative diagnosis of cancer is a critical challenge in order to ensure that each patient can be treated with the best tailored management with a reduction of unnecessary surgery for benign lesions. Fine needle aspiration cytology (FNAC) represents the first and most important diagnostic tool for the evaluation of thyroid lesions. According to the literature, FNAC is able to render a conclusive diagnosis in up to 70–80% of all cases. For the remaining 20–30% of nodules, cytological diagnoses fall into the category of indeterminate lesions mostly due to the lack of specific morphological features. According to the Bethesda system for reporting thyroid cytopathology (TBSRTC), indeterminate lesions can be sub-stratified into three different subcategories including “atypia of undetermined significance/follicular lesion of undetermined significance-AUS/FLUS”; “follicular or Hürthle cell neoplasm/suspicious for follicular or Hürthle cell neoplasm-FN/SFN”; and “suspicious for malignancy-SFM”. Many of these indeterminate lesions undergo repetition or diagnostic lobectomy. Nonetheless, the majority of these cases will have a benign diagnosis due to the fact that the rate of cancer ranges between 6 and 30%. It stands to reason that the application of ancillary technique, mostly molecular testing, emerged as a critical additional tool for those thyroid indeterminate lesions. Since the early 1990s, material collected from cytological samples yields sufficient and adequate cells for the detection of point mutation or gene fusions. Nonetheless, the further availability of new sequencing technologies such as next-generation sequencing (NGS) has led to more comprehensive molecular applications adopted now in clinical use. The current review investigates the multiple advances in the field of molecular testing applied in thyroid cytology.

Preoperative molecular testing in thyroid nodules with Bethesda VI cytology: Clinical experience and review of the literature

Risk assessment is critical to determine the timing of elective surgeries and preserve valuable resources in time of pandemic. This study was undertaken to better understand the potential value of molecular testing to risk‐stratify thyroid nodules with malignant cytology (Bethesda VI). Systematic review of the literature contributed 21 studies representing 2036 preoperative specimens. The BRAF p.V600E substitution was detected in 46% to 90% of cases with a pooled positivity rate of 70% (95% confidence intervals: 64%‐76%). None of the studies used comprehensive oncogene panels. Retrospective analysis of 531 clinical specimens evaluated with the next‐generation sequencing ThyGeNEXT Thyroid Oncogene Panel identified a total of 436 gene alterations. BRAF mutation rate was 64% in specimens tested as part of standard clinical care and 75% in specimens from cross‐sectional research studies (P = .022). Testing for additional actionable gene alterations such as TERT promoter mutations or RET and NTRK gene rearrangements further increased the diagnostic yield to 78%‐85% and up to 95% when including the ThyraMIR Thyroid miRNA Classifier. These data support the role of molecular cytopathology in surgical and therapeutic decision‐making and warrant additional studies.

Prevalence of BRAFV600E mutation in Asian series of papillary thyroid carcinoma-a contemporary systematic review

Papillary thyroid carcinoma (PTC), the most common malignancy of the endocrine system, is frequently driven by BRAFV600E mutation, which was reported in 35-60% cases in Western series. Numerous studies have recently emerged from Asian countries and regions; however sufficient summary is lacking to date. BRAF mutation serves as a diagnostic and prognostic tool in thyroid cancer, therefore establishing a rate of BRAF on the national scale could be of practical significance. We performed systematic reviews of available literature to investigate the prevalence of BRAF mutation in series of PTC from various Asian countries and regions. Out of the total 3,966 reports identified via initial screening, 138 studies encompassing over 40,000 PTCs were included for the final analysis. A vast majority (90.2%) of PTCs with known BRAF status were from East Asia, including China, South Korea, and Japan, with BRAF mutation rates of 71.2%, 75.5%, and 70.6%, respectively. Less abundant Indian and Saudi Arabian series found 45.6% and 46.3% prevalence of BRAFV600E in PTC, respectively. Much limited evidence was available from Thailand, Iran, Kazakhstan, Taiwan, Singapore, Indonesia, Hong Kong, Philippines, Vietnam, Iraq, and Myanmar. No relevant publications were found from other highly populated countries, such as Pakistan, Bangladesh, and Malaysia. After grouping by geographic region, we found that the highest rate of BRAFV600E was reported in the PTC series from East Asia (76.4%). Much lower rate (45-48%) was seen in PTC cohorts from South Asia, Central Asia, and the Middle East while the Southeast Asian series were in between (57%). Further subgroup analysis revealed that studies employing fresh frozen tissue and fine-needle aspirates showed higher rates of BRAF compared to those used formalin-fixed paraffin-embedded tissues. We found that the PTC series enrolled patients' cohorts after 2010 demonstrated a higher rate of BRAF compared to the earlier series. Finally, pediatric PTCs had lower BRAF prevalence compared to the baseline rate for the country. In conclusion, despite considerable among and within countries heterogeneity, the Asian PTC series showed a higher prevalence of BRAFV600E mutation than that in Western series. Causes of geographic heterogeneity, whether genuine (etiology, genetics) or methodology-related should be further investigated.

Ancillary molecular testing of indeterminate thyroid nodules

Cytological specimens from thyroid nodules are increasingly being adopted as the first available material for cost effectively managing patients in the era of personalized medicine. Cytology aspirates not only play a central role in providing accurate diagnoses, but are also being collected for ancillary molecular testing. Molecular analysis, including the evaluation of somatic mutations and other genomic alterations, has accordingly become well integrated in the cytological workup of thyroid lesions. Appropriately handled thyroid cytology preparations provide well-preserved and adequately cellular material with improved DNA/RNA quantity. The recent publication of the 2nd edition of The Bethesda System for Reporting Thyroid Cytopathology and the American Thyroid Association guidelines confirm the relevant role of molecular testing in the management of the different subcategories of indeterminate thyroid lesions. This review discusses the role of molecular testing for indeterminate thyroid nodules, including the recent introduction of the noninvasive, encapsulated follicular variant of papillary thyroid carcinoma (FVPTC), known also as noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP).

The Role of Molecular Testing for the Indeterminate Thyroid FNA

Thyroid nodules are common in the adult population where a majority are benign and only 4.0% to 6.5% are malignant. Fine needle aspiration (FNA) is a key method used in the early stages to evaluate and triage patients with thyroid nodules. While a definitive cytological diagnosis is provided in more than 70–75% of all thyroid FNA cases, the group of indeterminate lesions offers a challenge in terms of interpretation and clinical management. Molecular testing platforms have been developed, are recognized as an option by the 2015 American Thyroid Association Guidelines, and are frequently used in conjunction with FNA as an integral part of the cytologic evaluation. In this review, the utility of molecular testing options for nodules assigned to the group of indeterminate thyroid FNAs is described.

To Obtain More With Less: Cytologic Samples With Ancillary Molecular Techniques-The Useful Role of Liquid-Based Cytology

CONTEXT

- Fine-needle aspiration cytology has been increasingly used as the first tool in the evaluation of several diseases. Although cytology has a relevant role in the discrimination between benign and malignant lesions, conventional slides cannot lead to 100% conclusive results. It was hoped that the introduction of liquid-based cytology (LBC) would improve the efficacy of cytology through standardization, quality improvement, and the possibility of carrying out ancillary techniques on the residual stored material. In recent decades, the application of genomic alterations has been studied on cytologic samples with feasible and reliable results. The molecular analysis offers a powerful aid to define the best clinical or surgical approaches and follow-up for patients. In recent years, the application of different ancillary techniques has been carried out on conventional slides even though LBC represents a useful additional and alternative method for molecular testing.

OBJECTIVE

- To demonstrate the relevance of LBC as a valid aid to overcoming the difficulties encountered in the application of ancillary techniques on conventional slides.

DATA SOURCES

- We examined and reviewed our experience with the application of ancillary techniques on LBC performed on different body sites.

CONCLUSIONS

- We emphasize that LBC achieves significant and accurate results. It represents a valid method for cytologic evaluation and it provides highly reproducible and informative molecular yields.

Presurgical Screening of Fine Needle Aspirates from Thyroid Nodules for BRAF Mutations: A Prospective Single Center Experience

OBJECTIVE

Analysis of BRAF V600E mutation in thyroid fine needle aspirates (FNA) is an important adjunct to cytology, particularly among FNA placed in the "indeterminate category." However, such a prospective evaluation of FNA obtained from patients with thyroid nodules has been lacking from India.

MATERIAL AND METHODS

FNA from 277 patients were prospectively evaluated for BRAF mutations by Sanger's sequencing. A subset of 30 samples was also analyzed by pyrosequencing using the PyroMark BRAF mutation kit.

RESULTS

Overall, 27.2% of FNA samples were positive for mutations including 19 (35.8%) of the 53 histologically confirmed papillary thyroid carcinoma (PTC), 2 of the 25 follicular variants of PTC, and 1 anaplastic thyroid carcinoma. Only 1 (2.7%) of the 37 samples in the atypia of undetermined significance/follicular lesion of unknown significance category was BRAF positive. The sensitivity of cytology improved marginally from 67.1% to 68.3% when evaluated with BRAF. Further, a comparison of the clinicopathological characteristics of BRAF positive and negative PTCs showed a significant association (P = 0.05) between lymph node metastasis and BRAF positivity.

CONCLUSION

BRAF positivity was lower than that reported from East Asia with the test being useful in confirming malignancies among the suspicious of malignancy and malignant categories.

The largest CAP-certified Chinese reference laboratory experience with the Bethesda system for reporting thyroid cytopathology: correlation with histologic and BRAF data

INTRODUCTION

Thyroid fine needle aspiration biopsy (FNAB) has not been widely used in most areas of China. We investigated a large cohort of thyroid FNAB using the Bethesda system for reporting thyroid cytopathology (TBSRTC) from the largest College of American Pathology (CAP)-certified reference laboratory in China.

MATERIALS AND METHODS

Patients with thyroid FNAB between 2014 and 2016 from Guangzhou Kingmed Diagnostics were retrospectively retrieved and the histologic follow-up results and BRAF results were collected and analyzed.

RESULTS

A total of 7355 thyroid FNAB cases were identified. The average age of these patients was 48.03 years (range: 5-90 years). A total of 875 cases (11.9%) were reported as nondiagnostic, 4041 (54.9%) cases were benign, 736 cases (10.0%) were atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 53 cases (0.7%) were suspicious for follicular neoplasm, 615 cases (8.4%) were suspicious for malignancy, and 1035 cases (14.1%) were positive for malignancy. Histologic follow-up was available on 552 patients. Among 13 cases of AUS/FLUS, 8 (61.5%) had malignancy on histology; 195 (92.0%) of the suspicious for malignancy cases had malignancies on histology, and 320 (98.5%) of the positive for malignancy cases had malignancies on histology. BRAF analysis was performed on 578 cases. Sixty cases with BRAF data had histologic follow-up, all 4 benign cases had negative BRAF, one follicular adenoma had negative BRAF, and 37 of the 55 PTC cases (67.3%) had positive BRAF. BRAF mutation has a 100% positive predictive value of malignancy for the indeterminate thyroid FNABs.

CONCLUSIONS

This is the largest cohort of thyroid FNA reported using TBSRTC in China and the data are helpful for better understanding the status of thyroid FNA in China.

The diagnostic and prognostic role of liquid-based cytology: are we ready to monitor therapy and resistance?

Here, we evaluate the diagnostic and prognostic role of liquid-based cytology (LBC) in different body lesions, including thyroid, lung, effusions and malignant breast lesions. LBC has gained consensus after being applied to both non-gynecologic and fine-needle aspiration cytology. Although some remain sceptical regarding the diagnostic efficacy of LBC, mainly when used alone, in recent years, good results have been obtained as long as it showed a high diagnostic accuracy. Here, we discuss the additional possibility of storing material for the application of ancillary techniques (immunocytochemistry-molecular analysis) with several diagnostic and prognostic advantages, which may pave the way for the challenging evaluation of both monitoring responses to treatment and resistance to targeted therapies in thyroid, lung, breast carcinoma or malignant effusions. Furthermore, it provides the use of several molecular spots as specific targets for personalized therapy.

Comparison of EASYPREP(®) and SurePath(®) in thyroid fine-needle aspiration

BACKGROUND

While fine-needle aspiration cytology (FNAC) using conventional smear has been widely accepted as the primary diagnostic tool for thyroid lesions, liquid-based preparations (LBPs) are increasingly replacing it. A new automated LBP method, EASYPREP(®) (EP), was recently introduced and has shown relevant diagnostic efficacy in gynecologic samples. We compared the diagnostic utility of EP and SurePath(®) (SP), a more widely established LBP method, in thyroid FNAC.

METHODS

Under the ultrasonographic guidance, 253 thyroid FNAC samples were collected by sample-splitting manner. Three pathologists made cytologic diagnoses of EP and SP according to the Bethesda system independently and compared the cytomorphologic parameters. Cytohistologic correlation was performed in 30 resected cases.

RESULTS

Fifteen (5.9%) and 21 (8.3%) samples were unsatisfactory in SP and EP, respectively, owing to the unequal sample-splitting. Cytologic diagnoses of SP and EP were consistent in 228 cases (90.1%), and inconsistent in remainder mostly owing to the unequal distribution of pathognomic cells. While cytomorphologic parameters were not significantly different between two methods, EP showed less three-dimensional configuration in benign lesions. Cytohistologic correlation showed no significant differences in sensitivity (100% vs. 95.5%) and specificity (100% vs. 100%) between SP and EP. Labor time for processing 48 cases was 42% shorter with EP than with SP (28 min vs. 48 min).

CONCLUSIONS

The diagnostic utility of EP in thyroid FNAC was comparable to that of SP. EP allowed better visibility owing to better fragmentation of follicular clusters. The automated system of EP has the advantages of a shorter labor time for batch processing. Diagn. Cytopathol. 2016;44:283-290. © 2016 Wiley Periodicals, Inc.

Clinical impact of BRAF mutation on the diagnosis and prognosis of papillary thyroid carcinoma: a systematic review and meta-analysis

BACKGROUND

The possible role of BRAF(V) (600E) mutation in the diagnosis and prognosis of papillary thyroid carcinoma (PTC) remains controversial. A systematic review to investigate the diagnostic and prognostic role of BRAF(V) (600E) mutation in patients with PTC is urgently needed.

METHODS

A systematic review of relevant literatures was performed in PubMed, EMBASE and CENTRAL. The incremental accuracy (IA) of fine needle aspiration biopsy plus BRAF(V) (600E) mutation analysis over fine needle aspiration biopsy alone, and the statistical data about the association of BRAF(V) (600E) mutation and the prognosis of PTC (risk ratios (RR) for dichotomous data, standard mean differences for continuous data and hazard ratios (HRs) for disease-free survival (DFS) were pooled. Subgroup analysis was performed to explain the heterogeneities.

RESULTS

A total of 67 studies were included. The pooled IA was 2% (95% confidence interval (CI): 0·5-4%). The pooled RR for gender, multifocality, lymph node metastasis, extrathyroidal invasion and pathological stage was 1·11 (95% CI: 0·98-1·25), 1·17 (95% CI: 1·09-1·24), 1·36 (95% CI: 1·20-1·53), 1·60 (95% CI: 1·41-1·82), and 1·49 (95% CI: 1·33-1·68), respectively. The pooled standard mean differences for age and tumour size were 0·14 (95% CI: 0·04-0·23) and 0·21 (95% CI: 0·1-0·32), respectively. The pooled HR for DFS was 1·96 (95% CI: 1·62-2·37). Subgroup analysis showed that these statistical results were affected by the geographical background of patients, study design and detection methods.

CONCLUSIONS

BRAF(V) (600E) mutation analysis can not only be used in the diagnosis of PTC, but can also predict its prognosis.

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.

High-Resolution Melting Is a Sensitive, Cost-Effective, Time-Saving Technique for BRAF V600E Detection in Thyroid FNAB Washing Liquid: A Prospective Cohort Study

OBJECTIVE

The diagnostic accuracy of thyroid fine needle aspiration biopsy (FNAB) can be improved by the combination of cytological and molecular analysis. In this study, washing liquids of FNAB (wFNAB) were tested for the BRAF V600E mutation, using the sensitive and cost-effective technique called high-resolution melting (HRM). The aim was to demonstrate the feasibility of BRAF analysis in wFNAB and its diagnostic utility, combined with cytology.

DESIGN

Prospective cohort study.

METHODS

481 patients, corresponding to 648 FNAB samples, were subjected to both cytological (on cells smeared onto a glass slide) and molecular analysis (on fluids obtained washing the FNAB needle with 1 ml of saline) of the same aspiration. BRAF V600E analysis was performed by HRM after methodological validation for application to wFNAB (technique sensitivity: 5.4%).

RESULTS

The cytological results of the FNAB were: 136 (21%) nondiagnostic (THY1); 415 (64%) benign (THY2); 80 (12.4%) indeterminate (THY3); 9 (1.4%) suspicious for malignancy (THY4); 8 (1.2%) diagnostic of malignancy (THY5). The BRAF V600E mutation was found in 5 THY2, 2 THY3, 6 THY4 and 6 THY5 samples. Papillary carcinoma diagnosis was histologically confirmed in all BRAF+ thyroidectomized patients. BRAF combined with cytology improved the diagnostic value compared to cytology alone in a subgroup of 74 operated patients.

CONCLUSIONS

HRM was demonstrated to be a feasible method for BRAF analysis in wFNAB. Thanks to its sensitivity and cost-effectiveness, it might be routinely used on a large scale in clinical practice. In perspective, standby wFNAB samples could be analyzed a posteriori in case of indeterminate cytology and/or suspicious findings on ultrasound.

Evaluation of the Real-Q BRAF V600E Detection Assay in Fine-Needle Aspiration Samples of Thyroid Nodules

Recently, several molecular assays for detecting the BRAF V600E mutation in fine-needle aspiration (FNA) specimens have been developed. Herein, we tested 294 consecutive FNA samples from patients with thyroid nodules with the Real-Q BRAF V600E detection assay (Real-Q). These results were compared with an allele-specific PCR-based kit using dual-priming oligonucleotides (AS-PCR). Any discordant results between the two tests were also analyzed by mutant enrichment with 3'-modified oligonucleotide sequencing. A total of 128 cases were confirmed histologically; of these, 121 were diagnosed as papillary thyroid carcinoma (PTC). The BRAF mutation was detected by Real-Q and AS-PCR testing in 80.2% (95% CI, 71.9%-86.9%) and 76.9% (95% CI, 68.3%-84.0%), respectively, of FNA specimens with PTC. Combining the BRAF V600E molecular assays (Real-Q and AS-PCR) with cytological diagnoses of malignant and suspicious for malignant cells, the detection rates (sensitivity) of Real-Q and AS-PCR for diagnosis of PTC increased to 94.2% (95% CI, 88.4%-97.6%) and 92.6% (95% CI, 86.4%-96.5%), respectively. In conclusion, the detection of BRAF V600E mutations in PTC by Real-Q is compatible to that of AS-PCR.

Clinical Implication of Highly Sensitive Detection of the BRAFV600E Mutation in Fine-Needle Aspirations According to the Thyroid Bethesda System in Patients With Conventional Papillary Thyroid Carcinoma

BACKGROUND

We investigated the additional diagnostic yield of the mutation test and evaluated the frequency of the BRAF mutation in conventional PTC (cPTC) according to ultrasound (US) features and the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) based on the BRAFV600E mutation status.

MATERIALS AND METHODS

During the study period, 279 patients who underwent FNA with an additional BRAFV600E mutation test were diagnosed as cPTC after surgery. We analyzed the association between the mutation and several clinical factors.

RESULTS

Of the 279 cPTCs, 250 (89.6%) had the BRAFV600E mutation. The BRAF mutation test was helpful in diagnosing an additional 19% (53/279) of cPTCs. The frequency of the BRAF mutation in cPTCs with suspicious US features was higher than that of cPTCs with negative US features regardless of the BSRTC.

CONCLUSIONS

Suspicious US features may be helpful in deciding whether an additional BRAFV600E mutation test should be done in thyroid nodules with indeterminate cytology.

Additional BRAF mutation analysis may have additional diagnostic value in thyroid nodules with "suspicious for malignant" cytology alone even when the nodules do not show suspicious US features

The BRAF(V600E) mutation test has been more effective in thyroid nodules with suspicious US features than ones without suspicious features. Therefore, we investigated the role of the BRAF(V600E) mutation as an additional study to cytology in diagnosing a thyroid nodule without suspicious US features. This study was performed at Severance hospital from December 2010 through February 2012. During this period, 2,650 patients with 2,918 nodules underwent FNA with an additional BRAF(V600E) mutation test. Among them, we excluded thyroid nodules with suspicious US features. Finally, 485 thyroid nodules in 466 patients (mean age 50.3 years; range 9-80 years) were included in this study. We compared the differences between patients with malignant and benign thyroid nodules. We evaluated the detection rates of the BRAF(V600E) mutation according to the Bethesda System for Reporting Thyroid Cytopathology (BSRTC). There were 60 (60/485, 12.4 %) malignant and 425 (425/485, 87.6 %) benign nodules. The detection rate of the BRAF(V600E) mutation in thyroid nodules without suspicious US features was only 6.6 % (32/485). Most had malignant cytology (62.5 %, 20/32). For nodules without malignant cytology, only 12 nodules (2.6 %, 12/462) had the BRAF mutation. Among the 12 nodules, nine nodules were suspicious for malignancy on cytology. Additional BRAF mutation analysis shows additional diagnostic value in thyroid nodules with "suspicious for malignant" cytology alone even when the nodules do not show suspicious US features. Therefore, the test should be selectively performed in thyroid nodules without suspicious US features, considering cost-effectiveness as well as diagnostic accuracy.

Role of ancillary testing in thyroid fine needle aspiration: Review and update

Thyroid nodules are common, and ultrasound-guided fine needle aspiration identifies 70-75% as benign, and 4% as malignant. The remainder falls into categories of "indeterminate" with a widely ranging malignancy rate from 10-75%. The diagnosis and clinical management of indeterminate lesions is evolving, and we will review ancillary testing as an aid to diagnosis.

Is liquid-based cytology the magic bullet for performing molecular techniques?

OBJECTIVE

The role of pathology has evolved from the first microscopic definitions of diseases by Virchow to the new concept of molecular cytopathology. The management of diseases is now a multidisciplinary approach with the translation of morphological, imagery and molecular findings to therapeutic protocols. Obtaining the most reliable diagnostic material is the essential part of the medical management of patients.

STUDY DESIGN

Here, we try to gain a concise insight into the available data regarding the role of cytology in the application of molecular techniques, focusing on cancer cytopathology.

RESULTS

Obtaining cytological material is now feasible by different methods, and in some cases it is the only possible approach to a lesion which is not easily accessible for tissue sampling. The methods of obtaining cytological material have evolved in recent years in parallel with rapid advances in high-throughput molecular techniques, opening new windows for the diagnosis and management of diseases.

CONCLUSIONS

Different kinds of cytological material are reliable for the application of molecular techniques. Cytological material obtained in a liquid base has advantages such as the better preservation of cytomorphological features and the use of the remaining liquid for nucleic acid extraction even after long storage and the application of molecular methods.

The nightmare of indeterminate follicular proliferations: when liquid-based cytology and ancillary techniques are not a moon landing but a realistic plan

OBJECTIVE

Thyroid nodules are a common finding in the general population, including both nonneoplastic and neoplastic entities. Fine-needle aspiration cytology (FNAC) is the first tool for evaluating thyroid nodules. In spite of its high diagnostic accuracy, 25% of nodules result in the category of follicular neoplasms (FN), with varying risk of malignancy and different management strategies.

STUDY DESIGN

The use of ancillary techniques is reshaping the practice of FNAC. These tools can significantly empower the morphological diagnosis and prognosis of thyroid nodules, allowing a more accurate prediction of the nature of the lesion. Several studies have underlined the role of single or multiple testing for the category of FN as strong indicators of cancer. Every cytological preparation can be used for the application of ancillary techniques but the introduction of liquid-based cytology (LBC) might facilitate the application.

RESULTS

Our experience involving an immunocytochemical panel made up of HBME-1 and galectin-3 pointed to an 81% overall diagnostic accuracy in discriminating between low and high risk of malignancy in FN.

CONCLUSIONS

The application of these techniques on LBC represents an adjunct to the morphological evaluation of FN. They represent a critical and challenging, but also a feasible, tool in the preoperative diagnoses, allowing specific prognostic and predictive details regardless of the cytological preparation. © 2014 S. Karger AG, Basel.

Diagnostic and prognostic value of immunocytochemistry and BRAF mutation analysis on liquid-based biopsies of thyroid neoplasms suspicious for carcinoma

OBJECTIVE

In the field of fine-needle aspiration cytology, the category of suspicious for malignancy (SM) thyroid lesions, that bears 55-85% risk of malignant histology, is a challenging topic in which morphology alone is not always able to make a correct diagnosis. Recently, immunocytochemistry (ICC) has been referred to as helpful in differentiating low- and high-malignant risk lesions and BRAF activating mutations have been identified in a significant amount of papillary thyroid carcinomas (PTC). The introduction of the liquid-based cytology (LBC) may simplify the application of these techniques to thyroid cytology.

DESIGN

Our aim is to evaluate the diagnostic and prognostic role of both ICC and BRAF mutation for the SM category on LBC.

METHODS

From October 2010 through June 2011, 113 LBC cytological cases (including 37 SM and 76 PTC) underwent surgery. All cases were studied for BRAF mutation and ICC.

RESULTS

ICC resulted positive in 26 (86.6%) histologically malignant SM with 15 of which (40.5%) expressing a BRAF mutation. Overall, 63 cases showed a BRAF mutation resulting in PTC. Concerning the prognostic role of BRAF mutation for the two categories, we reported a significant correlation with multifocality, nodal involvement and extra-capsular invasion (P<0.0001).

CONCLUSIONS

Special techniques such as ICC and molecular markers might be successfully carried out on LBC-processed material. For both categories, ICC is more sensitive whereas BRAF analysis is an interesting support due to its high specificity adding a prognostic value in both SM and PTCs.

BRAF test and cytological diagnosis with a single fine needle cytology sample

OBJECTIVE

Recently, fine needle cytology (FNC) of the thyroid has been combined with biomolecular analysis. In particular, there has been detailed study of the V600E-BRAF mutation. The aim of our study is to demonstrate that with a single thyroid sample it is possible to obtain enough cellular material for both cytological diagnosis and a V600E-BRAF molecular test.

STUDY DESIGN

FNC was carried out under ultrasound guidance aided by an echographist and cytopathologist. We acquired one biopsy for each nodule with a 23-gauge needle without suction. The preparations were smeared by the pathologist onto one glass slide, air dried and stained with Diff-Quick. Cell adequacy was evaluated for each patient. The needle was washed by aspirating 2 ml of physiologic solution which was collected into a tube. The material was collected for molecular testing.

RESULTS

The following cytological diagnoses were made: not neoplastic, Tir2 (n = 227); indeterminate, Tir3 (n = 15); suspicious, Tir4 (n = 4), and malignancy, Tir5 (n = 12). The V600E-BRAF mutation was found in 0 of 227 Tir2 specimens, 2 of 15 (13.3%) Tir3 specimens, 2 of 4 (50%) Tir4 specimens and 9 of 12 (75%) Tir5 specimens.

CONCLUSIONS

Our data showed that, in a routine clinical setting, FNC specimens can be handled properly to provide both morphological and molecular information. In fact, our tests show that with a single specimen it is possible to set up a slide for the cytological diagnosis and to obtain enough residual cellular material for DNA extraction (>70 ng) and for the identification of the V600E-BRAF mutation.

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.