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

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.

Process improvement in thyroid fine needle aspiration: Standardizing number of smears for enhanced adequacy and diagnosis

Fine-needle aspiration (FNA) is a safe, cost-effective diagnostic procedure used in the evaluation of thyroid nodules. The number of thyroid FNAs has dramatically increased over the past few years. In the absence of standardized procedures regarding the number of needle passes needed for diagnosis and the lack of clarity on the use of conventional smears (CS) versus liquid-based preparations (LBP), the demand of thyroid FNAs has led to increased workload on cytology laboratories, which can negatively affect patient safety. We implemented a standardized two needle passes for CS and collection of all needle rinses and additional pass material in CytoRich Red for ThinPrep LBP and compared the non-diagnostic and diagnostic rates before and after this intervention. There were 290 pre-intervention cases and 348 post-intervention cases; of which, there were 17 (5.9%) non-diagnostic cases of the pre-intervention group and 27 (7.8) non-diagnostic cases of the post-intervention group. There was no statistically significant difference in non-diagnostic and diagnostic rates before and after the change (p = 0.347 by two-tailed Z test).

The evolving role of interventional cytopathology from thyroid FNA to NGS: Lessons learned at Federico II University of Naples

Fine-needle aspiration (FNA) guided by ultrasound (US) has emerged as a highly precise diagnostic method for managing thyroid nodules, significantly diminishing unnecessary surgeries. The effectiveness of US-guided FNA is high when a single specialist performs the FNA procedure and the microscopy. This paradigm has paved the way for the evolution of interventional cytopathology, a specialist with a pivotal role in the preoperative diagnostic process, encompassing patient history review, clinical examination, FNA execution under US guidance, preparation, and microscopic interpretation of cytological samples. As the landscape of precision medicine unfolds, molecular testing assumes greater importance in thyroid cytopathology, particularly in refining the risk of malignancy for indeterminate nodules. The updated Bethesda classification system underscores the clinical significance of molecular tests, emphasizing their role in refining diagnostic accuracy. With this evolving landscape, interventional cytopathologists must adapt by acquiring expertise in molecular technologies and addressing ongoing challenges in workflow harmonization and optimization. This paper delves into our decade-long experience as interventional cytopathologists, focusing on recent endeavours to ensure adequate samples not only for microscopic diagnosis but also for molecular testing. Additionally, here we review the challenges of integrating next-generation sequencing (NGS) technology into clinical practice, highlighting the importance of integrating clinically meaningful molecular data into comprehensive molecular cytology reports.

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.

Diagnostic Performance Comparison of Liquid-Based Preparation Methods in Thyroid FNAs

Introduction

Fine needle aspiration (FNA) is recognized worldwide as the primary diagnostic method for evaluating thyroid nodules. Samples collected by FNA can be spread directly onto slides, prepared for cell blocks, or processed as liquid-based cytology. Advocates of the traditional smear technique emphasize that background material such as colloid, cell sequencing characteristics in cell clusters, and cellularity is important in cytological diagnosis. They state that these properties are not observed in liquid-based liquids. Liquid-based cytology techniques aim to provide standardized slides of homogeneous cellular smears with well-preserved cell morphology, producing more precise visualization, shorter interpretation time, and more reproducible results. This study aimed to investigate and compare the diagnostic performance of liquid-based thyroid FNA samples prepared with SurePath and Cytospin over the last 6 years.

Methods

Patients who underwent ultrasound-guided FNA between January 2015 and December 2021 were included in the study. Cytology reports, pathology reports, and demographic information of the patients were collected from the Hospital Information Management System. The programs "SPSS for Windows 21" and "MedCalc Diagnostic Test Evaluation Calculator" were used for data analysis. Chi-square tests were used in crosstab analysis. The Kolmogorov-Smirnov two-sample test, two proportions test, and the confidence interval tests were used to analyze the variables of the methods. P < .05 was considered statistically significant.

Results

The study population comprised 4,855 patients, 83.8% female and 16.2% male. There were no statistical differences in age and gender distribution in the population of both methods. Nondiagnostic outcome rates were 11.2% for SurePath and 12.8% for Cytospin. Sensitivity, specificity, and accuracy values for SurePath and Cytospin methods were determined as 58.57%, 98.28%, and 91.12% and 79.07%, 96.88%, and 94.03%, respectively.

Conclusion

In our study, although the qualitative analytical results were slightly in favor of the cytospin method, we think both ways can be used safely, especially in hospitals where the clinics performing sampling activities are variable and many, as well as in pathology laboratories where the workload is intense.

Nondiagnostic Test Result Rates Following Thyroid Extra-Fine-Needle Aspiration

OBJECTIVES

The first Bethesda classification category of thyroid fine-needle aspiration biopsy (FNAB) is nondiagnostic (ND), which indicates that the specimen's cellularity is inadequate for evaluation. This work investigated the effect of needle diameter size on ND rates by comparing diagnostic outcomes of FNAB samples collected with 23-, 25-, and 27-gauge needles.

METHODS

This was a retrospective analysis of samples collected from patients undergoing FNAB between 2018 and 2021. It was conducted in an otolaryngology department in a university teaching hospital.

RESULTS

Of the 699 aspirations, 144, 335, and 220 were performed using 23-, 25-, and 27-gauge needles, respectively. ND rates increased significantly when using 27-gauge compared with 23- to 25-gauge needles (P = .002), and a significantly lower ND rate was found for the 25-gauge needle compared with the 27-gauge needle (P = .001). Furthermore, increased nodule size was associated with reduced ND rate (odds ratio, 0.801; 95% confidence interval, 0.691-0.929).

CONCLUSIONS

The 25-gauge needles are superior to 27-gauge needles in reducing ND rates of thyroid nodule FNAB specimens. Future prospective studies should be performed to confirm these findings.

Usefulness of Liquid-Based Cytology in Diagnosing Biliary Tract Cancer Compared to Conventional Smear and Forceps Biopsy

BACKGROUND/AIMS

Liquid-based cytology (LBC) has been shown to improve the diagnostic efficacy of brush cytology for thyroid, cervical and pancreatic cancer. To evaluate the diagnostic performance of LBC for biliary tract cancer, we compared it with conventional smears and forceps biopsies.

METHODS

A retrospective study was conducted of all consecutive patients who underwent brush cytology under ERCP from January 2010 to April 2020. The primary outcome was the diagnostic efficacy of conventional smears and LBC. The difference between the two groups was corrected using inverse probability weighting (IPW). The secondary outcome was the sensitivity and specificity of brush cytology and forceps biopsy. The secondary outcome was evaluated in patients who underwent both methods.

RESULTS

Among 162 patients, conventional smears were performed in 70 patients and LBC was performed in 92 patients. In the primary analysis using IPW, the sensitivity of conventional smears and LBC was 56.00% and 78.26% respectively (P = 0.009). The specificity was 100% for both methods. The accuracy was 66.15% for conventional smears and 83.33% for LBC (P = 0.012). In the secondary analysis, the sensitivity of conventional smears versus forceps biopsies was 62.16% versus 78.38% (P = 0.034) and 81.16% for both LBC and forceps biopsies. The specificity of both cytological examination and forceps biopsies was 100%.

CONCLUSIONS

Liquid-based cytology demonstrated better sensitivity and accuracy than conventional smears. Moreover, its diagnostic performance was close to that of forceps biopsies.

Recent Application of Artificial Intelligence in Non-Gynecological Cancer Cytopathology: A Systematic Review

Simple Summary

Artificial intelligence (AI) has attracted significant interest in the healthcare sector due to its promising results. Cytological examination is a critical step in the initial diagnosis of cancer. Here, we conducted a systematic review with quantitative analysis to understand the current status of AI applications in non-gynecological (non-GYN) cancer cytology. In our analysis, we found that most of the studies focused on classification and segmentation tasks. Overall, AI showed promising results for non-GYN cancer cytopathology analysis. However, the lack of well-annotated, large-scale datasets with Z-stacking and external cross-validation was the major limitation across all studies.

Abstract

State-of-the-art artificial intelligence (AI) has recently gained considerable interest in the healthcare sector and has provided solutions to problems through automated diagnosis. Cytological examination is a crucial step in the initial diagnosis of cancer, although it shows limited diagnostic efficacy. Recently, AI applications in the processing of cytopathological images have shown promising results despite the elementary level of the technology. Here, we performed a systematic review with a quantitative analysis of recent AI applications in non-gynecological (non-GYN) cancer cytology to understand the current technical status. We searched the major online databases, including MEDLINE, Cochrane Library, and EMBASE, for relevant English articles published from January 2010 to January 2021. The searched query terms were: “artificial intelligence”, “image processing”, “deep learning”, “cytopathology”, and “fine-needle aspiration cytology.” Out of 17,000 studies, only 26 studies (26 models) were included in the full-text review, whereas 13 studies were included for quantitative analysis. There were eight classes of AI models treated of according to target organs: thyroid (n = 11, 39%), urinary bladder (n = 6, 21%), lung (n = 4, 14%), breast (n = 2, 7%), pleural effusion (n = 2, 7%), ovary (n = 1, 4%), pancreas (n = 1, 4%), and prostate (n = 1, 4). Most of the studies focused on classification and segmentation tasks. Although most of the studies showed impressive results, the sizes of the training and validation datasets were limited. Overall, AI is also promising for non-GYN cancer cytopathology analysis, such as pathology or gynecological cytology. However, the lack of well-annotated, large-scale datasets with Z-stacking and external cross-validation was the major limitation found across all studies. Future studies with larger datasets with high-quality annotations and external validation are required.

Circular RNAs and thyroid cancer: closed molecules, open possibilities

Thyroid neoplasms requiring differential diagnosis between thyroid cancer and benign tumors can be detected in more than half of the healthy population. A generally accepted method that allows assessing the risk of malignant potential and determining the indications for surgical treatment of thyroid tumor is a fine-needle aspiration biopsy followed by a cytological examination. Nevertheless, in patients with indeterminate categories of cytological conclusions according to Bethesda system, the positive predictive value of the cytology result is significantly lower than desired and often leads to unjustified surgical treatment. In this regard, the search for alternative diagnostic solutions continues. Circular RNAs are a group of non-coding RNAs distinguished by a closed structure formed by covalent bonding of the nucleotide chain ends. Recent studies allow us to conclude that many different circular RNAs are involved in processes mediating oncogenesis in the thyroid gland, and their altered expression in tissue, blood, and exosomes of plasma may be a characteristic sign of thyroid cancer and certain clinicopathological features of its course. The purpose of this review is to analyze the accumulated data on the association of various circular RNAs with thyroid cancer and to discuss possible ways to improve the diagnosis and treatment of the disease based on the assessment of the expression of these molecules.

Comparison of Diagnostic Rates and Concordance with Subsequent Surgical Resections between Conventional Smear and ThinPrep Preparations versus ThinPrep Only in Thyroid Fine Needle Aspiration (T-FNA) Specimens

BACKGROUND

Thyroid fine needle aspiration (T-FNA) is a mainstay in management of thyroid nodules. However, the preparation of T-FNA specimens varies across institutions. Prior studies have compared diagnostic rates between different specimen preparations of T-FNA specimens and their associated advantages and disadvantages. However, few have compared the rates of all diagnostic categories of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) between liquid-based preparations (LBPs) and a combination of LBP and conventional smear (CS) preparations. Our study compares TBSRTC diagnostic rates between these 2 cohorts and correlates cytologic diagnoses with subsequent thyroid resections to evaluate rates of neoplasia (RON) and malignancy (ROM).

METHODS

584 consecutive thyroid FNA specimens were collected and stratified by preparation type (ThinPrep [TP] vs. CS &amp; TP). Diagnostic rates for each TBSRTC diagnostic category were calculated. The institution's electronic medical records database was searched for histologic diagnoses of previously sampled thyroid nodules to evaluate the RON and ROM.

RESULTS

Of 584 thyroid FNA specimens, 73 (12.5%) and 511 (87.5%) were evaluated by TP only and CS &amp; TP, respectively, reflecting the predominance of rapid on-site evaluation (ROSE) with CS for T-FNAs at our institution. Of the TP only and CS &amp; TP cohorts, 29 (39.7%) and 98 (19.2%) had subsequent resections, respectively. The frequency of non-diagnostic cases was lower in the CS &amp; TP cohort (12.7% vs. 26%). While the diagnostic rate of follicular lesion of undetermined significance was similar for both cohorts, SFN categorization was only utilized in the CS &amp; TP cohort (1.5% vs. 0%). Although RON and ROM were similar between cohorts in many of the TBSRTC categories, there was a higher RON associated with non-diagnostic specimens in the TP only cohort when the denominator included all non-diagnostic cases.

CONCLUSION

The combination of CS and LBP may potentially decrease the non-diagnostic rate of T-FNA specimens as well as the number of passes required for diagnosis, particularly with ROSE. Evaluation of morphologic features highlighted in conventional smears may facilitate diagnostic categorization in the "suspicious for follicular neoplasm" category.

Changes in thyroid fine needle aspiration practice during the COVID-19 pandemic

Purpose

To investigate the diagnostic accuracy of a different sample preparation protocol for fine needle aspiration cytology (FNAC) of thyroid nodules established during the COVID‐19 pandemic.

Methods

From April 2020, conventional smears during FNAC were ceased according to World Health Organization recommendations due to the increased infection risk for operators, and a new protocol using only liquid‐based cytology (LBC) was adopted. FNACs performed between April and July 2020 (COVID‐19 group) were retrospectively compared with those from December 2019 through March 2020 (Pre‐COVID‐19 group). The distribution of diagnoses based on SIAPEC‐IAP categories and the concordance between cytological and histological results were compared using the chi‐squared test.

Results

Categories based on FNAC for 90 and 82 thyroid nodules in the Pre‐COVID‐19 and COVID‐19 groups showed no significant difference in distribution (P = .081), with the following respective cases (and percentages): TIR1, 7 (8%) and 8 (10%); TIR1C, 0 (0%) and 6 (7%); TIR2, 59 (66%) and

55 (67%); TIR3A, 8 (9%) and 5 (6%); TIR3B, 1 (1%) and 2 (3%); TIR4, 5 (6%) and 1 (1%); and TIR5, 10 (12%) and 5 (7%). Among patients with potentially malignant lesions, surgery was performed for 12/16 (75%) nodules in the Pre‐COVID‐19 and 7/8 (88%) nodules in the COVID‐19 groups, with no significant differences between cytological and histological diagnoses (P = .931).

Conclusion

The new LBC‐only protocol provided similar diagnostic accuracy in comparison with conventional smears, and can be effectively applied during a viral pandemic improving operator safety.

Evaluation of Thyroid Fine-Needle Aspiration Biopsies according to Cytological Methods and Comparison with Histopathological Diagnosis

Objectives:

In this study, we aim to compare the results of aspiration of thyroid nodules evaluated according to the Bethesda category (BC) with tissue diagnoses in the operation materials and to compare the sensitivity, specificity and accuracy rates according to cytology methods.

Methods:

The previous fine-needle aspiration biopsy (FNAB) of thyroid nodules of 879 cases diagnosed histopathologically between 2010 and 2017 was examined. The FNAB results determined according to the Bethesda system were matched with tissue diagnoses, sensitivity, specificity, and accuracy rates were investigated according to cytology methods.

Results:

Sensitivity, specificity, Positive predictive value (PPV), Negative predictive value (NPV) and accuracy rates were found in all FNAB results (in units of %; Sensitivity; 84.7, Specificity; 81.1, PPV; 74.1, NPV; 89.2, Accuracy; 82.5). All of the cytological evaluation methods of thyroid FNABs were found to be reliable and effective (Generally, the results are 80% and above). Specificity and accuracy rates were close to the general average (82.5%) in all methods. However, in cases evaluated with liquid base cytology (LBC) method and in addition to LBC or conventional smear (CS), the sensitivity rates in cases where cell block (CB) were evaluated together were higher than cases in which LBC and CS were used alone (92.6% and 91.0%). When examined statistically, there was no significant difference concerning sensitivity, specificity and accuracy rates of cytological methods (p>0.05, respectively, p=0.576, 0.065, 0.643).

Conclusion:

In cytopathology, when evaluating thyroid aspirations, it is seen that the LBC method is used instead of CS. In our study, we recommend the use of the LBC method, which seems to have the highest sensitivity (taking into account its technical advantages), instead of CS. However, we think that both CS and LBC methods should be evaluated by supporting them with cell block sections.

Diagnostic value of liquid-based cytology and smear cytology in pancreatic endoscopic ultrasound-guided fine needle aspiration: A meta-analysis

BACKGROUND

Smear cytology (SC) using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the established and traditional choice for diagnosing pancreatic lesions. Liquid-based cytology (LBC) is a novel alternative cytological method, however, the comparative diagnostic efficacy of LBC remains inconclusive.

AIM

To examine the diagnostic efficacy of LBC and SC for pancreatic specimens obtained through EUS-FNA via a systematic review and meta-analysis.

METHODS

A systematic literature search was performed using PubMed, EMBASE, the Cochrane Library, and Web of Science. The numbers of true positives, false positives, true negatives, and false negatives for each cytological test (LBC and CS) were extracted from the included studies. The pooled sensitivity and specificity and the area under the summary receiver operating characteristic curve (AUC) were calculated, and the AUC was compared by Tukey's multiple comparisons test. The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies II tool.

RESULTS

A total of 1656 patients in eight studies were included. The pooled sensitivity and specificity and the AUC for LBC were 0.76 (95%CI: 0.72-0.79), 1.00 (95%CI: 0.98-1.00), and 0.9174, respectively, for diagnosing pancreatic lesions. The pooled estimates for SC were as follows: Sensitivity, 0.68 (95%CI: 0.64-0.71); specificity, 0.99 (95%CI: 0.96-100.00); and AUC, 0.9714. Similarly, the corresponding values for LBC combined with SC were 0.87 (95%CI: 0.84-0.90), 0.99 (95%CI: 0.96-1.00), and 0.9894. Tukey’s multiple comparisons test was used to compare the sensitivities and AUCs of the three diagnostic methods; statistically significant differences were found between the three methods, and LBC combined with SC was superior to both LBC (P < 0.05) and SC (P < 0.05). The pooled sensitivity and AUC did not change significantly in the sensitivity analysis.

CONCLUSION

LBC may be sensitive than SC in the cytological diagnosis of pancreatic lesions, however, the superior diagnostic performance of their combination emphasizes their integrated usage in the clinical evaluation of pancreatic lesions.

Continuous quality improvement program and its results of Korean Society for Cytopathology

Background

Since 1995, the Korean Society for Cytopathology has overseen the Continuous Quality Improvement program for cytopathology laboratories. The Committee of Quality Improvement has carried out an annual survey of cytology data for each laboratory and set standards for proficiency tests.

Methods

Evaluations were conducted four times per year from 2008 to 2018 and comprised statistics regarding cytology diagnoses of previous years, proficiency tests using cytology slides provided by the committee, assessment of adequacy of gynecology (GYN) cytology slides, and submission of cytology slides for proficiency tests.

Results

A total of 206 institutes participated in 2017, and the results were as follows. The number of cytology tests increased from year to year. The ratio of liquid-based cytology in GYN gradually decreased, as most of the GYN cytology had been performed at commercial laboratories. The distribution of GYN diagnoses demonstrated nearly 3.0% as atypical squamous cells. The rate for squamous cell carcinoma was less than 0.02%. The atypical squamous cell/squamous intraepithelial lesion ratio was about 3:1 and showed an upward trend. The major discordant rate of cytology-histology in GYN cytology was less than 1%. The proficiency test maintained a major discordant rate less than 2%. The rate of inappropriate specimens for GYN cytology slides gradually decreased.

Conclusions

The Continuous Quality Improvement program should be included in quality assurance programs. Moreover, these data can contribute to development of national cancer examination guidelines and facilitate cancer prevention and treatment.

Current status of cytopathology practices in Korea: annual report on the Continuous Quality Improvement program of the Korean Society for Cytopathology for 2018

BACKGROUND

The Korean Society for Cytopathology has conducted the Continuous Quality Improvement program for cytopathology laboratories in Korea since 1995. In 2018 as part of the program, an annual survey of cytologic data was administered to determine the current status of cytopathology practices in Korea.

METHODS

A questionnaire was administered to 211 cytopathology laboratories. Individual laboratories submitted their annual statistics regarding cytopathology practices, diagnoses of gynecologic samples, inadequacy rates, and gynecologic cytology-histology correlation review (CHCR) data for 2018. In addition, proficiency tests and sample adequacy assessments were conducted using five consequent gynecologic slides.

RESULTS

Over 10 million cytologic exams were performed in 2018, and this number has almost tripled since this survey was first conducted in 2004 (compounded annual growth rate of 7.2%). The number of non-gynecologic samples has increased gradually over time and comprised 24% of all exams. The overall unsatisfactory rate was 0.14%. The ratio of the cases with atypical squamous cells to squamous intraepithelial lesions accounted for up to 4.24. The major discrepancy rate of the CHCR in gynecologic samples was 0.52%. In the proficiency test, the major discrepancy rate was approximately 1%. In the sample adequacy assessment, a discrepancy was observed in 0.1% of cases.

CONCLUSIONS

This study represents the current status of cytopathology practices in Korea, illustrating the importance of the Continuous Quality Improvement program for increasing the accuracy and credibility of cytopathologic exams as well as developing national cancer exam guidelines and government projects on the prevention and treatment of cancer.

Atypical Histiocytoid Cells and Multinucleated Giant Cells in Fine-Needle Aspiration Cytology of the Thyroid Predict Lymph Node Metastasis of Papillary Thyroid Carcinoma

Preoperative detection of cervical lymph node metastasis in papillary thyroid carcinoma (PTC) is crucial for determining the surgical strategy to prevent locoregional recurrence of the disease. We identified the cytological predictors of lymph node metastasis in 222 consecutive patients with PTC using fine-needle aspiration cytology (FNAC) of the thyroid. Cervical lymph node metastases occurred in 99 (44.6%) of 222 PTC patients. Lymph node metastasis was significantly associated with tumor multifocality (p = 0.003), and high cellularity (p = 0.021), atypical histiocytoid cells (p < 0.001), and multinucleated giant cells (p < 0.001) in thyroid FNAC. The BRAF V600E mutation was marginally associated with lymph node metastasis (p = 0.054). Multivariate analysis revealed that atypical histiocytoid cells (odds ratio = 2.717; p = 0.001) and multinucleated giant cells (odds ratio = 3.070; p = 0.031) were independent predictors of lymph node metastasis in patients with PTC. In a subgroup analysis of 164 patients with microcarcinomas, atypical histiocytoid cells (odds ratio = 2.761; p = 0.005) was an independent predictor of lymph node metastasis. Cytological detection of atypical histiocytoid cells and multinucleated giant cells on thyroid FNAC can be used to preoperatively predict cervical lymph node metastasis in patients with PTC.

The management of haemoglobin interference for the MALDI-MSI proteomics analysis of thyroid fine needle aspiration biopsies

MALDI-MSI represents an ideal tool to explore the spatial distribution of proteins directly in situ, integrating molecular and cytomorphological information, enabling the discovery of potential diagnostic markers in thyroid cytopathology. However, red cells present in the fine needle aspiration biopsy (FNAB) specimens caused ion suppression of other proteins during the MALDI-MSI analysis due to large amount of haemoglobin. Aim of this study was to set up a sample preparation workflow able to manage this haemoglobin interference. Three protocols were compared using ex vivo cytological samples collected from fresh thyroid nodules of 9 patients who underwent thyroidectomy: (A) conventional air-dried smears, (B) cytological smears immediately fixed in ethanol, and (C) ThinPrep liquid-based preparation. Protocols C and A were also evaluated using real FNABs. Results show that protocol C markedly decreased the amount of haemoglobin, with respect to protocols A and B. Protein profiles obtained with protocols A and B were characterised by high inter-patient variability, probably related to the abundance of the haemoglobin, whereas similar spectra were observed for protocol C, where haemoglobin contents were lower. Our findings suggest protocol C as the sample preparation method for MALDI-MSI analysis. Graphical abstract.

Comparison of cytological adequacy and pain scale score in ultrasound-guided fine-needle aspiration of solid thyroid nodules for liquid-based cytology with with 23- and 25-gauge needles: a single-center prospective study

In ultrasound (US)-guided fine-needle aspiration (FNA) of solid thyroid nodules (STN) using liquid-based cytology (LBC), the most appropriate needle size for LBC remains unclear. This study compared the cytological adequacy and complications associated with using 23- and 25-gauge needles in US-guided FNA of STNs using LBC. US-guided FNA was performed in consecutive patients by one radiologist to diagnose STNs ≥ 5 mm in the largest diameter. The one-sampling technique through a single needle puncture and multiple to-and-fro needle motions was used in each patient. The 23- and 25-guage needles were used consecutively each day. After FNA, the pain and complications experienced by each patient were investigated by a nurse, who was blinded to the information of needle gauge used. A cytopathologist retrospectively analyzed the cytological adequacy and cellularity of the cases. Of the 99 STNs, eight (8.1%) exhibited inadequate cytology (4 each with 23- and 25-gauge needles). The rate of cytological adequacy was not statistically different between the groups (p = 0.631). The mean pain scale values with 23- and 25-gauge needles were 2.1 ± 1.3 and 1.6 ± 1.3, respectively (p = 0.135). There were no significant complications in either group. In conclusion, both 23- and 25-gauge needles are useful in LBC because cytological adequacy and complications were not statistically different with both sizes of the needles.

Endoscopic ultrasound-guided fine needle aspiration with liquid-based cytology preparation in the diagnosis of metastatic small-cell carcinoma in the pancreas

Pancreatic metastasis is extremely rare, particularly from small-cell lung cancer (SCLC). Studies on the role of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with liquid-based cytology (LBC) in the diagnosis of metastatic small-cell carcinoma in the pancreas have been rarely conducted. We report herein a case of pancreatic metastasis from SCLC diagnosed using EUS-FNA with LBC (ThinPrep). A 71-year-old man presented with chief complaints of hemoptysis and jaundice over the past 1 month. Lung & pancreas tumors with multiple liver nodules were detected on computed tomography. The aspirated material from the pancreas using EUS-FNA was prepared as a cytologic specimen with ThinPrep method, which revealed scattered and clustered "small blue cells" with scant cytoplasm and stippled chromatin with frequent apoptotic bodies. Immunocytochemical staining of the cellblock material revealed strong positivity for CD56 and thyroid transcription factor-1. Endobronchial biopsy for lung mass revealed nests of small, round, blue tumor cells with hyperchromatic nuclei showing salt and pepper chromatin, scant cytoplasm, and brisk mitotic activity. Therefore, a diagnosis of metastatic small-cell carcinoma to the pancreas with an extensive stage was finally made.

[Application of immunocytochemistry as a diagnostic aid: Experience in a tertiary university hospital in Cali, Colombia]

INTRODUCTION

Immunocytochemistry is very useful in the differentiation of benign and malignant lesions, through the use of specific antibodies that differentiate the cells according to their origin. This study aims to describe the application of immunohistochemistry to the cytological study of different sample types at the Valle del Lili Foundation.

MATERIALS AND METHODS

A descriptive, retrospective, observational study was carried out with cytologies registered in the database of the pathology department of the Fundación Valle del Lili, between December 2015 and October 2017.

RESULTS

Fifty-four cytological samples with immunocytochemistry were included. It was possible to perform both the cell block and the liquid-based cytology button to 38.88% (n=21) of the total samples, finding from the results of both types of cytology, a Cohen's Kappa coefficient of 0.80 (95%CI: (0.4-1.0), P<.001. The most commonly used markers were: Calretinin, MOC-31, EMA, TTF1, PAX8, and Calcitonin. Out of the cytological studies positive for malignancy, a definitive diagnosis was made with a biopsy in 58.1% (n=25), with a Cohen's Kappa coefficient of 1.0 (95%CI: 1.0-1.0), P<.001.

DISCUSSION

This study provided data that permits the implementation of liquid-based cytology button for immunocytochemical studies, using assessable markers with agreement with cell-block cytology. Furthermore, it provides data useful for future research in this field.