Reporting Thyroid Cytology Research Articles

Thyroid cytology in pediatric patients: a single-center study from 2015 to 2023-is there a necessity for distinct treatment approaches for patients with and without autoimmune thyroiditis?

The management of thyroid nodules is guided by the cytological classification provided by The Bethesda System for Reporting Thyroid Cytology. Notably, the biology of thyroid tumors in pediatric patients differs from that in adults, and there is limited research focused on pediatric cases. This study aimed to assess the effectiveness of the Bethesda system in pediatric patients treated at the largest tertiary pediatric thyroid center in Poland between 2015 and 2023. A retrospective analysis was conducted on 566 patients with thyroid nodules, of whom 555 underwent fine-needle aspiration biopsy (FNAB). A total of 217 patients underwent thyroid surgery. Of these, 206 had previously undergone FNAB with cytological evaluation at our center, while 11 patients underwent thyroid surgery due to a RET mutation or the need for an extended procedure. The initial FNAB results showed distribution across Bethesda categories as follows: 7.6% for category I, 54.6% for category II, 20.9% for category III, 4.1% for category IV, 7.6% for category V, and 5.6% for category VI. Among patients who underwent surgery, the distribution of Bethesda categories I through VI was 2.9%, 25.2%, 29.1%, 8.3%, 19.4%, and 15%, respectively. The risk of malignancy (ROM) from the initial FNAB was estimated at 33.3%, 11.5%, 22.2%, 4.8%, 84.4%, and 96.8% for Bethesda categories I through VI, respectively. In patients with autoimmune thyroiditis (AIT), the ROM was higher than in non-AIT patients for Bethesda categories I through IV, while it was lower in category VI. The sensitivity for detecting non-benign neoplasms across Bethesda categories III through VI was approximately 86% in both AIT and non-AIT patients. However, for papillary thyroid carcinoma, sensitivity in Bethesda categories V and VI was 86% in non-AIT patients but decreased to 61.5% in AIT patients. These findings emphasize the importance of considering surgical intervention in pediatric patients with Bethesda III-VI cytology, particularly in those with AIT.

Inter- and Intra-observer Reproducibility of Thyroid Fine Needle Aspiration Cytology: An investigation of Bethesda 2023 Using Immunohistochemical BRAFV600E Antibody

Abstract Background: The Bethesda System for Reporting Thyroid Cytology (TBSRTC) recommended for the interpretation of needle aspiration cytology of the thyroid, is the most widely used worldwide. Studies have shown that the disagreement between observers, especially in the Bethesda III and IV diagnostic categories, is not insignificant at 10%–40%. In the TBSRTC 2023 version, some definitions were removed and simplified, and molecular pathology was proposed as a complement to cytopathology. The current availability of molecular tests is limited because they can be performed in a few centers and are expensive. Therefore, our study investigated intra- and inter-observer agreement according to TBSRTC 2023 using only immunohistochemically BRAFV600E antibodies. Materials and Methods: The study included 173 cases with aspiration cytology evaluated between 2019 and 2022. The immunohistochemical procedure applied BRAFV600E (RM8) monoclonal antibody to cell block sections. All slides were assessed and categorized by three different observers. Data were interpreted using Cohen’s kappa and Fleiss’s kappa test in the Statistical Package for Social Sciences Windows 2021 program. Results: For the applied RM8 antibody, sensitivity was 64.71% and specificity was 87.27%. In terms of diagnostic categories, inter-observer agreement was good for Bethesda II (K = 0.606) and moderate for Bethesda III (K = 0.429), Bethesda IV (K = 0.523), Bethesda V (K = 0,464), and Bethesda VI (K = 0.544), respectively. Conclusion: In conclusion, the study reveals that the 2023 version of TBSRTC provides improvement, especially in the categories of uncertain diagnosis, but is still insufficient to improve cytological diagnostic accuracy, at which point molecular analyses become even more important.

Decreasing trend in thyroid cancer incidence: a study from central Italy (2007-2019).

Due to overdiagnosis, the incidence of thyroid cancer (TC) has increased in high-income countries, including Italy. Efforts have been made to address this issue since the mid-2010s, but more information is needed about how TC incidence has changed. We aim to examine the trend in TC incidence in the Lazio Region (central Italy) and assess the impact of the 2014 Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC) to identify potential changes in TC diagnosis. To identify TC cases, we conducted a population-based study (period 2007-2019) using the data from the Lazio Region Cancer Registry (5.8 million residents). We calculated the annual age-standardized incidence rates of TC for both sexes and analyzed the impact of ICCRTC on monthly incidence rates using segmented linear regression applied to interrupted time-series (ITS). Throughout the 13 years, there was a significant decline in TC annual incidence rates, more pronounced in females. Our results are consistent with reports from outside Europe (United States and South Korea). Following ICCRTC implementation in 2014, a step-change reduction in both sexes was revealed. Our study indicates a significant decrease in the incidence of TC, particularly among females. The ITS analysis highlights the possible role of ICCRTC in reducing overdiagnosis. As the Lazio Region reflects the Italian population in terms of various demographic, health, and lifestyle indicators, our findings can be applicable at the national level.

A comparison of the histopathologic features of thyroid carcinomas with NTRK fusions to those with other malignant fusions

BackgroundChromosomal rearrangements involving one of the NTRK genes result in oncogenic driver mutations in thyroid carcinoma (TC) and serve as a target for therapy. We compared the clinicopathologic features of thyroid carcinomas with NTRK fusions vs. thyroid neoplasms with other malignancy associated gene fusions within our institution. Materials and methodsOur pathology archives were searched from 2013 to 2023 for thyroid neoplasms with gene fusions, excluding THADA fusions and medullary thyroid carcinomas. Results55 thyroid lesions were identified: 22 with NTRK fusions (NTRK cohort) and 33 with other fusions (non-NTRK cohort). On fine needle aspiration (FNA), 54% of the NTRK cohort were classified as Category V as per Bethesda System for Reporting Thyroid Cytology (TBSRTC) and 51.5% of non-NTRK cohort as TBSRTC Category III. In the NTRK cohort, the most common reported fusion was ETV6::NTRK3 and the most common reported fusion in the non-NTRK cohort was PAX8::PPAR-gamma. On histologic examination both cohorts were most commonly diagnosed as PTC follicular variant. Invasive features were more common in the NTRK cohort in comparison to the non-NTRK cohort. Locoregional recurrence occurred in 2/22 NTRK cases and 2/33 non-NTRK cases, with average time from surgery to recurrence being 5.5 months and 21 months, respectively. The majority of patients in both groups are alive with no evidence of disease. ConclusionsThyroid neoplasms with a malignancy associated gene fusion are likely to be diagnosed as subtype/variant of PTC. Patients whose thyroid lesions harbor NTRK fusions present with a PTC-FV that on presentation has more aggressive clinicopathologic findings and are likely to have earlier disease recurrence.

Performance of Thyroid Fine-Needle Aspiration Biopsy in a Low- and Middle-Income Country

Introduction: The 6 categories of the Bethesda System for Reporting Thyroid Cytology (TBSRTC) with associated risk of malignancy (ROM) provide evidence-based clinical management guidelines. This study aimed to determine the ROM and accuracy of FNAB in South Africa (SA). Methods: Thyroid specimens from 3 pathology laboratories registered between January 2015 and December 2019 were considered for inclusion. ROM was obtained per TBSRTC category by cytohistological correlation and dividing the total number of specimens with malignant histology by the total number of cases operated. Accuracy was calculated based on the Bethesda category and eventual malignant histology. Results: Seventeen thousand seven hundred and seventy-three histology and 4,791 cytology cases were identified. Of the 4,791 cytology cases, 931 (19%) underwent surgery. More than a third (333, 35.8%) of cases were confirmed as malignant following histological assessment, with the majority being benign (584, 62.7%). The ROM for the nondiagnostic and benign categories was 24.3% and 20.5%. The highest ROM was for category VI (91.5%), followed by categories V (69.5%), IV (51.9%), and III (38.8%). Thyroid FNAB had a sensitivity of 73%, specificity of 74%, and overall accuracy of 74%. Conclusion: Bethesda categories II and IV have a relatively higher ROM in SA compared to findings from other developed countries. The diagnostic accuracy of thyroid FNAB in SA and the high rate of nondiagnostic diagnoses (38%) require further investigation. A national thyroid registry could provide location-specific data to aid the implementation of appropriate local policies and national guidelines for practicing thyroid surgeons.

Atypia of undetermined significance and ThyroSeq v3-positive call rates as quality control metrics for cytology laboratory performance.

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) recommends an upper limit of 10% for atypia of undetermined significance (AUS). Recent data suggest that this category might be overused when the rate of cases with molecular positive results is low. As a quality metric, the AUS and positive call rates for this facility's cytology laboratory and each cytopathologist (CP) were calculated. A retrospective analysis of all thyroid cytology cases in a 4.5-year period was performed. Cases were stratified by TBSRTC, and molecular testing results were collected for indeterminate categories. The AUS rate was calculated for each CP and the laboratory. The molecular positive call rate (PCR) was calculated with and without the addition of currently negative to the positive results obtained from the ThyroSeq report. A total of 7535 cases were classified as nondiagnostic, 7.6%; benign, 69%; AUS, 17.5%; follicular neoplasm/suspicious for follicular neoplasm, 1.4%; suspicious for malignancy, 0.7%; and malignant, 3.8%. The AUS rate for each CP ranged from 9.9% to 36.8%. The overall PCR was 24% (range, 13%-35.6% per CP). When including cases with currently negative results, the PCR increased to 35.5% for the cytology laboratory (range, 13%-42.6% per CP). Comparison analysis indicates a combination of overcalling benign cases and, less frequently, undercalling of higher TBSRTC category cases. The AUS rate in the context of PCR is a useful metric to assess cytology laboratory and cytopathologists' performance. Continuous feedback on this metric could help improve the overall quality of reporting thyroid cytology.

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

BackgroundThe Bethesda System for Reporting Thyroid Cytopathology (BSRTC) has evolved since it was first introduced in 2009 to become a worldwide accepted cytologic analysis reference, due to its simplicity and reproducibility. To date, the consistency of BSRTC throughout time has yet to be investigated. MethodsRetrospective single institution case series with chart review of all patients who underwent fine-needle aspirations for a thyroid nodule in our institution between the years 2010 and 2018 with a documented BSRTC classification. Data collection included demographics, risk factors, sonographic evaluation, nodule size, and final pathology when feasible. The main outcome is the difference in the rates of BSRTC categories benign, atypia of undetermined significance (AUS), follicular neoplasm, suspicious for malignancy, and malignant (BSRTC II-VI, respectively) between the study years. ResultsA total of 2830 thyroid nodules were included. BSRTC II-VI distribution was 83.9% (2373), 8.2%, (232), 2.7% (75), 3.3% (93), and 2.0% (57), respectively. There was no significant change in the overall trend of each BSRTC category distribution throughout the study. There was a significant increase in the benign cytology rate (BSRTC II) in 2011 compared to 2015 and 2018 (76.4% compared to 88.7% and 87.6%, respectively. P < .005) alongside a significant decline in the AUS category rate (BSRTC III) between the same years (13.0% compared to 4.8% and 5.5%, respectively. P < .005). ConclusionBSRTC showed consistency throughout the study across all observed categories. An overlap between AUS and benign may exist, possibly due to the heterogenic definition of AUS as reflected in the 2023 BSRTC subclassification for AUS.

Unveiling Variations: A Comprehensive Comparison of Five Globally Used Thyroid Cytology Reporting Systems With Histopathological Correlation.

Introduction Accurate cytological assessment is pivotal for managing thyroid lesions and various global reporting systems are in use, such as the globally acclaimed The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), alongside other reporting systems namely, the Japanese Reporting System for Thyroid Aspiration Cytology (JRSTAC), Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC), the UK Royal College of Pathologists System for Reporting Thyroid Cytopathology (UK RCPath), the Royal College of Pathologists of Australasia and Australian Society of Cytology Classification System (RCPA/ASC). Notably, variations exist among these systems which are influenced by country-specific statistics. Given the lack of large-scale data in India and the difference in prevalence of diagnostic entities compared to the western population, this study aimed to identify reporting systems suitable for the Indian population focusing on distinguishing neoplastic from non-neoplastic lesions. Materials and methods A cross-sectional analysis of 40 thyroid cytology cases with histopathological correlation was conducted. Pathologists independently assessed cytology slides using JRSTAC, ICCRTC, RCPA/ASC, UK RCPath and TBSRTC. Five performance indicators, sensitivity, specificity, positive predictive value (PPV) of neoplastic conditions, negative predictive value (NPV) of non-neoplastic conditions, diagnostic accuracy and two quality indicators, percentage of Atypia of undetermined significance (AUS) and AUS/Malignant ratio were analyzed and compared. Results Among 40 cases, 22 cases were neoplastic (16 papillary thyroid carcinoma, six follicular adenoma) and 18 non-neoplastic (14 multinodular goiter, four lymphocytic thyroiditis). Specific patterns emerged in cases labeled "Non-diagnostic", prompted questions about categorizing inadequately cellular cases as "benign" in light of the presence of specific findings. All reporting systems showed 100% specificity in detecting non-neoplastic and neoplastic conditions in Category 1 and Category 6 respectively. Performance and quality indicators varied among reporting systems with TBSRTC (PPV of neoplastic cases 85.71%, NPV of non-neoplastic cases 70.58%, specificity 85.7%, sensitivity 70.58%, diagnostic accuracy 60%, AUS percentage 22.5% and AUS/Malignant ratio 3%) and RCPA/ASC (PPV of neoplastic cases 76.47%, NPV of non-neoplastic cases 70.58%, specificity 75%, sensitivity 72.2%, diagnostic accuracy 62.5%, AUS percentage 15% and AUS/Malignant ratio 3%) showing better results. Conclusion Among the five thyroid cytology reporting systems studied, TBSRTC and RCPA/ASC showed better overall performance results and quality indicators were close to benchmark. Better performance by TBSRTC 2023 could be due to the detailed criterion mentioned per category with subcategorization of AUS and suspicious for malignancy by features of cytological and architectural atypia. Similarly, RCPA/ASC has subcategorized AUS with defined criteria and certain background features were included as an isolated criterion for the suspicious for malignancy category. These defined criteriaoutlined in TBSRTC and RCPA/ASC played a crucial role in minimizing and reclassifying cases from the indeterminate categories (AUS and suspicious for malignancy) into well-defined categories with established management protocols.

Cytological Analysis of Thyroid lesions According to the Bethesda System for Reporting Thyroid Cytology and their Correlation with Histopathology: A Prospective Study

Introduction: Fine-needle aspiration cytology (FNAC) has a crucial role in differentiating between nonneoplasticand neoplastic lesions of the thyroid. It is a quick outpatient department (OPD) procedure. It greatlyaffects the treatment decision. The current study was done to evaluate the role of FNAC as a diagnostic tool inthyroid lesions and establish a clinico-cytological and histological correlation.Aim: To study efficacy of Bethesda system for reporting (TBSRTC) FNAC of thyroid in view of offering guidancefor patient management, for review of distribution of diagnostic categories and correlation with histopathology.Materials and Methods: It is a prospective study of thyroid lesions carried out at the Department of Pathology, CAIMS,Karimnagar over a period of 3 years (January 2020 to January 2023) A total of 303 patients of neck swelling (thyroid),with satisfactory cases on 290 patients in cytology were undertaken for histopathology. Their clinico-cytological,biochemical, and histological correlation was done only in 133 patients only. Their statistical analysis was done.Results: Majority of cases were non neoplastic. The accuracy of cytodiagnosis was 89.3% and overall malignancyrate on histopathology was 16% (37 cases).Conclusion: FNAC of lesions in thyroid gland has a high accuracy in differentiating between malignant andbenign lesions. It is safe cost effective, minimally invasive, and OPD procedure. Using FNAC as the first line ofinvestigation which streamline the reporting terminologies and the number of surgeries on thyroid lesion hasreduced greatly.

Impact of the 3rd Edition of the Bethesda System for Reporting Thyroid Cytopathology on Grey Zone Categories

Introduction: Thyroid Bethesda Reporting System is a six-tiered system that aims to bring uniformity in reporting thyroid cytology and improve the communication with clinicians. The system has achieved its goal as a presurgical diagnostic method; however, it remains a screening method in the grey zone categories, namely atypia of undetermined significance (AUS) and follicular neoplasm (FN). The book recently released the 3rd edition, following the recent changes in thyroid pathology. One of the most important novelties is subgrouping AUS category and FN to be able to make a better risk stratification in these categories. Our group aims to retrospectively analyze a large dataset based on the new TBSRTC, with a focus on the grey zone categories. Methods: Only patients who underwent lobectomy or total thyroidectomy were included, allowing for direct comparison between cytological and histopathological results. Cytological evaluations, based on the TBSRTC 3rd edition, were methodically compared with their respective histopathological results, enabling a comprehensive analysis. Results: Of the 244 patients (female:male ratio = 8.8:1, mean age = 56), a total of 252 nodules were evaluated. A distinction was noted with 79 nodules (31%) diagnosed as AUS and 173 nodules (69%) as FN. Intriguingly, the risk of malignancy (ROM) for AUS-overall stood at 44.3%, with AUS-nuclear atypia at 50% and AUS-other at 43.2%. Although the AUS subdivisions did not demonstrate statistical significance, a significant disparity was observed in their distribution, with 15% as AUS-nuclear atypia compared to 85% as AUS-other. This disparity raises the question: Could AUS-other be considered the new waste-basket category in the TBSRTC 3rd edition? Using the TBSRTC 3rd edition as a base, we added a subclassification for FN nodules based on the presence or absence of papillary thyroid carcinoma (PTC) nuclear features. Our findings showed that differentiating FN with oncocytic characteristics correlated well with histological outcomes and ROMs. Though retrospective in design with inherent bias potential, our data suggest a possible improvement in PTC case segregation in the FN category when differentiating between FN nodules with and without PTC nuclear features. Conclusion: Our retrospective study sheds light on the potential advantages of the TBSRTC 3rd edition, particularly in refining the AUS and FN categories for thyroid nodules. The clear disparity in AUS subcategories raises important questions about their classification and potential future refinements. Moreover, the differentiation of FN nodules based on PTC nuclear features holds a promising approach for better risk stratification.

An investigation into noninvasive follicular thyroid neoplasms with papillary-like nuclear features: does the initial proposal on noninvasive follicular thyroid neoplasms with papillary-like nuclear features behavior hold true?

Current management of patients with noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP) is lobectomy with close clinical follow-up. Because this entity is still young, we present our 5-year institutional experience with NIFTP since that time. Cases of NIFTP diagnosed from 2017 to 2022 were identified. Data points including patient demographics, radiology, cytologic and pathologic diagnoses, molecular profiles, and clinical follow-up were documented. A literature review of NIFTP case series was performed. A total of 379 cases were included (mean age: 52 years, female:male ratio 3.3:1). Ultrasound findings were available for 260 patients, and 247 underwent fine-needle aspiration (FNA). The FNA diagnoses per the Bethesda System for Reporting Thyroid Cytology were nondiagnostic (n=2), benign (n=16), atypia of undetermined significance/follicular lesion of undetermined significance (n=119), follicular neoplasm/suspicious for follicular neoplasm (n=68), suspicious for malignancy (n=31), and malignant (n=11). Molecular testing was performed in 179 cases. Lobectomy was performed for 183, total thyroidectomy for 192, and nodulectomy for 4 cases. The average size of NIFTP was 2.3cm, and 232 cases had additional nodules (including benign and malignant neoplasms). Multifocal NIFTP occurred in 32 patients. Lymph nodes were evaluated in 196 cases with metastatic carcinoma in 29 cases (all with concurrent diagnoses of carcinoma). Most patients were alive at follow-up, 100 were lost to follow-up, and three died from other causes. Literature review revealed 2870 NIFTP cases with similar patient demographics and pathologic findings. We confirm that NIFTP is a low-risk neoplasm with indolent clinical behavior, which can be managed conservatively.

Evaluation of FNAC Thyroid Smears Using Bethesda System For Reporting Thyroid Cytopathology Nomenclature With Clinicopathological Correlation

Background: The study aimed to interpret thyroid cytology by the Bethesda System for reporting thyroid cytology (TBSRTC) and to analyze the distribution of lesions under various diagnostic categories and subcategories.&#x0D; Methodology: This study was conducted as an observational study at tertiary care centre on patients with thyroid lesions. After history taking and detailed local, general and systemic examination, thyroid function tests were conducted. Apart from this, ultrasonography of lesion was done. Patients were subjected to FNAC and after fixation smears were stained with Papanicolaou stain.&#x0D; Results: About 53% thyroid lesions were hemorrhagic, followed by 17% blood mixed colloid and 4% colorless serous fluid. Sample adequacy was noted in 93.5% cases in our study. According to Bethesda system of classification, majority of lesions were benign (81.5%) whereas 6.5% lesions were unsatisfactory. Only 6% lesions were categorsied as malignant.&#x0D; Conclusion: FNAC is widely accepted as the most accurate, sensitive, specific, and cost- effective diagnostic procedure in the preoperative assessment of thyroid nodules. It is the first line of investigation and can differentiate benign nodules from malignant nodules of the thyroid in 95% cases. Applying a standard reporting system for thyroid cytology may enhance the communication between pathologists and clinicians, assists them to find out the rate of malignancy in each cytological group, and facilitating a more reliable approach for patient management.

Assessment of thyroid lesions using fine-needle aspiration cytology in accordance with The Bethesda System and its histopathological correlation - A prospective study.

Background: Fine Needle Aspiration Cytology is a first-line diagnostic technique that provides an accurate and precise diagnosis for assessing thyroid abnormalities. This study was conducted to analyze the cytology smears of thyroid lesions using The Bethesda system of reporting thyroid cytology and to correlate the cytological findings with histopathology diagnosis to determine the diagnostic accuracy of FNAC. Materials and methods: A prospective cross-sectional study was carried out. FNAC of thyroid lesions of 203 patients were examined and reported as per the Bethesda system for reporting thyroid cytopathology. Of these, 33 patients underwent surgery, whose histopathological findings were compared and correlated with respective cytopathological diagnoses. The IBM SPSS (Statistical Package for the Social Sciences) software version 27 was used for data analysis. Results: Among 203 cases evaluated, there were 11 Non-diagnostic (Category I) cases, 171 benign (Category II) cases, 4 cases of atypia of undetermined significance (Category III), 7 were suspicious for Follicular Neoplasm (Category IV), 2 were suspicious for malignancy (Category V) and 8 were malignant (Category VI). Out of 203 patients, only 33 patients underwent surgery, of whom 26 (78.79%) were benign and 7 (21.21%) were malignant on histopathology. The corresponding values for sensitivity, specificity, and diagnostic precision of FNAC were 71.42%, 100%, and 93.93% respectively, while positive and negative predictive values were determined as 100% and 92.85% respectively. Conclusions: The study shows that thyroid tumors can be successfully categorized and reported cytologically as per The Bethesda system.

Hashimoto Thyroiditis beyond Cytology: A Correlation between Cytological, Hormonal, Serological, and Radiological Findings.

Hashimoto thyroiditis is the most common cause of chronic inflammation of the thyroid gland. Ultrasound is the modality for detection, while fine needle aspiration is the gold standard method for diagnosis. Serologic markers, such as antithyroidal peroxidase antibody (TPO) and antithyroglobulin antibody (TG), are usually elevated. The main objective is to appraise the incidence of neoplasms on a background of Hashimoto thyroiditis. Our second objective is to recognize the different sonographic appearances of Hashimoto thyroiditis, to focus on its nodular and focal patterns, and to measure the sensitivity of the ACR TIRAD system (2017) when interpreted on patients with Hashimoto thyroiditis. A single-center retrospective cross-sectional study. We studied 137 cases diagnosed cytologically as Hashimoto thyroiditis from January 2013-December 2019. The data collected were analyzed using SPSS (26th edition), and ultrasounds were reviewed by a single board-certified radiologist. The ACR thyroid imaging and Data System 2017 (ACR TI-RADs 2017) and the Bethesda System for reporting thyroid cytology 2017 (BSRTC 2017) were used for reporting ultrasound and cytology, respectively. The mean age was 44.66 years and the female : male was 9 : 1. Serologically, anti-Tg was high in 22 cases (38%), while anti-TPO was positive in all of the 60 cases studied. Histologically, 11 cases were diagnosed with papillary thyroid carcinoma (8%) and a single case with follicular adenoma (0.7%). Ultrasonographically, 50% of the cases showed diffuse pattern, in which 13% of them showed micronodules. 32.2% were macronodular, and 17.7% were a focal nodular pattern. 45 nodules were interpreted with the ACR TIRAD system (2017), in which 22.2% were TR2, 26.6% were TR3, 17.7% were TR4, and 33.3% were TR5. Hashimoto thyroiditis is a risk factor for developing thyroid neoplasms, which necessitate a proper assessment of the cytological material studied and a correlation with the clinical and radiological features. Recognizing the different types of Hashimoto thyroiditis and its variable appearances is significantly important in performing and interpreting thyroid ultrasound imaging. Microcalcification is the most sensitive parameter to discriminate between PTC and nodular type of Hashimoto thyroiditis. The TIRAD system (2017) is a useful tool for risk stratification; however, it might create unnecessary FNA studies in the setting of Hashimoto thyroiditis because of its variable appearances on ultrasound. A modified TIRAD system for patients with Hashimoto thyroiditis is important to alleviate this confusion. Finally, anti-TPO is a sensitive marker for detecting Hashimoto thyroiditis, which could be used for future referencing of newly diagnosed cases.

RETROSPECTIVE STUDY OF ULTRASONOGRAPHIC AND FNAC CORRELATION OF THYROID LESIONS WITH HISTOPATHOLOGY

INTRODUCTION: Thyroid diseases, a common clinical problem have prevalence rate of 4–7% in the general population. Fine-needle aspiration cytology (FNAC) is a minimally invasive, accurate diagnostic tool which can differentiate neoplastic from non-neoplastic lesions and reduces the number of unnecessary thyroidectomies, but has limitations . Our study was a retrospective an METHODOLOGY: alysis of 124 cases of thyroid lesions over a period of 3 years from April2019 to April 2022. The FNAC ndings were reviewed and data was compared with the histopathological, imaging ndings and data was analysed. Majority of the pat RESULTS: ients were females in the age group of 41–60 years with a mean age of 42 years and most were non-neoplastic lesions. 76 cases were diagnosed as colloid nodular goitre and benign cystic lesions by FNAC. 44 cases were diagnosed as neoplastic lesions (follicular neoplasm, papillary carcinoma, and suspected malignancy) by FNAC. 18 of these cases were non neoplastic lesions, 24 were papillary carcinoma, 2 were follicular carcinoma on histopathological examination . Statistical analysis of neoplastic lesions showed sensitivity, specicity, accuracy, false positive rate, false negative rate, positive predictive value, and negative predictive value of FNAC to be 69.09%, 90.7%, 80.8%, 9.2%, 30.9%, 86.3% and 77.6% respectively. Ultrasound was foun CONCLUSION: d to be more reliable than palpation, but denitive diagnosis can be reached only with FNAC/Biopsy. Bethesda system of reporting thyroid cytology should be meticulously followed to minimize errors and a repeat FNAC asked for discordant cases after a multidisciplinary team conference.

A comparative study between conventional and the Bethesda System for Reporting Thyroid Cytology of 240 cases.

Thyroid nodule is a common disorder of thyroid. Despite their benign nature, they can be associated with multiple pathologic conditions including thyroid cancer. Fine-needle aspiration plays an essential role in evaluating thyroid nodules. The Bethesda System for Reporting Thyroid Cytology (TBSRTC) has attempted to standardize reporting and cytological criteria in aspiration smears. The aim of this study is to compare the conventional and TBSRTC and to compare and correlate the cases with histological findings wherever available. The present study was a retrospective study undertaken in the department of pathology from January 2018 to December 2018 to access the validity of TBSRTC considering histopathology as the gold standard. May Grünwald Giemsa and Papanicolaou stained thyroid FNA smears of 240 patients were collected which were reported by the conventional system for reporting thyroid cytology and also categorized as per current Bethesda nomenclature for thyroid cytology. Diagnosis of both the reporting systems was then compared and correlated with the histological diagnosis wherever possible. A total of 240 cases were examined on cytology, out of which histopathological correlation was possible in 110 cases. For benign thyroid lesions, sensitivity and specificity with conventional system were 69.91% and 40.25%, respectively, while with TBSRTC, sensitivity and specificity were 84.04% and 29.94%, respectively. Sensitivity and specificity of conventional system for malignant thyroid lesions were 58.56% and 69.91%, respectively, while with TBSRTC, sensitivity and specificity were 73.69% and 95.12%, respectively. The Bethesda system found to be highly sensitive for benign thyroid lesions and highly specific for malignant thyroid lesions as compared to the conventional method of reporting of thyroid cytology. Bethesda system was found to be superior for reporting thyroid cytology over the conventional system of reporting for thyroid cytology.

ODP474 Critical Analysis of the Thyroid Cytopathologic Diagnosis of Atypia of Undetermined Significance and Associated Clinical Outcomes

Abstract Introduction FNA is the optimal test for classifying concerning thyroid nodules. Approximately 15-30% of FNAs are indeterminate, representing diagnostic challenge with intra- and inter-observer variability among cytologists. The Bethesda System (BS) for cytopathology was created in 2007 to standardize thyroid cytology with corresponding malignancy risk. Our goal is to identify the incidence of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/ FLUS) and the percent of malignant AUS/FLUS cases at our institution. Methods Chart review of 3068 adult patients with FNA performed from 2003 to 2015 was completed, with attention to reports considered "indeterminant". BS for reporting thyroid cytology was not in use at our institution during that time. Cytopathology reports were evaluated for key descriptors concerning for AUS, FLUS, or follicular neoplasm. Results 461 cytology reports included language consistent with possible "indeterminate" cytology. These reports were reviewed with our institution's cytopathologist and retrospectively assigned an equivalent BS category. 241 cases were consistent with BS category III (7.86% of all thyroid nodule FNAs done during this time period). Molecular marker studies were not being performed at our institution on indeterminate thyroid cytology specimens during this time period. Of the patients who had indeterminate cytology consistent with BS category III, 66.3% (160/241) went for surgery. The malignancy rate was 27.5% (44/160) in the BS category III group. Conclusion Our data demonstrated that category III nodules in some practice settings may have a higher risk of malignancy than traditionally believed, and that guidelines recommending repeat FNA or observation merit reconsideration. Molecular marker testing on indeterminate thyroid cytology specimens has been shown to be helpful in determining cases for surgery and is now being utilized at our institution. Presentation: No date and time listed

Operation rate and cancer prevalence among thyroid nodules with FNAC report of suspicious for malignancy (TIR4) or malignant (TIR5) according to Italian classification system: a systematic review and meta-analysis

BackgroundIn the Italian system for reporting thyroid cytology (ICCRTC), nodules suspicious for (TIR4) and consistent with (TIR5) malignancy are thought being 5% and 4–8% of all biopsies and having risk of malignancy of 60–80% and >95%, respectively. However, no evidence-based data exist about these figures. The present systematic review aimed at achieving solid estimates about TIR4 and TIR5 also considering potential influencing factors.MethodsThe review was conducted according to MOOSE. Databases of Google Scholar and Cochrane were searched. No language restriction was used. The last search was performed on February 26th 2022. Quality assessment was performed. Proportion meta-analyses were performed using random-effect model. Statistical analyses were performed using OpenMeta [Analyst].ResultsThe online search retrieved 271 articles and 16 were finally included for quantitative analysis. The risk of bias was generally low. The pooled cancer prevalence in TIR4 was 92.5% (95%CI 89.4–95.6%) with unexplained moderate heterogeneity. The pooled cancer rate among TIR5 was 99.7% (95%CI 99.3–100%) without heterogeneity. The resection rate in TIR4 and TIR5 showed heterogeneity, being the latter explained when using their prevalence among biopsies: the higher the prevalence, the higher the operation rate. The pooled risk difference between TIR5 and TIR4 was significant (OR 11.153).ConclusionsThese figures can form the basis for the next updated version of ICCRTC. Any institution using ICCRTC should revise its series of TIR4/TIR5 to calculate the cancer rate, and, importantly, consider the modifiers of the risk of malignancy. A cross check among institutions is advised.

The Italian Consensus for the Classification and Reporting of Thyroid Cytology: Cytohistologic and molecular correlations on 37,371 nodules from a single institution.

The Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC) includes six diagnostic categories (TIR 1/1C, TIR 2, TIR 3A, TIR 3B, TIR 4, and TIR 5), each indicating a different risk of malignancy. The objective of this monocentric retrospective study was to evaluate the distribution of the ICCRTC classes at the authors' institution and assess their cytohistologic correlations. The authors retrospectively collected 37,371 consecutive cytologic reports of thyroid nodules and described the clinical-pathologic features of the different cytologic categories. The cytologic diagnoses also were compared with histologic outcomes in a subset of patients. The cytologic classes were distributed as follows: nondiagnostic, 15.6%; benign, 66.5%; low-risk indeterminate, 10% (TIR 3A); high-risk indeterminate, 3.5% (TIR 3B); suspicious, 1.7%; and malignant, 2.6%. According to histology, the risk of malignancy was very high in the nondiagnostic category (29.8%), with young male patients more exposed to malignancy, and it was relatively high among benign (7.8%) and indeterminate nodules (32.5% in TIR 3A; 52.1% in TIR 3B), mainly because of the high prevalence of follicular architecture in malignant tumors. On histology, the malignancy rates were 92.4% and 99.3% for the suspicious and malignant categories, respectively; aggressive variants of papillary thyroid carcinoma were mostly diagnosed in these categories. In this series, nondiagnostic nodules showed high prevalence and, surprisingly, high malignancy rates. Malignant tumors with follicular architecture represented a diagnostic pitfall in benign and indeterminate nodules. The suspicious and malignant categories had high specificity for malignancy. Importantly, the ICCRTC had high reliability for identifying preoperatively aggressive histotypes of thyroid carcinoma.

Diagnostic Reliability of the American College of Radiology Thyroid Imaging Reporting and Data System in Royal Commission Hospital, Kingdom of Saudi Arabia

BACKGROUND: The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) classified and predicted the risk of thyroid nodule malignancy with ultrasound scan scoring system. AIM: Hence, we aimed to investigate the value of the combined use of ultrasound ACR TI-RADS scoring and ultrasound-guided thyroid fine needle aspiration cytology (FNAC) based on the Bethesda System for Reporting Thyroid Cytology (TBSRTC) for assessing the accuracy tests of diagnosing low and high-risk thyroid nodules of ACR TI-RADS. METHODS: We enrolled 392 patients with thyroid nodules who underwent ultrasound scanning and scoring using the ACR TI-RADS classification along with ultrasound-guided thyroid FNAC and scoring with TBSRTC. The two methods were grouped as low and high risk of malignancy to evaluate the accuracy of ACR TI-RADS. RESULTS: Three hundred and ninety-two patients were enrolled in the study. The mean (Standard deviation [SD]) age was 46.03 (13.96) years, 332 (84.7%) were females and the mean (SD) of body mass index was 31.90 (22.32) kg/m2 and Vitamin D 17.65 (11.15) nmol/L. The mean (SD) for thyroid function test was 5.37 (44.16) mmol/L for thyroid-stimulating hormone, 1.48 (1.49) ng/dL for free thyroxine (FT4), and 2.69 (0.70) nmol/L for free triiodothyronine (FT3). Most of the participants were euthyroid (63.8%), but 28.6% had hypothyroidism and 7.7% had hyperthyroidism. The accuracy tests of ACR TI-RADS in relation to TBSRTC, were sensitivity (87.8%), specificity (65.2%), positive predictive value (29.8%), and negative predictive value (97%). The area under the curve = 0.590, 95% CI = 0.530–0.650, p ˂ 0.006. CONCLUSION: ACR TI-RADS is a simple, practical, and reliable scoring system for assessing thyroid nodule; it has a better overall diagnostic performance and the ability to exclude unnecessary FNAC with high negative predictive value.