Reporting Thyroid Cytopathology Research Articles

Diagnostic interobserver agreement for thyroid fine-needle aspirates: Effects of reviewer experience and molecular diagnostics.

Few cytologically indeterminate thyroid fine-needle aspirations (FNAs) harbor BRAF V600E. Here, we assess interobserver agreement for The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) category III (atypia of undetermined significance [AUS]) FNAs harboring BRAF V600E and contrast their features with those harboring non-BRAF V600E alterations, with attention to cytopathology experience. Seven reviewers evaluated 5 AUS thyroid FNAs harboring BRAF V600E. To blind reviewers, cases were intermixed with 19 FNAs falling within other TBSRTC categories and in which genetic alterations other than BRAF V600E had been identified (24 FNAs total). Interobserver agreement against both "index" and most popular ("mode") diagnoses was calculated. Four additional BRAF V600E cases were independently reviewed. Reviewers included 3 trainees and 3 American Board of Pathology (board)-certified cytopathologists. Board-certified cytopathologists, whose experience ranged from 2 to more than 15 subspecialty practice years, had known AUS rates. BRAF V600E was identified in 5 of 260 (2%) AUS FNAs. Interobserver agreement was higher among cytopathologists with more experience. Mode diagnosis differed from index diagnosis in 6 of 11 cases harboring RAS-like alterations; mode diagnosis was AUS in 4 of 5 BRAF V600E FNAs. Atypia of undetermined significance of thyroid FNAs harboring BRAF V600E is uncommon yet relatively reproducible, particularly among pathologists with experience. It is advisable to sequence BRAF across V600 in such cases.

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.

A case series of thyroid fine needle aspiration biopsies diagnosed as follicular neoplasm with oncocytic features.

Oncocytic lesions of the thyroid are a heterogeneous group encompassing nonneoplastic and neoplastic entities ranging from benign to malignant and have traditionally been classified as separate entities in thyroid pathology. To illustrate the diversity of these thyroid lesions, we describe three cases of fine needle aspiration biopsies (FNAB) diagnosed as Bethesda Category IV: Follicular neoplasm, oncocytic type, under the 2017 Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), with ThyroSeq v3 molecular testing and subsequent surgical excision.

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.

What's new in thyroid pathology 2024: updates from the new WHO classification and Bethesda system.

In line with the release of the 5th edition WHO Classification of Tumors of Endocrine Organs (2022) and the 3rd edition of the Bethesda System for Reporting Thyroid Cytopathology (2023), the field of thyroid pathology and cytopathology has witnessed key transformations. This digest brings to the fore the refined terminologies, newly introduced categories, and contentious methodological considerations pivotal to the updated classification.

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.

A Comprehensive Approach to the Thyroid Bethesda Category III (AUS) in the Transition Zone Between 2nd Edition and 3rd Edition of The Bethesda System for Reporting Thyroid Cytopathology: Subcategorization, Nuclear Scoring, and More

Significant interobserver variabilities exist for Bethesda category III: atypia of undetermined significance (AUS) of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Thus, subcategorization of AUS including AUS “nuclear” and AUS “other” is proposed in the recent 3rd edition of TBSRTC. This study investigated the impact of the nuclear features/architectural features/nuclear score (NS) (3-tiered)/subcategories and subgroups on risk of malignancy (ROM) in thyroid fine-needle aspirations (FNA). 6940 FNAs were evaluated. 1224 (17.6%) cases diagnosed as AUS were reviewed, and 240 patients (initial FNAs of 260 nodules and 240 thyroidectomies) were included. Subcategories and subgroups were defined according to TBSRTC 2nd and 3rd editions. Histological diagnostic groups included nonneoplastic disease, benign neoplasm, low-risk neoplasm, and malignant neoplasm. Overall, ROM was 30.7%. ROM was significantly higher in FNAs with nuclear overlapping (35.5%), nuclear molding (56.9%), irregular contours (42.1%), nuclear grooves (74.1%), chromatin clearing (49.4%), and chromatin margination (57.7%), and these features were independent significant predictors for malignancy. FNAs with NS3 had significantly higher ROM (64.2%). Three-dimensional groups were significantly more frequent in malignant neoplasms (35.7%). ROM was significantly higher in AUS-nuclear subcategory (48.2%) and in AUS-nuclear and architectural subcategory (38.3%). The highest ROM was detected in AUS-nuclear1 subgroup (65.2%). ROM was significantly higher in the group including AUS-nuclear and AUS-nuclear and architectural subcategories, namely “high-risk group” than the group including other subcategories, namely “low-risk group” (42.0%vs 13.9%). In conclusion, subcategorization may not be the end point, and nuclear scoring and evaluation of architectural patterns according to strict criteria may provide data for remodeling of TBSRTC categories.

Clinical value of multi-gene testing in distinguishing benign and malignant thyroid nodules.

The newly released 2022 WHO Classification of Neuroendocrine Neoplasms (version 5) and a recent update on thyroid tumor classifications have emphasized genetic testing to an unprecedented level. Fine needle aspiration (FNA) has been widely applied for the preoperative diagnosis of thyroid nodules. However, it is limited mainly to testing for a single gene-BRAFV600E, whereas multi-gene testing data are scarce, especially in the Asian population. This study aimed to explore the clinical value of multi-gene testing in the differential diagnosis of benign and malignant thyroid nodules based on the 2023 Bethesda System for Reporting Thyroid Cytopathology (BSRTC). A total of 615 thyroid nodules underwent ultrasound-guided fine-needle aspiration cytology (FNAC) were collected from Sir Run Run Shaw Hospital, Zhejiang University School of Medicine. The next-generation sequencing platform was applied for multi-gene testing. A panel of well-recognized commonly mutated genes in thyroid cancer were analyzed, including BRAFV600E, KRAS, NRAS, HRAS, TERT, TP53, PAX8/PPARG, CCDC6/ RET and NCOA4/ RET. Gene mutations were identified in 324 nodules (52.7%), with BRAFV600E being the most prevalent driver gene alteration observed in this cohort (233/324; 79.1%), followed by RAS (77/324, 23.8%). The overall malignancy rate of gene mutations was 89.7% in our cohort, of which the lymph node metastasis rate was 45.3%. The combination of multi-gene testing and cytology resulted in 89.3% sensitivity, 95.2% specificity, 98.9% positive predictive value, 64.5% negative predictive value and 90.3% accuracy, which were significantly higher than those from mere cytology (sensitivity 68.6%, specificity 87.5%, positive predictive value 95.9%, negative predictive value 39.8%, accuracy 72.2%). Multi-gene testing could substantially enhance the detection rate of malignant thyroid nodules and protect patients with benign nodules from unnecessary surgeries. Multi-gene testing provides a valuable reference for individualized preoperative decision-making, which may serve as a crucial method for postoperative treatment and prognosis assessment.

Differentiated high grade thyroid carcinomas: Diagnostic consideration and clinical features

BackgroundDifferentiated high-grade thyroid carcinomas (DHGTCs) are a new diagnostic entity most recently defined in the 2022 World Health Organization's (WHO) Classification of Endocrine and Neuroendocrine Tumors. This new entity has been minimally described in the literature, and additional cases classified as such are missing. Materials and methodsCases of DHGTCs diagnosed at our institution from 2012 to 2022 were identified, and the following were reviewed: cytologic and histologic diagnoses, ancillary testing, immunohistochemical staining, treatments, and patient outcomes. Immunohistochemical staining for Ki67 was performed on selected cases lacking this immunostain. A systematic literature review of the English literature on DHGTCs from 2013 to 2023 was performed using PubMed and Embase. ResultsCase cohort included 32 cases of DHGTCs, with an average age of 52.6 years (range 17–84 years) and a male:female ratio of 1.3:1. All cases underwent fine needle aspiration (FNA) and were categorized by The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) as follows: 14 cases as malignant (43.8 %), 10 as follicular neoplasm (31.3 %), 5 as atypia of undetermined significance (15.6 %), 2 as suspicious for malignancy (6.2 %), and 1 as non-diagnostic (3.1 %). The average tumor size was 5.15 cm, and most were papillary thyroid carcinoma (28, 87.5 %), with classic subtype being the most common. Twenty-one cases revealed tumor necrosis and the mitotic activity in lesions without necrosis averaged to 5.5 mitoses per 2 mm2 (range 0–7). The average Ki67 proliferative index was 5.6 %. Extrathyroidal extension was seen in 17, angioinvasion in 21, lymphatic invasion in 7, and perineural invasion in 1 case. Foci of solid or trabecular growth were identified in five cases. Lymph node metastases at the time of diagnosis were noted in 10 cases and 7 demonstrated distant metastases or locoregional recurrence. To date, 25 patients are alive, and one has died from disease. ConclusionsOur institutional experience demonstrates that DHGTC is a rare, but aggressive thyroid tumor subtype that requires consideration in the setting of a well-differentiated thyroid neoplasm to appropriately assess for possible disease recurrence and determination of patient prognosis.

Diagnostic implication of thyroid spherules for cytological diagnosis of thyroid nodules.

Thyroid fine-needle aspiration (FNA) is a principal diagnostic procedure for thyroid nodules. A specific cytomorphological structure, known as the thyroid spherule, is often seen in FNA specimens. The clinical significance of these spherules in terms of diagnosis and prevalence remains largely unexplored. We performed a retrospective study on 310 thyroid FNA specimens and categorized them according to the Bethesda System for Reporting Thyroid Cytopathology. The presence, size and number of thyroid spherules in each specimen were examined and these data were subsequently correlated with the clinicopathological features. Thyroid spherules were almost exclusively detected in benign cases, comprising 7.6% of all benign diagnoses. The average diameter of spherules in benign cases was 84.9 μm. Benign cases and cases with atypia of undetermined significance cases primarily exhibited low cellularity, while follicular neoplasms and malignant cases typically showed moderate to high cellularity. In the subgroup of FNA cases with moderate to high cellularity, spherules were identified in 12 (20%) of 59 benign FNA cases. Within this group, the sensitivity and specificity of thyroid spherules for detecting benign FNA cases were 20% and 100%, respectively. Our results suggest that the presence of thyroid spherules in FNA specimens can serve as a highly specific marker for benign thyroid conditions. The prevalence of spherule detection is strongly influenced by the cellularity. In cases with moderate to high cellularity, the identification of spherules can assist the cytopathologists in diagnosing thyroid FNA cases as benign.

Bethesda 2023: nouvelle terminologie en cytopathologie thyroïdienne

A third update of The Bethesda System for Reporting Thyroid Cytopathology has been published in 2023 following the first (2010) and second (2017) versions. The main modifications are the following 1) a new co-Editor, 2) 4 associate editors, 3 of them from Europe, 3) the inclusion of 65 co-authors, 19 of them from Europe, 4) 2 new chapters: one dealing with pediatrics thyroid cytopathology and the other one describing molecular cytopathology profiling, 5) updated risks of malignancy (ROM), 6) a terminology in line with the 2022 WHO classification of thyroid tumors, 7) diagnostic categories now defined by a unique name, 8) 2 subtypes in the "Atypia of Undetermined Significance" category with corresponding ROM.

Thyroid Malignancy among Fine Needle Aspiration Cytology of Thyroid Lesions in a Tertiary Care Centre.

The most prevalent endocrine cancer in the world is thyroid cancer, and its incidence is on the rise. The distinction between benign and malignant thyroid nodules must be made, which is why fine needle aspiration cytology of thyroid lesion is necessary and required. This study aimed to find out the prevalence of thyroid malignancy among fine needle aspiration cytology of thyroid lesions in a tertiary care centre. A descriptive cross-sectional study was conducted among fine needle aspiration cytology of thyroid lesions in a tertiary care centre after obtaining ethical approval from the Institutional Review Committee. Data from 13 April 2020 to 13 April 2023 was collected between 19 May 2023 to 19 June 2023. All the patients with complete hospital record data were included in this study. However, repetitive fine needle aspiration cytology of thyroid lesion were excluded from the study. Fine needle aspiration cytology diagnoses were categorized in this study as per the Bethesda system for reporting thyroid cytopathology. The point estimate was calculated at a 95% Confidence Interval. Among 398 fine needle aspiration cytology of thyroid lesions, thyroid malignancy was seen in 12 (3.02%) (1.34-4.70, 95% Confidence Interval) patients. The prevalence of thyroid malignancy was found to be lower than other studies done in similar settings. cytology; malignancy; prevalence; thyroid.

Thyroid nodules and the risk of cancer based on fine-needle aspiration using Bethesda classification in Riyadh, Saudi Arabia

Background: The presence of thyroid nodules is common and can only be diagnosed through radiographic examination. Fine needle aspiration is an essential technique to identify the type of nodules and their malignancy categorization. This study aims to evaluate the effectiveness of the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) method in the Security Force Hospital, Riyadh, Saudi Arabia, and to estimate the frequency of Bethesda categorization in reporting fine needle aspiration sampling and predicting the malignancy risk in Riyadh. Methods: This is a retrospective chart review that included records of patients with sonographic thyroid nodules and an indicator for fine needle aspiration based on the American Thyroid Association guideline recommendations. The results of FNA were then classified based on the Bethesda system. Data analysis was executed through the Statistical Package for the Social Sciences (SPSS) version 26. Results: This study included 519 patients over three years. The average age was 49.71±12.4. 74.4% were asymptomatic, 50.7% had a thyroid nodule, while 33.9% had a multinodular goiter. 30.6% of the nodules had a size between 1 to 1.49 cm. 42% had smooth borders. The nodules most commonly had a low suspicion of malignancy by sonography, and 22.7% of the patients underwent thyroid surgery; of them, 54.2% had malignancy. Higher Bethesda classes and a sonographic pattern of intermediate suspicion were common predictors associated with a significantly higher risk of malignancy (p-value &amp;lt; 0.001). Conclusion: Thyroid malignancy is commonly detected by thyroid surgery; the use of Bethesda classification is a predictor of thyroid malignancy, and its application in Saudi hospitals should be improved.

Chapter 11: Pediatric Differentiated Thyroid Cancers

ABSTRACT The document discusses pediatric differentiated thyroid cancer (DTC), focusing on papillary thyroid carcinoma (PTC), which is increasingly prevalent globally, including in India. Despite a more aggressive initial presentation in children, the long-term prognosis is generally positive. Key differences between pediatric and adult DTC are highlighted, such as a higher risk of malignancy in children with thyroid nodules and common RET/PTC gene rearrangements. There is a debate on the age cutoff for defining pediatric DTC, but the document suggests that 18 years is considered appropriate in the Indian context. Diagnostic methods, including ultrasonography-guided fine needle aspirate (FNA) and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), are emphasized. The importance of genomic analysis for indeterminate cytology is also proposed. Treatment approaches involve total thyroidectomy due to higher multifocality in children, with consideration of potential complications. Post-operative risk stratification, utilizing the TNM staging system, is seen as crucial and correlates with disease-free survival. Post-operative staging includes TSH-stimulated thyroglobulin (Tg) and anti-thyroglobulin antibody (ATg) levels, along with a diagnostic whole-body 131I scan to assess surgical completeness. Radioactive iodine therapy (RAI) is recommended for iodine-avid persistent/metastatic disease, with an empirical activity of 30 mCi for remnant ablation and adjustments based on age or weight. Regular follow-ups include monitoring TSH-suppressed Tg, Anti-Tg levels, and neck ultrasound. Dynamic risk stratification at 2 years refines risk based on treatment responses. Genetic considerations reveal prevalent RET fusion oncogene and less common BRAF mutations, which are associated with RAI refractoriness. In summary, the document provides a comprehensive understanding of pediatric DTC, emphasizing the need for tailored guidelines in the Indian context. It covers various aspects of diagnosis, surgery, and post-operative care, with a focus on age-appropriate management and ongoing research in this specialized field.

Ultrasonographic Characteristics of Thyroid Nodules with Nondiagnostic and Atypia of Undetermined Significance in Fine-Needle Aspiration Cytology.

This study aimed to investigate ultrasound (US) features of thyroid nodules categorized as nondiagnostic (ND) and atypia of undetermined significance (AUS) according to the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) and their potential implications for clinical management. A retrospective study was conducted on patients who underwent thyroid nodules FNAC between 2019 and 2023. Nodules falling into the ND and AUS categories were analyzed for US features, nodule size, composition, echogenicity, shape, margin, echogenic foci, the distribution of the American College of Radiology's Thyroid Imaging Reporting and Data System (ACR TI-RADS) categories, and other parameters. The study included a total of 1,199 patients and 1,252 nodules (ND: 1110; AUS: 142). No significant differences in age, gender, nodule features, echogenicity, shape, margin, echogenic foci, TI-RADS scores, localization, number of nodules, or thyroid parenchymal disease presence were found between the ND and AUS categories (p > 0.05). Also, no statistically significant difference in nodule size (<10 mm vs. ≥10 mm) existed between the ND and AUS categories (p = 0.475). Both showed predominantly solid composition and hyperechoic/isoechoic echogenicity. High proportions of TI-RADS 4 nodules were observed in both groups, with 727 (65.5%) in ND and 95 (66.9%) in AUS. This study found no statistically significant differences in US characteristics between the ND and AUS categories, indicating potential similarities in their radiological appearances. Also, no significant difference in nodule size (<10 mm and ≥10 mm) was observed between these categories. Clinical management should consider further investigations, including repeat FNAC, due to the diagnostic challenges and malignancy risk in both categories.

Comparison of diagnostic accuracy of conventional method and Bethesda system for reporting thyroid cytopathology in the diagnosis of various lesions of the thyroid: Experience from a tertiary care center of northeastern India

Background: Fine-Needle Aspiration Cytology (FNAC) is a valuable, minimally invasive diagnostic tool for discerning benign and malignant thyroid lesions. In the realm of thyroid cytopathology, both the traditional approach and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) are widely utilized for diagnosing and categorizing these lesions. Aims and Objectives: This study aims to classify thyroid cytology smears using both the conventional method and the Bethesda system and to compare their findings with histopathological diagnoses. Method and Materials: A hospital-based cross-sectional study was conducted over one year, spanning from February 1, 2022, to January 31, 2023. We included 191 cases of FNAC thyroid lesions and categorized them following the guidelines of both the conventional system and the Bethesda system for reporting thyroid cytopathology. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy for both systems were calculated, with histopathology serving as the gold standard for comparison. Furthermore, we calculated the Risk of Malignancy (ROM) for each category within the Bethesda system. Results: The Bethesda system exhibited a notably high sensitivity of 83.33%, surpassing the conventional method's sensitivity of 50%, while both systems shared the same specificity of 90%. The diagnostic accuracy of the Bethesda system, at 89.13%, outperformed that of the conventional method, which stood at 84.78%. Conclusion: This study demonstrates a strong positive correlation with histopathology, indicating high sensitivity, specificity, and accuracy when employing TBSRTC, in contrast to the conventional method.

Non-papillary thyroid carcinoma diagnoses in The Bethesda System for Reporting Thyroid Cytopathology categories V and VI: An institutional experience

BackgroundThe non-papillary thyroid carcinoma (PTC) subgroups of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) categories V (Suspicious for malignancy) and VI (Malignant) are rare, and specific tumor typing is difficult. We aimed to analyze histologic outcomes and to investigate the points of caution. MethodsWe reviewed the electronic database and identified 12,215 cases of thyroid fine-needle aspiration cytology between 2013 and 2022. In total, 2783 patients were diagnosed with TBSRTC V or VI. Of these, 51 patients with non-PTC diagnosis were identified. Histological outcomes were analyzed with the cytologic findings. ResultsThe subgroups of non-PTC diagnoses in TBSRTC category V or VI consisted of medullary thyroid carcinoma (MTC) (13/51, 25.5 %), anaplastic thyroid carcinoma (3/51, 5.9 %), lymphoma (2/51, 3.9 %), metastatic tumor (4/51, 7.8 %), and malignant, not otherwise specified (NOS) (29/51, 56.9 %). The concordance rate of the histological outcomes was 30 % (12/40), predominantly comprising MTC cases. The obscuring factors for specific tumor typing in the suspicious for malignancy/malignant NOS cytology diagnosis group was mixed pattern of well differentiated thyroid carcinoma and less differentiated carcinoma cells (9/24, 37.5 %), low cellularity (7/24, 29.2 %) and a history of non-thyroid organ malignancy (6/24, 25 %). The less differentiated carcinoma component in mixed pattern consisted of 2 poorly differentiated thyroid carcinomas, 2 anaplastic thyroid carcinomas, 4 high-grade PTCs and 1 high-grade MTC. ConclusionThe high-grade feature of PTC or MTC cytology is a noteworthy obscuring factor in specific tumor typing of non-PTC cytology diagnosis.

Accuracy and diagnostic performance of the Bethesda system for reporting thyroid cytopathology in a tertiary endocrine surgical referral center in Belgium.

The Bethesda System for Reporting Thyroid Cytopathology is a commonly used classification for fine needle aspiration (FNA) cytology of suspicious thyroid nodules. The risk of malignancy (ROM) for each category has recently been analyzed in three international databases. This paper compares the diagnostic performance of the Bethesda classification in a high-volume referral center in Belgium. All consecutive thyroid procedures were registered in a prospective database from January 2010 till August 2022. Patient and surgical characteristics, preoperative Bethesda categories, and postoperative pathology results were analyzed. Out of 2219 consecutive thyroid procedures, 1226 patients underwent preoperative FNA. Papillary thyroid cancer was the most prevalent malignancy (N=119, 70.4%), followed by follicular (N=17, 10.1%) and medullary thyroid cancer (N=15, 8.9%). Micropapillary thyroid cancer was incidentally found in 46 (3.8%) patients. Bethesda categories I, II, III, IV, V, and VI, respectively, represented 250 (20.4%; ROM 4.4%), 546 (44.5%; ROM 3.8%), 96 (7.8%; ROM 20.8%), 231 (18.8%; ROM 15.2%), 62 (5.1%; ROM 72.6%), and 41 (3.3%; ROM 90.2%) patients. Overall ROM was 13.8%. An negative predictive value (NPV) of 96.2% was found. Overall specificity was 64.2% with a positive predictive value (PPV) of 31.9%. Diagnostic accuracy was 67.8%. Compared to international databases (CESQIP, EUROCRINE, and UKRETS), ROM in this study appeared lower for Bethesda category IV (15.2 vs. 26.7% and p=0.612). Despite being validated in numerous studies, ROM based on preoperative FNA cytology classified according to the Bethesda classification may vary among surgical centers and countries as this study reveals a higher NPV and lower PPV.

WITHDRAWN: The 2023 Bethesda System for Reporting Thyroid Cytopathology

WITHDRAWN: The 2023 Bethesda System for Reporting Thyroid Cytopathology

Bethesda Category III thyroid nodules: descriptive cytological aspects of a series

BackgroundThe Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is used for cytopathological diagnosis of fine needle aspiration (FNA) of thyroid nodules (TN). Diagnosis of Bethesda Category III (CIII) has estimated malignancy rates of around 10%-30%, which vary between different institutions. Objective. To review cases of FNA interpreted as CIII thyroid nodules. To evaluate cytopathological criteria used to interpret FNA for CIII thyroid nodules and the associations between cytological and radiological aspects. To determine the malignancy rate of thyroid nodules classified as CIII, based on the correlation with surgical procedure. Methods. Retrospective study of FNA’s cytologic criteria of TN classified as CIII, carried out between 2010 and 2016. The patients included in the study were those who underwent the first FNA in the service and who were diagnosed with CIII. The patients had their cytological slides and medical records reviewed to detect the conduct flow followed after the CIII diagnosis. All cases that had histological slides available of their thyroidectomy products, total or partial, reviewed. The associations between clinical, histological and cytological findings were statistically studied. Results. Among 63 patients with resected nodules, 17 (27%) were malignant, 13 of which were papillary thyroid carcinomas. Among the benign cases, 18 patients (28.1%) had chronic lymphocytic thyroiditis/Hashimoto’s thyroiditis. Papillae (p = .004) was the criterion best associated with the diagnosis of malignancy. Conclusion. The malignancy rate was consistent with the rate of malignancy predicted in the TBSRTC. It is important to point out that the sample of this study is relatively small, which compromises specific evaluations and reduces the robustness of the observed data. CIII is extensively studied in the literature, however there is still a need for more precise studies regarding the correlations between cytological findings and other parameters. Probably, more than other categories, CIII may require a combination of cytological, radiological and clinical interpretation, with pathology leading role in this diagnosis process.