Bethesda System For Reporting Thyroid Cytology Research Articles

Low reproducibility of equivocal categories of the Bethesda System for Reporting Thyroid Cytology makes the associated risk of malignancy specific to the diagnostic center

PurposeEquivocal categories (III, IV, V) of the Bethesda System for Reporting Thyroid Cytology (BSRTC) are characterized by high variability of the estimated risk of malignancy. The aim of the study was to analyze the reproducibility of classification of nodules into an equivocal category and the frequency of malignancy (FoM) observed in such categories.MethodsFive experienced cytopathologists from three centers (A, B, C) independently performed reclassification of smears obtained from 213 thyroid nodules with equivocal routine cytology and known results of the postoperative histopathological examination.ResultsThe interobserver agreement among all cytopathologists was poor, with a Krippendorff’s alpha coefficient equaling 0.34. The intra-center agreement was higher than the inter-center (fair vs poor). Pathologists of the center A classified smears into categories II and III significantly less often and categories IV and V more often than pathologists of centers B and C. The joint FoM of nodules classified into any of categories IV–VI (regarded as an indication for surgery) was different among centers (A: 40.0%, B: 66.7%, C: 80.6%). The FoM of category III nodules with features of nuclear atypia (AUS) in center B and C was two times higher than that of other nodules of category III (FLUS), while in center A the FoM was similar.ConclusionsThe use of published data on the risk of malignancy in nodules of particular BSRTC categories without concern for the uniqueness of the diagnostic center may lead to erroneous conclusions.

Molecular testing and thyroid nodule management in North America.

The incidence of thyroid cancer is rising for a variety of reasons. At the same time, the nomenclature revision of non-invasive encapsulated follicular-variant PTC to noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP) has modified the incidence of thyroid cancer. Given that thyroid neoplasia is a molecular event, it is important for the thyroid physician to evaluate each patient systematically. Most thyroid cancers are sporadic; however, some are familial and may be associated with syndromes with genetic implications. Advances in radiologic imaging have made ultrasonography a near equivalent of gross examination. The American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS) classifies nodules from TR1 to TR5 and is valuable in determining which patients should be guided toward fine-needle aspiration (FNA) sampling. While FNA procedures and processing may be varied, the key elements are cytologic diagnosis and collection of samples for potential molecular testing. The Bethesda System for Reporting Thyroid Cytology (BSRTC) is commonly used and categorizes each FNA specimen into one of six diagnoses. The indeterminate diagnoses with risk of malignancy (ROM) ranging from 10-75% comprise approximately 30% of thyroid FNA cases and for these, molecular testing is beneficial. In North America, the two most common molecular platforms are Veracyte Afirma GSC and ThyroSeq v3. Both panels cover an extensive array of genomic alterations associated with thyroid neoplasia and a negative result from either test effectively refines the ROM of an Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance (AUS/FLUS) or Follicular Neoplasm/Suspicious for a Follicular Neoplasm (FN/SFN) diagnosis to 3-4%. Given that the refined ROMs are comparable to that of a Benign BSRTC diagnosis, these patients are recommended for observation of their nodules. However, differences exist in the implication of Afirma GSC-Suspicious and ThyroSeq v3-Positive molecular results with regard to the probability of cancer. For either test, the molecular test result should be integrated with other clinical parameters to determine if surgery is indicated and, if so, the extent of surgery.

A Comparative Study of Thyroid Cytology Reporting by Bethesda System and Routine Cytology in a Teaching Institute of Sub Himalayan Region

Introduction: Fine needle aspiration cytology (FNAC) is an important preoperative diagnostic tool for thyroid lesions which are endemic in the Sub-Himalayan belt. But sometimes, the FNAC procedures are unable to guide clinicians for definite management. Bethesda System for Reporting Thyroid Cytology (BSRTC) has been formulated to be more sensitive and specific than routine cytological examination in diagnosis of thyroid swellings and act a better tool than the latter due to its objectivity. It may, thus, improve the clinical management of thyroid diseases and even may prevent unnecessary thyroidectomy. Aims and Objective: The study is aimed to compare the interpretation of thyroid FNAC smears by conventional reporting and by BSRTC in patients of thyroid swellings in the Sub-Himalayan regions. Material and Methods: This observational study was done at the Department of Pathology from July 2015 to June 2016. Total 145 cases of thyroid swellings were included for study and reported by both BSRTC and conventional (routine) reporting system. Each of the reporting system was correlated with the available histopathological findings and statistical assessments were performed. Results: Among the total 145 cases, colloid nodules followed by thyroiditis were most common benign conditions in both the reporting systems and among the malignancies; papillary carcinoma was the most predominant. Statistical assessment showed that sensitivity, specificity as well as positive and negative predictive values was higher in BSRTC compared to the conventional reporting system. Conclusion: BSRTC is more accurate than conventional reporting system for thyroid cytology and its management strategy can help to prevent unnecessary thyroidectomy.

Thyroid Nodules Cytopathology Applying the Bethesda System with Histopathological Correlation.

Background:Fine-needle aspiration cytology remains a valuable screening tool for preoperative management of thyroid nodules. However, the rates of false-negative and false-positive diagnosis remain a challenge for pathologists.Objectives:To assess the value of thyroid fine-needle aspiration as a screening tool and its accuracy of diagnoses relative to final histological diagnoses.Patients and Methods:A chart review was conducted of all adult patients who underwent fine-needle aspiration of thyroid nodule(s) and were subjected to thyroid surgery at King Abdulaziz Medical City, Jeddah, Saudi Arabia, between January 2007 and June 2014. The fine-needle aspiration results were correlated with final histopathology results.Results:Of the 408 aspirates from 373 patients, the Bethesda System for Reporting Thyroid Cytology (BSRTC) diagnostic categories were as follows: nondiagnostic in 26 aspirates (6.4%); benign in 128 (31.4%); atypia/follicular lesion of undetermined significance in 52 (12.7%); follicular neoplasm/suspicion for a follicular neoplasm in 83 (20.3%); suspicious for malignancy in 23 (5.6%) and malignant in 96 (23.5%). The comparative histopathological diagnoses were benign in 192 (47.1%) and malignant in 216 (52.9%) aspirates. The calculated risk of malignancy in the fine-needle aspiration categories was 34.6% in diagnostic category (DC) I, 15.6% in DC II, 50% in DC III, 52% in DC IV, 95.7% in DC V and 100% in DC VI. The sensitivity of fine-needle aspiration with BSRTC was 88.9%, specificity was 75.6%, positive predictive value was 79.7%, negative predictive value was 84.4% and accuracy was 81.5%.Conclusion:The results of this retrospective study demonstrated higher risks of malignancy in DC I, DC II, DC III and DC IV than that of the original BSRTC definition, along with a higher specificity and positive predictive value for cancer diagnosis, and a lower sensitivity and negative predictive value.

Application of the Bethesda System for Reporting Thyroid Cytopathology in the Eastern Province of Saudi Arabia: A Follow-Up Study

This is a follow-up study to our previous analysis of thyroid aspirates utilizing the Bethesda System for Reporting Thyroid Cytology (BSRTC). The same study design was utilized for 2 years comparing 2 periods. A total of 251 thyroid aspirates from 218 patients were reviewed and deemed comparable to the previous cohort. The variance and consequently the number of interpretations dropped from 26 to 11 with a statistically significant 58% reduction and more consistency. Our unsatisfactory rate dropped from 22 to 10% (reduction of 55%). The risk of malignancy in this follow-up study showed a similar trend: an increase in risk with each step up in the BSRTC categories starting from the ‘nondiagnostic' and up to ‘malignant'. Few of our benign cases ended up with resection. We noticed sensitivity to the word ‘follicular' in this benign category; therefore we propose a modification of the current BSRTC system by omitting the word ‘follicular' from the benign category. We strongly believe that this modification harbors no serious damage to the intentions of BSRTC. This follow-up study has shown that the previous awareness campaign about the implementation has worked and can be considered a valid performance improvement program.

Prospective evaluation of impact of using the Bethesda System for Reporting Thyroid Cytopathology: an institutional experience

The Bethesda System for Reporting Thyroid Cytology (BSRTC) refines the definition of and provides specific diagnostic criteria for fine-needle aspiration (FNA) assessment of thyroid lesions. This study was conducted to prospectively evaluate the diagnostic and clinical impact of using BSRTC for management of thyroid lesions and to compare diagnostic performance of post-BSRTC period with that of pre-BSRTC period. The study included FNA specimens obtained in our institution 2.5 years prior to and 2.5 years after implementing BSRTC. Nondiagnostic rate, distribution of the diagnostic categories, rate of surgical follow-up, cytohistologic concordant rate, and risk of malignancy were calculated and compared between pre- and post-BSRTC periods. In comparison to the pre-BSRTC period, the post-BSRTC period generated a lower nondiagnostic rate (19.9% versus 15.8%), a greater proportion of benign (65.3% versus 69.2%) and atypia of undetermined significance or follicular lesion of undetermined significance (4.4% versus 7.4%) in contrast with a decreased proportion of follicular neoplasm or suspicious for follicular neoplasm categories (5.6% versus 2.2%). Rate of surgical follow-up decreased for benign (13.8% versus 7.6%) and atypia of undetermined significance or follicular lesion of undetermined significance (61.5% versus 42.1%) categories, and overall surgical rate reduced (24.2% versus 18.1%). Implementation of BSRTC did not affect overall rate of cytohistologic concordance (78.4% versus 80.5%) or the overall rate of histologically proven malignancy (30.6 versus 36.9%), whereas the individual cytohistologic concordant rate and the malignant rate for each of the diagnostic categories did not differ between pre- and post-BSRTC. The implementation of BSRTC resulted in a decreased overall surgical rate, particularly for benign and follicular lesion of undetermined significance categories, without affecting overall cytohistologic concordance and rate of malignancy.

Thyroid Fine-Needle Aspiration Reporting Rates and Outcomes Before and After Bethesda Implementation Within a Combined Academic and Community Hospital System

The current study compares data from our hospital system before and after the 2008 implementation of the Bethesda System for Reporting Thyroid Cytology (BSRTC). To show the effects the BSRTC has had on the reporting rates and outcomes for thyroid lesions. A search for thyroid fine-needle aspiration biopsies (FNABs) was performed for 2002-2005 (before BSRTC) and 2009-2011 (after BSRTC). Diagnostic outcomes were reviewed for cases with available follow-up. For 2002-2005, cytology reports for 3302 thyroid FNABs were reviewed, and 309 (9.4%) were classified as suspicious. For 2009-2011, cytology reports for 3432 thyroid FNABs were reviewed; 72 (2.1%) were classified as "atypia of undetermined significance or follicular lesion of undetermined significance" (AUS/FLUS), and 142 (4.1%) were classified as suspicious. Follow-up material was available for 31 AUS/FLUS cases (43.0%), and 6 of these cases (19%) were malignant. Follow-up material was available for 60 cases (42.3%) classified as suspicious, and 23 of these cases (38%) were malignant. The AUS/FLUS rate of 2.1% at our institution is at the lower range of the <7% recommended by the BSRTC, and our rate of 19% for risk of malignancy for AUS/FLUS is slightly above the BSRTC recommendation of 5% to 15%. Implementation of the BSRTC did not significantly affect our institution's reporting rates, most likely because an essentially similar classification system was employed before implementation of the BSRTC.