Diagnostic Performance of Thyroid Core Needle Biopsy Using the Revised Reporting System: Comparison with Fine Needle Aspiration Cytology

The Diagnostic Role of Repeated Biopsy of Thyroid Nodules with Atypia of Undetermined Significance with Architectural Atypia on Core-Needle Biopsy

BACKGRUOUND

We aimed to evaluate the utility of repeat biopsy of thyroid nodules classified as atypia of undetermined significance with architectural atypia (IIIB) on core-needle biopsy (CNB).

METHODS

This retrospective study evaluated patients with thyroid nodules categorized as IIIB on CNB between 2013 and 2015. Demographic characteristics, subsequent biopsy results, and ultrasound (US) images were evaluated. The malignancy rates of nodules according to number of CNBs and the number of IIIB diagnoses was compared. Demographic and US features were evaluated to determine factors predictive of malignancy.

RESULTS

Of 1,003 IIIB nodules on CNB, the final diagnosis was determined for 328 (32.7%) nodules, with 121 of them confirmed as malignant, resulting in a malignancy rate of 36.9% (95% confidence interval, 31.7% to 42.1%). Repeat CNB was performed in 248 nodules (24.7%), with 75 (30.2%), 131 (52.8%), 13 (5.2%), 26 (10.5%), one (0.4%), and two (0.8%) reclassified into categories II, IIIB, IIIA, IV, V, and VI, respectively. Malignancy rates were not significantly affected by the number of CNBs (P=0.291) or the number of IIIB diagnoses (P=0.473). None of the nodules confirmed as category II on repeat CNB was malignant. US features significantly associated with malignancy (P<0.003) included solid composition, irregular margins, microcalcifications, and high suspicion on the US risk stratification system.

CONCLUSION

Repeat biopsy of nodules diagnosed with IIIB on CNB did not increase the detection of malignancy but can potentially reduce unnecessary surgery. Repeat biopsy should be performed selectively, with US features guiding the choice between repeat biopsy and diagnostic surgery.

[SFE-AFCE-SFMN 2022 consensus on the management of thyroid nodules: Interest and place of thyroid cytology]

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a symptom that is a frequent reason for consultation in endocrinology. Thyroid nodules are very common and mostly benign. Thyroid ultrasound and thyroid fine-needle aspiration biopsy (FNAB) are the reference tests for the analysis of these nodules. The aim of this article is to describe for the cytopathologist the key points of the SFE-AFCE-SFMN 2022 consensus involving thyroid cytology: the indications for thyroid FNAB, the technique and analysis, and the management (treatment, follow-up) following this cytological screening examination, a key element in the management of the thyroid nodule.

A comparative analysis of core needle biopsy and repeat fine needle aspiration in patients with inconclusive initial cytology of thyroid nodules

Purpose

To assess and compare the effectiveness of ultrasound-guided core needle biopsy (CNB) in comparison to repeat fine-needle aspiration(rFNA) for thyroid nodules that yield inconclusive results following the initial fine-needle aspiration (FNA).

Methods

A cohort of 471 patients who received an inconclusive cytological diagnosis following the initial FNA were included in this study. These patients subsequently underwent either CNB (n=242) or rFNA (n=229). The inconclusive FNA results encompassed categories I, III, and IV of The Bethesda System for Reporting Thyroid Cytopathology(TBSRTC), as well as the ultrasound images indicating malignancy despite FNA results falling under TBSRTC category II. This study assessed the sampling satisfaction rate, diagnostic efficacy, and complications associated with CNB compared to rFNA. Additionally, the impact of repeat puncture time and nodule size on diagnostic efficacy was analyzed.

Results

Following repeat punctures, the satisfaction rate of the CNB sampling was found to be significantly higher than that of rFNA (83.9% vs 66.8%). The diagnostic rate in the CNB group was significantly greater compared to that of the rFNA group (70.7% vs 35.8%). In patients with nodule maximum diameters ranging from 5 mm to 20 mm, the diagnostic accuracy was significantly higher in the CNB group compared to that in the rFNA group. In patients with intervals less than 90 days, between 90 days and one year, the diagnostic rate in the CNB group was found to be higher compared to that in the rFNA group. In CNB, not immediately adjacent to the capsule was a risk factor for nodular puncture bleeding (37.0% vs 22.7%.).

Conclusion

CNB demonstrated higher rates of satisfaction and diagnosis compared to the rFNA. The diagnostic effectiveness of CNB was not influenced by the time interval or the size of the thyroid nodule. Therefore, in cases where the initial FNA diagnosis of thyroid nodules is inconclusive, CNB should be considered as a viable option for re-puncture.

Examining the impact of several factors including COVID-19 on thyroid fine-needle aspiration biopsy

OBJECTIVE

The study explores various factors, including coronavirus disease 2019 (COVID-19) history and vaccination status, that influence the classification value of ultrasonography-guided thyroid fine needle aspiration biopsy (TFNAB) by comparing non-diagnostic (Bethesda-I) and diagnostic (Bethesda II-VI) results.

METHODS

We conducted a retrospective observational study in a high-volume tertiary care center involving patients who underwent TFNAB from November 2022 to April 2023. The study retrospectively analyzed the cytopathology of 482 thyroid nodules. Patients were categorized into non-diagnostic (n = 136) and Diagnostic groups (n = 346) based on TFNAB. A comprehensive set of parameters was examined, including demographic, anthropometric and clinical data, thyroid ultrasonography findings, COVID-19 history and immunization status.

RESULTS

The mean age was 55.1 ± 12.1 years in the non-diagnostic group and 53.5 ± 13 years in the Diagnostic group (p = .223). 75.7% (n = 103) of the non-Diagnostic group and 82.9% (n = 287) of the Diagnostic group were male (p = .070). The mean nodule longitudinal diameter of the Diagnostic group was significantly higher than that of the non-diagnostic group (p = .015). The TIRADS score of the nodules showed a statistical difference between the groups (p = .048). The groups had no significant differences regarding other ultrasonographic parameters and COVID-19-related variables.

CONCLUSION

It can be assumed that when the longitudinal diameter of the thyroid nodule is small and in TIRADS categories other than the TIRADS3 category, TFNAB is less likely to be diagnostic. However, future research may be needed to confirm these findings and uncover any long-term effects of COVID-19 or vaccines on thyroid nodule diagnostics.

Reevaluating diagnostic categories and associated malignancy risks in thyroid core needle biopsy

As the application of core needle biopsy (CNB) in evaluating thyroid nodules rises in clinical practice, the 2023 Korean Thyroid Association Management Guidelines for Patients with Thyroid Nodules have officially recognized its value for the first time. CNB procures tissue samples preserving both histologic structure and cytologic detail, thereby supplying substantial material for an accurate diagnosis and reducing the necessity for repeated biopsies or subsequent surgical interventions. The current review introduces the risk of malignancy within distinct diagnostic categories, emphasizing the implications of noninvasive follicular thyroid neoplasm with papillary-like nuclear features on these malignancy risks. Prior research has indicated diagnostic challenges associated with follicular-patterned lesions, resulting in notable variation within indeterminate diagnostic categories. The utilization of mutation-specific immunostaining in CNB enhances the accuracy of lesion classification. This review underlines the essential role of a multidisciplinary approach in diagnosing follicular-patterned lesions and the potential of mutation-specific immunostaining to strengthen diagnostic consensus and inform patient management decisions.

Preoperative Risk Stratification of Follicular-patterned Thyroid Lesions on Core Needle Biopsy by Histologic Subtyping and RAS Variant-specific Immunohistochemistry

Follicular-patterned lesions often have indeterminate results (diagnostic category III or IV) by core needle biopsy (CNB) and fine needle aspiration (FNA). However, CNB diagnoses follicular neoplasm (category IV) more frequently than FNA. Therefore, we aimed to develop a risk stratification system for CNB samples with category III/IV using immunohistochemistry (IHC). The specificity of the RAS Q61R antibody was validated on 58 thyroid nodules with six different types of RAS genetic variants and 40 cases of RAS wild-type. We then applied IHC analysis of RAS Q61R to 207 CNB samples with category III/IV in which all patients underwent surgical resection. RAS Q61R IHC had 98% sensitivity and 98% specificity for detecting the RAS p.Q16R variant. In an independent dataset, the positive rate of RAS Q61R was significantly higher in NIFTP (48%) and malignancies (45%) than in benign tumors (19%). The risk of NIFTP/malignancy was highest in the group with nuclear atypia and RAS Q61R expression (86%) and lowest in the group without both parameters (32%). The high-risk group with either nuclear atypia or RAS Q61R had 67.3% sensitivity, 73.4% specificity, 75.2% positive predictive value, and 65.1% negative predictive value for identifying NIFTP/malignancy. We conclude that RAS Q61R IHC can be a rule-in diagnostic test for NIFTP/malignancy in CNB category III/IV results. Combining of the histologic parameter (nuclear atypia) with RAS Q61R IHC results can further stratify CNB category III/IV into a high-risk group, which is sufficient for a surgical referral, and a low-risk group sufficient for observation.