Preoperative evaluation of thyroid nodules - Diagnosis and management strategies

Accuracy of ultrasound-guided fine-needle aspiration cytology in evaluation of thyroid nodules using different ultrasonographic and cytological features

BACKGROUND

Fine-needle aspiration cytology (FNAC) is a reliable method for preoperative evaluation of thyroid nodules particularly if ultrasound-guided (USG-FNAC). The main purpose of this study is to evaluate the efficacy of USG-FNAC and its accuracy.

METHODS

We retrospectively studied 212 thyroidectomy cases with preoperative ultrasonography and FNAC data during the period 2015-2022 using TI-RADS for final ultrasound diagnosis and Bethesda system for cytological diagnosis.

RESULTS

The studied cases were 200 females and 12 males. Thyroid cancer was more prevalent under 20 years old (78.5%). Papillary thyroid carcinoma comprises 84% of all cancer cases. Significant ultrasound features (p-value <0.05) favour malignancy were hypoechogenicity (66%), mixed echogenicity (84%), irregular border (61%), microcalcification (68%) and rim halo (63.6%). Malignancy was found in 21% of TI-RADS-2, 65% of TI-RADS-4 and 100% of TI-RADS-5. There is a significant difference between different categories of Bethesda system. All cases in Cat-VI were malignant (100%). Malignancy was also found in 81% of Cat-V, 20% of Cat-IV, 33% of Cat-III, 16% of Cat-II and 43% of Cat-I. Cytological features consistent with malignancy were as follows: grooving (94%), nuclear irregularities (89%), nuclear pseudoinclusion (89%) and little colloid (82%). In our study, USG-FNAC sensitivity was 83%, specificity 85%, PPV 85%, NPV 83% and accuracy 84%.

CONCLUSION

Ultrasound features in favour of malignancy in thyroid nodules are hypoechoic or complex echogenicity, irregular border, punctuate calcification and presence of rim halo. Cytological features in favour of malignancy are grooving, nuclear irregularities, nuclear pseudoinclusion and little or absent colloid.

Assessment of ChatGPT's adherence to ETA-thyroid nodule management guideline over two different time intervals 14 days apart: in binary and multiple-choice queries

OBJECTIVE

Artificial intelligence (AI) has significant potential in healthcare, particularly in providing decision-support in specialized domains like thyroid nodule management. This study assesses the effectiveness of ChatGPT-v4, an advanced AI model, in aligning with the European Thyroid Association (ETA) - 2023 guidelines.

METHODS

The study utilized a structured questionnaire comprising 100 questions, divided into true/false and multiple-choice formats, reflecting real-world clinical scenarios in thyroid nodule management. These questions encompassed diagnostic criteria, treatment options, follow-up protocols, and patient counseling. ChatGPT response was evaluated for accuracy, consistency, and comprehensiveness using a six-point Likert scale. The assessment occurred initially and was repeated after 14 days.

RESULTS

In the binary queries, the AI model showed an ability to correct some initially incorrect responses. However, there was a noticeable regression in certain responses. 8 of the 11 previously non-compliant responses remained unchanged, while 3 non-compliant responses were rectified. Conversely, 6 initially compliant answers transitioned to non-compliance after 14 days. In multiple-choice queries, the AI's performance was more consistent. A majority of the responses, 43 (86% of the total), were initially correct and maintained their correctness upon re-assessment. However, 4 responses that were initially incorrect remained unchanged, and 3 correct responses shifted to non-compliance over time.

CONCLUSION

ChatGPT exhibited improving potential as a clinical support tool in thyroid nodule management altgouh it showed varied performance for binary and multiple-choice questions.

CLINICAL TRIAL REGISTRATION

N/A.

BRAF Detection in FNAC Combined with Semi-Quantitative 99mTc-MIBI Technique and AI Model, an Economic and Efficient Predicting Tool for Malignancy in Thyroid Nodules

BACKGROUND

Technology allows us to predict a histopathological diagnosis, but the high costs prevent the large-scale use of these possibilities. The current liberal indication for surgery in benign thyroid conditions led to a rising frequency of incidental thyroid carcinoma, especially low-risk papillary micro-carcinomas.

METHODS

We selected a cohort of 148 patients with thyroid nodules by ultrasound characteristics and investigated them by fine needle aspiration cytology (FNAC)and prospective BRAF collection for 70 patients. Also, we selected 44 patients with thyroid nodules using semi-quantitative functional imaging with an oncological, 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI) radiotracer.

RESULTS

Following a correlation with final histopathological reports in patients who underwent thyroidectomy, we introduced the results in a machine learning program (AI) in order to obtain a pattern. For semi-quantitative functional visual pattern imaging, we found a sensitivity of 33%, a specificity of 66.67%, an accuracy of 60% and a negative predicting value (NPV) of 88.6%. For the wash-out index (WOind), we found a sensitivity of 57.14%, a specificity of 50%, an accuracy of 70% and an NPV of 90.06%.The results of BRAF in FNAC included 87.50% sensitivity, 75.00% specificity, 83.33% accuracy, 75.00% NPV and 87.50% PPV. The prevalence of malignancy in our small cohort was 11.4%.

CONCLUSIONS

We intend to continue combining preoperative investigations such as molecular detection in FNAC, 99mTc-MIBI scanning and AI training with the obtained results on a larger cohort. The combination of these investigations may generate an efficient and cost-effective diagnostic tool, but confirmation of the results on a larger scale is necessary.

Difficulties of Preoperative Diagnosis of Cribriform Morular Thyroid Carcinoma

Background

Cribriform morular thyroid carcinoma has been recently renamed in the 2022 WHO classification as a thyroid tumor of uncertain histogenesis. The epidemiologic, pathological, and pathophysiological characteristics distinguish it from papillary thyroid carcinoma (PTC). Preoperative genetic testing plays a role in facilitating the differential diagnosis.

Methods

This report presents a confirmed case of cribriform morular thyroid carcinoma. Initially, fine-needle aspiration cytology suggested a diagnosis of PTC. However, a genetic analysis did not reveal the typical mutations associated with follicular-cell-derived neoplasms.

Results

A 31-year-old woman was found to have a thyroid nodule at the left lobe measuring 11.8 × 10.2 × 12.4 mm. Ultrasonography indicated a hypoechoic, solid nodule with regular margins. Cytology revealed a papillary structure of tall cells, leading to a PTC diagnosis. Nevertheless, the genetic analysis failed to detect mutations such as BRAF V600E, NRAS Q61R, NRAS Q61K, HRAS Q61R, or HRAS Q61K mutation or the fusion of CCDC6-RET, NCOA4-RET, PAX8-PPARG, ETV6-NTRK3, TPM3-NTRK1, IRF2BP2-NTRK1, or SQSTM1-NTRK1 in the aspirated follicular cells. The patient subsequently underwent total thyroidectomy with central lymph node dissection. Pathological examination revealed a cribriform pattern of spindle-shaped cells with morular areas. Immunohistochemical staining showed positive results for β-catenin and TTF-1, except in the morular regions, and negative results for PAX8, thyroglobulin, and BRAF (clone VE1). The diagnosis was confirmed to be cribriform morular thyroid carcinoma.

Conclusion

Significant cytological similarity exists between PTC and cribriform morular thyroid carcinoma. Preoperative genetic analysis is important to differentiate these two diseases. Cribriform morular thyroid carcinoma can be differentiated from common follicular-cell-derived tumors by the absence of typical mutations; the presence of nuclear and cytoplasmic expressions of β-catenin; the presence of TTF-1, except in morular areas; and the absence of thyroglobulin.

Impact of fine-needle aspiration cytology in thyroidectomy extent and associated surgical morbidity in thyroid cancer

PURPOSE

To assess the impact of fine-needle aspiration cytology (FNAC) in the extent of surgery in patients with thyroid cancer (TC) and the associated surgical morbidity in primary and completion setting.

METHODS

A Swedish nationwide cohort of patients having surgery for TC (n = 2519) from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal surgery between 2004 and 2013 was obtained. Data was validated through scrutinizing FNAC and histology reports.

RESULTS

Among the 2519 cases operated for TC, the diagnosis was substantiated and validated through the histology report in 2332 cases (92.6%). Among these, 1679 patients (72%) were female, and the median age at TC diagnosis was 52.3 years (range 18-94.6). Less than total thyroidectomy (LTT) was undertaken in 944 whereas total thyroidectomy (TT) in 1388 cases. The intermediate FNAC categories of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/ FLUS), as well as suspicion for follicular neoplasm (SFN) lesions were more often encountered in LTT (n = 314, 33.3%) than TT (n = 63, 4.6%), whereas FNACs suspicion for malignancy and/or malignancy were overrepresented in TT (n = 963, 69.4%). Completion thyroidectomies were undertaken in 553 patients out of 944 that initially had LTT. In 201 cases with cancer lesions > 1 cm, other than FTC (Follicular TC)/ HTC (Hürthle cell TC) subjected to primary LTT, inadequate procedures were undertaken in 81 due to absent, Bethesda I or II FNAC categories, preoperatively. Complications at completion of surgery in this particular setting were 0.5% for RLN palsy (n = 1) and 1% (n = 2) for hypoparathyroidism 6 months postoperatively. The overall postoperative complication rate was higher in primary TT vs. LTT for RLN palsy (4.8% [n = 67] vs. 2.4% [n = 23]; p = 0.003) and permanent hypoparathyroidism (6.8% [n = 95] vs. 0.8% [n = 8]; p < 0.0001).

CONCLUSIONS

FNAC results appear to affect surgical planning in TC as intermediate FNAC categories lead more often to LTT. Overall, inadequate procedures necessitating completion surgery are encountered in up to 15% of TC patients subjected to LTT due to absent, inconclusive, or misleading FNAC, preoperatively. However, completion of thyroidectomy in this setting did not yield significant surgical morbidity. Primary LTT is a safer primary approach compared to TT in respect of RLN palsy and permanent hypoparathyroidism complication rates; therefore, primary TT should probably be reserved for lesions > 1 cm or even larger with suspicion for malignancy or malignant FNAC.

Diagnostic performance of shear wave elastography in thyroid nodules with indeterminate cytology: A systematic review and meta-analysis

Purpose

Thyroid nodules classified as indeterminate in previous fine-needle aspiration cytology often necessitate additional evaluation to determine their histology, while shear wave elastography (SWE) offers an alternative option in this regard. The objective of this study was to assess the diagnostic effectiveness of SWE in evaluating indeterminate nodules.

Methods

The PubMed, EMBASE, and Web of Science databases were searched from 1st January 1970 to 1st March 2023. The studies were reviewed and the data was extracted by two separate reviewers. A Bayesian bivariate model was utilized to quantitatively synthesize the diagnostic accuracy and yield of the studies in R.

Results

A total of seven studies, involving indeterminate thyroid nodules undergoing SWE were included, and the overall malignancy rate was 34.1% (307/900). The summarized estimates of sensitivity and specificity were 0.792 (95% credible interval [CI], 0.727-0.850) and 0.845 (95% CI, 0.797-0.887), respectively. The summarized estimate for the diagnostic odds ratio (DOR) was 17.8 (95% CI, 14.0-22.6). Summarized receiver operating characteristic (SROC) plots indicated a trade-off between sensitivity and specificity, and the estimate of AUC was 0.866 (95% CI, 0.834-0.895). The summary estimates for positive and negative likelihood ratios were 4.67 (95% CI, 3.98-5.85) and 0.26 (95% CI, 0.23-0.28), respectively.

Conclusions

The overall accuracy of SWE remains satisfactory in indeterminate thyroid nodules. However, it should be noted that the available data are still extremely limited, and more studies or guidelines are required to provide further insights.

Management of Thyroid Nodules

Thyroid nodules are common and the prevalence varies between 4 and 7% by palpation and 19-68% by high-resolution USG. Most thyroid nodules are benign, and the malignancy rate varies between 7 and 15% of patients. Thyroid nodules are detected incidentally during clinical examination or, more often, during imaging studies performed for another reason. All detected thyroid nodules should be evaluated clinically. The main test in evaluating thyroid function is thyroid stimulating hormone (TSH). If the serum TSH level is below the normal reference range, a radionuclide thyroid scan should be performed to determine whether the nodule is hyperfunctioning. If the serum TSH level is normal or high, ultrasonography (US) should be performed to evaluate the nodule. US is the most sensitive imaging method in the evaluation of thyroid nodules. Computed tomography (CT) and magnetic resonance imaging are not routinely used in the initial evaluation of thyroid nodules. There are many risk classification systems according to the USG characteristics of thyroid nodules, and the most widely used in clinical practice are the American Thyroid Association guideline and the American College of Radiology Thyroid Imaging Reporting and Data System. Fine needle aspiration biopsy (FNAB) is the gold standard method in the evaluation of nodules with indication according to USG risk class. In the cytological evaluation of FNAB, the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is the most frequently applied cytological classification. TBSRTC is a simplified, 6-category reporting system and was updated in 2023. The application of molecular tests to FNAB specimens, especially those diagnosed with Bethesda III and IV, is increasing to reduce the need for diagnostic surgery. Especially in Bethesda III and IV nodules, different methods are applied in the treatment of nodules according to the malignancy risk of each category, these are follow-up, surgical treatment, radioactive iodine treatment, and non-surgical ablation methods.

Real-Time Evaluation of Thyroid Cytology Using New Digital Microscopy Allows for Sample Adequacy Assessment, Morphological Classification, and Supports Molecular Analysis

Thyroid cytological examination, a key tool in preoperative thyroid nodule evaluation, is specific and accurate; some drawbacks are due to inadequate or indeterminate cytological reports and there is a need for an innovative approach overcoming the limits of traditional cytological diagnostics. Fluorescence laser confocal microscopes (FCM) is a new optical technique for allowing immediate digital imaging of fresh unfixed tissues and real-time assessment of sample adequacy and diagnostic evaluation for small biopsies and cytological samples. Currently, there are no data about the use of FCMs in the field of thyroid nodular pathology. The aims of this study were to test FCM technology for evaluating the adequacy of FNA samples at the time of the procedure and to assess the level of concordance between FCM cytological evaluations, paired conventional cytology, and final surgical histology. The secondary aim was to define the integrity of nucleic acids after FCM evaluation through NGS molecular analysis. Sample adequacy was correctly stated. Comparing FCM evaluation with the final histology, all cases resulting in malignant or suspicious for malignancy at FCM, were confirmed to be carcinomas (PPV 100%). In conclusion, we describe a successful application of FCM in thyroid preoperative cytological evaluation, with advantages in immediate adequacy assessment and diagnostic information, while preserving cellular specimens for permanent morphology and molecular analysis, thus improving timely and accurate patient management.