Ultrasound characteristics of thyroid nodules facilitate interpretation of the malignant risk of Bethesda system III/IV thyroid nodules and inform therapeutic schedule

Rates and Predictors of Malignancy in Bethesda III and IV Thyroid Nodules: A Prospective Study

AIM

Thyroid nodules, based on high-resolution ultrasonography (HRUS), are among the most common endocrine abnormalities that affect the general population because of their high estimated prevalence rates. Fine needle aspiration cytology (FNAC) is a safe, cost-effective modality to differentiate between benign and malignant thyroid nodules based on the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), thus avoiding unnecessary surgery. However, categories III and IV of BSRTC remain a controversial issue in clinical practice, encompassing a wide range of risks of malignancy. Hence, our study aimed to assess the malignancy rates of thyroid nodules classified as Bethesda III and IV categories as evidenced by post-thyroidectomy histopathology; study the association between the American College of Radiologists Thyroid Image Reporting and Data System (ACR-TIRADS) score of these two categories and the postoperative histopathological analysis; and study the predictors of malignancy in these two categories.

MATERIALS AND METHODS

A prospective study was conducted on 242 patients who underwent FNAC throughout the study from December 2022 to August 2023. All patients who performed FNAC were primarily subjected to history taking, clinical examination, thyroid-stimulating hormone (TSH), thyroid autoantibodies (antithyroglobulin (anti-TG) and thyroid peroxidase antibodies (TPO Abs)), and HRUS with a further categorization of thyroid nodules according to the ACR-TIRADS scoring system. The cytological aspirates were categorized according to the BSRTC. Patients with Bethesda III and IV categories were resorted to surgery according to clinical factors, sonographic features, and patients' preferences.

RESULTS

A total of 17 cases with Bethesda III and 65 patients with Bethesda IV were included. Seventy-one out of 82 patients (86.6%) underwent surgical intervention. The proportions of malignant nodules classified as TIRADS-2, TIRADS-3, TIRADS-4, and TIRADS-5 scores were 0.0, 4.5 (n=1/22), 22.7 (n=5/22), and 72.7% (n=16/22), respectively. The rate of malignancy was 18.2% (n=2/11) among class III and 33.3% (n=20/60) among class IV-categorized Bethesda thyroid nodules. In univariate logistic regression analysis, age ≥ 40 years, body mass index ≥ 30 kg/m², higher TSH, positive anti-TG antibodies, radiation exposure, irregular borders, marked hypoechogenicity, ill-defined margins, microcalcifications, solid consistency, taller than wide growth, solitary nodule, and nodule size > 2 cm, and suspicious lymph nodes were associated with higher malignancy risk. In multivariate regression analysis, positive anti-TG Abs, radiation exposure, irregular borders, taller-than-wide growth, hypoechogenicity, calcifications, and solid consistency remain to be independent predictors of malignancy.

CONCLUSION

The malignancy rates of Bethesda class III and IV nodules in this study met the estimated malignancy risk proposed by BSRTC. TIRADS scores 4 and 5 confer a higher risk of malignancy in Bethesda III and IV thyroid nodules. Positive thyroglobulin antibodies and radiation exposure are independent factors of malignancy in Bethesda III and IV nodules. Moreover, ultrasound features, including irregular borders, taller-than-wider growth, hypoechogenicity, calcifications, and solid consistency, are associated with increased malignancy risk and should be considered in the surgical selection of patients.

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.

Impact of ultrasound elastography in evaluating Bethesda category IV thyroid nodules with histopathological correlation

Introduction

Fine needle aspiration (FNA) is the gold standard method recommended in the diagnosis of thyroid nodules. Bethesda IV cytology results are identified in 7-9% of nodules investigated through FNA, with reported malignancy rate in a wide range of 10-40%. The recommended treatment is either surgical or risk additional molecular testing before surgery. However, a large number of nodules belonging to this category (60-80%) are observed to be benign after surgical excision, which can put the patient at risk of unnecessary surgical morbidity. This study aimed to assess the diagnostic performance of conventional ultrasound, the ACR TI-RADS score and elastography in cases of Bethesda IV cytology on FNA.

Methods

We evaluated ninety-seven consecutive cases with Bethesda category IV results on FNA by using conventional B-mode ultrasound, qualitative strain or shear-wave elastography (Hitachi Preirus Machine, Hitachi Inc., Japan and Aixplorer Mach 30 Supersonic Imagine, Aix-en-Provence, France) and all nodules were classified according to the ACR TI-RADS system. Conventional ultrasound was used to categorize the nodules as potentially malignant based on the following features: hypoechogenicity, inhomogeneity, a taller than wide shape, irregular margins, presence of microcalcifications, an interrupted thyroid capsule and suspicious cervical lymph nodes. Elastography classified nodules with increased stiffness as suspicious for malignancy.

Results

We considered pathology results as the gold standard diagnosis, finding that 32 out of 97 nodules were carcinomas (33%) and 65 out of 97 were benign nodules (67%). The benign group included twenty cases of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Finally, we compared ultrasound data with pathology results, which showed that nineteen out of the 32 malignant nodules presented with increased stiffness on elastography (p=0.0002). On conventional ultrasound, we found that microcalcifications (p=0.007), hypoechogenicity and irregular margins (p=0.006) are features which can distinguish between benign and malignant nodules with statistical significance.

Discussion

Integrating elastography as a parameter of the ACR TI-RADS score in the evaluation of Bethesda category IV nodules showed a sensitivity of 90.62% in detecting thyroid cancer cases (p=0.006). We can conclude that elastographic stiffness as an addition to high risk features observed on conventional ultrasound improves the detection of malignant nodules in cases with Bethesda IV cytology.

Volume reduction rate of radiofrequency ablation in ≤ 2 cm Bethesda IV thyroid nodules

OBJECTIVE

This prospective observational study aimed to evaluate the efficacy of radiofrequency ablation (RFA) in treating ≤ 2 cm thyroid nodules with Bethesda IV cytology and C-TIRADS 4A categorization. Additionally, the factors influencing the completed absorption of ablation (CAA) were examined.

METHODS

A total of 62 cases with 62 nodules underwent ultrasound-guided RFA and were included in the study. The volume reduction rate (VRR), CAA, and incomplete absorption of ablation (IAA) were assessed at the 1st, 3rd, 6th, and subsequent 6-month follow-ups. Clinical and ultrasound features were compared between the CAA and IAA groups at the 12th month follow-up.

RESULTS

The average VRR at the 1st, 3rd, 6th, 12th month, and last follow-up were -88.6%, 16.0%, 59.7%, 82.0%, and 98.2%, respectively. More than half of the nodules achieved a 90% VRR after 1 year of RFA, with 88.7% demonstrating CAA at the end of the study (follow-up duration of 14 to 63 months). Nodules with grade 3 vascularity and those associated with chronic thyroiditis showed delayed CAA at the 12th month follow-up (p = 0.036 and 0.003, respectively).

CONCLUSION

RFA is an effective technique for treating ≤ 2 cm thyroid nodules with Bethesda IV cytology and C-TIRADS 4A categorization. Nodules with grade 3 blood supply and patients with chronic thyroiditis exhibited an impact on the completed absorption following RFA.

CLINICAL RELEVANCE STATEMENT

Our study has shown that radiofrequency ablation is an effective treatment for ≤ 2 cm thyroid nodules classified as Bethesda IV cytology. However, we identified that high vascularity of the nodule and chronic thyroiditis are adverse factors affecting the completed absorption of the ablation.

KEY POINTS

•Radiofrequency ablation (RFA) is an effective technique for treatment of ≤ 2 cm Bethesda IV category thyroid nodules. •Higher blood supply and chronic thyroiditis influence the completed absorption after RFA.

Ultrasonographic predictors of thyroid cancer in Bethesda III and IV thyroid nodules

Background

Bethesda III and IV thyroid nodules continue to be difficult to manage. Although molecular testing may assist in decision-making, it is expensive, not widely available, and not without pitfalls. The objective of this study is to assess whether certain thyroid ultrasonographic features may predict the risk of thyroid cancer in patients with Bethesda III and IV thyroid nodules and be used as additional decision-making tools to complement cytopathological results in deciding on diagnostic thyroidectomy.

Methods

We retrospectively evaluated the ultrasonographic features of Bethesda categories III and IV thyroid nodules in patients who underwent subsequent thyroidectomy. We used the final histopathological examination of the surgical specimens as the gold-standard test and analyzed individual preoperative ultrasonographic features as predictors of malignancy.

Results

Of the 278 patients who were diagnosed with Bethesda III and IV thyroid nodules on fine needle aspiration cytology (FNAC), 111 (39.9%) had thyroid cancer, and 167 (59.9%) exhibited benign nodules. The malignancy rate was higher in patients with Bethesda IV nodules (28/50, 56%) than those with Bethesda III nodules (83/228, 36.4%; p=0.016). In univariate analysis, hypoechogenicity (55.6% in malignant vs. 35.3% in benign, p=0.006) and calcifications (54.5 in malignant vs. 35.4% in benign, p=0.008) were significantly different between the benign and malignant pathology groups, whereas the size of the dominant nodule, number of nodules, irregular borders, taller-than-wide shape, and the presence of lymph nodes were comparable between the two groups. These two ultrasonographic features (hypoechogenicity and calcifications) remained significantly associated with the risk of malignancy in multivariate logistic regression analysis (for hypoechogenicity, p=0.014, odds ratio: 2.1, 95% CI:1.0-3.7 and for calcifications, p=0.019, odds ratio: 1.98, 95% CI:1.12-3.50). The sensitivity, specificity, positive and negative predictive values, and accuracy were 31.5%, 83%, 55.6%,64.7%, and 62.6%, for hypoechogenicity, respectively and 32.4%, 82%, 54.5%, 67.8%, and 62%, for calcification, respectively.

Conclusions

Hypoechogenicity and calcifications in Bethesda III and IV thyroid nodules are strong predictors of thyroid cancer and associated with a two-fold increased risk of malignancy.

Preoperative evaluation of thyroid nodules - Diagnosis and management strategies

Thyroid cancer is the most common endocrine malignancy, with increasing incidence over the past few decades. Fine needle aspiration (FNA) biopsy is the gold standard for preoperative diagnosis of thyroid malignancies. Nevertheless, this method renders indeterminate results in up to 30% of the cases. Therefore, these patients are often referred to unnecessary surgery to establish the diagnosis. To improve the accuracy of preoperative diagnosis, several other ways, such as ultrasonography, elastography, immunohistochemical analysis, genetic testing, and core needle biopsy, have been developed and can be used either in association with or as an alternative to FNA. This review aims to evaluate all these diagnostic tools to determine the most appropriate way of managing thyroid nodules and subsequently improve the selection of cases referred to surgery.

An attempt to reduce unnecessary surgical procedures... Can ultrasound characteristics help in differentiating adenoma vs carcinoma in follicular thyroid neoplasms?

INTRODUCTION AND OBJECTIVES

Thyroid nodules frequently require ultrasound and Fine Needle Aspiration Cytology (FNAC) evaluation. However, FNA cytology does not allow differentiation between follicular adenoma and carcinoma on Bethesda type IV lesions. This situation leads to many unnecessary surgical procedures because it is not possible to assure the benignity of the lesions, even when most of the specimens correspond to adenomas or even other benign lesions. The objective is this study is to establish if there are any US characteristics that would help us to predict the risk of malignancy of nodules with a pathological diagnosis of follicular neoplasm in order to achieve a more conservative management for non-suspicious nodules.

MATERIAL AND METHODS

We studied 61 nodules in 61 patients (51 women and 10 men) that underwent thyroid surgery and had histopathological results of either follicular adenoma or carcinoma. Different US characteristics of the nodules were analysed (composition, echogenicity, margin, calcification status, the presence of halo and overall observer suspicion of malignancy) and were correlated with the histopathological analysis.

RESULTS

We have found a statistically significant association between the presence of calcifications, ill-defined borders and overall observer suspicion or impression (defined by well-known suspicious for malignancy ultrasonographic features, such as calcification, poorly defined margin, and a markedly hypoechoic solid nodule; and benign ultrasonographic features, such as predominantly cystic echogenic composition and the presence of a perinodular hypoechogenic halo) with follicular carcinoma. However all those features have shown low sensitivities in the present study (30%, 30% and 50%, respectively). On the other hand, the absence of halo sign has shown a sensitivity of 100% and a negative predictive value (NPV) of 100% in our study.

CONCLUSIONS

The presence of calcifications, ill-defined borders and the overall impression or suspicion of malignancy associate with a higher risk for follicular carcinoma in Bethesda type IV thyroid nodules but their absence do not allow to predict benignity in these nodules. Inversely, when a halo sign lesion is observed, benign follicular neoplasm should be considered.

Serum TSH as a predictor of malignancy in indeterminate thyroid nodules

INTRODUCTION

Thyroid nodules are lesions that are radiologically distinct from the thyroid parenchyma. Cervical ultrasound diagnoses 19-67% of nodules and is crucial in identifying those that lack cytological characterisation. Approximately 25% of biopsies reveal an indeterminate cytological result (Bethesda III), in which the risk of malignancy is variable (5-15%). The clinical importance of the diagnostic strategy used for thyroid nodules results from the need to exclude malignancy. The aim of this study was to evaluate the usefulness of serum thyroid-stimulating hormone (TSH) levels as a predictor of malignancy in cytologically indeterminate thyroid nodules.

METHODS

Our retrospective study included 40 patients with cytologically indeterminate thyroid nodules seen in our hospital between January 2013 and December 2017. Clinical parameters were reviewed, including age, gender, serum TSH levels, family history of thyroid carcinoma, radiation exposure and some sonographic features of the nodules. Statistical analysis was performed using SPSS. Statistical significance was defined as p<0.05.

RESULTS

Female gender was predominant (85%) and the mean (SD) age was 53.3 (15) years. Thyroid carcinoma was confirmed in 28% of patients. Median TSH levels were higher in patients with malignant (2.73µIU/ml) compared with benign (1.56µIU/ml) nodules (p<0.05). We demonstrated an increased risk of malignancy in patients with TSH levels of 2.68µIU/ml or above (p<0.05).

CONCLUSION

Higher serum TSH levels are associated with an increased risk of thyroid carcinoma in cytologically indeterminate nodules. TSH can become a fundamental diagnostic tool in stratifying the risk of malignancy and assist in diagnostic and therapeutic approaches to these nodules.

Impact of Ultrasonographic Features for Thyroid Malignancy in Patients With Bethesda Categories III, IV, and V: A Retrospective Observational Study in a Tertiary Center

Introduction: Although fine-needle aspiration biopsy (FNAB) with cytologic interpretation using the Bethesda System for Reporting Thyroid Cytopathology has been widely used for thyroid nodules, its efficiency in Bethesda categories of III, IV, and V has been questioned due to variable risk of malignancy. We aimed to evaluate the impact of radiological parameters in Bethesda category III, IV, and V for thyroid malignancy.

Methods: We performed a retrospective review of patients with Bethesda category III, IV, and V, and subsequent thyroidectomy. Demographic, ultrasonographic, and clinical variables were recorded. Independent variables for thyroid malignancy and the predictive power of imaging findings were analyzed.

Results: There were 159 patients with a mean age of 48.1±13.4 years. Hypoechogenicity of the index nodule was the most common finding in 87 patients (54.7%). There were 74 (46.5%), 34 (21.4%), and 51 patients (32.1%) with Bethesda III, IV, and V categories, respectively. There were 91 patients (57.2%) with a diagnosis of thyroid malignancy. Overall malignant pathology was detected in 18 (24.3%), 25 (73.5%), and 48 patients (94.1%) in Bethesda III, IV, and V categories, respectively (p=0.001). The presence of solitary nodule, hypoechogenicity, and solid structure of index nodule and Bethesda category IV and V were significant variables for final malignant pathology (p<0.05 for all).

Conclusion: Hypoechogenicity and solid structure in a solitary index nodule should be regarded as significant ultrasonographic findings for thyroid malignancy. Bethesda category IV and V were also significantly associated with malignancy.

Ultrasonography and Fine-Needle Aspiration in Indeterminate Thyroid Nodules: A Systematic Review of Diagnostic Test Accuracy

OBJECTIVES/HYPOTHESIS

Sonographic risk criteria may assist in further prognostication of indeterminate thyroid nodules (ITNs). Our aim was to determine whether sonographic criteria could further delineate the post-test probability of malignancy in ITNs.

STUDY DESIGN

Meta-analysis of diagnostic test accuracy.

METHODS

A systematic review of Web of Science, MEDLINE, EMBASE, and CINAHL was performed from inception to April 15, 2021. Eligible studies included those which reported ultrasonographic evaluations with the American Thyroid Association (ATA) or the Thyroid Imaging Reporting and Data System (TIRADS) in adult patients with ITNs. ATA or TIRADS were scored as low (negative) or high (positive) malignancy risk using a previously validated binary classification. Primary outcomes included pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratio for all sonographic criteria. Studies were appraised using Quality Assessment of Diagnostic Accuracy Studies and the data were pooled using bivariate random-effects models.

RESULTS

Seventeen studies were included in the analysis. For Bethesda III, ATA had a specificity (0.90, 95% confidence interval (CI): 0.74-0.94), but a sensitivity of 0.52 (95% CI: 0.25-0.77). Conversely, K-TIRADS had the highest sensitivity (0.78, 95% CI: 0.62-0.89) with a specificity of 0.53 (95% CI: 0.31-0.74). Furthermore, American College of Radiology and EU TIRADS had specificities of 0.60 (95% CI: 0.36-0.80) and 0.81 (95% CI: 0.73-0.87) with sensitivities of 0.70 (95% CI: 0.37-0.90) and 0.38 (95% CI: 0.20-0.60), respectively. There were few studies with Bethesda IV nodules.

CONCLUSIONS

Though dependent on malignancy rates, Bethesda III nodules with low-suspicion TIRADS features may benefit from clinical observation, whereas nodules with high-suspicion ATA features may require molecular testing and/or surgery.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.

Analysis of Clinical-Radiological-Pathological Factors in FN/SFN Bethesda Category Thyroid Nodules, Contribution of FNAB Repeat, Single Center Experience

Objectives:

Follicular neoplasm/suspected follicular neoplasm (FN/FNS) Bethesda Category (BC)-4 group cases are known as the gray zone. Nodules diagnosed in cytology are excised. However, very few of these nodules are malignant. Our aim is to investigate the usability of clinical-radiological-pathological parameters to reduce unnecessary surgery. In addition, we questioned the benefit of repeating fine-needle aspiration biopsy (rFNAB) in these nodules, which is not recommended, but performed for clinical or patient-related reasons.

Methods:

The files of all thyroid FNAB patients conducted in our institution between January 2014 and September 2020 were scanned in the database. In our study, 185 (5.1%) nodules with cytology results of which were classified as FN/FNS were identified among 3624 nodules that were applied FNAB during this period. Twenty-eight patients were excluded from the study group. 157 nodules belonging to 157 patients between the ages of 21 and 82 years who were operated and met the study criteria were identified from patients with these nodules. The files of all patients were scanned and the results of age, gender, ultrasonographic nodule characteristics, FNAB repeat, type of surgery, and postoperative pathology were recorded. All data were analyzed by comparing them with nodule features. SPSS 15.0 for Windows program was used for statistical analysis.

Results:

A significant correlation was found between the incidence of malignancy and male gender and hypervascularization (p=0.017 and p=0.002, respectively). Malignancy was less in nodules larger than 2 cm (p=0.014). There was no relationship between other clinical and radiological features and malignancy. In 29 nodules with rFNAB, a significant correlation was found between malignancy and advanced age (52.9-years-old), presence of nodules smaller than 2 cm and hypervascularization (p=0.047, p=0.047, and p=0.030, respectively).

Conclusion:

We recommend careful review of patients with hypervascular, hypoechogenic, and microcalcific BC-4 nodules (male gender and older patients at greater risk). Because of the serious risk of malignancy, patients with these features should be prepared for patient management with total thyroidectomy after examination with frozen section applied to the nodule during the operation.

Outcome of atypia of undetermined significance/follicular lesion of undetermined significance in thyroid fine-needle aspirations: A six-year institutional experience

BACKGROUND

Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) is one of six diagnostic categories of The Bethesda System for Reporting Thyroid Cytopathology (BSRTC). The goal of our study is to assess the outcome of cases classified as AUS/FLUS at our institution.

METHODS

AUS/FLUS cases were identified by computer searching of the thyroid fine-needle aspiration (FNA) cases performed between 2010 and 2016. Outcomes were categorized as: follow-up surgery, repeat FNA or no follow-up available. Demographics, ultrasound findings and FNA diagnostic criteria were reviewed for AUS/FLUS cases with follow-up surgical pathology diagnosis.

RESULTS

Our AUS/FLUS thyroid FNA rate was 6% (117 out of 1984 FNAs). Only 15% of the AUS/FLUS cases had repeat FNA, while 41% underwent surgery. The risk of malignancy (ROM) for cases with follow-up surgery was 17%. When considering all AUS/FLUS cases, the ROM was 7%. Statistically, benign neoplasms were more likely to be single lesions on ultrasound comparing to malignant neoplasms, and to exhibit architectural atypia as opposed to non-neoplastic lesions on FNA. The malignancy rates among patients that directly went to surgical resection (17%) and patients having repeat FNA after the first AUS/FLUS diagnosis followed by surgery (29%) was not significantly different. However, repeat FNA was able to reclassify the majority of cases into more definitive categories.

CONCLUSION

The outcome of the thyroid FNAs diagnosed as AUS/FLUS in our institution meets the benchmark statistics for AUS/FLUS rate and ROM. This study constitutes a valuable quality assurance measure and serves as a baseline for subsequent quality improvement.

Clinical Applications of Superb Microvascular Imaging in the Superficial Tissues and Organs: A Systematic Review

Superb microvascular imaging (SMI) is an innovative Doppler technique for vascular examination. It uses an intelligent algorithm that efficiently separates low-speed flow signals from motion artifacts so that it can assess microvessels and the vessel distribution in detail. This article reviews the clinical applications of SMI in the disorders of superficial tissues and organs including thyroid nodules, breast tumors and lymph node diseases etc. More information of diseases that are closely associated with angiogenesis can be shown by SMI than other noninvasive examinations. Although some limitations exist, this safe and convenient technique is becoming acceptable and would play a more important role in disease diagnosis and therapeutic responses evaluation.

An attempt to reduce unnecessary surgical procedures... Can ultrasound characteristics help in differentiating adenoma vs carcinoma in follicular thyroid neoplasms?

INTRODUCTION AND OBJECTIVES

Thyroid nodules frequently require ultrasound and Fine Needle Aspiration Cytology (FNAC) evaluation. However, FNA cytology does not allow differentiation between follicular adenoma and carcinoma on Bethesda type IV lesions. This situation leads to many unnecessary surgical procedures because it is not possible to assure the benignity of the lesions, even when most of the specimens correspond to adenomas or even other benign lesions. The objective in this study is to establish if there are any US characteristics that would help us to predict the risk of malignancy of nodules with a pathological diagnosis of follicular neoplasm in order to achieve a more conservative management for non-suspicious nodules.

MATERIAL AND METHODS

We studied 61 nodules in 61 patients (51 women and 10 men) that underwent thyroid surgery and had histopathological results of either follicular adenoma or carcinoma. Different US characteristics of the nodules were analysed (composition, echogenicity, margin, calcification status, the presence of halo and overall observer suspicion of malignancy) and were correlated with the histopathological analysis.

RESULTS

We have found a statistically significant association between the presence of calcifications, ill-defined borders and overall observer suspicion or impression (defined by well-known suspicious for malignancy ultrasonographic features, such as calcification, poorly defined margin, and a markedly hypoechoic solid nodule; and benign ultrasonographic features, such as predominantly cystic echogenic composition and the presence of a perinodular hypoechogenic halo) with follicular carcinoma. However all those features have shown low sensitivities in the present study (30%, 30% and 50%, respectively). On the other hand, the absence of halo sign has shown a sensitivity of 100% and a negative predictive value (NPV) of 100% in our study.

CONCLUSIONS

The presence of calcifications, ill-defined borders and the overall impression or suspicion of malignancy are associated with a higher risk for follicular carcinoma in Bethesda type IV thyroid nodules but their absence does not allow to predict benignity in these nodules. Inversely, when a halo sign lesion is observed, benign follicular neoplasm should be considered.

Hürthle cell lesions of the thyroid: Progress made and challenges remaining

Hürthle cell-predominant thyroid fine needle aspirations (FNA) are encountered frequently in routine practice, yet they are often challenging to diagnose accurately and are associated with significant interobserver variability. This is largely due to the ubiquity of Hürthle cells in thyroid pathology, ranging from nonneoplastic conditions to aggressive malignancies. Although limitations in cytomorphologic diagnoses likely will remain for the foreseeable future, our knowledge of the molecular pathogenesis of Hürthle cell neoplasia and application of molecular testing to cytologic material have increased dramatically within the past decade. This review provides context behind the challenges in diagnosis of Hürthle cell lesions and summarizes the more recent advances in diagnostic tools.

Thyroid FNA: Is cytopathologist review of ultrasound features useful?

Cytopathologist review of thyroid ultrasound (US) has been proposed to be useful in diagnosis and patient triage. This review explores the implications for practicing cytopathologists of integrating US review into the thyroid fine-needle aspiration diagnosis. At present, there is no agreed-upon system for combining cytologic and US features and communicating those results as a single report. If cytologists are performing tasks that require expertise in US interpretation, then they should know and be fully conversant with US interpretation. Whether cytologists performing aspirations require expertise in US interpretation is not clear. Regardless, cytologists should avoid using US results to alter their cytologic interpretations unless they clearly communicate that this is what they are doing. An evidence-based integrated reporting system that would allow cytologists to clearly explain to other physicians exactly how they reached their interpretation might provide value beyond current standard practice.

Ultrasound characteristics of thyroid nodules facilitate interpretation of the malignant risk of Bethesda system III/IV thyroid nodules and inform therapeutic schedule

BACKGROUND

This study was designed to explore whether ultrasound of thyroid nodules facilitates the interpretation of the malignant risk of Bethesda III/IV thyroid nodules to inform further therapies.

METHODS

We reviewed patient records in which the results of ultrasound-guided fine-needle aspiration (US-FNA) were classified by the Bethesda III/IV in our institution between January 2016 and June 2018. Studies were retrieved from PubMed, Cochrane Central Register of Controlled Trials, ISI Web of Science, Science Direct, Wiley Online Library, EMBASE, China National Knowledge Infrastructure, WanFang, and Chinese VIP. The odds ratio (OR) was used to measure associations between risk factors and thyroid nodule malignancy.

RESULTS

Fifty-nine cases of Bethesda III/IV with corresponding surgeries were included, and the malignancy risk was 54.2%. Meta-analysis revealed irregular borders, solitary nodules, hypoechogenicity, microcalcifications, and being taller than wide, all of which increased the malignancy risk of thyroid nodules. Combined ORs for these factors were 4.08 (95% CI: 2.34-7.14, P < .001), 2.18 (95% CI: 1.39-3.42, P = .001), 2.02 (95% CI: 1.35-3.01, P = .001), 3.21 (95% CI: 2.26-4.56, P < .001), and 4.35 (95% CI: 3.07-6.15, P < .001), respectively.

CONCLUSION

As the risk of malignancy for papillary thyroid carcinoma (PTC) is high, when any one of the five ultrasound features of malignancy were confirmed, repeated FNA is recommended to confirm PTC-type malignancy, even though nodules were Bethesda III/IV classification. However, repeated FNA should be avoided when none of these ultrasound features are identified because repeated FNA does not contribute to identifying non-PTC type malignancies, such as follicular thyroid carcinoma and poorly differentiated thyroid carcinoma.