Incidentally discovered thyroid nodules: frequency in an adult population during Doppler ultrasonographic evaluation of cervical vessels

A practical approach for the management of small thyroid nodules referred for biopsy

OBJECTIVE

Current guidelines recommend against routine ultrasound (US) guided fine-needle aspiration biopsy (FNAB) of small (<1 cm) thyroid nodules and suggest follow-up of ≥5 mm small nodules only if they are TI-RADS-5. This study aims to determine the best suspicious ultrasound features related to cytology results in patients referred for FNAB of small thyroid nodules and construct an algorithm for declining unnecessary biopsies and selection of patients to be followed up.

METHODS

This prospective observational study enrolled patients referred for US-guided biopsy of ≤1 cm thyroid nodules. Ultrasound features including composition, echogenicity, shape, margin, echogenic focus, hypoechoic rim, vascularity were assessed. The cytology results were dichotomised as either benign or malignant/high risk. The features with excellent interobserver reliability and more than 90% sensitivity were selected.

RESULTS

Overall, 95 patients [82 (86.3%) females, mean age 48.5 ± 11.9 years] with 95 small (≤1 cm) thyroid nodules were biopsied. Cytology revealed 15 (15.8%) malignant nodules. Pure solid composition, hypoechogenicity, taller than wide shape and irregular margin of the nodules were significantly associated with malignancy. Hypoechogenicity (100%) and pure solid composition (93%) had very high sensitivity and excellent interobserver agreement (Cohen's Kappa 0.83, P = .003 for both) for predicting high risk/malignant nodule. In the absence of these two features, 48 (50.5%) nodules either would not require FNAB or follow-up.

CONCLUSION

The presence of cyst or iso/hyperechogenicity within a small thyroid nodule in patients already referred for invasive sampling safely allows for declining a decision of FNAB or follow-up without the concern of missing malignancy.

Differential diagnosis of thyroid nodules through a combination of multiple ultrasonography techniques: A decision-tree model

The present study aimed to establish a decision tree (DT) model by combining the parameters of conventional gray-scale ultrasonography (US), elastosonography (ES), color Doppler US (CDUS) and contrast-enhanced US (CEUS) for the differential diagnosis of thyroid nodules. A single-center, retrospective study of 321 thyroid nodules was conducted. For 222 nodules, parameters of conventional gray-scale US, CDUS, ES and CEUS were evaluated using univariate logistic regression. Factors for with P<0.10 were further assessed using multivariate logistic regression. Significant factors (P<0.05) were used to establish a DT. The diagnostic accuracy of this DT was then evaluated by its application to the other 99 nodules. After univariate logistic analysis, factors including gender, number of nodules and diffuse disease were excluded, due to P>0.10. The results of multivariate logistic analysis determined that the following factors were required for the DT: Extent of blood flow determined by CDUS (P=0.002), area ratio determined by ES (P=0.033), peak phase patterns determined by CEUS (P<0.001) and micro-calcification determined by conventional gray-scale US (P=0.015). When compared to the pathological or cytological results of 99 nodules, the resulting DT had a sensitivity of 98.6%, specificity of 80.1%, positive predictive value of 93.5% and negative predictive value of 95.5%. These results suggested that a DT combining conventional gray-scale US, ES, CDUS and CEUS may be helpful for differentiating between types of thyroid nodules.

Color Doppler ultrasonography diagnostic value in detection of malignant nodules in cysts with pathologically proven thyroid malignancy: a systematic review and meta-analysis

AIMS

Today, the color Doppler ultrasonography is used to further evaluate suspected malignant tumors. This study investigates the malignant thyroid nodules using color Doppler.

METHODS

After extracting true positive, false positive, false negative, and true negative among included studies, a quality was evaluated by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (with 95% confidence interval) were found using a random effect model. Summary receiver operating characteristic curves (SROC) were used to assess relationship between sensitivity and specificity. The area under the curve of the SROC was calculated to estimate the performance of color Doppler ultrasound to distinguish malignant thyroid nodules. Our registration code in PROSPERO is CRD42018111198.

RESULTS

Of 1125 articles, 288 articles were selected for the further investigation. After excluding irrelevant and poor articles, 20 studies were included for the meta-analysis. According to a random effect model, the pooled sensitivity and specificity of color Doppler ultrasound to distinguish malignant thyroid nodules were estimated as 0.74 (95% CI 0.62-0.83; [Formula: see text]) and 0.70 (95% CI 0.56-0.81; [Formula: see text]), respectively. The SROC curve consists of representing the paired results for sensitivity and specificity. According to SROC, AUC = 0.78 (95% CI 0.74-0.81) is between 0.75 and 0.92, so that color Doppler ultrasound has a good accuracy.

CONCLUSION

Color Doppler is a valuable non-invasive method for evaluating thyroid nodules, and it is a high-sensitivity diagnostic tool for assessing thyroid nodules. Resistive index > 0.75 and a pattern III or more in color Doppler predicts malignant with the confidence. Due to its precision, cost-efficiency, easy access, and non-invasive nature, color Doppler should be included in the standard clinical protocol for the decision-making period and the treatment evaluation.

Clinical Diagnostic Evaluation of Thyroid Nodules

The presence of a thyroid nodule may be recognized by the patient or the clinician on palpation of the neck or it may be an incidental finding during an imaging study for some other indication. The method of detection is less important, however, than distinguishing benign lesions from more aggressive neoplasms. This article outlines the diagnostic algorithm for the evaluation of thyroid nodules including biochemical testing, imaging, and, when appropriate, fine-needle aspiration. In addition, the authors review the natural history of benign nodules, follow-up strategies, and indications for repeat aspiration.

Does the ACR TI-RADS scoring allow us to safely avoid unnecessary thyroid biopsy? single center analysis in a large cohort

INTRODUCTION

The American College of Radiology (ACR) has recently proposed a guideline that recommends clinicians to perform thyroid fine-needle aspiration biopsy (FNAB) on the basis of ultrasound features. In this study, we focused on nodules for which no biopsy is recommended by the ACR Thyroid Imaging, Reporting and Data System (TI-RADS) guideline.

SUBJECTS AND METHODS

Two-thousand eight-hundred and forty-seven consecutive patients with thyroid nodules who underwent FNAB according to the 2009 American Thyroid Association (ATA) guideline were included. The nodules were re-classified according to the ACR TI-RADS guideline as benign (TR1), not suspicious (TR2), mildly suspicious (TR3), moderately suspicious (TR4) and highly suspicious (TR5). The TR3 category was stratified into two subcategories as regard to the nodule size (TR3; <25 mm and TR3; ≥25 mm).

RESULTS

Two-hundred and thirty-three (8.2%) patients with non-diagnostic FNABs were excluded. When the TR2 and TR3; <25 mm categories were merged, FNAB was suggestive of thyroid cancer in 17 of 1382 patients (1.2%). FNAB revealed Bethesda IV-VI in 5 of 273 patients with the TR3; ≥25 mm category (1.8%), in 61 of 896 patients with the TR4 category (6.8%), and in 18 of 63 of patients with the TR5 category (28.6%). The ACR TI-RADS scoring was 98.8% (95% CI: 98 to 99.3) specific for identification of a benign nodule.

CONCLUSION

Our data suggest that ACR TI-RADS scoring is an applicable and potentially cost-effective approach to determine thyroid nodules to be biopsied, although a small proportion of thyroid cancers would be missed.

Morphological Changes Induced by Bipolar Radiofrequency Ablation in Thyroid Nodules - a Preclinical Ex Vivo Investigation

Introduction: Recently, radiofrequency ablation (RFA) has been increasingly used for the treatment of thyroid nodules. However, immediate morphological changes associated with bipolar devices are poorly shown. Aims: To present the results of analysis of gross and microscopic alterations in human thyroid tissue induced by RFA delivered through the application of the original patented device. Materials and methods: In total, there were 37 surgically removed thyroid glands in females aged 32-67 at presentation: 16 nodules were follicular adenoma (labelled as 'parenchymal' solid benign nodules) and adenomatous colloid goitre was represented by 21 cases. The thyroid gland was routinely processed and the nodules were sliced into two parts - one was a subject for histological routine processing according to the principles that universally apply in surgical pathology, the other one was used for the RFA procedure. Results: No significant difference in size reduction between parenchymal and colloid nodules was revealed (p>0.1, t-test) straight after the treatment. In addition, RFA equally effectively induced necrosis in follicular adenoma and adenomatous colloid goitre (p>0.1, analysis of variance test). As expected, tumour size correlated with size reduction (the smaller the size of the nodule, the greater percentage of the nodule volume that was ablated): r=-0.48 (p<0.0001). Conclusion: The results make it possible to move from ex vivo experiments to clinical practice.

The Influence of Patient Age on Thyroid Nodule Formation, Multinodularity, and Thyroid Cancer Risk

INTRODUCTION

Although advancing age is known to influence the formation of thyroid nodules, the precise relationship remains unclear. Furthermore, it is uncertain whether age influences the risk that any thyroid nodule may prove cancerous.

AIM

The aim was to determine the impact of patient age on nodule formation, multinodularity, and risk of thyroid malignancy.

METHOD

We conducted a prospective cohort analysis of consecutive adults (ages 20-95 y) who presented for evaluation of nodular disease from 1995 to 2011. A total of 6391 patients underwent ultrasound and fine-needle aspiration of 12 115 nodules ≥ 1 cm. Patients were divided into six age groups and compared using sonographic, cytological, and histological endpoints.

RESULT

The prevalence of thyroid nodular disease increases with advancing age. The mean number of nodules at presentation increased from 1.5 in the youngest cohort (age, 20-30 y) to 2.2 in the oldest cohort (age, >70 y; P < .001), demonstrating a 1.6% annual increased risk for multinodularity (odds ratio, 1.02; P < .001). In contrast, the risk of malignancy in a newly identified nodule declined with advancing age. Thyroid cancer incidence per patient was 22.9% in the youngest cohort, but 12.6% in the oldest cohort (odds ratio, 0.972; P < .001), demonstrating a 2.2% decrease per year in the relative risk of malignancy between ages 20 and 60 years, which stabilized thereafter. Despite a lower likelihood of malignancy, identified cancers in older patients demonstrated higher risk histological phenotypes. Although nearly all malignancies in younger patients were well-differentiated, older patients were more likely to have higher risk papillary thyroid carcinoma variants, poorly differentiated cancer, or anaplastic carcinoma (P < .001).

CONCLUSION

With advancing age, the prevalence of clinically relevant thyroid nodules increases, whereas the risk that such nodules are malignant decreases. Nonetheless, when thyroid cancer is detected in older individuals, a higher-risk histological phenotype is more likely. These data provide insight into the clinical paradox that confronts physicians managing this common illness.

Imaging-detected incidental thyroid nodules that undergo surgery: a single-center experience over 1 year

BACKGROUND AND PURPOSE

Incidental thyroid nodules are commonly seen on imaging, and their work-up can ultimately lead to surgery. We describe characteristics and pathology results of imaging-detected incidental thyroid nodules that underwent surgery.

MATERIALS AND METHODS

A retrospective review was performed of 303 patients who underwent thyroid surgery over a 1-year period to identify patients who presented with incidental thyroid nodules on imaging. Medical records were reviewed for the types of imaging studies that led to detection, nodule characteristics, and surgical pathology.

RESULTS

Of 303 patients, 208 patients (69%) had surgery for thyroid nodules. Forty-seven of 208 patients (23%) had incidental thyroid nodules detected on imaging. The most common technique leading to detection was CT (47%). All patients underwent biopsy before surgery. The cytology results were nondiagnostic (6%), benign (4%), atypia of undetermined significance or follicular neoplasm of undetermined significance (23%), follicular neoplasm or suspicious for follicular neoplasm (19%), suspicious for malignancy (17%), and diagnostic of malignancy (30%). Surgical pathology was benign in 24 of 47 (51%) cases of incidental thyroid nodules. In the 23 incidental cancers, the most common histologic type was papillary (87%), the mean size was 1.4 cm, and nodal metastases were present in 7 of 23 cases (30%). No incidental cancers on imaging had distant metastases.

CONCLUSIONS

Imaging-detected incidental thyroid nodules led to nearly one-fourth of surgeries for thyroid nodules, and almost half were initially detected on CT. Despite indeterminate or suspicious cytology results that lead to surgery, more than half were benign on final pathology. Guidelines for work-up of incidental thyroid nodules detected on CT could help reduce unnecessary investigations and surgery.

Biochemical and ultrasonographic parameters influencing thyroid nodules elasticity

Elastography is a method of tissue stiffness assessment. It has already been demonstrated that thyroid cancers are less elastic than benign lesions. However, little is known about other factors, which might influence the stiffness of thyroid nodules and disrupt the prediction of malignancy using this technique. The aim of this study was to conduct the first systematic assessment of factors potentially affecting the elasticity of thyroid lesions. One hundred and twenty-two patients with thyroid nodular disease admitted for thyroidectomy underwent preoperative ultrasonography and sonoelastography. The definite diagnosis of thyroid lesions was based on histological examination. What was evaluated in the study was the influence of composition, size, localization, nodularity, and selected laboratory parameters on thyroid nodule elasticity. Firstly, association between the above-mentioned factors and elasticity was assessed in benign lesions. Secondly, all nodules (benign and malignant) were divided into subgroups according to the presence or absence of particular features, which turned out to be an important disturbing factor increasing the stiffness of the lesion in the first step of analysis. There were 22 malignant and 371 benign lesions. The analysis of benign lesions revealed that the presence calcifications (p < 0.0001) significantly increased nodule stiffness. Partially, cystic nodules were significantly less elastic than solid ones (p = 0.03). There was also positive correlation between nodule size and stiffness (p < 0.0001). Lesions localized in the isthmus were significantly less elastic than nodules in other localizations. (p = 0.0001). Solitary nodules were less elastic than lesions in multinodular goiter (p = 0.006). Correlation between Tg concentration and stiffness was significant (p < 0.0001, r = 0.24). The concentration of anti-thyroid autoantibodies was associated with stiffness at the border of significance. However, there was no significant difference between benign lesions in patients with diagnosed chronic autoimmune thyroiditis and patients without the disease. The analysis of the entire group of nodules revealed that shear wave elastography is a valuable modality of thyroid nodule assessment, with sensitivity of over 95 % and specificity of about 70 %. However, the stiffness value of the lesion might be increased in the case of nodules containing calcifications, cystic component, and those of size above 20 mm. Certain clinical conditions or attributes of the lesions influence the stiffness values of thyroid nodules. Identifying these variables is the basis for a credible interpretation of the results of a sonoelastographic examination and makes it possible to estimate the risk of thyroid nodule malignancy adequately.