The management of the solitary thyroid nodule: a review

The Performance of the American Thyroid Association (ATA) and American College of Radiology (ACR-TIRAD) Thyroid Nodule Risk-Stratification Systems in Determining High-Risk Nodules, and the Correlation of Site, Size, and Autoimmunity with High-Risk Features

Introduction

Neck ultrasonography (US) and fine-needle aspiration (FNA) biopsy are usually used to evaluate thyroid nodules. This study aimed to evaluate the performance of two popular thyroid imaging reporting systems in detecting thyroid malignancy and to evaluate the correlation between thyroid autoimmunity, nodule site, and size in the development of malignancy.

Methods

This prospective study was conducted from January 2019 to July 2021 in Basrah, Iraq. The American Thyroid Association (ATA) and American College of Radiology-Thyroid Imaging Reporting and Data (ACR-TIRAD) systems were used to evaluate the malignant potential of 143 thyroid nodules in 131 patients.

Results

The sensitivity and positive predictive value (PPV) of the ATA system for detecting malignancy were 96% and 20.8% for low-risk and 100% and 4.3% for high-risk nodules, respectively. ACR-TIRAD sensitivity and PPV were 84% and 22.1% for low-risk and 80% and 4.2% for high-risk nodules, respectively. The specificity and negative predictive value (NPV) of the ATA system for detecting malignancy were 11.6% and 92.3% for low-risk and 10.5% and 100% for high-risk nodules, respectively. The ACR-TIRAD specificity and NPV were 28% and 87.8% for low-risk and 26% and 96.9% for high-risk nodules, respectively. The strength of the correlation between FNA performed across different Bethesda categories and age, sex, nodule size, and positive thyroid peroxidase (TPO) antibodies were 0.25, 0.01, 0.22, and 0.4, respectively.

Conclusion

Both systems are effective; however, adopting TI-RADS stratification results in fewer biopsies being performed for thyroid nodule assessment. Only sex was found to be significantly correlated with FNA performance in thyroid-nodule evaluation.

Evaluation of Thyroid Nodules

This is a brief overview of the initial workup of patients with thyroid nodules. Most nodules are incidentally discovered, benign, and do not require surgery, but the clinician's job is to determine which nodules are concerning and what the appropriate workup should be. Ultrasound examination is the best imaging modality to evaluation thyroid nodules and, when biopsy is indicated, fine needle aspiration is the proper technique to sample thyroid nodules.

Clinicopathological features of thyroid cancer in the elderly compared to younger counterparts: single-center experience

PURPOSE

The incidence of thyroid cancer is increased in elderly patients. It tends to be larger and have more aggressive characteristics in these patients. Our aim was to compare features of thyroid carcinoma in geriatric and non-geriatric patients.

METHODS

In total, 933 patients with thyroid cancer were retrospectively reviewed. Thyroid functions, ultrasonography features of malignant nodules, cytological and histopathological findings and the rates of recurrence and persistence were compared in patients ≥65 and <65 years old.

RESULTS

There were 153 malignant foci in 109 (11.7%) patients ≥65 and 1185 malignant foci in 824 (88.3%) patients <65 years old. Mean nodule diameter was significantly higher in geriatric patients (p = 0.008). Most of the ultrasonographical features of malignant nodules were similar in two groups. Hypoechoic halo was observed in 16.4 and 28.6% of malignant nodules in geriatric and non-geriatric group, respectively (p = 0.034). There was no significant difference in cytological diagnosis. Histopathologically, tumor diameter, rates of microcarcinomas and incidentality were similar. Of all cancer types, 88.8% in geriatric and 93.9% in non-geriatric group were papillary thyroid cancer (p = 0.028). Hurthle cell cancer constituted 3.9 and 1.1% of carcinomas in geriatric and non-geriatric patients, respectively (p = 0.015); 2.0 and 0.2% of tumors in geriatric and non-geriatric group were anaplastic, respectively (p = 0.012). Capsular and vascular invasion, extrathyroidal extension, persistence and recurrence rates were similar.

CONCLUSIONS

Rates of anaplastic cancer and Hurthle cell cancer which is known to have worser prognosis among other differentiated thyroid cancers are increased in geriatric ages. Cytological evaluation of thyroid nodules should strongly be considered due to increased tendency for aggressive tumor types in these patients.

Thyroid Hormones, Autoantibodies, Ultrasonography, and Clinical Parameters for Predicting Thyroid Cancer

Our objective was to evaluate thyroid nodule malignancy prediction using thyroid function tests, autoantibodies, ultrasonographic imaging, and clinical data. We conducted a retrospective cohort study in 1400 patients with nodular thyroid disease (NTD). The thyroid stimulating hormone (TSH) concentration was significantly higher in patients with differentiated thyroid cancer (DTC) versus benign thyroid nodular disease (BTND) (p = 0.004). The receiver operating characteristic curve of TSH showed an AUC of 0.58 (95% CI 0.53-0.62, p = 0.001), sensitivity of 74%, and specificity of 57% at a cut-off of 1.59 mIU/L. There was an incremental increase in TSH concentration along with the increasing tumor size (p < 0.001). Thyroglobulin antibody (TgAb) concentration was associated with an increased risk of malignancy (p = 0.029), but this association was lost when the effect of TSH was taken into account (p = 0.11). Thyroid ultrasonographic characteristics, including fewer than three nodules, hypoechoic appearance, solid component, poorly defined margin, intranodular or peripheral-intranodular flow, and punctate calcification, can be used to predict the risk of thyroid cancer. In conclusion, our study suggests that preoperative serum TSH concentration, age, and ultrasonographic features can be used to predict the risk of malignancy in patients with NTD.

What is the Role of Diffusion Weigh Magnetic Resonance Imaging in Evaluation of Thyroid Nodules?

This study aimed to compare ultrasonography (US), contrast-enhanced computed tomography (CCT) of the neck, and diffusion-weigh magnetic resonance imaging (DW-MRI) in differentiating between benign and malignant nodules while approaching to thyroid nodules, and to estimate sensitivity and specificity of these methods. On thyroid US, echogenicity, calcification, presence/absence of halo, nodule size being larger/smaller than 20 mm, and nodule nature (cystic/solid nature) were evaluated. Findings on CCT of the neck were grouped according to the heterogeneity/homogeneity, presence/absence of enhancement, and intensity. On DW-MRI, diffusion restriction was evaluated. The findings of these tests were compared with postoperative histopathological findings, and specificity and sensitivity of the tests in differentiating malignant and benign nodules were assessed. The study included 38 patients (34 females, 4 males). The sensitivity and specificity of DW-MRI were 20 and 75 %, respectively. Presence of a >20 mm nodule in thyroid US had the highest sensitivity, whereas thyroid fine-needle aspiration biopsy (FNAB) had the highest specificity in detecting malignancy. The sensitivities and specificities of CCT of the neck and DW-MRI appeared relatively low. Evaluation of thyroid US findings together with thyroid FNAB findings provided high specificity and sensitivity and yielded better results than findings of CCT of the neck and DW-MRI.

Technetium-99m methoxyisobutylisonitrile scintigraphy in the assessment of cold thyroid nodules: is it time to change the approach to the management of cold thyroid nodules?

BACKGROUND

Scanning with technetium-99m methoxyisobutylisonitrile (Tc-MIBI) is recommended for evaluating thyroid nodule metabolism. In addition, it may help differentiate between benign and malignant nodules; however, the efficacy of this technique has not been fully elucidated. Therefore, it is not currently performed for routine clinical application. This prospective study was conducted to investigate the clinical significance of Tc-MIBI scintigraphy in the assessment of patients with cold thyroid nodules.

PATIENTS AND METHODS

This prospective study was conducted on 104 patients with cold thyroid nodules greater than 1 cm in diameter as detected on Tc-pertechnetate scintigraphy. Uptake of MIBI in thyroid nodules was compared with that in the surrounding normal thyroid tissue for both early and delayed images, and a score of 0-3 was assigned to each nodule as follows: 0, cold; 1, decreased; 2, equal; 3, increased. The thyroid scan was performed 20 and 40 min after intravenous injection of 555 MBq of Tc-MIBI. The patients underwent fine-needle aspiration cytology (FNAC). Detailed statistical parameters were determined on a per-nodule basis for each qualitative and quantitative scan analysis, as defined by histology.

RESULTS

A total of 104 patients (93 women and 11 men; mean age 40.76±11.40 years, range 20-73) with a total number of 167 cold nodules were included in this study. When Tc-MIBI uptake was regarded as the criterion of malignancy in Tc-MIBI scintigraphy, the accuracy was between 69.46 and 92.21% on using seven different methods. In addition, FNAC findings indicated a sensitivity of 66.66%, a specificity of 100%, a negative predictive value of 95.72%, a positive predictive value of 100%, and an accuracy of 96.06%. Six malignant cold nodules were detected on a positive Tc-MIBI scan, which were determined as benign nodules on FNAC examinations.

CONCLUSION

The study demonstrated that Tc-MIBI scanning can be complementary to other diagnostic techniques in patients with cold thyroid nodules. In addition, because of its availability, rather low cost, simple protocol, and objective semiquantitative information, Tc-MIBI scanning seems to hold promise in routine imaging of cold thyroid nodules.

Diagnostic value and cost considerations of routine fine-needle aspirations in the follow-up of thyroid nodules with benign readings

BACKGROUND

Fine-needle aspiration (FNA) is the most accurate tool to identify malignancy in solitary thyroid nodules. Although some recommend routinely repeating FNA for nodules that are initially read as benign, there is no consensus. We evaluated clinical relevancy and considered costs of routine follow-up FNA in nodules initially read as benign.

METHODS

We reviewed the records of all 739 patients who underwent FNA of solitary thyroid nodules at our institution from 1988 to 2004. A total of 815 aspirations were required to obtain satisfactory specimens. According to their physicians practice, some patients had a "follow-up biopsy" after an initially benign FNA reading as a matter of routine (Group I approach) or if their clinical status changed (Group II approach). The outcome information for at least 4 years after the initial FNA in these two groups was compared. In addition, hypothetical costs relating to both methods for deciding whether to do a follow-up FNA were considered.

RESULTS

The initial FNA was benign in 576 (78%), suspicious for follicular neoplasms in 106 (14.4%), and malignant in 57 patients (7.7%). Follow-up FNA was performed in 292 patients with initially benign lesions, 235 in Group I approach and 57 in Group II approach. The FNA diagnosis according to Group I approach remained benign on follow-up biopsy in 96.2% (226/235), was altered to follicular neoplasm in 3% (7/235), and was suspicious for malignancy in 0.8% (2/235). When following Group II approach, the follow-up FNA was benign in 93% (53/57), undetermined in 1.7% (1/57), and showed follicular neoplasm in 5.3% (3/57). Combining Groups I and II methods, 5 of 292 patients had a malignant nodule on histological examination, a false-negative rate of 1.7% for the initial FNA, but without a difference in prevalence of thyroid malignancy between the groups. Cost-consequence analysis showed no benefit in routine follow-up FNA after initially benign FNA readings.

CONCLUSIONS

Routine follow-up FNA in patients whose initial FNA is benign has a low diagnostic upgrading value and is relatively costly. In patients whose initial FNA is benign, we recommend the FNA be repeated only if clinically suspicious signs or complaints develop.

Management of Thyroid nodules in adult patients

Thyroid nodule is a common presentation and requires a structured diagnostic approach to ascertain the risk of malignancy and determine appropriate management. This review article highlights the key points in the history and examination which can help with risk stratification. It also discussed the application of fine needle aspiration cytology findings and the British Thyroid Association Guidelines in clinical practice.

Treatment of thyroid cancer based on risk groups

The understanding of the prognostic factors and risk groups is crucial in the management of well differentiated thyroid cancer. The important prognostic factors are age, grade of tumor, extrathyroidal extension, size of tumor, and distant metastases. Based on these prognostic factors, patients can be divided into low-, intermediate-, and high-risk groups. The treatment decisions should be based on risk group analysis. Extent of thyroidectomy and adjuvant therapy can be based on the risk group analysis. The histopathologic studies are very important to distinguish well differentiated from the tall cell, insular, and poorly differentiated thyroid cancer.

Ultrasound of thyroid cancer

The management of thyroid nodules is multi-disciplinary and involves head and neck surgeons, pathologists and radiologists. Ultrasound is easy to perform, widely available, does not involve ionizing radiation and is readily combined with fine needle aspiration cytology (FNAC). It is therefore an ideal investigation of choice for evaluating thyroid nodules. It evaluates specific features that help in identifying the nature of the nodule and FNAC helps in diagnostic accuracy. In addition, following treatment for thyroid cancer ultrasound provides a safe tool for disease surveillance. This paper discusses the role of ultrasound in the management of patients with thyroid cancer.

Thyroid cancer review 1: presentation and investigation of thyroid cancer

Thyroid cancer is uncommon with an estimated lifetime risk of 0.8% for women and 0.3% for men. The incidence appears to be increasing by 4% per year and is currently the eighth commonest cancer in women. Managing thyroid cancer is challenging, as no prospective randomised trials exist. Most of the information is derived from large patient cohorts in which therapy has not been randomly assigned. This is the first of the three review papers we have written on the management of thyroid cancer.

Advances in the management of thyroid cancer

The incidence of thyroid cancer is rapidly increasing in the United States. A large number of incidentalomas are found during routine head and neck evaluations. The diagnostic workup still revolves around fine needle aspiration biopsy. Ultrasound guided fine needle aspiration biopsy is likely to yield the best results. Surgical resection offers the best treatment choice. Controversy continues in relation to total versus less than total thyroidectomy. The incidence of complications is inversely proportional to the extent of surgery and obviously related to the experience of the operating surgeon. The decision regarding the extent of thyroidectomy should be based on prognostic factors and risk groups. Prognostic factors are well defined, such as age, grade of the tumor, extrathyroidal extension, size, distant metastasis, and histology. Nodal metastasis has minimal implications. Based on prognostic factors, thyroid cancer can be divided into low, intermediate and high risk groups. In the high risk group and in selected intermediate risk patients, radioactive iodine dosimetry and ablation should be considered after total thyroidectomy. PET scanning and the use of recombinant TSH have been major advances in follow-up care for patients with thyroid cancer. Thyroglobulin appears to be a very good tumor marker for follow-up. No major breakthrough is noted in the management of anaplastic thyroid cancer, however, identification of RET mutation has been extremely helpful in evaluating the family members of the patient with medullary thyroid cancer with strong consideration given to total thyroidectomy.

Does a Leu 512 Arg thyrotropin receptor mutation cause an autonomously functioning papillary carcinoma?

In the last decade, studies were first done to determine the frequency of Gsalpha and later thyrotropin receptor (TSHR) mutations in benign autonomously functioning thyroid nodules (AFTN). Different frequencies ranging from 0% to 38% for GSp mutations and from 20% to 86% for TSHR mutations were found. There were only some limited case reports related to TSHR genetic alterations in malignant AFTN. Their role in autonomously functioning thyroid carcinomas is not well established. We present a patient who had thyroidectomy for toxic multinodular goiter and a papillary carcinoma was demonstrated histopathologically. Genomic DNA was isolated from two solid areas in the hot nodule and peripheral leukocytes of the patient. After amplifying the related regions, TSHR and GSalpha genes were analyzed by single-strand conformation polymorphism (SSCP) analysis. The precise localization of the mutations was identified by automatic DNA sequence analysis. An activating mutation of the TSHR gene (Leu 512 Arg) was found in the autonomously functioning papillary carcinoma. It is believed that this mutation causes constitutive activation of the cyclic adenosine monophosphate (cAMP) signal transduction pathway and thereby causes thyrotoxicosis and a hot thyroid nodule in an autonomously functioning papillary carcinoma.