Comparison of 5 Thyroid Ultrasound Stratification Systems for Differentiation of Benign and Malignant Nodules and to Avoid Biopsy Using Histology as Reference Standard

ObjectiveWe aimed to compare the thyroid ultrasound risk stratification systems (RSSs) of the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS), European TI-RADS, Korean TI-RADS, and American Thyroid Association (ATA), American Association of Clinical Endocrinologists, American College of Endocrinology, and Associazione Medici Endocrinologi guidelines to differentiate benign from malignant thyroid nodules and to avoid unnecessary fine needle aspiration (FNA).MethodsThe records of 1143 nodules ≥1 cm that underwent FNA biopsy and thyroidectomy between 2012 and 2020 at our institution were reviewed. Ultrasound categories and FNA recommendation indications of 5 international RSSs were compared with histopathological findings as benign or malignant. The ultrasound categories and recommended FNA indications, the proportion of the avoidable FNA procedures, and false negative rates (FNRs) by different systems were compared with each other.ResultsOf the 1143 nodules, 45% had thyroid malignancy. FNA recommendation and ultrasound risk classification of ATA guidelines had the highest area under curves of 0.619, and 0.715, respectively. ACR TI-RADS, American Association of Clinical Endocrinologists/American College of Endocrinology/Associazione Medici Endocrinologi guidelines, European TI-RADS, ATA guidelines, and Korean TI-RADS would have avoided FNA for 34.7%, 31%, 25.7%, 20%, and 6% of nodules with an FNR of 24%, 28.5%, 22%, 7.2%, and 1.9%, respectively.ConclusionOur findings showed that all RSSs classified the nodules appropriately for malignancy. ATA guidelines had the highest area under curves and a low FNR, whereas ACR TI-RADS would have spared more patients from FNA with a high FNR.     

Comparison of the Efficacy and Safety of the American Thyroid Association Guidelines and American College of Radiology TI-RADS

ObjectiveTo evaluate the 2015 American Thyroid Association (ATA) guidelines and 2017 American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS) for their efficacy in predicting malignant thyroid nodules and safety in recommending fine needle aspiration (FNA).MethodsWe reviewed data of 970 thyroid nodules from 908 patients with core needle biopsy pathology. We calculated the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for each guideline to predict malignancies. We compared the areas under the curve and FNA recommendations between the 2 guidelines.ResultsAccording to the core needle biopsy pathology, 59.9% (581/970) of the thyroid nodules were malignant. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value was 68%, 91%, 33%, 67%, and 70%, respectively, for the ATA guidelines and 70%, 84%, 49%, 71%, and 68%, respectively, for the ACR TI-RADS. Areas under the curve (ATA: 0.71 vs ACR TI-RADS: 0.74; P = .054) were similar when predicting malignancies. For the 545 nodules with maximum diameter ≥1.0 cm, the ACR TI-RADS recommended FNA less often than the ATA guidelines (83.3% [454/545] vs 87.7% [478/545]; P = .01). For the 321 malignant nodules with maximum diameter ≥1.0 cm, the proportions of FNA recommendations were not significantly different (ACR TI-RADS: 90.7% [291/321] vs ATA: 92.5% [297/321]; P = .06).ConclusionThe 2015 ATA guidelines and 2017 ACR TI-RADS showed a similar ability in predicting malignancies. Reducing FNA recommendations by the ACR TI-RADS would not lead to a significant decrease in the FNA recommendations given for malignancies with maximum diameter ≥1.0 cm.     

¿Está de acuerdo nuestra conducta ante el nódulo tiroideo y cáncer diferenciado de tiroides con la guía norteamericana y el consenso europeo?

IntroductionThe aim of this study was to assess the approaches of specialists in Spain to patients with thyroid nodules and differentiated thyroid carcinoma and to compare them with the American guideline and European consensus.Material and methodsWe performed a cross-sectional study based on a questionnaire addressed to clinical endocrinologists specialized in thyroid cancer and specialists in nuclear medicine throughout Spain.ResultsA total of 177 questionnaires were completed, representing an overall response rate of 85%; 74% of responses were from endocrinologists and 24% from physicians active in nuclear medicine; 82% of respondents worked in third-level hospitals, 10% in second level hospitals and the remainder in private practice. Most used ultrasonography and cytology to assess thyroid nodules and collaborated with a group of surgeons expert in thyroid surgery. The majority preferred total or subtotal thyroidectomy in tumors with a diameter of 1 cm or more, and systematic lymph node dissection. Only 43 (24%) preferred prophylactic central lymph node dissection. Eighty-one respondents (45%) would still use whole body scan with ¹³¹I or ¹²³I before ¹³¹I ablation. Follow-up was based on cervical echography and thyroglobulin determination; however, 101 (57%) respondents continued to use diagnostic whole body scan in the follow-up.ConclusionThe approaches of the respondents were mainly in accordance with the guideline and consensus, although some variations were found, especially in the use of whole body scan with ¹³¹I before ablation and in follow-up.     

Thyroid-Related Factors that Influence Preoperative Localization of Parathyroid Adenomas

ObjectiveTo evaluate the effect that thyroid-related factors have on the preoperative localization of parathyroid adenomas.MethodsThis retrospective study included adult patients who were referred for further evaluation of primary hyperparathyroidism between December 2005 and October 2009 at a teaching and research hospital in Turkey. High-frequency ultrasonography and sestamibi scintigraphy (MIBI) were performed in all patients. Surgical procedure involved focal or bilateral exploration on the basis of concordant or discordant imaging studies. Selection of patients for minimally invasive parathyroidectomy was made based on the presence or absence of a single parathyroid adenoma detected by both ultrasonography and MIBI scan. Patients with negative or discordant imaging studies and a concomitant thyroid nodule underwent bilateral neck exploration.ResultsTwo hundred and forty-eight patients with primary hyperparathyroidism who underwent parathyroidectomy were included in the study. Parathyroid gland abnormalities were successfully detected preoperatively by ultrasonography in 231 patients and by MIBI scan in 152 patients. When used together, ultrasonography and MIBI scan were unsuccessful in detecting an abnormality in 11 cases. MIBI scan visualized a lesion in 6 cases that remained undiagnosed by ultrasonography. Fifty-six of 85 patients with lesions detected by ultrasonography, but not by MIBI scan, had thyroid nodules. The frequency of thyroid nodules was higher in the 96 patients in whom a MIBI scan could visualize a parathyroid lesion than in the 152 patients in whom MIBI scan was successful (P = .004). No difference was observed regarding ipsilateral thyroid lobe involvement or nodule volume. Parathyroid adenomas were significantly smaller in patients with negative MIBI scans (P < .001).ConclusionOur results suggest that ultrasonography is more sensitive than MIBI scan in the detection of parathyroid adenomas, particularly in the presence of small parathyroid adenomas or other thyroid related-factors. (Endocr Pract. 2012;18:26-33)     

Predicting Malignant Involvement in a Thyroid Nodule: Role of Ultrasonography

ObjectiveTo assess how ultrasonography can contribute during the evaluation of a thyroid nodule and whether this technique can have a role in predicting malignant involvement.MethodsIn this retrospective study, data were analyzed on 220 consecutive patients (with 348 thyroid nodules) who underwent thyroidectomy and had previously undergone assessment by high-resolution thyroid ultrasonography. Nodule size, echogenicity, regularity of margins, halo sign, presence or absence of calcifications, and invasion of surrounding tissues were evaluated. The nodules were classified as low, medium, or high risk for malignant involvement on the basis of nodule characteristics found on ultrasonography. All nodules were submitted to cytologic examination by fine-needle aspiration (FNA) before thyroidectomy. Ultrasound, FNA, and pathologic postoperative results were compared.ResultsAmong the 348 thyroid nodules, 56 were ultrasonographically classified as low risk, 268 as medium risk, and 24 as high risk for malignant potential. Fifty of 56 (89.3%) low-risk nodules and 213 of 268 (79.5%) medium-risk nodules were diagnosed as benign at pathologic postoperative examination. In contrast, however, only 6 of 24 (25%) high-risk nodules were diagnosed as benign. Among the 18 high-risk nodules of 1-cm diameter or larger, FNA showed a 20% false-negative result.ConclusionHigh-risk classification of a thyroid nodule on ultrasonography had a positive predictive value for malignant involvement of 75%. Nodule characteristics analyzed by ultrasonography should be considered at the time of surgical intervention. (Endocr Pract. 2007;13: 219-224)     

Consistency of Thyroid Imaging Reporting and Data System Reporting in Community-Based Imaging Centers Versus a Large Tertiary Hospital

ObjectiveIn our country, thyroid nodules are sonographically evaluated in health maintenance organization (HMO) imaging centers, and patients are referred to tertiary hospitals for ultrasound-guided fine-needle aspiration (FNA) biopsy when indicated. We evaluated the concordance in Thyroid Imaging Reporting and Data System (TI-RADS) classification reporting between these sites.MethodsWe conducted a retrospective cohort study reviewing the sonographic features of thyroid nodules evaluated both at the HMO and a large tertiary center between January 2018 and December 2019. The primary outcome was concordance between the TI-RADS classification at both sites. Additional endpoints included correlation of TI-RADS to the Bethesda category following FNA and correlation of TI-RADS with malignancy on final pathology at each site.ResultsThe records of 336 patients with 370 nodules were reviewed. The level of concordance was poor (19.8%), with 277 (74.8%) nodules demonstrating higher TI-RADS and 20 (5.4%) lower TI-RADS at the HMO compared to the hospital (P < .001; weighted κ = 0.120). FNA results were available for 236 (63.8%) nodules. The Bethesda category strongly correlated with the hospital TI-RADS (P < .001), yet not with HMO TI-RADS (P = .123). In the surgically removed 57 nodules, a strong correlation was identified between the malignancy on final pathology and TI-RADS documented at the hospital (P < .001), yet not at the HMO (P = .259).ConclusionsThere is poor agreement between TI-RADS classification on ultrasound performed in the HMO compared to a tertiary hospital. The hospital’s TI-RADS strongly correlated with the Bethesda category and the final risk of malignancy, unlike the HMO.     

Evaluation Of Various Doses Of Recombinant Human Thyrotropin In Patients With Multinodular Goiters

ObjectiveTo assess the safety, adverse effects, and radioactive iodine uptake (RAIU) of recombinant human thyrotropin (rhTSH) using a range of doses in patients with multinodular goiters.MethodsIn this open-label study conducted between June 2002 and December 2004, euthyroid patients with small nontoxic multinodular goiters and normal thyrotropin concentrations were recruited from 4 sites in the United States. Baseline assessments included thyroid function tests, electrocardiogram, Holter monitoring, hyperthyroid symptom scale, flow-volume loop, and measurement of thyroglobulin and thyroperoxidase antibodies. Patients had a baseline 24-hour scan and thyroid iodine I 123 (¹²³I) uptake evaluated at 6, 24, and 48 hours after rhTSH administration. Each patient received a single intramuscular injection of 0.03-mg, 0.1-mg, or 0.3-mg rhTSH followed 24 hours later by 400 μCi ¹²³I orally. Iodine 123 uptakes were again measured 6, 24, and 48 hours later, and a scintigram scan was performed at 24 hours. Thyroid function tests, flow-volume loop, Holter monitoring and/or electrocardiograms, and thyroid ultrasonography to assess thyroid size were performed serially.ResultsTwenty-eight patients participated. Median goiter size was 20 mL (range, 7-79 mL). After each rhTSH dose, the radioiodine uptake approximately doubled at each time point compared with baseline uptake. Small rises in serum thyroxine and triiodothyronine were seen in some patients, especially after 0.3-mg rhTSH, and mild symptoms of hyperthyroidism developed in several patients. Flow-volume loop showed transient, mild asymptomatic worsening in 1 patient with a 35.2 mL goiter, although thyroid volume measurements were unchanged. Minor electrocardiogram and/or Holter changes were seen in several patients.ConclusionsA flat dose-response curve exists over the range of rhTSH doses tested, with an approximate doubling of thyroid RAIU. All patients tolerated rhTSH well, but the rise in thyroid hormone levels and adverse effects after rhTSH doses of 0.1 mg or higher theoretically might not be well tolerated in older or sicker patients and appear unjustified given the lack of a greater rise in RAIU compared with the 0.03-mg dose. Future studies evaluating rhTSH doses less than 0.1 mg in patients with multinodular goiter are justified. (Endocr Pract. 2008;14:832-839)     

Thyroid Cytology and Risk of Thyroid Cancer: Differences Among Indeterminate Specimens

ObjectiveTo assess the potential for stratification of indeterminate cytologic findings on fine-needle aspiration (FNA) of thyroid nodules in an effort to improve therapeutic strategies.MethodsWe attempted to determine the malignant risk associated with various indeterminate FNA cytologic patterns by correlation of specimens with the final histologic diagnosis. For this analysis, we identified 294 computerized medical records of surgically treated thyroid nodules during a 5-year period at our institution with the corresponding FNA cytology reports available.ResultsOf the 294 surgical cases, 162 with a positive or indeterminate cytologic report were selected, reviewed, and classified. Of 52 patients with positive cytologic findings on FNA, 51 (98%) had a final histologic report of a malignant thyroid nodule. Of 110 patients with indeterminate specimens, 30 (27%) had a final histologic diagnosis of thyroid carcinoma. The presence of nuclear atypia was predictive of thyroid carcinoma in 75% of patients, a Hürthle cell cytologic pattern was associated with a malignant thyroid nodule in 33%, and a hypercellular smear was suggestive of malignant involvement in 26% of cases. The lowest rate of malignant potential was associated with cytologic microfollicular and scant colloid alone subtype (6%).ConclusionThe results of this study show that indeterminate thyroid cytologic specimens can be subdivided into groups with different malignant risks. A microfollicular cytologic pattern in the absence of a hypercellular smear or nuclear atypia does not support a recommendation of surgical treatment. A malignant cytologic diagnosis has a high positive predictive value for detection of thyroid cancer. (Endocr Pract. 2004;10:330-334)     

Agreement Between American and European Thyroid Imaging,Reporting, and Data System (TIRADS) in the Diagnosis of 473 Thyroid Nodules From a Single Center in Brazil

ObjectiveTo compare 2 ultrasound-based risk stratification systems in malignancy risk assessment of thyroid nodules and the clinical applicability of these guidelines in Brazil.MethodsWe retrospectively reviewed the ultrasound findings of 314 patients (473 thyroid nodules) who underwent fine-needle aspiration (FNA) biopsy and/or surgery between February 2018 and March 2019. All nodules were classified using 2 systems: the Thyroid Imaging, Reporting, and Data System (TIRADS) of the American College of Radiology (ACR-TIRADS) and the TIRADS of the European Thyroid Association (EU-TIRADS). Both risk stratification systems were analyzed. We identified the diagnostic predictive values that yielded optimal sensitivity, specificity, positive predictive value, negative predictive value, and accuracy.ResultsOf the 473 nodules, all underwent FNA, and histopathology was performed for 332 nodules. The agreement between the ACR-TIRADS and EU-TIRADS results and that between cytology and histopathology findings was 92.6% (kappa = 0.84) and 86.7% (kappa = 0.73), respectively. The area under the curve for the ACR-TIRADS and EU-TIRADS was 0.871 and 0.828, respectively (P < .001). The EU-TIRADS had the best sensitivity and negative predictive value, whereas the ACR-TIRADS had the best specificity, positive predictive value, and accuracy. Of the 473 nodules studied, only 158 (33.4%) followed the FNA size criteria suggested by the ACR-TIRADS.ConclusionACR-TIRADS and EU-TIRADS had good diagnostic performances. However, most aspirated nodules did not follow the TIRADS indication; thus, the overuse of FNA as a diagnostic tool was observed.     

Value of Repeating A Nondiagnostic Thyroid Fine-Needle Aspiration Biopsy

ObjectiveTo assess the value of repeating a biopsy when the initial thyroid fine-needle aspiration (FNA) biopsy is nondiagnostic.MethodsBetween 1990 and 2003, 4,311 thyroid FNAs were performed at the Cleveland Clinic Foundation, of which 220 (5%) were nondiagnostic. Among 189 patients whose medical records were available for retrospective review, 106 underwent a repeated FNA (FNA #2), and 14 had a second repeated FNA (FNA #3). Thyroid ultrasonography was used in the evaluation in 113 FNAs.ResultsThe first and second repeated FNAs were diagnostic in 58% (62 of 106 patients) and 50% (7 of 14 patients), respectively. The rate of malignant disease in patients with no repeated FNAs versus 1 or more repeated FNAs was 4.8% (4 of 83) versus 11.3% (12 of 106), respectively. Ultrasound-guided FNA yielded a diagnosis among 33 of 113 biopsies (29.2%), and FNA without ultrasound guidance provided a diagnosis in 30 of 159 biopsies (18.9%). Thus, the use of thyroid ultrasonography significantly improved the likelihood of establishing a diagnosis (P = 0.017). We found that repeating the FNA up to 2 times provides a diagnosis in up to 60% of cases.ConclusionThe overall prevalence of thyroid cancer in patients with nondiagnostic FNA is not trivial—8.5% in our study group of 189 patients. An aggressive approach toward nondiagnostic FNA biopsies is recommended, with performance of at least 2 repeated FNA biopsies, preferably with the help of ultrasound guidance. (Endocr Pract. 2007;13:735-742)     

The value of 99mTc-MIBI scan in the detection of malignancy potential of hypermetabolic thyroid incidentalomas of 18F-FDG PET/CT

Aim of the studyIncreasingly use of PET/CT leads to discovery of incidental findings. Hypermetabolic thyroid nodules are one of the unexpected lesions in PET/CT imaging with an increased risk of thyroid cancers. Our study aims to determine the malignant potential of incidentally detected 18F-FDG avid thyroid nodules by using Tc-99m MIBI imaging.Materials and methodsPET/CT scans were performed for nonthyroidal purposes and were evaluated for the presence of hypermetabolic thyroid nodules. Tc-99m MIBI scans and ultrasonography-guided fine needle aspiration biopsies were subsequently performed for all patients.ResultsPrimary thyroid malignancies were identified in 25% of patients with increased focal FDG uptake at definitive diagnosis. Among the patients with FDG avid thyroid nodules, Tc-99m MIBI scan showed true-positive results in all thyroid carcinomas (n:7) with a 36.3% (4/11) false-positivity rate. In three patients with indeterminate cytology results, Tc-99m MIBI scan findings were also negative. The sensitivity, specificity, positive predictive value of Tc-99m MIBI scan in predicting the malignancy of FDG-positive thyroid nodules were 100%, 77%, 63.6%, respectively.ConclusionThe implementation of ^99mTc-MIBI scan performed by dual phase and SPECT/CT modality might be a helpful cost-effective approach in addition to FNAB in patients with ¹⁸F-FDG-positive thyroid nodules and indeterminate cytology to improve the patients’ prognosis and reduce unnecessary thyroid operations with associated use of FNAB.     

Do all Thyroid Nodules >4 cm need to be Removed? An Evaluation of Thyroid Fine-Needle Aspiration Biopsy in Large Thyroid Nodules

Objective: Controversy exists regarding the ability of fine-needle aspiration (FNA) biopsy to rule out malignancy when thyroid nodules exceed 4 cm in diameter. The goal of this study was to provide data regarding FNA accuracy in a clinical setting for detecting/ruling out malignancy in large thyroid nodules (≥4 cm) and discuss FNA utility in guiding surgical decisions.Methods: All thyroid FNA cases performed at Marshfield Clinic from 1/1/2000 to 12/31/2010 followed by complete or partial thyroidectomy on nodules of at least 4 cm were identified. Demographics, medical history, nodule biopsy characteristics, surgical procedures, and diagnosis data were abstracted. FNA was compared to histologic evaluation of surgical specimens.Results: A total of 198 patients with large thyroid nodules were identified. Most had a single large nodule, but ~40% were multinodular, and 206 total nodules were assessed. Females outnumbered males, and the mean age was ~50 years. After surgery, cancer was histologically identified in 49/206 (23.8%) nodules, including 9/123 nodules that had been categorized as benign by FNA, corresponding to a false-negative rate of 7.3%. Sensitivity/specificity for detecting malignancy by FNA was ~80%. The positive predictive value (PPV) was just below 60%, and the negative predictive value (NPV) was 93% but rose to 96% when papillary microcarcinomas were excluded.Conclusion: While FNA sensitivity in large nodules was relatively low, NPV was high, especially if incidental papillary microcarcinomas were excluded. When cancer prevalence and NPV are known, FNA can be a reliable “rule out” test in nodules ≥4 cm. This information is critical and can help guide the surgery decision, especially in high-risk patients. The decision for surgery should not be solely based on nodule size but should consider additional factors including cancer prevalence, clinical history, ultrasound features, surgical risk, and life expectancy.Abbreviations:FNA = fine-needle aspirationNPV = negative predictive valuePPV = positive predictive value     

Hürthle cell Thyroid Carcinoma Presenting as A “Hot” Nodule

ObjectiveTo report an unusual clinical scenario and a rare histopathologic finding of Hürthle cell thyroid carcinoma in a patient with an autonomous thyroid nodule.MethodsWe describe the presentation and clinical course leading to the surprising histopathologic diagnosis of Hürthle cell carcinoma in a pediatric patient who was diagnosed with hyperthyroidism presenting as a solitary toxic nodule.ResultsA 13-year-old white girl presented with a recent history of a palpable thyroid nodule during a routine primary care clinic visit. She was asymptomatic, and thyroid function tests revealed a suppressed thyrotropin concentration, high-normal free thyroxine concentration, and elevated triiodothyronine concentration. The patient underwent dedicated thyroid ultrasonography revealing a 3.5-cm complex mass in the left lobe with increased central vascularity. Iodine 123 imaging of the thyroid demonstrated homogenous, hyperintense activity in the left lobe. The right lobe was not visualized. A solitary toxic nodule was diagnosed, and, considering her age, she was referred for surgical management. The patient underwent a left lobectomy with isthmusectomy. Pathologic examination revealed a 5-cm, encapsulated, well-differentiated Hürthle cell carcinoma with negative margins and no lymphovascular invasion. The patient underwent subsequent completion thyroidectomy with no evidence of residual carcinoma in the right thyroid lobe.ConclusionsMalignancy in autonomously functioning thyroid nodules is rare. Most of the thyroid nodules presenting as “hot” on radioiodine scintigraphy are benign follicular adenomas. However, this case represents a rare clinical entity, and it highlights the need for clinicians to be vigilant and aware that occasionally carcinomas can masquerade as scintigraphic “hot” nodules. (Endocr Pract. 2011;17:e68-e72)     

Diagnostic Use of Ultrasonography in Patients with Nodular Thyroid Disease

ObjectiveTo review the published reports pertaining to the diagnostic utility of ultrasonography for evaluation of thyroid nodules.MethodsVarious roles for diagnostic thyroid ultrasonography and screening ultrasound studies of the thyroid are discussed, and ultrasound characteristics of thyroid nodules and their association with malignant potential are described.ResultsIn two studies that correlated ultrasound findings with physical examination findings in patients with a solitary thyroid nodule detected by palpation, 16% of such patients had no corresponding nodule evident on ultrasonography, and 45% of such patients had an additional nodule detected by ultrasonography. Similarly, approximately 18% of patients with a palpable multinodular thyroid had no nodules larger than 1 cm in diameter on ultrasound studies. Thyroid nodules larger than 1 cm have been found by ultrasonography to be present in from 2 to almost 5% of the population with normal findings on examination of the thyroid. Use of screening ultrasound study of the thyroid has been suggested for patients with a history of childhood irradiation to the head and neck or a family history of thyroid cancer. Numerous investigations that have evaluated ultrasound features of thyroid nodules have suggested five characteristics as suggestive of malignant potential—hypoechogenicity, microcalcifications. irregular or microlobulated border, absent or irregular thick halo, and increased intranodular vascularity.ConclusionCorrelation of ultrasound and palpation findings will provide a comprehensive evaluation of nodular thyroid disease. Moreover, real-time ultrasonography facilitates characterization of features associated with an increased risk of a malignant lesion. High-resolution thyroid ultrasonography is a dynamic tool for endocrinologists. (Endocr Pract. 2004;10:246-252)     

Impact of Electronic Consultation on Timeliness and Guideline Concordance of Workups Leading to Thyroid Nodule Fine-Needle Aspiration Biopsy

ObjectiveElectronic consultations (e-consults) are commonly used to obtain endocrinology input on clinical questions without a face-to-face visit, but sparse data exist on the resultant quality of care for specific conditions. We examined workups resulting in a thyroid nodule fine-needle aspiration (FNA) biopsy to investigate whether endocrinology e-consults were more timely and similarly guideline-concordant compared with endocrinology face-to-face visits and whether endocrinology e-consults were more guideline-concordant compared with workups without endocrinology input.MethodsWe retrospectively reviewed charts of 302 thyroid FNA biopsies conducted in the Veterans Affairs health system between May 1, 2017, and February 4, 2020 (e-consult, n = 99; face-to-face visit, n = 100; no endocrinology input, n = 103). We used t tests to compare timeliness, χ² tests to compare the proportion of guideline-concordant workups, and multivariable linear and logistic models to control for demographic factors.ResultsFNAs preceded by an endocrinology e-consult had more timely workups compared with those preceded by endocrinology face-to-face visits in terms of days elapsed between referral and FNA biopsy (geometric mean 44.7 days vs 61.7 days, P = .01). The difference in the summary measure of guideline concordance across groups was not statistically significant (P =.38).ConclusionE-consults were faster than face-to-face consults and similarly guideline-concordant compared with both face-to-face consults and no endocrinology input for workups resulting in FNA. Decisions about the appropriate use of e-consults for thyroid nodules should take into account these data while also considering the potential benefits of direct patient-endocrinologist interaction for complex situations.     

Unusual Case of Amiodarone-Induced Thyrotoxicosis “Illicit” use of a Technetium Scan to Diagnose a Transiently Toxic Thyroid Nodule

ObjectiveTo present an unusual case of amiodarone-induced thyrotoxicosis (AIT) associated with an autonomously functioning thyroid nodule, which was detected by means of a technetium scan; review the existing literature regarding the association of AIT with autonomous thyroid nodules; and explore the use of radioisotope imaging studies in patients with AIT.MethodsWe describe a 62-year-old man with paroxysmal atrial fibrillation, receiving long-term amiodarone therapy, who was referred by his cardiologist for evaluation of abnormal thyroid function tests. He was found to have an unusual case of AIT, associated with an autonomously functioning thyroid nodule.ResultsThyroid function studies obtained by the patient’s cardiologist had shown a completely suppressed thyrotropin level and a free thyroxine level of 3.5 ng/dL. A 24-hour thyroid iodine 123 uptake and technetium Tc 99m pertechnetate scan revealed a “single, strong focus in the right thyroid lobe, with the rest of the thyroid gland...not well visualized.” Thyroid ultrasonography disclosed a single, well-defined 1.5-cm solid nodule. Repeated thyroid function studies revealed a normal thyrotropin level of 2.87 μIU/mL and a normal free thyroxine level of 2.4 ng/dL. The patient was managed conservatively with follow-up surveillance.ConclusionProspective studies should be performed to better ascertain the value of Tc 99m thyroid scanning in determining the cause of AIT. Until such studies have been completed, we suggest that nuclear studies are unlikely to be cost-effective for assessing all patients with AIT. One logical strategy would be to gain experience with scans in only those patients with known thyroid nodules, which have been detected during physical examination or by ultrasonography. The potential clinical utility of such an approach would be of considerable interest. (Endocr Pract. 2007;13:413-416)     

Transverse and Longitudinal Ultrasound Location of Thyroid Nodules and Risk of Thyroid Cancer

BackgroundThe high prevalence of thyroid nodules demands accurate assessment tools to avoid unnecessary biopsies. Prior studies demonstrated a correlation between the longitudinal location of thyroid nodules and the likelihood of malignancy. No study has evaluated the predictive value of transverse location on ultrasonography with malignancy.MethodsWe retrospectively reviewed the records of thyroid nodules that underwent fine-needle aspiration over 13 years, including demographics, risk factors, nodule sonographic features, location, and surgical pathology. Univariate and multivariable logistic regression models were used to evaluate the risk of malignancy.ResultsOf the 668 thyroid nodules, 604 were analyzed with a definitive diagnosis. Thirty-seven nodules were malignant, representing a prevalence of 6.1%. In the longitudinal plane, the upper pole nodules carried the highest incidence of malignancy (14.9%). In the transverse plane, the highest incidence of malignancy occurred in nodules located laterally (12.5%) and anterior-laterally (11.8%). Compared with the upper pole, the odds of malignancy were significantly lower for lower pole (odds ratio [OR] = 0.26, 95% confidence interval [CI]: 0.09-0.70) and midlobe nodules (OR = 0.31, 95% CI: 0.12-0.83). In the transverse plane, posteriorly situated nodules carried a significantly lower risk of malignancy (OR = 0.07, 95% CI: 0.01-0.69). Multiple logistic regression confirmed these associations after adjusting for age, sex, family history, radiation exposure, nodule size, and sonographic characteristics.ConclusionBoth the transverse and longitudinal planes were independent predictors of cancer in thyroid nodules. Lateral, anterior-lateral, and upper pole nodules carried the highest risk and posterior nodules had the lowest risk of malignancy.     

The Role of Core-Needle Biopsy for Thyroid Nodules with Initially Nondiagnostic Fine-Needle Aspiration Results: A Systematic Review and Meta-Analysis

Objective: This study evaluated the prevalence of nondiagnostic results, diagnostic performance, and complications of core-needle biopsy (CNB) compared with repeat fine-needle aspiration (FNA) for thyroid nodules with previous nondiagnostic FNA findings.Methods: The Ovid-MEDLINE and EMBASE databases were thoroughly searched for studies evaluating CNB or repeat FNA for thyroid nodules with initially nondiagnostic FNA results. Pooled proportions of nondiagnostic results of CNB and repeat FNA were calculated. A meta-analysis was performed to evaluate the diagnostic accuracy of CNB and repeat FNA for a diagnosis of malignancy using a bivariate random-effects model. Complication rates were also evaluated.Results: A review of 52 articles identified 4 eligible articles, involving 1,028 patients with 1,028 thyroid nodules, which were included in the meta-analysis. CNB demonstrated significantly lower rates of nondiagnostic results (6.4%) than repeat FNA (36.5%) (P<.0001). In the 3 studies that analyzed the diagnostic accuracy of CNB in diagnosing malignancy, CNB demonstrated significantly higher summary estimates of sensitivity (89.8%) than repeat FNA (60.6%) (P = .022), but summary specificity did not differ between CNB (99.2%) and repeat FNA (99.0%) (P = .576). None of the patients who underwent CNB or repeat FNA experienced any major complications.Conclusion: CNB demonstrates lower rates of nondiagnostic results and higher diagnostic accuracy than repeat FNA. CNB, rather than repeat FNA, can be utilized to diagnose thyroid nodules previously nondiagnostic on FNA.Abbreviations:CI = confidence intervalCNB = core-needle biopsyFNA = fine-needle aspirationSROC = summary receiver operating characteristicUS = ultrasound     

Drivers of the Decision to Biopsy and Follow-Up of Small Suspicious Thyroid Nodules

Objective: In 2015, the updated American Thyroid Association (ATA) guidelines recommended observation for suspicious subcentimeter thyroid nodules, based on their indolent course. We aimed to evaluate the frequency of biopsy in suspicious thyroid nodules since the introduction of these guidelines, including factors contributing to clinical decision-making in a tertiary care center.Methods: We conducted a retrospective study of patients in the Mayo Clinic, Rochester, Minnesota, with new, subcentimeter suspicious thyroid nodules (by report or by sonographic features) between March, 2015, and November, 2017, not previously biopsied.Results: We identified 141 nodules in 129 patients: mean age 58.1 ± 14.1 years, 74% female, 87% Caucasian. The frequency of biopsy in suspicious thyroid nodules was 39%. Ultrasound features that were the strongest predictors for biopsy on multivariate analysis included: nodule volume (odds ratio [OR] 37.3 [7.5–188.7]), radiology recommendation for biopsy (OR 2.6 [1.8–3.9]) and radiology report of the nodule as “suspicious” (OR 2.1 [1.4–3.2]). Patient’s age and degree of comorbidities did not change the likelihood for biopsy, nor did it vary by clinician type or how the nodule was initially found (incidentally or not incidentally). Among 86 nodules that were not biopsied, 41% had no specific follow-up recommendations.Conclusion: One third of suspicious thyroid nodules underwent biopsy since the release of updated ATA guidelines. Factors driving thyroid biopsy seem to be associated with nodule characteristics but not with patient factors including age and comorbidities. Further studies and development of decision aides may be helpful in providing individualized approaches for suspicious thyroid nodules.Abbreviations: ATA = American Thyroid Association; OR = odds ratio     

Management of Nondiagnostic Thyroid Fine-Needle Aspiration Biopsy: Survey of Endocrinologists

ObjectiveTo evaluate the approach of endocrinologists in the setting of nondiagnostic thyroid fine-needle aspiration (FNA) biopsies.MethodsIn 2002, we surveyed physicians attending the national annual meetings of the American Association of Clinical Endocrinologists and the Endocrine Society of North America, using a 13-item questionnaire. The responses were tallied and analyzed.ResultsOf the 143 respondents, 139 were endocrinologists, with a male:female ratio of 2.5:1. Most respondents were involved in a medical practice in North America, but Europe, Asia, New Zealand, and Australia were also represented. Of those performing thyroid FNA biopsy, 31% used thyroid ultrasound guidance. Among the survey respondents, 16%, 49%, 20%, and 15% performed less than 2, 2 to 5, 6 to 10, and more than 10 thyroid FNA biopsies per month, respectively. Among the respondents, 13.5%, 44%, 28.5%, 10%, and 4% had nondiagnostic rates of less than 5%, 5 to 10%, 11 to 20%, 21 to 30%, and more than 30%, respectively. The approach of the respondents to an initially nondiagnostic FNA was repeated FNA biopsy in 87%, observation in 7%, levothyroxine suppression in 4%, and thyroid scintigraphy in 2%. Respondents believed that the most cost-effective approach in a patient with nondiagnostic FNA was repeated biopsy (82%), monitoring the size of the thyroid nodule (17%), and surgical referral (< 1%). No one was willing to repeat the thyroid biopsy more than three times.ConclusionOn the basis of findings in our survey, most endocrinologists repeat thyroid FNA at least once when confronted with a nondiagnostic result. No published studies have demonstrated the cost-effectiveness of this approach versus proceeding to surgical intervention or observation. We hope that this survey will encourage further studies on this issue. (Endocr Pract. 2004;10: 317-323)