Sonographically suspicious thyroid nodules with initially benign cytologic results: the role of a core needle biopsy

The Diagnostic Role of Repeated Biopsy of Thyroid Nodules with Atypia of Undetermined Significance with Architectural Atypia on Core-Needle Biopsy

BACKGRUOUND

We aimed to evaluate the utility of repeat biopsy of thyroid nodules classified as atypia of undetermined significance with architectural atypia (IIIB) on core-needle biopsy (CNB).

METHODS

This retrospective study evaluated patients with thyroid nodules categorized as IIIB on CNB between 2013 and 2015. Demographic characteristics, subsequent biopsy results, and ultrasound (US) images were evaluated. The malignancy rates of nodules according to number of CNBs and the number of IIIB diagnoses was compared. Demographic and US features were evaluated to determine factors predictive of malignancy.

RESULTS

Of 1,003 IIIB nodules on CNB, the final diagnosis was determined for 328 (32.7%) nodules, with 121 of them confirmed as malignant, resulting in a malignancy rate of 36.9% (95% confidence interval, 31.7% to 42.1%). Repeat CNB was performed in 248 nodules (24.7%), with 75 (30.2%), 131 (52.8%), 13 (5.2%), 26 (10.5%), one (0.4%), and two (0.8%) reclassified into categories II, IIIB, IIIA, IV, V, and VI, respectively. Malignancy rates were not significantly affected by the number of CNBs (P=0.291) or the number of IIIB diagnoses (P=0.473). None of the nodules confirmed as category II on repeat CNB was malignant. US features significantly associated with malignancy (P<0.003) included solid composition, irregular margins, microcalcifications, and high suspicion on the US risk stratification system.

CONCLUSION

Repeat biopsy of nodules diagnosed with IIIB on CNB did not increase the detection of malignancy but can potentially reduce unnecessary surgery. Repeat biopsy should be performed selectively, with US features guiding the choice between repeat biopsy and diagnostic surgery.

Reevaluating diagnostic categories and associated malignancy risks in thyroid core needle biopsy

As the application of core needle biopsy (CNB) in evaluating thyroid nodules rises in clinical practice, the 2023 Korean Thyroid Association Management Guidelines for Patients with Thyroid Nodules have officially recognized its value for the first time. CNB procures tissue samples preserving both histologic structure and cytologic detail, thereby supplying substantial material for an accurate diagnosis and reducing the necessity for repeated biopsies or subsequent surgical interventions. The current review introduces the risk of malignancy within distinct diagnostic categories, emphasizing the implications of noninvasive follicular thyroid neoplasm with papillary-like nuclear features on these malignancy risks. Prior research has indicated diagnostic challenges associated with follicular-patterned lesions, resulting in notable variation within indeterminate diagnostic categories. The utilization of mutation-specific immunostaining in CNB enhances the accuracy of lesion classification. This review underlines the essential role of a multidisciplinary approach in diagnosing follicular-patterned lesions and the potential of mutation-specific immunostaining to strengthen diagnostic consensus and inform patient management decisions.

Follow-up of benign thyroid nodules confirmed by ultrasound-guided core needle biopsy after inconclusive cytology on fine-needle aspiration biopsy

PURPOSE

The goal of this study was to follow benign thyroid nodules confirmed by ultrasound (US)-guided core needle biopsy (CNB) after inconclusive cytology on fine-needle aspiration (FNA) biopsy.

METHODS

Sixty-two thyroid nodules from 62 patients with CNB-confirmed benign histology that initially had inconclusive cytology on FNA were retrospectively included. The thyroid nodules were followed for 38.7 months (median, 27.5 months; range, 6 to 101 months), and the US findings of biopsied nodules, such as the interval change in size, US characteristics, and imaging category based on the Korean Thyroid Imaging Reporting and Data System (K-TIRADS), were evaluated. In addition, patients' clinical records were reviewed for any further management or newly diagnosed thyroid malignancy.

RESULTS

Among 62 cases, three (4.8%) showed interval size growth, while 59 (95.2%) demonstrated no interval change or a decrease in size. There was no upgrade of K-TIRADS category or any newly diagnosed malignancy during the follow-up period.

CONCLUSION

US-guided CNB-confirmed benign thyroid nodules with inconclusive cytology on FNA showed a stable status during follow-up, and repeated CNB could be helpful in the management of nodules with inconclusive cytology on FNA.

Diagnostic Performance of Core Needle Biopsy for Characterizing Thyroidectomy Bed Lesions

Objective

Thyroidectomy bed lesions frequently show suspicious ultrasound (US) features after thyroid surgery. Fine-needle aspiration (FNA) may not provide definitive pathological information about the lesions. Although core-needle biopsy (CNB) has excellent diagnostic performance in characterizing suspicious thyroid nodules, no published studies have evaluated the performance of CNB specifically for thyroidectomy bed lesions. Therefore, we aimed to evaluate the diagnostic performance and safety of CNB for characterizing thyroidectomy bed lesions.

Materials and Methods

A total of 124 thyroidectomy bed lesions in 113 patients (79 female and 34 male; age, 23–85 years) who underwent US-guided CNB between December 2008 and December 2020 were included. We reviewed the US imaging features of the target lesions and the histories of previous biopsies. The pathologic results, diagnostic performance for malignancy, and complications of CNB were analyzed.

Results

All samples (100%) obtained by CNB were adequate for pathological analysis. Pathological analysis revealed inconclusive results in two lesions (1.6%). According to the reference standard, 50 lesions were ultimately malignant (40.3%), and 72 were benign (58.1%), excluding the two inconclusive lesions. The performance of CNB for diagnosing malignant thyroidectomy bed lesions in the 122 lesions had a sensitivity of 98.0% (49/50), a specificity of 100% (72/72), positive predictive value of 100% (49/49), and negative predictive value of 98.6% (72/73). Eleven lesions were referred for CNB after prior inconclusive FNA results in thyroidectomy bed lesions, for all of which CNB yielded correct conclusive pathologic diagnoses. According to the pathological analysis of CNB, there were various benign lesions (58.9%, 73/124) besides recurrence, including benign postoperative lesions other than suture granuloma (32.3%, 40/124), suture granuloma (15.3%, 19/124), remnant thyroid tissue (5.6%, 7/124), parathyroid lesions (4%, 5/124), and abscesses (1.6%, 2/124). No major or minor complications were associated with the CNB procedure.

Conclusion

US-guided CNB is accurate and safe for characterizing thyroidectomy bed lesions.

Diagnostic Performance of Thyroid Core Needle Biopsy Using the Revised Reporting System: Comparison with Fine Needle Aspiration Cytology

BACKGROUND

We aim to validate the diagnostic performance of thyroid core needle biopsy (CNB) for diagnosing malignancy in clinical settings to align with the changes made in recently updated thyroid CNB guidelines.

METHODS

We retrospectively analyzed 1,381 thyroid CNB and 2,223 fine needle aspiration (FNA) samples. The FNA and CNB slides were interpreted according to the Bethesda System for Reporting Thyroid Cytopathology and updated practice guidelines for thyroid CNB, respectively.

RESULTS

Compared to FNA, CNB showed lower rates of inconclusive results categories I (2.8% vs. 11.2%) and III (1.2% vs. 6.2%), and higher rates of categories II (60.9% vs. 50.4%) and IV (17.5% vs. 2.0%). The upper and lower bounds of the risk of malignancy (ROM) for category IV of CNB were 43.2% and 26.6%, respectively. The CNB subcategory IVb with nuclear atypia had a higher ROM than the subcategory without nuclear atypia (40%-62% vs. 23%-36%). In histologically confirmed cases, there was no significant difference in the diagnostic performance between CNB and FNA for malignancy. However, neoplastic diseases were more frequently detected by CNB than by FNA (88.8% vs. 77.6%, P=0.046). In category IV, there was no difference in unnecessary surgery rate between CNB and FNA (4.7% vs. 6.9%, P=0.6361).

CONCLUSION

Thyroid CNB decreased the rate of inconclusive results and showed a higher category IV diagnostic rate than FNA. The revised guidelines for thyroid CNB proved to be an excellent reporting system for assessing thyroid nodules.

Analysis of the Influence of Thyroid Nodule Characteristics on the Results of Shear Wave Elastography

OBJECTIVE

To analyze the ultrasonic characteristics of false-negative and false-positive results of shear wave elastography (SWE) in the diagnosis of thyroid nodules to clarify the influence of nodular characteristics on SWE and to guide the clinical application of SWE.

METHODS

A total of 435 thyroid nodules from 343 patients with the diagnosis confirmed by surgical pathology were analyzed. Preoperative ultrasonography and SWE were conducted. The conventional ultrasound characteristics of thyroid nodules and the maximum Young's modulus were recorded. The false negativity and false positivity of SWE for the diagnosis of thyroid nodules were calculated. The ultrasonic characteristics of thyroid nodules with SWE false results were analyzed, and logistic regression analysis was adopted to determine the ultrasonic characteristics associated with SWE false results of thyroid nodules.

RESULTS

Among 323 malignant nodules, the SWE false negativity was 27.2% (88/323). The false positivity of SWE in 112 benign nodules was 19.6% (22/112). Regression analysis showed that an increase in the nodule volume increased the risk of SWE false-positive results (odds ratio [OR] 3.286; 95% confidence interval [CI]: 1.572-6.871; P = 0.002) and decreased the risk of false-negative results (OR 0.238; 95% CI: 0.115-0.493; P < 0.001). Nodules with coarse calcification had an increased risk of SWE false-positive results compared with those without calcification (OR 5.303; 95% CI: 1.098-25.619; P = 0.038). However, nodules with scattered hyperechoic foci had a reduced risk of SWE false-negative results (OR 0.515; 95% CI: 0.280-0.951; P = 0.034).

CONCLUSION

Nodular size and calcification were correlated with SWE false results, and the clinical application of SWE should be combined with conventional ultrasound features. Fine needle aspiration or a puncture biopsy should be conducted if necessary.

Effect of the size of benign thyroid degenerative nodules on ACR TI-RADS categories

PURPOSE

Our study aimed to identify ultrasound characteristics of benign thyroid degenerative nodules and reveal the correlation between their sizes and 2017 ACR Thyroid Imaging Reporting and Data System (TI-RADS) categories.

METHODS

A total of 174 thyroid degenerative nodules were divided into three groups: 0.5-1 cm group (70 nodules), 1-2 cm group (27 nodules), and > 2 cm group (77 nodules). The ultrasound appearance of each nodule was evaluated, and the ACR TI-RADS scores and levels of the nodules were also calculated and compared among the three groups.

RESULTS

The ultrasound appearance of degenerative nodules of different sizes is diversified, and the 0.5-1 cm group tended to have more malignant features and higher TI-RADS scores and categories. The scatterplot of Spearman correlation showed a significant negative correlation between the nodule sizes and TI-RADS categories.

CONCLUSION

The 2017 ACR TI-RADS, which recommends fine-needle aspiration according to the nodule size and category, is still useful in managing these nodules, and following the clinical recommendations of ACR TI-RADS is necessary.

2021 Korean Thyroid Imaging Reporting and Data System and Imaging-Based Management of Thyroid Nodules: Korean Society of Thyroid Radiology Consensus Statement and Recommendations

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Diagnostic performance of core needle biopsy as a first-line diagnostic tool for thyroid nodules according to ultrasound patterns: Comparison with fine needle aspiration using propensity score matching analysis

OBJECTIVE

This study aimed to compare the diagnostic performance of core-needle biopsy (CNB) to fine-needle aspiration (FNA) as a first-line diagnostic tool in initially detected thyroid nodules, according to ultrasound (US) patterns.

MATERIALS AND METHODS

This study included 778 consecutive nodules from 705 patients who underwent CNB from one institution and 627 nodules from 583 patients who underwent FNA from two institutions. Adjustments for significant differences in patients' characteristics were facilitated via propensity score matching. We compared the diagnostic performance of CNB and FNA for thyroid malignancy according to three diagnostic criteria for all nodules and the US patterns.

RESULTS

A 1:1 matching of 469 patients yielded no significant differences between CNB and FNA for any covariates. CNB showed a significantly higher sensitivity for malignancy than FNA with any criterion (criterion 1: category VI, criterion 2: category V and VI, criterion 3: category IV, V and VI) in overall and high suspicion nodules (90.1-99.5% vs 69.7%-88.3%, all P-values < 0.001) and low/intermediate suspicion nodules, except criterion 1 (61.9%-100% vs 36.4%-45.5%, all P ≤ .016). In ROC curve analysis, the areas under the ROC curve of CNB were significantly higher than those for FNA with any criterion in overall and high suspicion nodules (P < .001) and in low/intermediate suspicion nodules, except criterion 1 (P ≤ .008). CNB had a slightly higher minor complication rate than FNA (0.7% vs 0%, P ≥ .069).

CONCLUSION

Our study suggests that CNB has a complementary role as an alternative first-line diagnostic tool to FNA for the initial diagnosis of thyroid nodules when performed by an experienced operator.

The efficacy and safety of microwave ablation versus lobectomy for the treatment of benign thyroid nodules greater than 4 cm

PURPOSE

To evaluate the safety and effectiveness of microwave ablation (MWA) versus lobectomy for the treatment of benign thyroid nodules > 4 cm.

METHODS

We retrospectively analyzed the data of 48 patients who underwent MWA and 53 patients who underwent lobectomy to treat benign thyroid nodules > 4 cm. The patients were followed up for 12 months. The volume reduction ratio (VRR) was calculated. The operation time, incision length, hospitalization time, complications, thyroid function, symptoms, and cosmetic improvement were analyzed and compared between the two groups.

RESULTS

During the 12-month follow-up, the mean nodule volume in the MWA group was reduced from 36.1 ± 23.1 to 4.0 ± 4.1 ml, and the mean VRR of the nodules was 90 ± 5% in the MWA group, which was comparable with that in the surgery group. No significant postoperative change in thyroid function was observed in the MWA group. Compared with the surgery group, the incidence of complications and postoperative pain in the MWA group were lower, the operation time, incision length, and hospitalization time in the MWA group were shorter, and satisfaction with the esthetic results in the MWA group was greater.

CONCLUSION

MWA is safe and effective for the treatment of benign thyroid nodules > 4 cm. Moreover, MWA is associated with a faster recovery, fewer complications, better protection of thyroid function, and superior esthetic results relative to thyroid lobectomy.

Degenerating Thyroid Nodules: Ultrasound Diagnosis, Clinical Significance, and Management

Degenerating nodules (DNs), which primarily manifest as benign thyroid nodules, are one of the main causes of discordance in ultrasonography (US) and cytological assessments. Intranodular hemorrhage is one of the mechanisms contributing to discordant nodules, and an impaired blood supply may explain further DN shrinkage and infarction. The surgical specimens can be divided into acute and chronic stages based on the histological changes, which usually mimic the US features of malignant tumors. Serial US follow-up should be recommended instead of other unnecessary procedures. However, repeated fine-needle aspiration, diagnostic surgery, or core-needle biopsy may still be necessary for indeterminable or highly suspicious DNs.

Assessing the diagnostic performance of thyroid biopsy with recommendations for appropriate interpretation

Purpose

The diagnostic performance of thyroid biopsy is influenced by several factors, including differences in the Bethesda categorization for malignancy, the inclusion or exclusion of non-diagnostic results, the definition used for the final diagnosis, and the definition of an inconclusive diagnosis. The purpose of this study was to provide an understanding of the factors influencing the diagnostic performance of thyroid biopsy.

Methods

We collected data retrospectively between January and December 2013 from a cohort of 6,762 thyroid nodules from 6,493 consecutive patients who underwent biopsy. In total, 4,822 nodules from 4,553 patients were included. We calculated the biopsy sensitivity according to the inclusion of different Bethesda categories in the numerator and the exclusion of non-diagnostic results, as well as the diagnostic accuracy according to different definitions of a benign diagnosis. We obtained the conclusive and inconclusive diagnosis rates.

Results

The sensitivity increased when more Bethesda categories were included in the numerator and when non-diagnostic results were excluded. When a benign thyroid nodule diagnosis was defined as benign findings on surgical resection, concordant benign results on at least two occasions, or an initial benign biopsy result and follow-up for more than 12 months, the accuracy was higher than when the diagnosis was based on surgical resection alone (91.1% vs. 68.7%). A higher conclusive diagnosis rate was obtained when Bethesda categories I and III were considered inconclusive than when Bethesda categories I, III and IV were considered inconclusive (78.3% vs. 72.8%, P<0.001).

Conclusion

Understanding the concepts presented herein is important in order to appropriately interpret the diagnostic performance of thyroid biopsy.

Ultrasound-guided fine-needle aspiration or core needle biopsy for diagnosing follicular thyroid carcinoma?

OBJECTIVE

We evaluated the preoperative diagnostic values of ultrasound (US), fine-needle aspiration (FNA) and core needle biopsy (CNB) leading to surgery in patients with FTC.

METHODS

From October 1994 to July 2016, 298 patients with FTC who had preoperative US images and underwent US-guided FNA or CNB and surgery were included in this study. We evaluated the results of preoperative FNA or CNB based on the Bethesda system and the US findings according to the Korean thyroid imaging reporting and data system (K-TIRADS).

RESULTS

Predominant US features of FTC showed solid, hypo- or iso-echogenicity, oval smooth margin and halo with no calcification. Based on K-TIRADS, 140 (47.0%) patients with FTC were categorized as low suspicion, 133 (44.63%) as intermediate suspicion and 25 (8.4%) as high suspicion at US. Considering only FNA cytology (n = 230), 6.9% were revealed as Bethesda class I, 16.1% as class II, 37.0% as class III, 29.1% as class IV and 10.9% as class V. Considering the 68 cases with CNB results, 2.9% were revealed as class I, 4.4% as class II, 20.6% as class III and 72.1% as class IV. Despite multiple FNAs, 16.7% of the 84 patients with FTC still obtained Bethesda class I or class II. CNB results in patients with FTC had a significantly higher rate of Bethesda class IV compared to the FNA results (P < .001). FTCs with distant metastasis exhibited a significantly higher rate of Bethesda classes IV and V compared to those without distant metastasis (P = .004).

CONCLUSION

Surgery for FTC is deferred only with preoperative US and FNA. CNB in patients with FTC can lead to surgery better than FNA. Therefore, if the US feature is characteristic and a serially growing large nodule is suspected, the first attempt of CNB may be helpful in selecting a surgical candidate.

Prognostic Value of Hyperechoic Echo Halo in cN0 Papillary Thyroid Microcarcinoma and Its Correlation with Age and Gender

Purpose. To investigate the pathology and prognostic value of hyperechoic echo halo in cN0 papillary thyroid microcarcinoma (PTMC) and the relationship between age, gender, and the formation of abnormal hyperechoic echo halo and cervical lymph node metastasis. Data of 97 patients who underwent surgical treatment for the first time for single PTMC between April 2016 and March 2017 were analyzed retrospectively. The boundary status of the PTMC was determined preoperatively. Grayscale values of the nodular center, hyperechoic echo halo, and normal thyroid tissue were acquired with Adobe Photoshop CS6 software. The histopathology of the boundary and status of the cervical lymph node metastasis were analyzed. Formation of abnormal hyperechoic halo and cervical lymph node metastasis in relation to age and gender were explored. The abnormal hyperechoic halo mainly represents cancer cell infiltration with reactive hyperplasia of inflammatory cells and fibrous tissue. In the hyperechoic halo group, the grayscale values for the nodular center, hyperechoic echo halo, and normal thyroid tissue were 1552.6 ± 578.6, 5792.0 ± 747.6, and 3582.7 ± 759.0, respectively (P < 0.05). The cervical lymph node metastasis rate was significantly lower in patients with hyperechoic halo (15.0%) than in those without (41.6%; P < 0.05) and significantly higher in those aged <45 years (53.3%) than in those aged ≥45 years (28.4%; P < 0.05). There were no significant correlations between gender and cervical lymph node metastasis or between age, gender, and hyperechoic halo formation (P > 0.05). cN0 PTMC patients with abnormal hyperechoic halo and age >45 years have a significantly reduced risk of cervical lymph node metastasis and relatively good prognosis.

Impact of ultrasound-guided fine needle aspiration cytology for diagnosis of thyroid nodules

BACKGROUND

Previous clinical studies have reported that ultrasound-guided fine needle aspiration cytology (UGFNAC) can be used for the diagnosis of thyroid nodules (TN) effectively. However, no study has systematically explored its diagnosis accuracy in patients with TN. Thus, this study will assess its diagnosis accuracy for TN.

METHODS

We will perform a comprehensive literature search from the following databases from their inceptions to the present without language restrictions: MEDILINE, EMBASE, Cochrane Library, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. We will consider all case-controlled studies investigating the impacts of UGFNAC diagnosis for patients with TN for inclusion. Two authors will independently carry out study selection, data collection, and methodological quality assessment. Quality Assessment of Diagnostic Accuracy Studies tool will be used for methodological quality evaluation. We will use RevMan V.5.3 and Stata V.12.0 software to perform statistical analysis.

RESULTS

We will apply sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio to judge the diagnostic accuracy of UGFNAC for TN.

CONCLUSION

The results of this study will provide latest evidence for the diagnostic accuracy of UGFNAC for TN.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019138805.

The Role of Core Needle Biopsy for the Evaluation of Thyroid Nodules with Suspicious Ultrasound Features

Objective

Recent studies demonstrated that core needle biopsy (CNB) can effectively reduce the possibility of inconclusive results and prevent unnecessary diagnostic surgery. However, the effectiveness of CNB in patients with suspicious thyroid nodules has not been fully evaluated. This prospective study aimed to determine the potential of CNB to assess thyroid nodules with suspicious ultrasound (US) features.

Materials and Methods

Patients undergoing CNB for thyroid nodules with suspicious features on US were enrolled between May and August 2016. Diagnostic performance and the incidence of non-diagnostic results, inconclusive results, conclusive results, malignancy, unnecessary surgery, and complications were analyzed. Subgroup analysis according to nodule size was performed. The risk factors associated with inconclusive results were evaluated using multivariate logistic regression analysis.

Results

A total of 93 patients (102 thyroid nodules) were evaluated. All samples obtained from CNB were adequate for diagnosis. Inconclusive results were seen in 12.7% of cases. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for diagnosis of malignancy were 93.8%, 100%, 100%, 78.9%, and 95%, respectively. None of the patients underwent unnecessary surgery. The diagnostic performance was not significantly different according to nodule size. On multivariate logistic regression analysis, larger nodule size and shorter needle length were independent risk factors associated with inconclusive results.

Conclusion

Samples obtained by CNB were sufficient for diagnosis in all cases and resulted in high diagnostic values and conclusive results in the evaluation of suspicious thyroid nodules. These findings indicated that CNB is a promising diagnostic tool for suspicious thyroid nodules.

Core needle biopsy of thyroid nodules: outcomes and safety from a large single-center single-operator study

Background There currently remains a debate over the use of core needle biopsy (CNB) or fine needle aspiration (FNA) for diagnosis of thyroid nodules. The major drawbacks of previous CNB studies include heterogeneity of the study population, variable techniques, devices, and operator experience affecting the outcome of the procedure. Purpose To assess the diagnostic performance and safety of CNB of thyroid nodules performed by a single experienced operator in consecutive patients. Material and Methods From January 2012 to December 2012, 538 thyroid nodules that underwent CNB were retrospectively evaluated. All CNB procedures were performed by a single operator with 18 years of experience. The histopathology of the surgical specimens was considered as the standard reference for malignancy. A final diagnosis of benignity was made by surgery, one benign lesion on FNA and/or CNB with no change on follow-up examinations (>1 year) or benign lesion on ≥2 FNA and/or CNB. The diagnostic performance, incidence of technical failure, unnecessary surgery, and complication were evaluated. Results The diagnostic accuracy, sensitivity, and specificity of CNB for malignancy were 92.0%, 85.3%, and 100%, respectively. The non-diagnostic result rate of CNB was 4.8% (26/538) and the inconclusive result rate was 24.3% (131/538). The incidence of technical failure was 0.6% (3/541) and unnecessary surgery was 0.6%. The complication rate was 0.2%, without life-threatening complications. The sensitivity, specificity, and accuracy were 85.3% (156/183), 100.0% (154/154), and 92.0% (310/337), respectively. Conclusion CNB shows a high diagnostic performance for detection of thyroid malignancy and follicular neoplasm, with low rates of technical failure and complications.

A Comparison of Ultrasound-Guided Fine Needle Aspiration versus Core Needle Biopsy for Thyroid Nodules: Pain, Tolerability, and Complications

BACKGROUND

To compare pain, tolerability, and complications associated with fine needle aspiration (FNA) versus core needle biopsy (CNB).

METHODS

FNAs were performed using 23-gauge needles and CNBs were performed using 18-gauge double-action spring-activated needles in 100 patients for each procedure. Patients were asked to record a pain score using a 10-cm visual analog scale and procedure tolerability. Complications and number of biopsies were recorded.

RESULTS

The median pain scores were similar for the FNA and CNB approaches during and 20 minutes after the biopsy procedures (3.7 vs. 3.6, P=0.454; 0.9 vs. 1.1, P=0.296, respectively). The procedure was tolerable in all 100 FNA patients and in 97 CNB patients (P=0.246). The mean number of biopsies was fewer in the CNB group (1.4 vs. 1.2, P=0.002). By subgroup analysis (staff vs. non-staff), no significant difference was detected in any parameter. There were no major complications in either group, but three patients who underwent CNB had minor complications (P=0.246).

CONCLUSION

FNA and CNB show no significant differences for diagnosing thyroid nodules in terms of pain, tolerability, or complications.

Update on the role of ultrasound guided radiofrequency ablation for thyroid nodule treatment

Thyroid nodules can be frequently detected in general population, most of them are benign, however malignant cases are rising in the past decades. Ultrasound (US) is the most common imaging modality to assess thyroid nodular lesions, plan patient work-up and guide minimally invasive treatment. The present review paper has been researched to evaluate the current status of radiofrequency ablation (RFA) treatment in order to evaluate indications, techniques, complications, limitations and outcome assessment in benign solid, partially cystic nodules and recurrent malignant nodules. RFA comparison with other ablation techniques has been provided as well. US guided Radiofrequency ablation has been proved to be effective and safe in cases of benign thyroid nodules and a promising treatment method alternative to surgery for patients with recurrent papillary thyroid cancer. It's major role lies in significant reduction of thyroid nodule mean volume and improvement of the patient symptoms. However, future multicenter studies are warranted to better clarify the multi-parametric patient selection criteria and evaluate RFA technique efficacy, advantages and limitations in the variety of thyroid nodular disease.

Recent Advances in Core Needle Biopsy for Thyroid Nodules

Core needle biopsy (CNB) was introduced as an alternative diagnostic tool to fine-needle aspiration (FNA), and is increasingly being used in the preoperative assessment of thyroid nodules. CNB provides a definitive diagnosis in most cases, but it sometimes may be inconclusive. CNB has the advantage of enabling a histologic examination in relation to the surrounding thyroid tissue, immunohistochemistry, and molecular testing that can provide a more accurate assessment than FNA in selected cases. Nevertheless, CNB should be performed only by experienced experts in thyroid interventions to prevent complications because CNB needles are larger in caliber than FNA needles. As recent evidence has accumulated, and with improvements in the technique and devices for thyroid CNB, the Korean Society of Thyroid Radiology released its 2016 thyroid CNB guidelines and the Korean Endocrine Pathology Thyroid Core Needle Biopsy Study Group published a consensus statement on the pathology reporting system for thyroid CNB in 2015. This review presents the current consensus and recommendations regarding thyroid CNB, focusing on indications, complications, and pathologic classification and reporting.

Efficacy and safety of core-needle biopsy in initially detected thyroid nodules via propensity score analysis

We compared the efficacy and complications of core-needle biopsy (CNB) with those of fine-needle aspiration (FNA) in a large population of patients with initially detected thyroid nodules via a propensity score analysis. Outpatients with initially detected thyroid nodules, who had undergone CNB or FNA between January 2013 and December 2013, were selected. This study included 4,822 thyroid nodules from 4,553 consecutive patients. Adjustments for significant differences in patients’ baseline characteristics were facilitated via propensity score analysis. Subgroup analyses were performed according to nodule sizes ≥ 1 cm. The non-diagnostic result rate, malignancy rate, complication rate, and diagnostic accuracy were compared. A 1:1 matching of 1,615 patients yielded no significant differences between two groups for any covariate. The non-diagnostic result rate was significantly lower in the core-needle biopsy group than in the fine-needle aspiration group (5.2% vs. 12.1%), while the malignancy rate (23.7% vs. 11.8%) and sensitivity (75.9% vs. 55.6%) were significantly higher. However, the specificities were similar (100% and 99.9%, respectively). Propensity score and subgroup analyses showed similar results. The complication rate was similar between groups in matched cohorts. CNB is a promising and safe diagnostic tool for patients with initially detected thyroid nodules.

US Elastography Using Carotid Artery Pulsation May Increase the Diagnostic Accuracy for Thyroid Nodules with US-Pathology Discordance

This study evaluated the diagnostic performance of ultrasound elastography (USE) using carotid arterial pulsation and determined the reproducibility of USE for thyroid nodules. A total of 148 patients with 173 thyroid nodules participated. The mean elasticity contrast index (ECI) was significantly higher in malignant nodules (3.1 ± 1.5) than in benign nodules (1.7 ± 0.8) (p < 0.001). When a cut-off ECI value of 3.5 was used, the diagnostic accuracy (78.6%) of gray-scale ultrasound (US) + ECI was the highest compared with that of the gray-scale US (76.9%) and ECI (67.1%). In 16 of 43 nodules (37.2%) with US-pathology, discordance could be correctly reclassified as benign (8 of 11) or malignant (8 of 32). The intra-class correlation coefficient for inter-observer agreement was 0.96, and those for intra-observer agreement were 0.97 and 0.98. Thyroid nodules with ECI values of >3.5 may have an additional value to increase the diagnostic accuracy for nodules with US-pathology discordance with reproducible results.

Cytology-Ultrasonography Risk-Stratification Scoring System Based on Fine-Needle Aspiration Cytology and the Korean-Thyroid Imaging Reporting and Data System

BACKGROUND

The malignancy risk of a cytology diagnosis may depend on the ultrasonography (US) patterns of thyroid nodules, and management should be determined by the combined malignancy risk of fine-needle aspiration (FNA) cytology and US patterns. This study was performed to develop a clinically applicable cytology-ultrasonography (CU) scoring system for malignancy risk stratification based on FNA cytology and US patterns, according to the Korean-Thyroid Imaging Reporting and Data System (K-TIRADS).

METHODS

This retrospective Institutional Review Board-approved study included 1651 thyroid nodules (≥1 cm) with final diagnoses. The malignancy risk was assessed of the combined results of FNA cytology and the K-TIRADS for the development of the CU system. The interaction between FNA cytology and US pattern (K-TIRADS) in the malignancy risk of nodules was investigated by using a binominal test.

RESULTS

The malignancy risk of nodules could be stratified into four CU scores (very low risk, <3%; low risk, ≥3%, <30%; high risk, ≥30%, <90%; very high risk, ≥90%). In nodules with non-diagnostic, benign, and atypia of undetermined significance/follicular lesion of undetermined significance cytology results, low-suspicion US pattern (K-TIRADS 3) significantly decreased the malignancy risk of nodules (p = 0.003, 0.013, and 0.027, respectively), and a high-suspicion US pattern (K-TIRADS 5) significantly increased the malignancy risk of nodules (p ≤ 0.001). A Bethesda 1 or 4 cytology result did not significantly change the malignancy risk of any K-TIRADS (p ≥ 0.518 and p ≥ 0.137, respectively). A Bethesda 2 cytology result decreased and a Bethesda 5 or 6 cytology result increased the malignancy risk of K-TIRADS 3, 4, and 5 (p ≤ 0.001). A Bethesda 3 cytology result increased the malignancy risk of K-TIRADS 3 and 4 (p < 0.001 and p = 0.024, respectively).

CONCLUSION

The malignancy risk of thyroid nodules can be stratified by the CU risk-stratification system, based on FNA cytology and the K-TIRADS. The proposed CU scoring system may be helpful in the management of thyroid nodules after FNA.

Ultrasound-Pathology Discordant Nodules on Core-Needle Biopsy: Malignancy Risk and Management Strategy

BACKGROUND

The reported malignancy rates of thyroid nodules that appear suspicious on ultrasound (US) but yield benign fine-needle aspiration (FNA) cytology results range from 13.6% to 56.6%. However, the malignancy risk of nodules that are discordant on US and core-needle biopsy (CNB) pathological findings has not been evaluated. This study evaluated the malignancy risk associated with thyroid nodules that are suspicious on US but yield benign CNB results.

METHODS

Between July 2008 and November 2011, 1309 patients with 1313 thyroid nodules underwent US-guided CNB. Among these, 166 thyroid nodules that were suspicious on US but yielded benign CNB results were retrospectively reviewed. Benign nodules were diagnosed by surgery, FNA, and/or CNB that was repeated at least twice or CNB and lesion size stability on follow-up. The malignancy risk of US-pathology discordant nodules was calculated according to recommendations by Moon et al., and a further evaluation was conducted using four different US risk systems. Factors that differentiated benign from malignant nodules were assessed using the chi-square test or Fisher's exact test. Moreover, the histological findings of US-pathology discordant nodules were analyzed.

RESULTS

Patients with benign and malignant nodules did not differ significantly regarding clinical and demographic characteristics. Of the 166 US-pathology discordant nodules, seven (4.2%) were confirmed malignant. The malignancy risks associated with the five US risk systems ranged from 3.6% to 5.5%. Regarding suspicious US features, only the number of suspicious features was associated with malignancy (p = 0.002). Histological analysis of benign CNB specimens with suspicious US features revealed fibrosis (77.6%), thyroiditis (28.7%), calcifications (10.6%), and hemosiderin deposition (6.4%).

CONCLUSIONS

The malignancy risk among thyroid nodules with discordant US and CNB results ranged from 3.6% to 5.5%, depending on US risk systems. However, repeated biopsy may be necessary for selected thyroid nodules with more than two suspicious US features.

What Is the Ideal Core Number for Ultrasonography-Guided Thyroid Biopsy of Cytologically Inconclusive Nodules?

BACKGROUND AND PURPOSE

Core needle biopsy of the thyroid under ultrasonographic guidance provides a larger tissue sample and may facilitate a more precise histologic diagnosis, reducing the need for repetitive fine-needle aspiration or a diagnostic operation. However, there is no consensus regarding the ideal number of specimens to be obtained for ultrasonography-guided core needle biopsy. The aim of this study was to decide the ideal core number for ultrasonography-guided core needle biopsy of cytologically inconclusive nodules.

MATERIALS AND METHODS

Sixty consecutive biopsies were performed in 60 thyroid nodules with Bethesda Category I or III cytology. Three biopsy cores were obtained for each thyroid nodule. The first biopsy specimens were taken from the nodule, while the second and third specimens obtained included the nodular tissue, nodular capsule, and surrounding parenchyma. Diagnostic ability was evaluated according to the following: protocol A, first specimen; protocol B, first and second specimens; and protocol C, all specimens. The McNemar test was used for statistical analysis.

RESULTS

Of the 60 nodules, diagnostic ability was achieved in 41 nodules (68%) with protocol A, in 56 nodules (93%) with protocol B, and in 58 nodules (97%) with protocol C. The diagnostic ability of protocols B and C was significantly higher than that of protocol A (all P values < .001). However, the diagnostic ability of protocol B was not significantly different from that of protocol C.

CONCLUSIONS

Ultrasonography-guided core needle biopsy for cytologically inconclusive thyroid nodules should obtain at least 2 core specimens with intranodular and capsule targets.

Core Needle Biopsy of the Thyroid: 2016 Consensus Statement and Recommendations from Korean Society of Thyroid Radiology

Core needle biopsy (CNB) has been suggested as a complementary diagnostic method to fine-needle aspiration in patients with thyroid nodules. Many recent CNB studies have suggested a more advanced role for CNB, but there are still no guidelines on its use. Therefore, the Task Force Committee of the Korean Society of Thyroid Radiology has developed the present consensus statement and recommendations for the role of CNB in the diagnosis of thyroid nodules. These recommendations are based on evidence from the current literature and expert consensus.

Follicular variant of papillary thyroid carcinoma: comparison of ultrasound-guided core needle biopsy and ultrasound-guided fine needle aspiration in a multicentre study

OBJECTIVE

Pre-operative diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) by ultrasound-guided fine needle aspiration (US-FNA) remains a challenge. The goal of this study was to investigate whether ultrasound-guided core needle biopsy (US-CNB) is superior to US-FNA in refining the surgical indications for the treatment of FVPTC.

DESIGN

This retrospective study enrolled 212 patients with 218 FVPTCs who were surgically confirmed at three university hospitals from January 2008 through December 2014. All patients underwent both or either US-FNA or US-CNB. FNA and CNB results were divided into identified surgical candidates or not based on the Bethesda system. Relevant clinical information and the rate of surgical candidates were compared between US-FNA and US-CNB groups.

RESULTS

Among 218 thyroid nodules, US-FNA was performed for 200 nodules and US-CNB for 51 nodules. Thirty-three nodules underwent both US-FNA and US-CNB. The rates of surgical candidates identified by US-FNA and US-CNB were 61·5% and 86·3%, respectively (P = 0·001). The rates of surgical candidates identified by repeat US-FNA and initial US-FNA with subsequent US-CNB were 53·9% and 78·8%, respectively (P = 0·042). A precise diagnosis of FVPTC was made in 1% of the patients in the US-FNA group and in 29·4% of the patients in the US-CNB group. The predominant US findings of FVPTCs included solid tumours (89·4%), wider-than-tall shape (82·6%), no calcifications (51·3%), hypoechogenicity (46·3%) and indeterminate diagnosis on US (50·5%).

CONCLUSIONS

In patients with FVPTC, US-CNB is a superior indicator for surgery compared to US-FNA. If a FVPTC is suspected but is initially indeterminate at FNA cytology, subsequent US-CNB should be considered instead of repeat US-FNA.

First-Line Use of Core Needle Biopsy for High-Yield Preliminary Diagnosis of Thyroid Nodules

BACKGROUND AND PURPOSE

Although core needle biopsy was introduced as a diagnostic alternative to fine-needle aspiration, the utility and safety of core needle biopsy for thyroid nodules in a large population has yet to be studied comprehensively. We evaluate core needle biopsy yields on a large-scale basis to investigate its potential in the preliminary diagnosis of thyroid nodules.

MATERIALS AND METHODS

Between March 2005 and December 2013, 2448 initially detected thyroid nodules from 2120 consecutive patients who underwent core needle biopsy were retrospectively evaluated. Of these, 72 thyroid nodules from 63 patients were excluded due to prior fine-needle aspiration attempts. The inconclusive and conclusive result rates, diagnostic accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and unnecessary surgery rate of core needle biopsy were evaluated.

RESULTS

With core needle biopsy as the first-line method, the inconclusive result rate was 11.9% (283/2376) and the conclusive result rate was 88.1% (2093/2376). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of core needle biopsy for the diagnosis of malignancy were 96.7% (1160/1200), 89.7% (347/387), 100% (813/813), 100% (347/347), and 95.3% (813/853), respectively. There were no major complications and 12 minor complications.

CONCLUSIONS

We have demonstrated that first-line use of core needle biopsy may well improve diagnostic accuracy in thyroid nodules, reducing inconclusive or false-negative results and unnecessary operations. Such benefits underscore the promising role of core needle biopsy in managing thyroid nodules and optimizing related surgical decision-making.

The role of core-needle biopsy in the diagnosis of thyroid malignancy in 4580 patients with 4746 thyroid nodules: a systematic review and meta-analysis

To evaluate the effectiveness and complications of core-needle biopsy (CNB) compared to fine-needle aspiration (FNA) for diagnosing thyroid malignancy. The Ovid-MEDLINE and EMBASE databases were searched for studies using CNB for diagnosing thyroid malignancy. A meta-analysis was performed to evaluate the diagnostic accuracy, the incidence of non-diagnostic, inconclusive results, and the complications of CNB and FNA. To overcome the heterogeneity, additional analyses based on three, homogeneous inclusion criteria were performed and subgroup analyses were performed. Twenty eligible studies of 4580 patients (4746 nodules) were included. Both CNB and FNA demonstrated a high sensitivity (91 %, 74 %, respectively; p = .053) and specificity (99 %, 100 %, respectively; p = .914). The area under the curve was larger in CNB (0.99) than in FNA (0.94). CNB demonstrated a significantly lower pooled proportion of non-diagnostic (5.5 %; p < .001) and inconclusive results (8.0 %; p < .001) than FNA (22.6 %, 40.2 %, respectively). The complications rate of FNA (0.0 %) was lower than that of CNB (0.01 %), although not significantly (p = .948). This meta-analysis showed variable heterogeneities, i.e., no heterogeneity to considerable heterogeneity. Additional meta-analyses based on three, homogeneous inclusion criteria demonstrated that heterogeneities were reduced, and the results are in agreement with those of all of the included studies. Subgroup analyses have explained the cause of heterogeneity across studies. Both CNB and FNA may be acceptable diagnostic tools for diagnosing thyroid malignancy. CNB may be a complementary diagnostic tool in nodules with initially non-diagnostic and indeterminate results on previous FNA.

Comparison of the efficacy and safety of ultrasound-guided core needle biopsy versus fine-needle aspiration for evaluating thyroid nodules

OBJECTIVE

Ultrasound-guided core needle biopsy (UG-CNB) is a procedure that is often performed either after repeated inadequate or nondiagnostic ultrasound-guided fine-needle aspiration (UG-FNA) or in combination with UG-FNA in the evaluation of thyroid nodules. The purpose of this study was to compare the efficacy and safety of UG-CNB and UG-FNA for evaluating thyroid nodules.

METHODS

This was a retrospective study of 350 consecutive patients who had thyroid nodules biopsied by UG-CNB or UG-FNA from January 2007 until November 2011 at our institution. Biopsy results were compared to the surgical specimen pathology reports for the 105 patients who subsequently underwent hemi- or total thyroidectomy in order to determine whether UG-CNB has advantages over UG-FNA for diagnosing thyroid malignancy and neoplasia.

RESULTS

Out of 461 thyroid nodules biopsied from 350 patients, 365 (79%) involved UG-CNB and 96 (21%) involved UG-FNA. The UG-FNA biopsy group had a significantly higher rate of inadequate sampling than the UG-CNB group (P<.0001; Fisher's exact test). Out of 365 UG-CNB samples, 6 (2%) were deemed inadequate for histologic diagnosis, whereas 26 (27%) of the 96 UG-FNA samples were considered inadequate for cellularity. Comparison of biopsy results with the surgical specimen pathology reports revealed that the diagnostic accuracy of UG-CNB and UG-FNA for detecting malignancy was similar, at 89 and 94%, respectively (not significant by Fisher's exact test). However, the UG-CNB group had a higher detection rate for benign follicular lesions compared to the UG-FNA group (65% versus 48% for UG-FNA; P = .002). Although UG-FNA detected neoplasia with high sensitivity (100%), the specificity was poor (30%). Neither biopsy group had any significant immediate or delayed procedure-related complications.

CONCLUSION

Our study demonstrated that UG-CNB is safe and is less likely to result in a nondiagnostic biopsy. The accuracy of the UG-CNB technique is similar to that of UG-FNA for detecting thyroid malignancy.

Complications following US-guided core-needle biopsy for thyroid lesions: a retrospective study of 6,169 consecutive patients with 6,687 thyroid nodules

OBJECTIVES

To present the various complications of ultrasound (US)-guided core needle biopsy (CNB) of thyroid lesions in a large patient series.

METHODS

From January 2008 to March 2013, 6,169 patients underwent US-guided CNB of 6,687 thyroid nodules at a single institution. We assessed the number and types of major and minor complications, and evaluated the factors associated with complications.

RESULTS

Overall, 53 complications were observed in 50 patients (0.81 %), including 4 major and 49 minor complications. The major complications were massive haematoma (n = 2), pseudoaneurysm (n = 1) and voice change leading to disability that lasted for more than 30 days (n = 1). The minor complications were small to moderate haematoma (n = 42), carotid injury (n = 2), voice change that recovered within 30 days (n = 3), tracheal puncture (n = 1) and dysphagia (n = 1). Oedema (n = 12), vertebral puncture (n = 3) and vasovagal reaction (n = 1) were recorded as side effects. The presence of a coprocedure was the only significant factor associated with complications after thyroid CNB (P = 0.023).

CONCLUSIONS

US-guided CNB of thyroid lesions was found in a large population to be a safe procedure with a low complication rate.

KEY POINTS

• The complication rate after US-guided CNB for thyroid lesions was 0.81 % (50/6,169). • The rate of major complications was 0.06 % (4/6,169). • Vascular injury was the most common complication (47/6,169; 0.76 %). • None of the patients experienced permanent problems resulting from complications.

Fine-needle aspiration versus core needle biopsy for diagnosis of thyroid malignancy and neoplasm: a matched cohort study

OBJECTIVES

To compare the diagnostic performances of fine-needle aspiration (FNA) and core needle biopsy (CNB) in the diagnosis of thyroid malignancy and neoplasm in patients who underwent surgery for thyroid nodules.

METHODS

This retrospective study was approved by the institutional review board, and the need to obtain informed consent was waived. 3192 patients who underwent FNA (n = 3048) or CNB (n = 144) for diagnosis of thyroid nodules and then proceeded with surgery were included. Surgical pathologic diagnosis was the reference standard. Diagnostic performances of FNA and CNB to predict malignancy and neoplasm were compared. Propensity score matching was used to match patients with FNA with those with CNB because there were significant differences in the number of nodules and nodule characteristics between the FNA and CNB groups.

RESULTS

Before matching, the sensitivity and accuracy of FNA were significantly higher or comparable with those of CNB, and the specificity, negative predictive value and positive predictive value were comparable. After matching, the diagnostic performances were similar, with the exception of specificity for predicting neoplasm being higher with CNB than with FNA.

CONCLUSION

FNA showed comparable diagnostic performance to CNB; therefore, there may be no benefit in performing CNB to diagnose papillary thyroid carcinoma and neoplasm.

KEY POINTS

• Diagnostic performances of FNA and CNB for thyroid malignancy and neoplasm were compared. • FNA showed comparable performances to CNB both before and after statistical matching. • There may be no benefit in performing CNB, given the comparable performances.

Ultrasonography Diagnosis and Imaging-Based Management of Thyroid Nodules: Revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations

The rate of detection of thyroid nodules and carcinomas has increased with the widespread use of ultrasonography (US), which is the mainstay for the detection and risk stratification of thyroid nodules as well as for providing guidance for their biopsy and nonsurgical treatment. The Korean Society of Thyroid Radiology (KSThR) published their first recommendations for the US-based diagnosis and management of thyroid nodules in 2011. These recommendations have been used as the standard guidelines for the past several years in Korea. Lately, the application of US has been further emphasized for the personalized management of patients with thyroid nodules. The Task Force on Thyroid Nodules of the KSThR has revised the recommendations for the ultrasound diagnosis and imaging-based management of thyroid nodules. The review and recommendations in this report have been based on a comprehensive analysis of the current literature and the consensus of experts.

Thyroid Imaging Reporting and Data System Risk Stratification of Thyroid Nodules: Categorization Based on Solidity and Echogenicity

BACKGROUND

Although ultrasonography (US) has an essential role in assessing the malignancy risk of thyroid nodules, a malignancy risk-stratification system has not been established. The purpose of this study was to develop a clinically feasible US risk-stratification system--the Thyroid Imaging Reporting and Data System (TIRADS)--primarily based on the solidity and echogenicity of thyroid nodules.

METHODS

From January 2010 to May 2011, a total of consecutive 2000 thyroid nodules (≥ 1 cm) with final diagnoses were enrolled from the database of low and high cancer volume institutions (1000 nodules from each institution). For the development of TIRADS, the type and predictive value of US predictors in the groups categorized by solidity and echogenicity were analyzed, and the US predictors were integrated and categorized according to the malignancy risk.

RESULTS

The suspicious US features of microcalcification, taller than wide shape, and spiculated/microlobulated margin were independently predictive of malignancy in the solid or hypoechoic nodule group (p < 0.001, respectively). Meanwhile, only microcalcification was independently predictive of malignancy in the partially cystic nodule group (p = 0.006), and microcalcification and spiculated/microlobulated margin were independently predictive of malignancy in the iso- and hyperechoic nodule group (p = 0.002 and p = 0.015, respectively). Although the presence of any suspicious US features had a high malignancy risk in the group of solid hypoechoic nodules, it had an intermediate malignancy risk in the group of partially cystic or iso- and hyperechoic nodules. The malignancy risk of thyroid nodules was stratified into five TIRADS categories by integrating the type and predictive values of US predictors based on solidity and echogenicity.

CONCLUSION

The malignancy risk of thyroid nodules can be stratified by TIRADS according to US patterns by combining solidity, echogenicity, and suspicious US features. The proposed risk-stratification system based on solidity and echogenicity will be useful for risk stratification and management decision of thyroid nodules.

Malignant-looking thyroid nodules with size reduction: core needle biopsy results

Purpose

The aim of this study was to evaluate whether malignant-looking thyroid nodules with size reduction were malignant or not.

Methods

From November 2010 to July 2011, we retrospectively enrolled 16 patients with 16 nodules (11 females and five males; mean age, 55 years) who underwent core needle biopsy (CNB), and whose thyroid nodules had malignant ultrasonographic (US) features, although they showed size reduction (>20% decrease in maximum diameter) during the follow-up period (mean, 37±27 months). The histologic findings of the CNB specimen were reviewed and correlated with the US findings. US studies were analyzed for their internal content, shape, margin, echogenicity, the presence of microcalcification and macrocalcification, inner isoechoic rim, and low-echoic halo.

Results

All nodules were confirmed as benign by CNB. Pathologic analysis was available for 12 CNB specimens. US imaging showed central hypoechogenicity or marked hypoechogenicity in all cases and a peripheral isoechoic rim in 15 nodules. US-pathologic correlation showed that the central hypoechoic area was primarily composed of fibrosis (12/12) and hemorrhage (8/12) and that the isoechoic rim was composed of follicular cells.

Conclusion

In our study, the CNB results of all of the malignant-looking thyroid nodules with size reduction were benign and were primarily composed of internal fibrosis and hemorrhage. Understanding these US and pathologic features could prevent repeated fine-needle aspiration or unnecessary diagnostic surgery.

The Role of Core-Needle Biopsy as a First-Line Diagnostic Tool for Initially Detected Thyroid Nodules

BACKGROUND

The aim of this study was to evaluate the role of core-needle biopsy (CNB) as a first-line diagnostic tool for initially detected thyroid nodules.

METHODS

This observational study evaluated 632 initially detected thyroid nodules in 632 consecutive patients who underwent CNB between October 2008 and December 2011. CNB results were categorized into the six categories of the Bethesda System. A final diagnosis of malignancy was based on surgery or CNB, whereas a final diagnosis of benign nodules was based on surgery, two benign biopsy results, or benign cytology of stable size after one year. The rates of Bethesda category 1 and inconclusive results, diagnostic performance, unnecessary surgery, and complications were evaluated. Subgroup analysis based on nodule size was performed. Risk factors for inconclusive results were evaluated by multivariate logistic regression analysis.

RESULTS

The rates of Bethesda category 1 and inconclusive results by CNB were 1.3% and 5.9%, respectively. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for the diagnosis of malignancy were 97.6%, 90.0%, 100%, 100%, and 92.3%, respectively. The rate of unnecessary surgery was 0.5%, and the complications rate was 0.2%. Based on subgroup analysis, the diagnostic performance was not significantly associated with nodule size. There were no independent risk factors associated with inconclusive results.

CONCLUSION

CNB showed low rates of Bethesda category 1 and inconclusive results and a high diagnostic accuracy. CNB also minimized unnecessary surgery. CNB seems to be a promising diagnostic tool for patients with initially detected thyroid nodules.

Thyroid nodules with minimal cystic changes have a low risk of malignancy

PURPOSE

The goal of this study was to determine the risk of malignancy of thyroid nodules with minimal cystic changes.

METHODS

A total of consecutive 1,000 thyroid nodules (≥1 cm) with final diagnoses from twoinstitutions were included in this study. The risk of malignancy of thyroid nodules was analyzed according to the internal content, which was categorized as purely solid, minimally cystic (cystic changes ≤10%), and partially cystic (cystic changes >10%). We also assessed the risk of malignancy of nodules with minimal cystic changes depending on echogenicity and presence of any suspicious ultrasonografic (US) features.

RESULTS

The overall frequency of purely solid, minimally cystic, and partially cystic noduleswas 730/1,000 (73%), 61/1,000 (6.1%), and 209/1,000 (20.9%), respectively, with risks ofmalignancy of 14.8% (108/730), 3.3% (2/61), and 3.3% (7/209), respectively. The risk ofmalignancy of nodules with minimal cystic changes was significantly lower than that of purelysolid nodules (P=0.013). The risk of malignancy of nodules with minimal cystic changes was also lower than that of purely solid nodules in the group of hypoechoic nodules (P=0.063) and in the group of nodules with suspicious US features (P=0.028), but was not significantly different from that of partially cystic nodules regardless of echogenicity or the presence of suspicious US features (P≥0.652).

CONCLUSION

Thyroid nodules with minimal cystic changes have a low risk of malignancy, similar to that of partially cystic nodules regardless of echogenicity or the presence of suspicious US features. The US lexicon could define solid nodules as nodules with purely solid internal content in order to enhance the accuracy of estimated risks of malignancy.

Ultrasonography-Based Thyroidal and Perithyroidal Anatomy and Its Clinical Significance

Ultrasonography (US)-guided procedures such as ethanol ablation, radiofrequency ablation, laser ablation, selective nerve block, and core needle biopsy have been widely applied in the diagnosis and management of thyroid and neck lesions. For a safe and effective US-guided procedure, knowledge of neck anatomy, particularly that of the nerves, vessels, and other critical structures, is essential. However, most previous reports evaluated neck anatomy based on cadavers, computed tomography, or magnetic resonance imaging rather than US. Therefore, the aim of this article was to elucidate US-based thyroidal and perithyroidal anatomy, as well as its clinical significance in the use of prevention techniques for complications during the US-guided procedures. Knowledge of these areas may be helpful for maximizing the efficacy and minimizing the complications of US-guided procedures for the thyroid and other neck lesions.

Effectiveness and limitations of core needle biopsy in the diagnosis of thyroid nodules: review of current literature

Fine needle aspiration (FNA) is currently accepted as an easy, safe, and reliable tool for the diagnosis of thyroid nodules. Nonetheless, a proportion of FNA samples are categorized into non-diagnostic or indeterminate cytology, which frustrates both the clinician and patient. To overcome this limitation of FNA, core needle biopsy (CNB) of the thyroid has been proposed as an additional diagnostic method for more accurate and decisive diagnosis for thyroid nodules of concern. In this review, we focus on the effectiveness and limitations of CNB, and what factors should be considered when CNB is utilized in the diagnosis of thyroid nodules.

Ultrasound-guided core-needle biopsy in thyroid nodules. A study of 676 consecutive cases with surgical correlation

OBJECTIVES

To analyze the diagnostic accuracy of ultrasound-guided core-needle biopsy (CNB) of thyroid nodules.

METHODS

Of 3517 CNBs performed using an 18G spring-loaded device in one institution, we retrospectively reviewed 676 nodules in 629 consecutive patients who underwent surgery. CNB and pathological examination were compared. CNB diagnosis was standardized in four categories: insufficient (I), benign (B), follicular lesion (FOL), and malignant (M). Main outcome measures were predictive positive values (PPV), false positives (FP), and false negatives (FN).

RESULTS

CNB showed a low rate of insufficient and FOL diagnoses (5.8 % and 4.5 %). On surgery, there were eight FNs in 374 benign CNBs and three FPs in 148 malignant CNBs. The 154 nodules classified as FOL in CNB included, at surgery, 122 neoplasms; 28 of them malignant. PPV for malignancy of a malignant CNB was 98 %, and for a CNB diagnosis of FOL 18.2 %. Sensitivity for malignancy if CNB of FOL and M are considered positive was 95.6. Only one major complication was observed.

CONCLUSIONS

CNB is reliable, safe, and accurate to evaluate thyroid nodules and can be an alternative technique to FNA. It has low rate of non-diagnostic and undetermined cases, with high sensitivity and PPV.

KEY POINTS

Thyroid core-needle biopsy (CNB) has high sensitivity and PPV. Pitfalls of CNB are rare. Pitfalls are due to cystic cancer, histological heterogeneity, and mistakes in analysis. CNB is a reliable, safe, and accurate method to approach thyroid nodules. CNB can be used primarily or after insufficient or indeterminate FNA.

The Role of Core Needle Biopsy and Its Impact on Surgical Management in Patients with Medullary Thyroid Cancer: Clinical Experience at 3 Medical Institutions

BACKGROUND AND PURPOSE

Medullary thyroid carcinoma is an uncommon malignancy that is challenging to diagnose. Our aim was to present our experience using core needle biopsy for the diagnosis of medullary thyroid carcinoma compared with fine-needle aspiration.

MATERIALS AND METHODS

Between January 2000 and March 2012, 202 thyroid nodules in 191 patients were diagnosed as medullary thyroid cancer by using sonography-guided fine-needle aspiration, core needle biopsy, or surgery. One hundred eighty-three thyroid nodules in 172 patients were included on the basis of the final diagnosis. We evaluated the sensitivity and positive predictive value of fine-needle aspiration and core needle biopsy for the diagnosis of medullary thyroid cancer. We compared the rate of a delayed diagnosis, a diagnostic surgery, and surgery with an incorrect diagnosis for fine-needle aspiration and core needle biopsy and investigated the factors related to the fine-needle aspiration misdiagnosis of medullary thyroid cancer.

RESULTS

Fine-needle aspiration showed 43.8% sensitivity and 85.1% positive predictive value for the diagnosis of medullary thyroid cancer; 25.7% (44/171) of patients had a delayed diagnosis, while 18.7% (32/171) underwent an operation for accurate diagnosis, and 20.5% (35/171) underwent an operation with an incorrect diagnosis. Core needle biopsy achieved 100% sensitivity and positive predictive value without a delay in diagnosis (0/22), the need for a diagnostic operation (0/22), or an operation for an incorrect diagnosis (0/22). A calcitonin level of <100 pg/mL was the only significant factor for predicting the fine-needle aspiration misdiagnosis of medullary thyroid cancer (P = .034).

CONCLUSIONS

Core needle biopsy showed a superior sensitivity and positive predictive value to fine-needle aspiration and could optimize the surgical management in patients with medullary thyroid cancer. Because the ability of fine-needle aspiration to diagnose medullary thyroid cancer significantly decreases in patients with serum calcitonin levels of <100 pg/mL, core needle biopsy could be indicated for these patients to optimize their surgical management.

Thyroid core needle biopsy: taking stock of the situation

Recently, the microhistologic evaluation by core needle biopsy (CNB) has been reported as high accurate to diagnose thyroid nodules with previous indeterminate or not adequate fine-needle aspiration cytology. In addition, sparse data have been reported regarding the use of CNB in other conditions. Aim of this review was to furnish the state of the art of this topic by summarizing published data about the diagnostic performance of CNB in thyroid lesions, and provide an easy to use reference for clinical practice. Sources encompass studies published through May 2014. Original articles were investigated and following specific aspects were discussed: 1. The "large" needle biopsy in 90's; 2. Complications by and patient's comfort with thyroid CNB; 3. Advantages provided by examination of a microhistologic sample of thyroid nodule; 4. Use of CNB in thyroid nodules with previous not adequate (Thy 1/Class 1/Category I) cytology; 5. Use of CNB in thyroid neoplasms (Thy 3/Class 3/Category III-IV) cytology; 6. Use of CNB in specific ultrasonographic presentations of thyroid nodules or in patients with peculiar clinical contexts; 7. First-line approach by CNB in thyroid nodules; 8. Immunohistochemistry and molecular tests on CNB samples; and 9. Future perspective.

Diagnosis of thyroid follicular neoplasm: fine-needle aspiration versus core-needle biopsy

BACKGROUND

Although fine-needle aspiration (FNA) is a safe and accurate diagnostic procedure for assessing thyroid nodules, it has limitations in diagnosing follicular neoplasms due to its relatively high false-positive rate. The purpose of the present study was to evaluate the diagnostic role of core-needle biopsy (CNB) for thyroid nodules with follicular neoplasm (FN) in comparison with FNA.

METHODS

A series of 107 patients (24 men, 83 women; mean age, 47.4 years) from 231 FNAs and 107 patients (29 men, 78 women; mean age, 46.3 years) from 186 CNBs with FN readings, all of whom underwent surgery, from October 2008 to December 2013 were retrospectively analyzed. The false-positive rate, unnecessary surgery rate, and malignancy rate for the FNA and CNB patients according to the final diagnosis following surgery were evaluated.

RESULTS

The CNB showed a significantly lower false-positive and unnecessary surgery rate than the FNA (4.7% versus 30.8%, 3.7% versus 26.2%, p < 0.001, respectively). In the FNA group, 33 patients (30.8%) had non-neoplasms, including nodular hyperplasia (n = 32) and chronic lymphocytic thyroiditis (n = 1). In the CNB group, 5 patients (4.7%) had non-neoplasms, all of which were nodular hyperplasia. Moreover, the CNB group showed a significantly higher malignancy rate than FNA (57.9% versus 28%, p < 0.001).

CONCLUSIONS

CNB showed a significantly lower false-positive rate and a higher malignancy rate than FNA in diagnosing FN. Therefore, CNB could minimize unnecessary surgery and provide diagnostic confidence when managing patients with FN to perform surgery.

Thyroid nodules with initially non-diagnostic, fine-needle aspiration results: comparison of core-needle biopsy and repeated fine-needle aspiration

OBJECTIVE

To evaluate the role of core-needle biopsy (CNB) by comparing the results of CNB and repeated fine-needle aspiration (FNA) for thyroid nodules with initially non-diagnostic FNA results.

METHODS

From October 2008 to December 2011, 360 nodules - 180 consecutive repeated FNAs and 180 consecutive CNBs -- from 360 patients (83 men, 277 women; mean age, 54.4 years) with initially non-diagnostic FNA results were analyzed retrospectively. The incidence of non-diagnostic results, inconclusive results, diagnostic surgery, and diagnostic performance of repeated FNA and CNB were assessed, and factors affecting second non-diagnostic results were evaluated.

RESULTS

CNB achieved a significantly lower non-diagnostic and inconclusive rate than repeated FNA (1.1 % versus 40.0 %, P < 0.001; 7.2 % versus 72.0 %, P < 0.001). All diagnostic performances with CNB were higher than repeated FNA. The diagnostic surgery rate was lower with CNB than with repeated FNA (3.6 % versus 16.7 %, P = 0.047). Multivariate logistic regression analysis showed that repeated FNA was the most important factor for second non-diagnostic results (OR = 56.06, P < 0.001), followed by nodules with rim calcification (OR = 7.46, P = 0.003).

CONCLUSIONS

CNB is more useful than repeated FNA for reducing the number of non-diagnostic and inconclusive results and for preventing unnecessary diagnostic surgery for thyroid nodules with initially non-diagnostic FNA results.

KEY POINTS

• Core-needle biopsy achieved a lower number of non-diagnostic and inconclusive results. • Core-needle biopsy achieved better diagnostic performance. • Use of core-needle biopsy could prevent unnecessary diagnostic surgery. • Repeated fine-needle aspiration was significantly associated with a second non-diagnosis.

The use of core needle biopsy as first-line in diagnosis of thyroid nodules reduces false negative and inconclusive data reported by fine-needle aspiration

BACKGROUND

The reported reliability of core needle biopsy (CNB) is high in assessing thyroid nodules after inconclusive fine-needle aspiration (FNA) attempts. However, first-line use of CNB for nodules considered at risk by ultrasonography (US) has yet to be studied. The aim of this study were: 1) to evaluate the potential merit of using CNB first-line instead of conventional FNA in thyroid nodules with suspicious ultrasonographic features; 2) to compare CNB and FNA as a first-line diagnostic procedure in thyroid lesions at higher risk of cancer.

METHODS

Seventy-seven patients with a suspicious-appearing, recently discovered solid thyroid nodule were initially enrolled as study participants. No patients had undergone prior thyroid fine-needle aspiration/biopsy. Based on study design, all patients were proposed to undergo CNB as first-line diagnostic aspiration, while those patients refusing to do so underwent conventional FNA.

RESULTS

Five patients refused the study, and a total of 31 and 41 thyroid nodules were subjected to CNB and FNA, respectively. At follow-up, the overall rate of malignancy was of 80% (CNB, 77%; FNA, 83%). However, the diagnostic accuracy of CNB (97%) was significantly (P < 0.05) higher than that of FNA (78%). In one benign lesion, CNB was inconclusive. Four (12%) of the 34 cancers of the FNA group were not initially diagnosed because of false negative (N = 1), indeterminate (N = 2) or not adequate (N = 1) samples.

CONCLUSIONS

CNB can reduce the false negative and inconclusive results of conventional FNA and should be considered a first-line method in assessing solid thyroid nodules at high risk of malignancy.

Core needle biopsy can minimise the non-diagnostic results and need for diagnostic surgery in patients with calcified thyroid nodules

PURPOSE

To evaluate the role of core needle biopsy (CNB) for calcified thyroid nodules.

METHODS

Between October 2008 and July 2011, 264 patients underwent ultrasound-guided CNB for 272 calcified thyroid nodules at our institution. We retrospectively evaluated the incidence of technical failure, non-diagnostic readings, and the diagnostic performance of CNB, and analysed the relationship between the types of calcification and the CNB results. Finally, the incidence of diagnostic surgery was calculated.

RESULTS

The incidence of technical failure was 1.1 % (3/275) and that of non-diagnostic results was 0.7 % (2/272). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CNB were 94.7 %, 89.5 %, 100 %, 100 %, and 90.2 %, respectively. There were no significant differences according to the calcification subtype for either the non-diagnostic results or the incidence of technical failure (P > 0.99 and P > 0.99). CNB could prevent diagnostic surgery for 92.9 % (13/14) of the patients who showed more than two non-diagnostic results in previous FNA.

CONCLUSIONS

CNB can minimise the non-diagnostic results as well as diagnostic surgery in patients with calcified thyroid nodules. Therefore, CNB may be used as a first-line diagnostic tool for calcified thyroid nodules rather than FNA.

KEY POINTS

CNB results show the low incidence of technical failure (1.1 %, 3/275). • CNB results show the low non-diagnostic rate (0.7 %, 2/272). There were no significant differences according to the calcification subtype. CNB can prevent unnecessary diagnostic surgery in 92.9 % (13/14).