Current status of core needle biopsy of the thyroid

[Ultrasound-guided core-needle biopsy for diagnosis of thyroid cancer]

OBJECTIVE

To improve preoperative examination of patients with follicular thyroid tumors using ultrasound-guided core-needle biopsy.

MATERIAL AND METHODS

All patients with Bethesda IV (follicular tumor) underwent ultrasound-guided core-needle biopsy of thyroid neoplasm according to original technique (patent No. 2826474 RU). Preoperative histological specimen after core needle biopsy was compared with urgent and elective histological examination. Statistical analysis was carried out using Kolmogorov-Smirnov and Kruskal-Wallis tests. Differences were significant at p<0.05.

RESULTS

Thyroid tumors were available for core needle biopsy in all 45 cases (100%). Repeated cytological analysis confirmed TI-RADS category 3 in 22 (48.89%), TI-RADS 4 in 15 (33.33%) and TI-RADS 5 in 8 (17.77%) patients. Histological examination revealed colloidal goiter in 13 patients (28.89%), adenomatous hyperplasia in 15 (33.33%), follicular adenoma in 9 (20%), and follicular neoplasia with undetermined malignant potential in 2 (4.44%) cases. The quality of histological material made it possible to assess morphological type of tumor, capsule vascularization and cell atypia, invasion into capsule or vessels. In case of colloidal goiter, we were able to assess dimensions of follicles, presence of colloid, cell polymorphism, mitosis and cytoplasm content.

CONCLUSION

Ultrasound-guided core-needle biopsy can reduce the number of unjustified surgical interventions in patients with follicular tumors and optimize management of patients with nodular thyroid lesions.

Parenchymal microcalcifications in the thyroid gland: Clinical significance and management strategy

This study is firstly, to investigate the presence of microcalcification among the patients who underwent thyroid ultrasound and biopsy and to evaluate the incidence of intrathyroid lymphatic spread and cervical lymph node metastasis of thyroid cancer with thyroid microcalcifications. Also, we compared the diagnostic performance between fine needle aspiration (FNA) and core needle biopsy (CNB) for assessing parenchymal microcalcifications in the thyroid gland. We retrospectively assessed total 66 patients with thyroid microcalcifications on ultrasound. The histopathologic characteristics of the surgical specimens considered as the gold standard for diagnosing malignancy. Patients with surgically proven malignancy were evaluated for multifocality, intrathyroid lymphatic spread in the opposite lobe, or cervical lymph node metastasis. Among the 66 confirmed patients, 53 patients had malignant lesions (80.3%) and 13 patients had benign lesions (19.7%). The pathologic results of the 44 patients who underwent total thyroidectomy. Among them, 33 patients (75%) showed multifocality, 30 patients (68.2%) showed intrathyroid lymphatic tumor spread. CNB was performed on 41 patients, and FNA was performed on 54 patients. Both CNB and FNA were performed on 29 patients. There were no statistical differences in terms of diagnostic performance between CNB and FNA. Thyroid microcalcifications demonstrate a high prevalence of malignancy. Both CNB and FNA demonstrate similar diagnostic accuracies.

Core Needle Biopsy in Suspicious Malignant Thyroid Nodules with Repeated Nondiagnostic Fine Needle Aspiration

Key message

The clinician could have CNB in mind for thyroid nodules when FNA results were nondiagnostic. Our study would suggest CNB a safe and efficient method for investigating thyroid nodules.

Abstract

Usefulness of preoperative tissue sampling and pathology diagnoses in thyroid tumors were accepted worldwide. We investigate the role of Core needle biopsy (CNB) in the thyroid nodules lesions when FNA results are nondiagnostic. We conducted a cross-sectional study to evaluate twenty-six CNBs results of suspicious malignant thyroid nodules with nondiagnostic repeated fine needle aspiration. 25 from 26 CNBs were diagnostic. Twenty-one needle biopsy reports were papillary thyroid carcinoma, three CNB samples diagnosed medullary thyroid carcinoma and one of them had anaplastic results. All diagnostic needle biopsies results were compatible with final pathology. Our study would suggest CNB a safe and efficient method for investigating thyroid nodules while repeated FNA yielded nondiagnostic results.

Diagnostic Utility of p62 Expression in Intranuclear Inclusions in Thyroid Core Needle Biopsy Specimens

BACKGROUND/AIM

Core needle biopsy (CNB) has been widely used as an alternative method to ultrasound-guided fine-needle aspiration cytology for histological diagnosis of thyroid specimens. However, nuclear artifactual vacuoles (NuVas) produced during tissue processing can be very difficult and sometimes impossible to distinguish from intranuclear inclusions (NuIns). P62 is an autophagy receptor that recognizes, targets, and eliminates toxic cellular materials during autophagy. Herein, we examined the utility of p62 immunohistochemical staining to detect NuIns in thyroid core needle biopsy specimens.

PATIENTS AND METHODS

Thirty-five thyroid CNB slides from 32 patients and corresponding resection specimens stained with hematoxylin and eosin were reviewed by two pathologists. The immunohistochemical staining pattern of p62 was used to differentiate NuIns from NuVas. The diameter of each nucleus (A) and NuIn (B) was measured, and the number of p62-expressing NuIn-positive (p62In) cells was counted using 1/2 (B/A) and 1/3 (B/A) criteria. The criterion of 1/3 includes NuIns larger than 1/3 and smaller than 1/2 of the nuclear diameter. The criteria of 1/2 includes NuIns larger than 1/2 of the nuclear diameter.

RESULTS

By applying the 1/2 criterion, there were no p62In cells in follicular adenoma (FA) samples. However, in papillary thyroid carcinoma (PTC) samples, 22 of 25 specimens exhibited p62In cells. The sensitivity and specificity to distinguish FA from PTC using the 1/2 criterion were 0.88 and 1.00, respectively. By applying the 1/3 criterion, there was one p62In cell hit in FA samples. However, 23 of 25 PTC specimens showed p62In cells. The sensitivity and specificity to distinguish FA from PTC using the 1/3 criterion were 1.00 and 0.90, respectively.

CONCLUSION

P62 is a useful marker for distinguishing FA and PTC based on CNB specimens. We suggest the 1/2 criteria for identifying p62In cells.

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.

Whirling technique for thyroid fine needle aspiration biopsy: a preliminary study of effectiveness and safety

PURPOSE

This study was aimed to compare thyroid fine needle aspiration biopsy (FNAB) techniques (conventional vs. whirling) in terms of cell harvesting ability ex vivo, the unsatisfactory rate and complication rate in vivo, and multi-operator performance in a phantom study.

METHODS

In the ex vivo study, cell counts per background at ×100 magnification were compared between both techniques. In the in vivo study, 70 patients who underwent whirling FNAB from July 2019 to November 2019 were retrospectively compared to 140 matched patients who underwent conventional FNAB from January 2018 to November 2019 regarding the unsatisfactory rate and complication rate. As a subgroup analysis, thyroid nodules in difficult biopsy situations (nodule diameter <10 mm and location within 3 mm from major anatomical structures) were compared. In the phantom study, eight operators with varying experience recorded levels of dexterity and needle tip visualization, and their preferences for both techniques.

RESULTS

In the ex vivo study, cell counts were comparable between both techniques in all thyroid nodule mimickers (80.0% vs. 87.5%, P=0.178). In the in vivo study, the unsatisfactory rate was comparable between the two groups (15.7% vs. 12.9%, P=0.859). In the subgroup analysis, the whirling technique demonstrated a lower unsatisfactory rate (5.9% vs. 24.2%, P=0.045) and a lower complication rate (0% vs. 6.1%, P=0.553). In the phantom study, the whirling technique demonstrated better dexterity and needle tip visualization and was preferred by all operators.

CONCLUSION

This newly proposed whirling technique for thyroid FNAB may be effective and safe, especially in difficult biopsy situations.

Distribution and malignancy risk of six categories of the pathology reporting system for thyroid core-needle biopsy in 1,216 consecutive thyroid nodules

PURPOSE

The purpose of this study was to present the distribution of lesions among the six categories of the pathology reporting system for thyroid core-needle biopsy (CNB), along with the range of malignancy risk of each category based on different diagnostic criteria for benignity in a clinical cohort.

METHODS

For 1,216 consecutive nodules (≥1 cm) of 1,125 patients who underwent CNB at two hospitals, the diagnostic results based on the six categories of thyroid CNB were analyzed. Patients were divided into three groups according to prior fine-needle aspiration (FNA) status: second-line CNB for nodules where prior FNA yielded nondiagnostic or unsatisfactory results (n=57), second-line CNB for nodules with prior FNA results of atypia/follicular lesion of undetermined significance (AUS/FLUS) (n=303), and first-line CNB (n=856).

RESULTS

The proportion of nodules in each CNB category and the range of the malignancy rate for each category was as follows, in order from category I to VI: 1.8%, 23.1%-75.0%; 57.9%, 0.7%-16.7%; 16.0%, 13.2%-46.7%; 8.8%, 53.8%-56.8%; 2.0%, 100%; and 13.5%, 100%. First-line CNB was associated with a higher rate of conclusive diagnoses (category II, IV, or VI) (725 of 856, 84.7%) than second-line CNB with prior nondiagnostic or AUS/FLUS FNA results (241 of 360, 66.9%; P<0.001).

CONCLUSION

The overall distribution of nodules across the six categories of thyroid CNB and the ranges of malignancy risk for those categories were presented in a clinical cohort. First-line CNB tended to produce a higher rate of conclusive results than second-line CNB with prior inconclusive FNA results.

2019 Practice guidelines for thyroid core needle biopsy: a report of the Clinical Practice Guidelines Development Committee of the Korean Thyroid Association

Ultrasound-guided core needle biopsy (CNB) has been increasingly used for the pre-operative diagnosis of thyroid nodules. Since the Korean Society of the Thyroid Radiology published the ‘Consensus Statement and Recommendations for Thyroid CNB’ in 2017 and the Korean Endocrine Pathology Thyroid CNB Study Group published ‘Pathology Reporting of Thyroid Core Needle Biopsy’ in 2015, advances have occurred rapidly not only in the management guidelines for thyroid nodules but also in the diagnostic terminology and classification schemes. The Clinical Practice Guidelines Development Committee of the Korean Thyroid Association (KTA) reviewed publications on thyroid CNB from 1995 to September 2019 and updated the recommendations and statements for the diagnosis and management of thyroid nodules using CNB. Recommendations for the resolution of clinical controversies regarding the use of CNB were based on expert opinion. These practical guidelines include recommendations and statements regarding indications for CNB, patient preparation, CNB technique, biopsy-related complications, biopsy specimen preparation and processing, and pathology interpretation and reporting of thyroid CNB.

Revisiting Rupture of Benign Thyroid Nodules after Radiofrequency Ablation: Various Types and Imaging Features

BACKGROUND

To evaluate the imaging features, clinical manifestations, and prognosis of patients with thyroid nodule rupture after radiofrequency ablation (RFA).

METHODS

The records of 12 patients who experienced thyroid nodule rupture after RFA at four Korean thyroid centers between March 2010 and July 2017 were retrospectively reviewed. Clinical data evaluated included baseline patient characteristics, treatment methods, initial presenting symptoms, imaging features, treatment, and prognosis.

RESULTS

The most common symptoms of post-RFA nodule rupture were sudden neck bulging and pain. Based on imaging features, the localization of nodule rupture was classified into three types: anterior, posterolateral, and medial types. The anterior type is the most often, followed by posterolateral and medial type. Eight patients recovered completely after conservative treatment. Four patients who did not improve with conservative management required invasive procedures, including incision and drainage or aspiration.

CONCLUSION

Thyroid nodule rupture after RFA can be classified into three types based on its localization: anterior, posterolateral, and medial types. Because majority of thyroid nodule ruptures after RFA can be managed conservatively, familiarity with these imaging features is essential in avoiding unnecessary imaging workup or invasive procedures.

Preoperative Diagnostic Categories of Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features in Thyroid Core Needle Biopsy and Its Impact on Risk of Malignancy

This study was designed to evaluate the preoperative diagnostic categories of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) using thyroid core needle biopsy (CNB) and to analyze its impact on the risk of malignancy (ROM). A total of 2687 consecutive thyroid CNBs were reviewed retrospectively and classified into six diagnostic categories using a standardized reporting system similar to the Bethesda System for Reporting Thyroid Cytopathology. Diagnostic categories of CNBs were compared with the final surgical diagnoses, and the ROM in each category was calculated both before and after excluding NIFTP from malignancy. Of 946 surgically resected cases, 683 were diagnosed as papillary thyroid carcinoma (PTC), and 32 (4.7% of PTC) were reclassified as NIFTP. The CNB diagnostic categories of NIFTP were as follows: follicular neoplasm in 20 (62.5%; 14, with nuclear atypia), indeterminate lesion in 11 (34.4%), and suspicious for malignancy in one (3.1%). When combined, NIFTP and encapsulated follicular variant of PTC (EFVPTC) were more often categorized as follicular neoplasm compared with other PTC variants including infiltrative FVPTC. Exclusion of NIFTP from malignant diagnosis led to a significant decrease in the ROM in follicular neoplasm with nuclear atypia category. Thus, thyroid CNB enables to differentiate NIFTP/EFVPTC from other PTCs, providing a useful guide for optimal treatment in patients with these tumors.

Core needle biopsy in the management of thyroid nodules with an indeterminate fine-needle aspiration report

Ultrasonography (US)-guided fine-needle aspiration biopsy (FNAB) cytology is widely used but is limited due to its pathologically indeterminate results in diagnosing thyroid nodules. Recently, US-guided core-needle biopsy (CNB) was introduced as an effective and safe technique for diagnosing indeterminate thyroid nodules. Using CNB, information about architectural histologic structure such as nodule capsule or more immunochemical staining can be obtained which lead to a more accurate diagnosis. Up to 98% of indeterminate thyroid lesions can be classified as malignant or benign when CNB is used for follow-up analysis. Other evidences revealed the effectiveness of CNB in reducing inconclusive results and improving the diagnostic performance of thyroid nodules initially diagnosed as AUS/FLUS by FNAB. In this review, we investigate how to deal with indeterminate thyroid nodules diagnosed by FNAB and determine how CNB has a role in diagnosing these indeterminate thyroid nodules.

Risk of Malignancy According to the Sub-classification of Atypia of Undetermined Significance and Suspicious Follicular Neoplasm Categories in Thyroid Core Needle Biopsies

The objective of this study was to evaluate the risk of malignancy (ROM) associated with atypia of undetermined significance (AUS) and suspicious follicular neoplasm (SFN) core needle biopsy (CNB) categories after further sub-classification. Data from 2267 thyroid nodules evaluated by ultrasound-guided CNB, from January to December 2015, were retrospectively reviewed. AUS nodules (n = 556) were sub-classified as follows: (1) architectural atypia (AUS-A; n = 369, 66.4%), (2) cytologic atypia (AUS-C; n = 35, 6.3%), (3) cytologic/architectural atypia (AUS-C/A; n = 85, 15.3%), or (4) oncocytic atypia (AUS-O; n = 67, 12.1%). SFN nodules (n = 172) were sub-classified as follows: (1) architectural atypia only (SFN-A; n = 110, 64%), (2) cytologic/architectural atypia (SFN-C/A; n = 24, 14%), or (3) oncocytic atypia (SFN-O; n = 38, 22%). Diagnostic surgery was performed in 162 (30.2%) AUS cases and 105 (61%) SFN cases. The ROM of each sub-category was evaluated. The overall ROM was 15.3-52.5% in AUS nodules and 35.5-58.1% in SFN nodules. The ROM was higher in the AUS-C (22.9-88.9%) and AUS-C/A (32.9-90.3%) groups than AUS-A (11.9-40%) and AUS-O (7.5-41.7%). In the SFN category, ROM in the SFN-C/A group was also higher than SFN-A or SFN-O (37.5-75%, 40-57.9%, and 21.1-47.1%, respectively). Our study shows that the ROM was higher in AUS or SFN sub-categories with cytologic atypia than those without cytologic atypia. Because of the heterogeneous nature of AUS and SFN categories, sub-classification may be a more effective approach for risk stratification, allowing optimal management of patients with thyroid nodules.

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.

Malignancy risk of initially benign thyroid nodules: validation with various Thyroid Imaging Reporting and Data System guidelines

OBJECTIVE

Some authors have found little or no diagnostic benefit from repeated biopsy of benign thyroid nodules. However, to our knowledge, integration of Thyroid Imaging Reporting and Data System (TIRADS) guidelines with one biopsy for sufficient benign thyroid nodule diagnosis has not been previously described. We investigated malignancy rate and probability by using various malignancy stratification systems in initially biopsy-proven benign nodules and sought to determine their clinical relevance in management of benign thyroid nodules.

METHODS

This retrospective study collected 6762 thyroid nodules from 6493 consecutive patients who underwent biopsy between January 2013 and December 2013. The initial biopsy with ≥1 year of follow-up was used as the gold standard for benign diagnosis. For our study purpose, we analyzed 2747 (57.0%, 2747 of 4822, 532 women, 2111 men; 229 malignant and 2518 benign) thyroid nodules diagnosed by initial biopsy with 28.2 ± 9.1 (range, 12-41) months of follow-up. We calculated the malignancy probability of thyroid nodules by using various malignancy risk stratification systems.

RESULTS

The overall calculated thyroid malignancy rate was 8.3% (229 of 2747). Initially biopsy-proven benign nodules exhibited a ≤3.0% malignancy probability when assessed as "low suspicion" by Korean-TIRADS (K-TIRADS), "low suspicion" by the ATA guideline, and "very probably benign" by the French TIRADS guideline and gave a score of ≤3 by the web-based TIRADS.

CONCLUSION

When initially biopsy-proven benign nodules exhibit a "low suspicion" US pattern and low malignancy probability, as stratified by various TIRADS guidelines, imaging surveillance instead of second biopsy is warranted.

KEY POINTS

• One biopsy is sufficient for initially biopsy-proven benign nodules. • Repetitive biopsy is necessary for imaging-pathology mismatched nodules. • Scoring risk stratification permits personalized management.

Ultrasonographic Echogenicity and Histopathologic Correlation of Thyroid Nodules in Core Needle Biopsy Specimens

Objective

To determine the histopathologic features associated with ultrasonographic echogenicity of thyroid nodules.

Materials and Methods

This study included 95 nodules of 95 patients (76 women, 19 men; mean age 47.5 ± 12.9 years) with homogeneous echogenicity in which core needle biopsy was performed during a one year period. The nodule echogenicity was categorized into 4 grades (hyperechogenicity, isoechogenicity, mild hypoechogenicity, and marked hypoechogenicity). The biopsy specimens were evaluated by a pathologist regarding the histopathologic features of fibrosis, lymphoid infiltration, microfollicular pattern, uniform follicular pattern, and hypercellularity in nodules. We evaluated the association of each histopathologic feature among 3 categories of nodule echogenicity by multinomial regression analysis.

Results

The nodule echogenicity was isoechoic in 28 (29.5%), mildly hypoechoic in 37 (38.9%), and markedly hypoechoic in 30 (31.6%), and there was no hyperechoic nodule. There was a trend of increasing frequency of fibrosis (> 30%) as nodule echogenicity decreased (isoechogenicity, 10.7%; mild hypoechogenicity, 32.4%; and marked hypoechogenicity, 80%; p < 0.001). The microfollicular pattern, uniform follicular pattern, and hypercellularity were frequently found in mildly hypoechoic nodules than in isoechoic nodules (p ≤ 0.018). The fibrosis (> 30%) and hypercellularity were independently associated with mild or marked hypoechogenicity as compared to isoechogenicity (fibrosis; p ≤ 0.004 and hypercellularity; p ≤ 0.036), and only fibrosis (> 30%) was independently associated with marked hypoechogenicity as compared to mild hypoechogenicity (p = 0.004).

Conclusion

The fibrosis (> 30%) and high cellularity are independently associated with mild or marked hypoechogenicity of nodules. The knowledge of the relationship of echogenicity and histopathology of thyroid nodules could improve management of patients with thyroid nodules.

Primary Imaging Test and Appropriate Biopsy Methods for Thyroid Nodules: Guidelines by Korean Society of Radiology and National Evidence-Based Healthcare Collaborating Agency

The Korean Society of Radiology and the National Evidence-based Healthcare Collaborating Agency developed guidelines for primary imaging tests and appropriate biopsy methods for thyroid nodules. These guidelines were developed using an adaptation process by collaboration between the development committee and the working group. The development committee, composed of research methodology experts, established the overall plan and provided support about methodological strategies. The working group, composed of radiologist experts in thyroid imaging, wrote the proposals. The guidelines recommend neck ultrasound (US) as a first-line imaging modality for the diagnosis of thyroid nodules in patients with suspected nodules, and US-guided fine-needle aspiration as a primary method for histologic examination of thyroid nodules.

Evaluation of Modified Core-Needle Biopsy in the Diagnosis of Thyroid Nodules

Objective

Core needle biopsy (CNB) of the thyroid is an additional diagnostic method for non-diagnostic or indeterminate cytology samples. We sought to evaluate a new modified core biopsy technique and compare the concordance of its diagnosis with the final diagnosis of the surgically resected specimen.

Materials and Methods

A retrospective analysis was conducted on 842 patients who had a thyroid CNB with or without a previous fine-needle aspiration from August 2002 to March 2015; 38% of patients ultimately underwent thyroidectomy. We divided the patients into two groups for comparison: conventional group (n = 329) and new modified technique group (n = 513) that enabled sampling of not only the lesion but also the margin and surrounding parenchyma. The diagnostic conclusiveness of CNB and concordant rate with thyroidectomy was compared between the two groups.

Results

The overall diagnostic conclusiveness did not exhibit a significant increase (77% in the conventional technique group and 75% in the modified technique group, p = 0.408). In terms of the diagnostic concordance rate between CNB and thyroidectomy, no overall significant increase was observed (83% in the conventional technique group and 88% in the modified technique group, p = 0.194). However, only in follicular-patterned lesions (nodular hyperplasia, follicular neoplasm, and follicular variant of papillary thyroid carcinoma), a significant increase in the diagnostic concordance rate was observed (83% in the conventional group and 94% in the modified technique group, p = 0.033).

Conclusion

Modified CNB technique can be beneficial for the accurate diagnosis of follicular-patterned thyroid lesions.

The role of core needle biopsy in the diagnosis of initially detected thyroid nodules: a systematic review and meta-analysis

OBJECTIVES

To systematically review the published literature and evaluate the efficacy and safety of core needle biopsy (CNB) for initially detected thyroid nodules.

METHODS

The Ovid-MEDLINE and Embase databases were searched for studies evaluating CNB for the diagnosis of initially detected thyroid nodules. A meta-analysis was performed to evaluate non-diagnostic results, inconclusive results and diagnostic accuracy for a diagnosis of malignancy with CNB. To overcome heterogeneity, multiple subgroup analyses were performed. The complication rate was also evaluated.

RESULTS

Thirteen eligible studies, which included a total sample size of 9,166 patients with 13,585 nodules, were included. The pooled proportions were 3.5% (95% CI 2.4-5.1) for non-diagnostic results and 13.8% (95% CI 9.1-20.3) for inconclusive results. Considerable heterogeneity was observed among the studies in terms of the pooled proportions for CNB (I²=92.9%, 97%). With regard to the diagnostic performance for malignancy, the sensitivity was 80% (95% CI 75-85) and the specificity was 100% (95% CI 93-100). Only two major complications of CNB were observed.

CONCLUSIONS

CNB demonstrates a low non-diagnostic result rate and high diagnostic accuracy for initially detected thyroid nodules and a low major complication rate. These findings indicate that CNB may be a feasible diagnostic tool for patients with initially detected thyroid nodules.

KEY POINTS

CNB demonstrates high diagnostic accuracy for initially detected thyroid nodules. CNB demonstrates a low major complication rate. CNB may be a feasible diagnostic tool for patients with initially detected thyroid nodules.

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.

Histogram analysis of greyscale sonograms to differentiate between the subtypes of follicular variant of papillary thyroid cancer

AIM

To evaluate the diagnostic value of histogram analysis using ultrasound (US) to differentiate between the subtypes of follicular variant of papillary thyroid carcinoma (FVPTC).

MATERIALS AND METHODS

The present study included 151 patients with surgically confirmed FVPTC diagnosed between January 2014 and May 2016. Their preoperative US features were reviewed retrospectively. Histogram parameters (mean, maximum, minimum, range, root mean square, skewness, kurtosis, energy, entropy, and correlation) were obtained for each nodule.

RESULTS

The 152 nodules in 151 patients comprised 48 non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTPs; 31.6%), 60 invasive encapsulated FVPTCs (EFVPTCs; 39.5%), and 44 infiltrative FVPTCs (28.9%). The US features differed significantly between the subtypes of FVPTC. Discrimination was achieved between NIFTPs and infiltrative FVPTC, and between invasive EFVPTC and infiltrative FVPTC using histogram parameters; however, the parameters were not significantly different between NIFTP and invasive EFVPTC.

CONCLUSION

It is feasible to use greyscale histogram analysis to differentiate between NIFTP and infiltrative FVPTC, but not between NIFTP and invasive EFVPTC. Histograms can be used as a supplementary tool to differentiate the subtypes of FVPTC.

Reliability of core needle biopsy as a second-line procedure in thyroid nodules with an indeterminate fine-needle aspiration report: a systematic review and meta-analysis

PURPOSE

This study was undertaken to summarize the published data and to provide more robust estimates regarding the issue of core needle biopsy (CNB) for discriminating thyroid nodules with indeterminate fine-needle aspiration (FNA) results.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The sources comprised studies published through November 2017. Original articles that investigated CNB in indeterminate thyroid lesions were searched. A random-effects model was used for statistical pooling of the data. The I² index was used to quantify the heterogeneity among the studies. The Egger test was carried out to evaluate the possible presence of significant publication bias. Quality assessment of the studies was performed according to QUADAS-2.

RESULTS

A total of 205 articles were retrieved, seven were initially selected, and the data of five papers were ultimately pooled in a meta-analysis. The overall cancer rate was 34%. The rate of cancers correctly diagnosed by CNB was 83% (95% confidence interval [CI], 76 to 89), with neither heterogeneity (I²=25%) nor publication bias (Egger test, P=0.918). The rate of benign nodules correctly assessed by CNB was 84% (95% CI, 65 to 97), with significant heterogeneity (I²=93.4%) and publication bias (Egger test, P=0.016).

CONCLUSION

Evidence was found that CNB can correctly diagnose the majority of nodules previously read as indeterminate on FNA.

Statement and Recommendations on Interventional Ultrasound as a Thyroid Diagnostic and Treatment Procedure

The recently published guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on interventional ultrasound (INVUS)-guided procedures summarize the intended interdisciplinary and multiprofessional approach. Herewith, we report on recommendations for interventional procedures for diagnosis and treatment of the thyroid gland.

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.

The efficacy and safety of high-intensity focused ultrasound ablation of benign thyroid nodules

High-intensity focused ultrasound (HIFU) is a promising form of thermal ablation of benign thyroid nodules, but evidence supporting its use is scarce. The present review evaluated the efficacy and safety of single-session HIFU treatment of benign thyroid nodules. As reported in the literature, the extent of nodule shrinkage following treatment ranged from 48.8% to 68.8%. Like other forms of ablation, the shrinkage rate was greatest in the first 3-6 months, and the best responders were patients with small (≤10 mL) nodules. Complications were uncommon, but temporary vocal cord palsy occurred in 3%-4% of patients, and was related to the distance between the HIFU beam and the recurrent laryngeal nerve. Despite being safe and efficacious, a larger-scale prospective trial is required.

Ethanol and thermal ablation for malignant thyroid tumours

Papillary thyroid carcinoma (PTC) is the most common subtype of thyroid malignancy and has a good prognosis and low mortality rate. Surgery is the standard treatment for patients with primary and recurrent thyroid cancer. Although patients with PTC usually exhibit excellent treatment outcome, the incidence of recurrence in the neck ranges from 20% to 59%. When a patient with thyroid cancer is contraindicated for surgery, ultrasound (US)-guided ablation techniques, including ethanol ablation (EA) and thermal ablations, are suggested alternatives. In this review, we evaluated the indications, devices, techniques, clinical outcomes, and complications associated with US-guided EA and thermal ablations based on available scientific evidence and expert opinions regarding the use of ablation for primary and recurrent thyroid cancers.