Utility of a formatted pathologic reporting system in thyroid core needle biopsy: A validation study of 1998 consecutive cases

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.

Preoperative evaluation of thyroid nodules - Diagnosis and management strategies

Thyroid cancer is the most common endocrine malignancy, with increasing incidence over the past few decades. Fine needle aspiration (FNA) biopsy is the gold standard for preoperative diagnosis of thyroid malignancies. Nevertheless, this method renders indeterminate results in up to 30% of the cases. Therefore, these patients are often referred to unnecessary surgery to establish the diagnosis. To improve the accuracy of preoperative diagnosis, several other ways, such as ultrasonography, elastography, immunohistochemical analysis, genetic testing, and core needle biopsy, have been developed and can be used either in association with or as an alternative to FNA. This review aims to evaluate all these diagnostic tools to determine the most appropriate way of managing thyroid nodules and subsequently improve the selection of cases referred to surgery.

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.

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

OBJECTIVE

To evaluate the 2015 American Thyroid Association (ATA) guidelines and 2017 American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS) for their efficacy in predicting malignant thyroid nodules and safety in recommending fine needle aspiration (FNA).

METHODS

We reviewed data of 970 thyroid nodules from 908 patients with core needle biopsy pathology. We calculated the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for each guideline to predict malignancies. We compared the areas under the curve and FNA recommendations between the 2 guidelines.

RESULTS

According to the core needle biopsy pathology, 59.9% (581/970) of the thyroid nodules were malignant. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value was 68%, 91%, 33%, 67%, and 70%, respectively, for the ATA guidelines and 70%, 84%, 49%, 71%, and 68%, respectively, for the ACR TI-RADS. Areas under the curve (ATA: 0.71 vs ACR TI-RADS: 0.74; P = .054) were similar when predicting malignancies. For the 545 nodules with maximum diameter ≥1.0 cm, the ACR TI-RADS recommended FNA less often than the ATA guidelines (83.3% [454/545] vs 87.7% [478/545]; P = .01). For the 321 malignant nodules with maximum diameter ≥1.0 cm, the proportions of FNA recommendations were not significantly different (ACR TI-RADS: 90.7% [291/321] vs ATA: 92.5% [297/321]; P = .06).

CONCLUSION

The 2015 ATA guidelines and 2017 ACR TI-RADS showed a similar ability in predicting malignancies. Reducing FNA recommendations by the ACR TI-RADS would not lead to a significant decrease in the FNA recommendations given for malignancies with maximum diameter ≥1.0 cm.

Preoperative diagnostic categories of fine needle aspiration cytology for histologically proven thyroid follicular adenoma and carcinoma, and Hurthle cell adenoma and carcinoma: Analysis of cause of under- or misdiagnoses

Cytologic diagnosis of thyroid follicular adenoma and carcinoma, and Hurthle cell adenoma and carcinoma (FACHAC) is challenging due to cytomorphologic features that overlap with other follicular-patterned lesions. This study was designed to analyze diagnostic categories (DCs) of preoperative fine needle aspiration cytology (FNAC) of histologically proven thyroid FACHACs to evaluate under- or misdiagnoses in FNAC and elucidate potential causes for such phenomena. A total of 104 thyroid nodules with preoperative FNAC which were diagnosed as FACHAC in resection specimens were included in this study. Of these, 66 cases had also undergone thyroid core needle biopsy (CNB); FNAC and CNB DCs were compared in these cases. Various cytologic and histologic parameters were compared between the nodules with different FNAC DCs. After a review of FNAC slides, DCs were re-assigned in 20 (19.2%) out of the 104 cases. Of the 66 cases with CNB diagnoses which were mostly classified as lower DCs in FNAC, 31 (47.0%) were diagnosed as suspicious for a follicular neoplasm in CNB. Cases which were underdiagnosed in FNACs were associated with lower cellularity, predominant macrofollicular pattern, absence of microfollicles arranged in trabecular pattern, and absence of transgressing vessels in cytology smears. High cellularity, microfollicles arranged in trabecular pattern, nucleolar prominence, and large cell dysplasia were more frequently found in malignancy than in benign neoplasm. In conclusion, thyroid FACHACs seem to be under- and misdiagnosed in preoperative FNAC. Innate characteristics of the nodules were associated with under-diagnosis as well as the quality of the FNAC specimens. Certain cytomorphologic features can be helpful in differentiating malignancy among FACHACs.

Diagnostic Efficacy and Safety of Core Needle Biopsy as a First-Line Diagnostic Method for Thyroid Nodules: A Prospective Cohort Study

Background: The diagnostic role of ultrasonography (US)-guided core needle biopsy (CNB) as a first-line diagnostic method for thyroid nodules remains controversial. This study was performed to determine the diagnostic efficacy and safety of CNB as a first-line diagnostic method for thyroid nodules. Methods: From February 2016 to January 2018, CNB was prospectively performed by an experienced radiologist in all consecutive patients with thyroid nodules indicated for fine-needle aspiration (FNA). Three patients refused this protocol. Finally, 212 consecutive patients with 248 thyroid nodules were enrolled in this prospective study. Combined CNB/FNA was selectively performed in 43 patients. The diagnostic efficacy of CNB was evaluated by the rate of inconclusive results (nondiagnostic or indeterminate results), and its feasibility was estimated by calculating the successful biopsy rate and by measuring the procedure time from the time of the initial skin puncture to the last withdrawal of the biopsy needle from the skin. The safety of the procedure was evaluated by the major and minor complication rates. A US evaluation was performed before and after manual self-compression to assess for hemorrhage at the biopsy site, and delayed complications were assessed 5-7 days after the biopsy. Any hemorrhage that did not require hospitalization was classified as a minor complication. Results: CNB was performed once (n = 125, 50.4%), twice (n = 122, 49.2%), or three times (n = 1, 0.4%) per nodule. The diagnostic results of CNB were as follows: nondiagnostic (0.8%), benign (63.3%), indeterminate (10.1%), follicular neoplasm (3.2%), suspected malignancy (2.4%), and malignancy (20.1%); the rate of inconclusive results was 10.9%. The successful biopsy rate of CNB was 100%, and the median procedure time was 102 seconds (interquartile range 51-181 seconds). There were no major or delayed complications. There were 6 cases (2.8%) of minor complications, which included 2 cases (0.9%) with symptomatic hematomas and 4 cases (1.9%) with asymptomatic small hematomas. Conclusion: The findings confirm that CNB is effective in reducing the rate of inconclusive results and it is safe. CNB may be used as an alternative first-line diagnostic method for thyroid nodules by an experienced operator.

Usage and Diagnostic Yield of Fine-Needle Aspiration Cytology and Core Needle Biopsy in Thyroid Nodules: A Systematic Review and Meta-Analysis of Literature Published by Korean Authors

Objectives

The usefulness of core needle biopsy (CNB) for the diagnosis of thyroid nodules remains controversial, and preferences vary across hospitals. The purpose of this study was to assess the actual use of CNB in Korea and to analyze the advantages and disadvantages of CNB through a systematic review and meta-analysis of papers published by Korean authors.

Methods

A meta-analysis of full-text publications published in English presenting data from Korea retrieved from the Embase literature database was performed.

Results

CNB led to a significantly lower proportion of non-diagnostic results than fine-needle aspiration (FNA). However, the frequency of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) did not decrease as a result of performing CNB in nodules with initial AUS/FLUS results, while it increased in consecutive cases. A subcategory analysis of AUS/FLUS showed that the increased frequency of AUS/FLUS findings on CNB was due to more frequent diagnoses of architectural atypia and follicular neoplasm, which resulted in a higher frequency of inconclusive findings in consecutive cases compared to FNA. Hospitals favoring CNB had a higher proportion of AUS/FLUS diagnoses. Although the complication rate did not differ significantly between CNB and FNA, serious complications of CNB did occur.

Conclusion

A reduced frequency of non-diagnostic results may be a definite advantage of CNB over FNA. However, the increased frequency of diagnoses of architectural atypia and follicular neoplasm should be considered when selecting CNB as a diagnostic tool.

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.

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.