Ultrasound-Guided Core Needle Biopsy Techniques for Intermediate or Low Suspicion Thyroid Nodules: Which Method is Effective for Diagnosis?

Educational exchange in thyroid core needle biopsy diagnosis: enhancing pathological interpretation through guideline integration and peer learning

BACKGROUND

While fine needle aspiration cytology (FNAC) plays an essential role in the screening of thyroid nodules, core needle biopsy (CNB) acts as an alternative method to address FNAC limitations. However, diagnosing thyroid CNB samples can be challenging due to variations in background and levels of experience. Effective training is indispensable to mitigate this challenge. We aim to evaluate the impact of an educational program on improving the accuracy of CNB diagnostics.

METHODS

The 2-week observational program included a host mentor pathologist with extensive experience and a visiting pathologist. The CNB classification by The Practice Guidelines Committee of the Korean Thyroid Association was used for the report. Two rounds of reviewing the case were carried out, and the level of agreement between the reviewers was analyzed.

RESULTS

The first-round assessment showed a concordance between two pathologists for 247 thyroid CNB specimens by 84.2%, with a kappa coefficient of 0.74 (indicating substantial agreement). This finding was attributed to the discordance in the use of categories III and V. After peer learning, the two pathologists evaluated 30 new cases, which showed an overall improvement in the level of agreement. The percentage of agreement between pathologists on thyroid CNB diagnosis was 86.7%, as measured by kappa coefficient of 0.80.

CONCLUSIONS

This educational program, consisting of guided mentorship and peer learning, can substantially enhance the diagnostic accuracy of thyroid CNB. It is useful in promoting consistent diagnostic standards and contributes to the ongoing development of global pathology practices.

Biopsy strategies for intermediate and high suspicion thyroid nodules with macrocalcifications

OBJECTIVES

(1) To find strategies to improve diagnostic performance of ultrasound-guided biopsy of intermediate and high suspicion thyroid nodules with macrocalcifications. (2) To find malignancy rates of nodules with macrocalcification.

MATERIALS AND METHODS

From 2018 to 2022, fine-needle aspiration biopsy (FNAB) and core needle biopsy (CNB) were retrospectively evaluated. Macrocalcifications were categorized into three types: intra-nodular, rim and entirely calcified. Diagnostic performance was compared between biopsy modes (FNAB vs. CNB) and FNAB techniques (to-and-fro vs. whirling). Multivariate logistic regression was performed to determine features associated with performance of FNAB. Malignancy rates were calculated according to macrocalcification types.

RESULTS

A total of 114 procedures (87 FNAB and 27 CNB) in 89 nodules per 86 patients (mean age, 64 years; 76 women) were performed. Overall, CNB performed better than FNAB (unsatisfactory rate: 3.7% vs. 33.3%, p = .005). For macrocalcification thicker than 2 mm, whirling FNAB technique demonstrated a comparable unsatisfactory rate with statistical trends toward significance (to-and-fro: 69.2% vs. whirling: 27.8%, p = .055). The entirely calcified nodule was associated with poor performance of FNAB (adjusted odds ratio 4.46 [95% CI: 1.19-16.67], p = .027). Overall malignancy was 22.5%, higher in intra-nodular macrocalcification than rim and entirely calcified types (68.4% vs. 21.1% vs. 10.5%, p = .025).

CONCLUSION

For the entirely calcified type, CNB should be considered first to improve diagnosis. For other types, FNAB can be performed, and whirling technique may be an alternative technique in thicker macrocalcification. Malignancy in intermediate and high suspicion nodules with macrocalcification have non-negligible rates.

Diagnostic efficacy, performance and safety of side-cut core needle biopsy for thyroid nodules: comparison of automated and semi-automated biopsy needles

PURPOSE

This study was performed to compare the utility of the semi-automated and automated side-cut core biopsy needles for thyroid nodules.

METHODS

Between January 2014 and March 2020, biopsy was performed for 278 thyroid nodules using the semi-automated core needle and for 225 nodules using the automated core needle. Nondiagnostic rate, inconclusive rate, diagnostic performance and complication rates were evaluated and compared between two core needle types.

RESULTS

There were 1.2% (6/503) nondiagnostic results and 15.9% (80/503) inconclusive results. Nondiagnostic rate between two needle types was not significantly different. The semi-automated type (33/278, 11.9%) showed lower inconclusive rate than the automated type (47/225, 20.9%) (p = 0.006). The sensitivity, specificity, PPV, NPV and diagnostic accuracy for diagnosis of malignancy of the semi-automated type were 70.18, 100, 100, 84.96 and 88.89%, respectively; the corresponding rates of automated type were 70.45, 100, 100, 86.6, and 89.84%. There were 12 minor complications: four hematomas (4/278, 1.4%) for the semi-automated type and eight hematomas (8/225, 3.6%) for the automated type, which difference was not statistically significant.

CONCLUSION

Core needle biopsy for thyroid nodules using either the semi-automated or automated needle is a safe diagnostic tool. Semi-automated needle has lower inconclusive rate than automated needle.

Is thyroid core needle biopsy a valid compliment to fine-needle aspiration?

Fine-needle aspiration (FNA) has long been considered the first and an important diagnostic tool in the evaluation of thyroid nodules. The advantages of FNA include simplicity, safety, cost-effectiveness, high diagnostic accuracy, and low complication rate. Nevertheless, limitations associated with FNA include a substantial rate of inconclusive results and indeterminate interpretations. Therefore, core needle biopsy (CNB) of the thyroid gland has been proposed as a complementary or even alternate diagnostic method to evaluate thyroid nodules. Although controversial, a growing number of researchers have reported CNB to be an effective and safe sampling method for thyroid nodules, especially for cases with inadequate or indeterminate FNA yields. Skeptics highlight local pain and bleeding risk. Supporters highlight the potential likelihood of overcoming FNA limitations by obtaining a larger amount of tissue and using architecture and cellular details to guide possible ancillary testing. This review evaluates the indications, advantages, and disadvantages of CNB as compared with FNA of the thyroid gland.

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.

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.