Suspicious thyroid nodules ≥4 cm require diagnostic lobectomy regardless of their benign fine needle aspiration results

The necessity of fine-needle aspiration biopsy in surgical decision-making for thyroid nodules larger than 3 cm

Ultrasound-guided fine-needle aspiration biopsy (FNAB) is an essential diagnostic tool for detecting malignancy in thyroid nodules. The objective of this study was to evaluate the necessity of FNAB in the treatment decision-making process for thyroid nodules exceeding 3 cm in size. The records of patients who underwent thyroidectomy in our center between 2018 and 2023 were retrospectively reviewed. The study included patients with an index nodule size exceeding 3 cm. Exclusion criteria were missing data, treatment for a different oncological condition, recurrent disease, and purely cystic nodule. Patients were categorized into 2 groups based on the size of the index nodule: Group 1 included nodules measuring between 3 to 4 cm, and Group 2 included nodules 4 cm and larger. Demographic data, FNAB results, and histopathological findings were recorded. The specificity, sensitivity, false negative, and false positive rates of FNAB were calculated. There were 1935 patients who underwent thyroidectomy within the specified date range. In 359 of these patients, the index nodule size was 3 cm or more. There were 188 patients with nodule size between 3 and 4 cm. The mean age was 50.42 ± 13.34 years, and 257 patients were female (F/M ratio = 2.5/1). Fine needle aspiration biopsy was performed on 237 patients, resulting in 65 false negatives. Both the incidence of malignancy and the rate of FNAB false negatives were higher in nodules measuring 4 cm or larger. This study identified a high malignancy rate and a significant rate of false negatives in FNAB of thyroid nodules larger than 3 cm. These findings highlight the importance of carefully considering these factors in the surgical planning of such nodules.

The Utility of ACR TI-RADS in Predicting False-Negative Fine Needle Aspiration for Thyroid Cancer

BACKGROUND

Thyroid nodule fine needle aspiration (FNA) biopsies are associated with a low false-negative rate. There is limited data regarding the predictive value of American College of Radiology Thyroid Imaging Reporting and Data System for false-negative FNA.

METHODS

This single-center retrospective study evaluated 119 patients who underwent thyroidectomy. The association of TR category, along with other clinical variables, with false-negative FNA was evaluated.

RESULTS

The overall false-negative rate of FNA was 10.8% (n = 9). False-negative FNAs were associated with younger age (mean 42 years vs 50.6 years, P = .04), larger nodule size (mean 4.4 cm vs 3.2 cm, P = .03), and a lower TR category (median 3 v 4, P = .01).

DISCUSSION

Lower TR category, younger age, and larger nodule size were associated with false-negative FNA of thyroid nodules. These findings should be taken into context when counseling patients with thyroid nodules who have a benign FNA.

Diagnostic Performance of ACR TI-RADS and ATA Guidelines in the Prediction of Thyroid Malignancy: A Prospective Single Tertiary Center Study and Literature Review

AIM

This study sought to compare two common risk stratification systems in terms of their diagnostic performance for the evaluation of thyroid malignancy.

METHODS

The American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS) and the American Thyroid Association (ATA) guidelines were compared among 571 thyroid nodules with definitive fine needle aspiration (FNA) cytology or postoperative histopathology. Ultrasound characteristics such as composition, echogenicity, shape, margin, size, and vascularity were assessed for each thyroid nodule. Diagnostic performance measures were determined and compared through receiver operating characteristic (ROC) curves, and decision curve analysis (DCA).

RESULTS

Of 571 nodules, 65 (11.4%) were malignant. The AUC, sensitivity, specificity, positive predictive value, and negative predictive value were 0.691, 49.2%, 84.9%, 29.6%, and 92.8% for ATA guideline, and 0.776, 72.3%, 79.2%, 30.9%, and 95.7%, for ACR TI-RADS, respectively. ACR TI-RADS was more sensitive (p = 0.003), while the ATA guideline was more specific (p < 0.001). DCA demonstrated that the ACR TI-RADS provided a greater net benefit than the ATA guideline. In addition, the net reduction in unnecessary biopsies is higher for ACR TI-RADS than ATA guidelines. The total number of indicated biopsies and unnecessary FNA rates were lower in ACR TI-RADS compared to ATA guideline (293 vs. 527 and 80.2 vs. 87.8). ACR TI-RADS presented no biopsy indication in seven malignant nodules (all categorized as TR2), whereas ATA guideline missed one. Hypoechogenicity was the most significant predictor of malignancy (OR = 8.34, 95% CI: 3.75-19.45), followed by a taller-than-wide shape (OR = 6.73, 95% CI: 3.07-14.77).

CONCLUSIONS

Our findings suggest that each system has particular advantages in the evaluation of thyroid nodules. ACR TI-RADS reduces unnecessary FNA rates, however, malignant nodules categorized as TR2 might be missed using this system. Further evaluation of this group of nodules using Doppler and other ultrasound modalities is recommended.

Do large thyroid nodules (≥4 cm) without suspicious cytology need surgery?

Background

Fine-needle aspiration biopsy (FNAB) is a good diagnostic tool for thyroid nodules; however, its high false-negative rate for giant nodules remains controversial. Many clinicians recommend surgical resection for nodules >4 cm owing to an increased risk of malignancy and an increased false-negative rate. This study aimed to examine the feasibility of this approach and investigate the incidence of malignancy in thyroid nodules >4 cm without suspicious cytology based on medical records in our center.

Methods

This was a retrospective analysis of 453 patients that underwent preoperative FNAB for nodules measuring >4 cm between January 2017 and August 2022 at Severance Hospital, Seoul.

Results

Among the 453 patients, 140 nodules were benign and 119 were indeterminate. Among 259 patients, the final pathology results were divided into benign (149) and cancerous (110) groups, and the prevalence of malignancy was 38.9% in the benign group and 55.5% in the indeterminate group. Among the malignancies, follicular carcinoma and follicular variants of papillary carcinoma were observed in 83% of the cytologically benign group and 62.8% of the indeterminate group.

Conclusion

Preoperative FNAB had high false-negative rates and low diagnostic accuracy in patients with thyroid nodules >4 cm without suspicious cytologic features; therefore, diagnostic surgery may be considered a treatment option.

Incidental Detection of Papillary Thyroid Carcinoma in Tc-99 m PSMA Imaging in a Case with Negative FNA Result

Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein and is expressed in multiple solid malignant neoplasms. We presented a case of a prostate cancer patient who went through Tc-99 m PSMA SPECT, and multifocal increased radiotracer uptake in the thyroid gland was demonstrated. Despite negative FNA results for malignancy, post-operative histopathologic examination illustrated papillary thyroid carcinoma.

Navigating the Debate on Managing Large (≥4 cm) Thyroid Nodules

PURPOSE

Discordant practice guidelines for managing large thyroid nodules may result in unnecessary surgeries and costs. Recent data suggest similar false-negative rates in fine needle aspiration (FNA) biopsies between small (<4 cm) and large (≥4 cm) nodules, indicating that monitoring rather than surgery may be appropriate for large biopsy-negative nodules. We investigated the management of thyroid nodules ≥4 cm to determine the proportion of surgeries not necessary for diagnostic purposes and examined for potential predictors.

METHODS

This was a retrospective cohort study of patients who received a FNA of nodule(s) ≥4 cm between 11/1/2014 and 10/31/2019 at the University of Vermont Medical Center. A surgery was considered unnecessary if the FNA result was benign in the absence of any of the following: compressive symptoms, family history of thyroid cancer in a first degree relative, history of neck irradiation, toxic nodule or toxic multinodular goiter, or substernal extension. Data were analyzed with Wilcoxon rank sum tests, chi square, or Fisher's exact tests.

RESULTS

177 patients had a ≥4 cm nodule during the timeframe and half (54.2%) had surgery. Patients who underwent surgery were significantly younger (51.5 years vs. 62 years; P < 0.001), more likely to report obstructive symptoms (34.4% vs. 12.1%; P < 0.001) and had a larger nodule size (5.0 cm vs. 4.7 cm; P=0.26). Forty-one patients with benign (Bethesda II) FNA results had surgery, all with negative surgical pathology. Thirteen percentage (23/177) of surgeries were potentially not necessary for diagnostic purposes.

CONCLUSION

Approximately half of our patients with ≥4 cm nodules had surgery, with 13% having surgery not necessary for diagnostic purposes revealing opportunities for improving care and costs.