Discrepancies between the ultrasonographic and gross pathological size of papillary thyroid carcinomas

Diagnostic Accuracy of Preoperative Radiologic Findings in Papillary Thyroid Microcarcinoma: Discrepancies with the Postoperative Pathologic Diagnosis and Implications for Clinical Outcomes

BACKGRUOUND

The diagnostic accuracy of preoperative radiologic findings in predicting the tumor characteristics and clinical outcomes of papillary thyroid microcarcinoma (PTMC) was evaluated across all risk groups.

METHODS

In total, 939 PTMC patients, comprising both low-risk and non-low-risk groups, who underwent surgery were enrolled. The preoperative tumor size and lymph node metastasis (LNM) were evaluated by ultrasonography within 6 months before surgery and compared with the postoperative pathologic findings. Discrepancies between the preoperative and postoperative tumor sizes were analyzed, and clinical outcomes were assessed.

RESULTS

The agreement rate between radiological and pathological tumor size was approximately 60%. Significant discrepancies were noted, including an increase in tumor size in 24.3% of cases. Notably, in 10.8% of patients, the postoperative tumor size exceeded 1 cm, despite being initially classified as 0.5 to 1.0 cm based on preoperative imaging. A postoperative tumor size >1 cm was associated with aggressive pathologic factors such as multiplicity, microscopic extrathyroidal extension, and LNM, as well as a higher risk of distant metastasis. In 30.1% of patients, LNM was diagnosed after surgery despite not being suspected before the procedure. This group was characterized by smaller metastatic foci and lower risks of distant metastasis or recurrence than patients with LNM detected both before and after surgery.

CONCLUSION

Among all risk groups of PTMCs, a subset showed an increase in tumor size, reaching 1 cm after surgery. These cases require special consideration due to their association with adverse clinical outcomes, including an elevated risk of distant metastasis.

Construction and validation of nomograms to reduce completion thyroidectomy by predicting lymph node metastasis in low-risk papillary thyroid carcinoma

CONTEXT

More than 5 central lymph nodes metastases (CLNM) or lateral lymph node metastasis (LLNM) indicates a higher risk of recurrence in low-risk papillary thyroid carcinoma (PTC) and may lead to completion thyroidectomy (CTx) in patients initially undergoing lobectomy.

OBJECTIVE

To screen potentially high-risk patients from low-risk patients by using preoperative and intraoperative clinicopathological features to predict lymph node status.

METHODS

A retrospective analysis of 8301 PTC patients in Wuhan Union Hospital database (2009-2021) was performed according to the 2015 American Thyroid Association (ATA) and 2021 National Comprehensive Cancer Network (NCCN) guidelines, respectively. Logistic regression and best subsets regression were used to identify risk factors. Nomograms were established and externally validated using the Differentiated Thyroid Cancer in China cohort.

RESULTS

More than 5 CLNM or LLNM was detected in 1648 (19.9%) patients. Two predictive models containing age, gender, maximum tumor size, free thyroxine (FT4) and palpable node (all p < 0.05) were established. The nomogram based on NCCN criteria showed better discriminative power and consistency with a specificity of 0.706 and a sensitivity of 0.725, and external validation indicated that 76% of potentially high-risk patients could achieve preoperative conversion of surgical strategy.

CONCLUSIONS

Models based on large cohorts with good predictive performance were constructed and validated. Preoperative low-risk (T1-2N0M0) patients with age younger than 40 years, male gender, large tumor size, low FT4 and palpable nodes may be at high risk of LLNM or more than 5 CLNM, and they should receive more aggressive initial therapy to reduce CTx.

Comparative analysis of pre-operative ultrasound and histopathology in small papillary thyroid carcinoma in the era of active surveillance

BACKGROUND

Contemporary management of small papillary thyroid carcinomas (PTC) includes active surveillance (AS) as a number of these tumours are indolent. Overseas studies have reported AS in tumours up to 15 mm. This study aims to look at an Australian cohort of patients who have had surgery for non-incidental PTCs and analyse their pre-operative ultrasound and histopathology data to investigate potential issues that might arise in the era of AS.

METHODS

Retrospective review of 82 patients who had surgical removal of PTCs ≤15 mm in diameter. Pre-operative ultrasound imaging was reviewed by an experienced sonologist and histopathology data was obtained from medical records. The AS risk stratification framework by Brito et al. was used to determine those who were feasible for AS based on ultrasound findings.

RESULTS

Review of pre-operative ultrasounds demonstrated there were 68 (82.9%) patients who were shown to be either appropriate or ideal for AS. On review of histopathology, 49 (69%) patients had at least one adverse pathological risk factor. This is more than half of the patients that were originally identified as candidates for AS.

CONCLUSION

Our study has revealed a large proportion were suitable for AS but when compared with histopathological guidelines there was a high incidence of adverse pathological features found. This discrepancy indicates that although the guidelines are important, there are unknown pathological variables that need to be considered in patients selected for AS.

NOMOGRAM COMBINING PREOPERATIVE ULTRASONOGRAPHY WITH CLINICAL FEATURES FOR PREDICTING LYMPH NODES POSTERIOR TO THE RIGHT RECURRENT LARYNGEAL NERVE METASTASIS IN PATIENTS WITH PAPILLARY THYROID CANCER

Aim

To establish a nomogram combining preoperative ultrasonic and clinical features for predicting lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) metastasis in papillary thyroid carcinoma (PTC) patients.

Methods

Preoperative ultrasonic and clinical variables of patients with PTC from 2014 to 2021 were retrospectively analyzed. The risk factors associated with LN-prRLN metastasis were identified and validated through a developed nomogram model based on univariate and multivariate logistic regression analysis.

Results

A total of 615 patients (690 lesions) were enrolled for the training dataset and 207 patients (226 lesions) for the validation dataset with 54 (6.57%) patients developing LN-prRLN metastasis. Multivariate logistic regression analysis demonstrated that the preoperative ultrasound measurement of larger tumors (≥20 mm), higher TI-RADS category (category 5), and higher thyroglobulin level (9.86 ng/mL) in patients with PTC were predictive factors for LN-prRLN metastasis. The nomogram model was established and verified yielding a relatively good predictive performance in the training and validation dataset (AUC: 0.868 vs. 0.851).

Conclusions

The nomogram combining preoperative ultrasonography with clinical features in this study is highly predictive of LN-prRLN metastasis in patients with PTC, which may provide more personalized recommendations for clinicians in preoperative decision-making for complete dissection of LN-prRLN.

Diagnostic Performance of Different Thyroid Imaging Reporting and Data Systems (Kwak-TIRADS, EU-TIRADS and ACR TI-RADS) for Risk Stratification of Small Thyroid Nodules (≤10 mm)

Due to the widespread use of ultrasound, small thyroid nodules (TNs) ≤ 10 mm are common findings. Standardized approaches for the risk stratification of TNs with Thyroid Imaging Reporting and Data Systems (TIRADS) were evaluated for the clinical routine. With TIRADS, the risk of malignancy in TNs is calculated by scoring the number or combination of suspicious ultrasound features, leading to recommendations for further diagnostic steps. However, there are only scarce data on the performance of TIRADS for small TNs. The aim was to compare three different TIRADS for risk stratification of small TNs in routine clinical practice. We conducted a retrospective cohort analysis of TNs ≤ 10 mm and their available histology. Nodules were classified according to three different TIRADS. In the study, 140 patients (n = 113 female) with 145 thyroid nodules (n = 76 malignant) were included. Most of the malignant nodules were papillary carcinoma (97%), and the remaining 3% were medullary carcinoma. For all tested TIRADS, the prevalence of malignancy rose with increasing category levels. The highest negative predictive value was found for ACR TI-RADS and the highest positive predictive value for Kwak-TIRADS. All tested variants of TIRADS showed comparable diagnostic performance for the risk stratification of small TNs. TIRADS seems to be a promising tool to reliably assess the risk of malignancy of small TNs.

Re-visiting the ATA 2015 sonographic guidelines - who are we missing?: A retrospective review

BACKGROUND

The American Thyroid Association published revised guidelines in 2015 on the management of differentiated thyroid cancer in adults. One of the key changes introduced in the revision proposes that diagnostic biopsy be based on ultrasound findings (i.e. size and nodule characteristics). The overall effect of these changes results in fewer nodules requiring biopsy. This study was conducted to determine if the changes to the guidelines will result in overlooked thyroid cancers, specifically malignancies with aggressive characteristics measuring between 1 and 1.49 cm.

METHODS

Patients (n = 2083) with thyroid nodules who underwent total or subtotal/hemi thyroidectomy with or without neck dissection by a single surgeon between 2006 and 2016 were retrospectively enrolled. Demographic information and nodule characteristics were collected for all patients. Ultrasonography and final pathology reports were reviewed for patients with thyroid nodules between the sizes of 1-1.49 cm (n = 155).

RESULTS

45% (n = 70) of patients with nodules between 1 and 1.49 cm were "low suspicion" nodules according to ultrasound. 47 of these nodules contained malignancies on final histopathological examination, 100% of which were of the papillary subtype. 21% (n = 10) of these malignant nodules demonstrated extrathyroidal extension and 34% (n = 16) were associated with regional metastases.

CONCLUSIONS

Reliance on sonographic patterns alone could result in missed cancer diagnoses in patients with thyroid nodules measuring between 1 and 1.49 cm. Moreover, a portion of these malignancies may be associated with aggressive features. The effect of this finding on long-term outcomes is unclear.

Insight into Differentiated Thyroid Cancer Gross Pathological Specimen Shrinkage and Its Influence on TNM Staging

INTRODUCTION

This study aimed at comparing thyroid cancer staging when taking into account the differences between the "T" assessment" using ultrasound (US) and histopathological measurements.

MATERIAL AND METHODS

This retrospective study included all consecutive differentiated follicular thyroid cancer (DTC) and medullary thyroid cancer (MTC) patients who underwent postoperative histopathological staging assessment at a single institution. Anaplastic thyroid carcinomas were excluded from the present study. Each malignant thyroid nodule was precisely evaluated by measuring its long axis using both US and gross specimen histopathological examination. T stage classification was attributed to each tumor as regards US (solely according to the tumor dimension) and histopathology: (1) solely according to the tumor dimension and (2) according to the tumor dimension and extrathyroidal extension features when present.

RESULTS

Retrospective comparison between US and histopathology size of the operated thyroid nodules showed a mean diminution of 7.52% of the tumor long axis. Tumors ≤10 mm at histopathological examination showed a larger decrease in size of 13% (p = 0.054, statistically significant) compared to the US measurements. Ten out of 72 (13.8%) patients showed final T downstaging in comparison to US assessment: (US) T2 to T1b in 6 patients (1 MTC) and (US) T1b to T1a in 4 patients (1 MTC). Two (2.9%) DTC patients were downstaged from stage 2 to stage 1.

CONCLUSION

Precise thyroid tumor US measurement may differ significantly from that obtained by histopathological assessment, which may result in a different TNM staging and subsequent patient management.

Ultrasonographic imaging of papillary thyroid carcinoma variants

Ultrasonography (US) is routinely used to evaluate thyroid nodules. The US features of papillary thyroid carcinoma (PTC), the most common thyroid malignancy, include hypoechogenicity, spiculated/microlobulated margins, microcalcifications, and a nonparallel orientation. However, many PTC variants have been identified, some of which differ from the classic type of PTC in terms of biological behavior and clinical outcomes. This review describes the US features and clinical implications of the variants of PTC. With the introduction of active surveillance replacing immediate biopsy or surgical treatment of indolent, small PTCs, an understanding of the US characteristics of PTC variants will facilitate the individualized management of patients with PTC.