Clinically significant cancer rates in incidentally discovered thyroid nodules by routine imaging

Thyroid Incidentalomas: Scrutinizing the Mode of Detection and Evaluating its Contribution to Thyroid Cancer Diagnosis

There is an ongoing debate about the reasons behind the increasing incidence of thyroid cancer in the last two to three decades. Here, we investigate how thyroid nodules were detected in a large series of consultations for thyroid nodular pathology.

METHODS

In total, 576 patients were analyzed, with a total of 1014 nodules described.

RESULTS

In 347 (60.2%) cases, the diagnosis of a thyroid nodule was incidental, mostly during imaging tests for other reasons. Incidental diagnosis occurred among all ranges of nodule diameter and between palpable and non-palpable cases, even within a small proportion of symptomatic cases. In univariate analysis, incidental diagnosis was associated with smaller nodule diameter, non-palpable nodules, asymptomatic cases, older patient age, less advanced stages (T1-2), and conservative management. After multivariate analysis, older age, euthyroidism, and smaller diameter were statistically significant. Incidental diagnosis contributed to the diagnosis of 53.8% of the cases of cancer. Advanced T stages (T3-4) were more common in non-incidental diagnoses.

CONCLUSION

Our results indicate that incidental diagnosis of thyroid nodules is a significant contributor to thyroid cancer diagnosis in all ranges of nodule diameter, especially at earlier stages.

Ultrasound Radiomics Nomogram to Diagnose Sub-Centimeter Thyroid Nodules Based on ACR TI-RADS

The aim of the present study was to develop a radiomics nomogram to assess whether thyroid nodules (TNs) < 1 cm are benign or malignant. From March 2021 to March 2022, 156 patients were admitted to the Affiliated Hospital of Nantong University, and from September 2017 to March 2022, 116 patients were retrospectively collected from the Jiangsu Provincial Hospital of Integrated Traditional Chinese and Western Medicine. These patients were divided into a training group and an external test group. A radiomics nomogram was established using multivariate logistics regression analysis using the radiomics score and clinical data, including the ultrasound feature scoring terms from the thyroid imaging reporting and data system (TI-RADS). The radiomics nomogram incorporated the correlated predictors, and compared with the clinical model (training set AUC: 0.795; test set AUC: 0.783) and radiomics model (training set AUC: 0.774; test set AUC: 0.740), had better discrimination performance and correction effects in both the training set (AUC: 0.866) and the test set (AUC: 0.866). Both the decision curve analysis and clinical impact curve showed that the nomogram had a high clinical application value. The nomogram constructed based on TI-RADS and radiomics features had good results in predicting and distinguishing benign and malignant TNs < 1 cm.

The Role of the ACR TI-RADS Scoring System to Evaluate Solid and Cystic Thyroid Nodules Compared With Those Solid Nodules With or Without Echogenic Foci and Their Cytology Results

Objective:

The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) is a reporting system for thyroid nodules detected with sonography and proposed by the ACR. The scoring of punctate echogenic foci (PEF) increases the TI-RADS score and leads to a biopsy of many thyroid nodules, otherwise found clinically. The aim of this study was to assess the risk of malignancy for mixed and solid nodules, with and without PEF, and cytologic correlation.

Materials and Methods:

Thyroid sonograms and ultrasound-guided thyroid biopsies were performed, at a University of Iowa Hospitals & Clinics for 105 patients, during July 2019 to June 2020. All these retrospective clinical studies were reviewed against the cytologic examinations.

Results:

Based on the 189 thyroid nodule biopsies reviewed, 82.5% were benign compared with 17.5% malignant lesions. A solid nodule composition was noted in 35.2%, and had a higher risk for malignancy, compared with 7.7% of the mixed nodules. There was a 33.3% incidence of malignancy for solid nodules with PEF, compared with 35.8% of lesions lacking PEF. For mixed nodules, 6.2% nodules demonstrated PEF and 7.7% of nodules, without PEF, were malignant.

Conclusion:

In this cohort, solid nodules had a higher risk of malignancy than mixed nodules. PEF did not increase the risk of malignancy in either solid or mixed thyroid nodules, in these patients. These findings would suggest that existing guidelines may overestimate the value of PEF in scoring, as well as determining which thyroid nodules require biopsy.

The influence of incidental detection of thyroid nodule on thyroid cancer risk and prognosis-A systematic review

BACKGROUND

Clinically inapparent thyroid nodules discovered serendipitously on imaging for nonthyroid indications are termed as thyroid incidentalomas. It is unclear whether these incidentalomas have a lower prevalence of malignancy or slower tumour progression compared to symptomatic nodules. The aims of this systematic review were to determine the impact of incidental detection of thyroid nodules on both the risk of malignancy and on prognosis in patients with thyroid cancer.

METHOD

PubMed and MEDLINE® on Web of Science databases were searched from inception to March 2020 for English language articles reporting on human studies of thyroid cancer risk and/or prognosis in incidental and nonincidental nodules.

RESULTS

Eighteen observational studies published between 1998 and 2020 were eligible for analysis; four studies reported on risk, nine on prognosis and five studies reported on both risk and prognosis. When comparing the incidental and nonincidental groups in the risk study, the odds of incidental detection in the cancer and benign groups ranged from 0.16 to 0.5 and 0.06 to 0.38, respectively (odds ratio [OR] = 0.64-2.86) in case-control studies (n = 6); the risk of malignancy for thyroid nodules ranged from 4% to 23.5% in the incidental and 3.8% to 28.7% in the nonincidental groups (relative risk = 0.13-6.27) in the cohort studies (n = 3). A meta-analysis of the eligible case-control studies (n = 3) showed a nonsignificant summated OR of 1.04 (95% confidence interval = 0.63-1.70; p = .88). In the prognosis study, five direct and thirteen indirect markers of prognosis were compared between the incidental and nonincidental groups. A meta-analysis was not possible but incidentally detected thyroid cancer had better progression-free and overall survival.

CONCLUSION

Current evidence suggests that investigation and management of thyroid nodules should not be influenced by the mode of detection.

A Single-Center Retrospective Study of the Impact of Thyroid Cancer on the Malignant Risk of Contralateral TI-RADS 3 and 4 Nodules

BACKGROUND

The incidence of thyroid nodules increases in the general population. Similarly, we have also seen a dramatic increase in the number of thyroid surgeries. However, the mortality rate of thyroid cancer remained stable or even decreased. The purpose of our study was to investigate whether thyroid cancer affects the malignant risk of the contralateral TI-RADS 3 and 4 nodules.

METHODS

We conducted a retrospective cohort study in our institution for all thyroid procedures due to nodules from December 2018 to December 2019. All eligible patients were divided into the experimental group (bilateral nodules) and the control group (unilateral nodules) to assess whether the proportion of malignant nodules was different between the two groups. Multivariate logistic regression analysis was used to control potential confounding factors to investigate whether their differences were statistically significant.

RESULTS

A total of 330 patients underwent thyroid surgery, of whom 137 were eligible, including 84 in the experimental group and 53 in the control group. The proportion of malignant nodules was significantly different between the experimental group and the control group (29.8% versus 58.5%, unadjusted OR 0.30, 95% CI: 0.17-0.82, p=0.001). However, after controlling for potential confounding factors, including age (p=0.004), gender (p=0.775), and TI-RADS classification (p ≤ 0.001), we found that the difference was not significant (adjusted OR 1.08, 95% CI: 0.39-3.01, p=0.886).

CONCLUSION

There is no evidence that thyroid cancer affects the malignant risk of the contralateral TI-RADS 3 and 4 nodules. This study has been registered with the Chinese Clinical Trial Registry (clinical trial registration number: ChiCTR2000038611, registration time: September 26, 2020).

Computed Tomography and MR Imaging of Thyroid Disease

Over the past several years, there has been an increase in the discovery of thyroid cancers, likely because of the marked increased utilization of computed tomography (CT) and MR imaging. Despite the increase in number of thyroid cancers, the overall mortality remains unchanged because most of these cancers are the differentiated type and have a more indolent behavior. CT and MR imaging are important in the preoperative evaluation of thyroid goiters and thyroid cancer. This article discusses the imaging characteristics of benign and malignant thyroid diseases, and the important information that needs to be relayed to the surgeon.

Incidentally Discovered Thyroid Nodules by Routine Magnetic Resonance Imaging of the Cervical Spine: Incidence and Clinical Significance

OBJECTIVE

The aim of our study was to present the prevalence of thyroid nodules we incidentally discovered by routine Magnetic Resonance Imaging (MRI) of the cervical spine, to evaluate their clinical significance, and to discuss the current clinical approach to incidental thyroid nodules.

METHODS

We retrospectively evaluated the cervical spinal MRI studies of 512 patients. Thyroid glands were evaluated for morphologic and signal characteristics and examined for the presence of nodule(s). The nodules with a maximum diameter of 5 mm or more were taken into analysis.

RESULTS

Of 512 MRI studies, 254 revealed incidental thyroid nodule(s) (49.6%). The mean maximum nodule diameter was 7.48±2.92 mm. Thirty-eight of 254 incidental thyroid nodules were radiologically reported, 35 reported nodules were evaluated by US, and 22 were further analyzed by fine needle aspiration cytology. The final diagnosis of 11 aspirated nodules was an adenomatous nodule, whereas 3 were papillary thyroid carcinoma. One of the patients with papillary thyroid carcinoma was a 32-year-old man with a nodule with a maximum diameter of 7 mm.

CONCLUSION

Incidental thyroid nodule is a frequent non-spinal lesion detected by routine cervical spinal MRI. The 3-tiered system which is recommended in the clinical approach to incidental thyroid nodules may miss some clinically significant thyroid nodules. We suggest the criteria of this system to be re-evaluated and modified if necessary. In addition, we would like to emphasize the need for a guideline for radiologists for reporting incidental thyroid nodules on MRI on the basis of a standard clinical approach.

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.

High Rates of Underlying Thyroid Cancer in Patients Undergoing Thyroidectomy for Hyperthyroidism

BACKGROUND

The rate of thyroid cancer in patients with hyperthyroidism is reported to be rare, and patients with toxic thyroid nodules do not routinely undergo fine-needle aspiration (FNA) to evaluate for malignancy. However, higher rates of malignancy in hyperthyroid patients may exist than previously reported. This study examines the rate of malignancy in patients with hyperthyroidism who have undergone thyroidectomy.

METHODS

A retrospective review of prospectively collected data of 138 patients with hyperthyroidism who underwent thyroidectomy at a single institution was performed. Patients were divided into three groups: Graves' disease (n = 80), toxic multinodular goiter (n = 46), and toxic solitary nodule (n = 12). Patients with previous thyroid surgery were excluded from the study. All patients had biochemical confirmation of hyperthyroidism with thyroid-stimulating hormone <0.1 mIU/L and clinical diagnosis by a referring physician.

RESULTS

Of 138 patients, 22% (31/138) were found to have malignancy on final pathology. The breakdown of malignancy by hyperthyroid condition was as follows: 16% in Graves' disease, 24% in toxic multinodular goiter patients, and 50% in toxic solitary nodule patients.

CONCLUSIONS

There is a clinically significant rate of malignancy seen in patients who undergo thyroidectomy for hyperthyroidism. Patients with distinct thyroid nodules in the presence of hyperthyroidism may have the highest rates of malignancy and should undergo appropriate workup with ultrasound and FNA to exclude underlying malignancy. In cases with suspicious ultrasound features and/or FNA cytopathology, surgical treatment should be considered as initial management.

Controversy regarding when clinically suspicious thyroid nodules should be subjected to surgery: Review of current guidelines

BACKGROUND

The work-up of a thyroid nodule to diagnose malignancy is not always straightforward. There are various international thyroid societies each with their own guidelines on the approach to a thyroid nodule. The aim is therefore to determine whether a clinically suspicious thyroid nodule should be subjected to surgery.

METHOD

A review of various international thyroid society guidelines on their approach to a suspicious thyroid nodule.

RESULTS

Sixty-two relevant articles were identified of which 4 current international thyroid guidelines, consisting of 6 different international societies, were reviewed. The commonalities of each of the thyroid society guidelines are imaging, with ultrasound, and cytopathology as the main diagnostic investigations. The description and the size of the nodule are the 2 most important factors on ultrasound; however, the guidelines vary in their recommendations whether to biopsy a suspicious thyroid nodule. An indeterminate group exists whereby thyroid nodules cannot be confirmed as malignant even with fine needle aspiration cytology (FNA). Although further investigations (Technetium-99m -sestamethoxyisobutylisonitryl scan, 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan, and molecular testing) may assist in the diagnosis, there are limitations. There are differences in the guidelines whether suspicious nodules should be subjected to surgery.

CONCLUSION

Ultrasound and cytopathology are the 2 most appropriate investigations to diagnose whether a suspicious thyroid nodule is benign or malignant. The clinician needs to be aware of the differences between the guidelines from the various international thyroid societies, specifically concerning the indeterminate group of patients where a definitive diagnosis cannot be made. Management decisions should be discussed with a thyroid multidisciplinary team for a consensus decision whether or not to subject a patient with a suspicious thyroid nodule to surgery.