Risk of thyroid cancer in a lung cancer screening population of the National Lung Screening Trial according to the presence of incidental thyroid nodules detected on low-dose chest CT

Significance of Incidental Thyroid Findings in a Large Community-based Lung Cancer Screening Cohort

OBJECTIVES

Investigate incidental findings of neck pathology on lung cancer screening computer tomography scans and determine clinical relevance in a population of heavy smokers.

METHODS

A retrospective chart review was conducted utilizing a database of patients who underwent a chest computed tomography (CT) through a robust community-based hospital lung cancer screening program in 2019 and 2020. Demographics, medical history, imaging reports, and any pathology results were analyzed.

RESULTS

A total of 1738 patients received a lung screening scan during the study period. The median age of the patient population was 64 (range: 50-79), 886 (51%) were male, and 1599 (92%) were Caucasian. Ninety-four (5.4%) were found to have neck findings on their CT report, including thyroid nodules, calcifications, heterogeneity or enlargements, pathologic appearing lymph nodes, or parathyroids. Forty-two patients had evidence of follow-up for their thyroid findings, and three of these ultimately underwent surgical intervention.

CONCLUSION

The results of our study demonstrate that lung cancer screening chest scans can discover clinically relevant findings in the neck. The risks and benefits of screening needs to be thoroughly evaluated. Given the relatively low incidence of findings in this population, a prospective study in conjunction with screening questionnaire for symptoms may increase the yield of incidental findings.

LEVEL OF EVIDENCE

3 Laryngoscope, 135:964-968, 2025.

Incidental Thyroid Nodules on Computed Tomography: A Systematic Review and Meta-Analysis Examining Prevalence, Follow-Up, and Risk of Malignancy

Background: The increased utilization of computed tomography (CT) has led to a higher detection rate of thyroid incidentalomas. Currently, there are no widely agreed-upon guidelines for managing these incidentalomas. This study aims to investigate the prevalence, follow-up practices, and malignancy rates of thyroid incidentalomas detected by CT. Methods: We conducted a comprehensive search of PubMed, Embase, and Cochrane databases to identify relevant studies published before April 12, 2024 (PROSPERO #42024535501). Studies reporting on the prevalence, follow-up, and risk of malignancy (ROM) of thyroid incidentalomas detected by CT were included. Combined outcomes were analyzed using pooled proportion with a random-effects model. The risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials (RoB 2) and the Newcastle-Ottawa Scale tool. Subgroup analyses were conducted based on characteristics including size of the incidentaloma, CT area, and age of the study population. Results: Thirty-eight studies involving 195,959 patients were included in the prevalence analysis, revealing a prevalence of thyroid incidentalomas on CT of 8.3% (confidence interval [CI], 7.4-9.3). The prevalence was higher in neck CT (16.5%, CI, 11.0-22.1) compared with chest CT (6.6%, CI, 5.3-7.9). Multiple incidentalomas were found in 27.0% (CI, 12.9-41.1) of patients. Of the nodules, 46.3% (CI, 32.3-60.3) were ≥1 cm, and 28.6% (CI, 19.9-37.3) were ≥1.5 cm. Thyroid ultrasounds, biopsies, and surgeries were performed in 34.9% (CI, 26.1-43.7), 28.4% (CI, 19.9-36.9), and 8.2% (CI, 2.1-14.4) of cases, respectively. Additionally, 25 studies with 6272 patients reported a ROM of 3.9% (CI, 3.0-4.9) for thyroid incidentalomas detected on CT. A higher ROM was observed in incidentalomas ≥1 cm (11.7%, CI, 3.9-19.4) and ≥1.5 cm (24.9%, CI, 0-52.7) compared with those <1 cm (0.1%, CI, 0-0.8) and <1.5 cm (0%, CI, 0-0.2). Conclusions: Most thyroid incidentalomas identified on CT are benign. Implementing a collaborative protocol between radiologists and thyroid specialists to manage high-risk thyroid incidentalomas can ensure appropriate follow-up and optimal patient care.

Thyroid and adrenal incidentalomas on chest CT: Prevalence, diagnostic work-up and outcomes in a cohort of COVID-19 suspected patients

OBJECTIVE

Due to increased use of computed tomography (CT), prevalence of thyroid and adrenal incidentalomas is rising. Yet, previous studies on the outcomes of diagnostic work-up of incidentalomas are subjected to inclusion bias. Therefore, we aimed to investigate prevalence and outcomes of diagnostic work-up of thyroid and adrenal incidentalomas detected on chest CT in a less selected population of COVID-19 suspected patients.

DESIGN

A retrospective, observational cohort study.

METHODS

We included all COVID-19 suspected patients who underwent chest CT between March 2020 and March 2021. Radiology reports and medical records were reviewed for the presence and subsequent diagnostic work-up of thyroid and adrenal incidentalomas.

RESULTS

A total of 1,992 consecutive COVID-19 patients were included (59.4% male, median age 71 years [IQR: 71-80]). Thyroid and adrenal incidentalomas were identified in 95 (4.8%) and 133 (6.7%) patients, respectively. Higher prevalence was observed with increasing age, among female patients and in patients with malignancy. Forty-four incidentalomas were further analyzed, but no malignancies were found. Only three lesions were hormonally active (1 thyrotoxicosis and 2 mild autonomous cortisol secretion). Diagnostic work-up did not lead to any change in clinical management in 97.7% of the analyzed patients.

CONCLUSION

Prevalence rates of thyroid and adrenal incidentalomas on chest CT in a less selected COVID-19 cohort were 4.8% and 6.7%, respectively. Yet, as all incidentalomas turned out to be benign and only three lesions were (mildly) hormonally active, this raises the question whether intensive diagnostic work-up of incidentalomas is necessary in all patients.