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.