Incidental Thyroid Nodules on the COVID-19 Positive CT Chest

Abstract

Background: The recent widespread of COVID-19 led to a marked increase in the number of CT chest examinations. This led to frequent encounters of associated incidental findings as thyroid nodules. Thyroid imaging reporting and data system (TI-RADS) using variable ultrasound feature-allowed systematic reproducible approach for diagnosis and management of thyroid nodules. Objective: This study aimed to detect the prevalence of incidental thyroid nodules in CT chest for COVID-19 cases as well as the percentage of malignant nodules among them and the concordance of TI-RADS classification with fine-needle aspiration cytology (FNAC) results. Patients and methods: This retrospective study included 895 patients with CT findings of COVID-19 pneumonia. 203 patients were excluded due to absent PCR confirmation of COVID-19, lack of ultrasound confirmation of thyroid nodules or lack of FNAC results, so our study included 692 patients with confirmed COVID-19 pneumonia. Results: A solitary thyroid nodule was discovered in 134 CT chest scans of 692 patients with confirmed COVID-19 pulmonary pneumonia, with a 19.4% incidence. These patients underwent ultrasound evaluation for the thyroid nodule. The nodules with TI-RADS 1-3 score were considered benign yet those with 4-5 score were classified as malignant. The results of the FNAC were compared to the thyroid TI-RADS classification, with nodules classified as Bethesda II-III being benign and those classified as Bethesda IV to VI being malignant. Conclusion: Incidental thyroid nodule discovered during CT chest examination is an important finding and should be investigated and categorized using the TI-RADS system as even though the incidence of malignancy is not high, early diagnosis of thyroid malignancy can have a huge effect on the patient outcome.