Incidental thyroid nodules on Covid 19-related thoracic tomography scans: A giant cohort

Abstract

Abstract Introduction: Computerized thoracic tomography (CT) imaging was extensively employed, especially in the early era of the Coronavirus pandemic. An incidental thyroid nodule (ITN) is defined as a nodule not previously detected or suspected clinically but identified by an imaging study. This study aimed to determine the incidence of thyroid nodules incidentally detected in thoracic CTs for the suspicion of Covid-19 pneumonia.Materials and methods Adult patients who underwent thoracic CT in our hospital for Covid-19 management between March 2020 and September 2020 were retrospectively identified. Medical information registered in the hospital and national health system were reviewed. The prevalence of incidental thyroid nodules at CT, thyroid function test results of patients with incidental lesions, correlation of CT findings with ultrasonography (US) findings, and fine-needle aspiration biopsy (FNAB) results were evaluated.Results We determined 36.939 adult patients that had a CT scan. Among these, 624 had a previous history of thyroid operation, and 1201 had already been diagnosed with a thyroid pathology. The final analysis included 35.113 patients. There was information about the thyroid gland in CT reports of 3049 patients. The prevalence of ITN was 3.82% (1343/35113 patients), and thyroid heterogeneity was 1.11% (388/35113 patients). While it was explicitly stated that no pathology was found in the thyroid gland in 3.75% (1318/35113) of the patients, no information was given about the thyroid gland in 91.32% (32064/35113) of the patient. Thus, the number of patients informed about the thyroid was 3049 (8.68%), and the number of patients with thyroid pathology was 1731 (4.93%). It was observed that 308 of 1731 (17.80%) patients had follow-up thyroid US. An FNAB was indicated in 238 (87.50%) patients. Of the 238 patients with biopsy indication, only 115 (48.31%) underwent a thyroid FNAB. The cytological diagnosis was benign in 59 (51.30%), non-diagnostic in 30 (26.08%), atypia of uncertain significance in 22 (19.13%), suspected follicular neoplasia/follicular neoplasia in 4 (3.46%) patients. Thyroidectomy was performed in six more patients due to giant nodules, and the final diagnosis was benign in 2 and papillary thyroid cancer in 3 patients.Conclusion In conclusion, increased use of thoracic CT during Covid 19 pandemic probably caused increased detection of ITNs. In this large-scale study, the prevalence of thyroid nodules reported in thoracic CT was 3.82%, and thyroid cancer was detected in 1.30% of patients evaluated in the US. Therefore, Thoracic CT scans taken for different reasons might provide the opportunity for early diagnosis and treatment of thyroid cancers.