Subacute thyroiditis during the COVID-19 pandemic: a prospective study.

PURPOSE: Subacute thyroiditis(SAT) is a destructive thyroiditis associated with viral infections. Several SAT cases associated with SARS-CoV-2 infection/vaccination were recently reported. We aimed to evaluate prospectively all cases applied to our tertiary center and their relationship with SARS-CoV-2 during 16 months of the pandemic. Cases during similar pre-pandemic period were recorded for numeric comparison. METHODS: Prospective study took place between March 2020 and July 2021. SAT was diagnosed by classical criteria. Swabs for SARS-CoV-2 and a wide respiratory viral panel (RV-PCR) were taken. Previous COVID-19 was assessed by SARS-CoV-2 IgM&IgG levels. Study group was divided into three as: CoV-SAT, patients who had or still have COVID-19, Vac-SAT, patients diagnosed within three months after SARS-CoV-2 vaccination and NonCoV-SAT, those not associated with COVID-19 or vaccination. RESULTS: Out of 64 patients, 18.8% (n = 12) was classified as CoV-SAT, 9.3% (n = 6) as Vac-SAT and 71.9% as (n = 46) NonCoV-SAT. SARS-CoV-2 RT-PCR tests on the diagnosis of SAT were negative in all, but two patients tested positive five days later, in second testing, performed upon clinical necessity. CoV-SAT and NonCoV-SAT groups were similar in terms of clinical, laboratory, and treatment characteristics. However, symptoms were milder and treatment was easier in Vac-SAT group (p = 0.006). CONCLUSIONS: Total number of SAT cases during the pandemic period was comparable to pre-pandemic period. However, a considerable rate of SARS-CoV-2 exposure in SAT patients was established. COVID-19 presented with SAT, as the first manifestation in three cases. Vaccine-related cases developed in a shorter time period, clinical presentation was milder, and only a few required corticosteroids.

Recombinant human thyrotropin versus thyroid hormone withdrawal in differentiated thyroid carcinoma follow-up: a single center experience.

Introduction: Our goal was to evaluate and compare the diagnostic utility of thyroid hormone withdrawal (THW) and recombinant thyroid-stimulating hormone (rhTSH) methods in detecting recurrence/persistence (R/PD) of differentiated thyroid carcinoma (DTC). Methods: The study included 413 patients with DTC who underwent total thyroidectomy and had remnant ablation. DxWBS, s-Tg levels, R/PD were evaluated retrospectively. A s-Tg level≥2 ng/mL was considered as "positive s-Tg". Results: DxWBS and s-Tg levels were evaluated with rhTSH in 116 and THW in 297 subjects, respectively. The sensitivity and specificity of "positive s-Tg" for R/PD in THW group were 77.3% and 92.7%, with 90.3% accuracy, respectively. The sensitivity and specificity of "positive s-Tg" for R/PD in rhTSH group were 58.8% and 100% with 93.9 % accuracy, respectively. An uptake outside thyroid bed at WBS showed a sensitivity of 17.1%, specificity of 100% for R/PD with 89.4% accuracy in THW group. An uptake outside thyroid bed at WBS showed a sensitivity of 7.7%, specificity of 100% for R/PD with 88.8% accuracy in rhTSH group. Conclusion: Method of TSH stimulation did not influence the reliability of DxWBS. The "positive s-Tg level" had a higher sensitivity with THW when compared to rhTSH in detecting R/PD.

THE ASSOCIATION BETWEEN LYMPH NODE METASTASIS AND MOLECULAR MARKERS IN DIFFERENTIATED THYROID CANCER.

CONTEXT: There is no consensus regarding routine usage and benefits of molecular markers for prediction of prognosis and assessment of risk groups in differentiated thyroid cancer (DTC). OBJECTIVE: We aimed to investigate NIS, Galectin-3, PTEN, P53 and Ki67 expressions in tumor tissue and metastatic lymph nodes in PTC and their association with lymph node metastasis and prognosis. MATERIAL AND METHODS: Ninety two papillary thyroid cancer patients who underwent total thyroidectomy and central lymph node dissection were included in this study. NIS, Galectin-3, PTEN, P53 and Ki67 immunohistochemical stainings were performed for all surgical tumor tissues and metastatic lymph nodes of the 38 patients. Age, gender, tumor size, multifocality, capsular invasion, extrathyroidal extension and lymphocytic thyroiditis were assessed retrospectively. RESULTS: Seventy three females (79.3%) and nineteen males (20.7%) were included in this study. Risk of lymph node metastasis was higher in tumors with capsular invasion and extrathyroidal extension (p=0.03 and p < 0.001). NIS, PTEN and Galectin-3 protein expressions in tumor tissue were not associated with gender, tumor size, multifocality, extrathyroidal extension, capsular invasion, lymph node metastasis and tumor recurrence. Mean Ki 67 proliferation index was 2.08±0.95%. Ki 67 proliferation index was associated with tumor size (p=0.012). Intensity and expression of NIS and PTEN in tumor tissue were concordant with intensity and expression in metastatic lymph nodes (p<0.001). Ki 67 proliferation index in tumor was concordant with metastatic lymph nodes (p=0.02). CONCLUSIONS: NIS, PTEN, Galectin-3, Ki67 and P53 expressions were not associated with the risk of lymph node metastasis in PTC patients. Routine analysis of these markers does not seem to be favorable. Further studies with new markers are necessary to determine prognostic predictors.