Prevalence of papillary thyroid cancer in subacute thyroiditis patients may be higher than it is presumed: retrospective analysis of 137 patients

Abstract

BackgroundThe association of subacute thyroiditis (SAT) and papillary thyroid carcinoma is a rare finding. In this study, we aimed to investigate the prevalence of differentiated thyroid cancer in a cohort of patients followed with the diagnosis of SAT.Patients and methodsWe retrospectively screened medical records of Endocrinology and Metabolism outpatient clinic in the past 20 years for patients with SAT. Patients with nodules and suspicious ultrasonography findings who underwent fine needle aspiration biopsy (FNAB) and operated due to malignancy risk were identified.ResultsWe identified 137 (100 females, 37 males) patients with reliable records to confirm the diagnosis of SAT. The mean age of female patients was 41.1 ± 9.1 (range, 20–64) and of male patients was 43.0 ± 9.3 (range, 20–65). One or more FNAB was performed in 23 of the patients (16.8%) at the beginning and/or during the follow-up period when needed. Seven patients with suspicious FNAB findings were operated, and histopathological examination of the nodules confirmed the diagnosis of papillary thyroid carcinoma in 6 patients (4.4%).ConclusionsOur observations suggesting a relatively higher prevalence of thyroid cancer in a small series of SAT patients warrant further studies to identify the real frequency of differentiated thyroid cancer and its association with inflammatory pathogenesis of SAT. This finding is compatible with the trend of increased thyroid cancer incidence all over the world. A repeat ultrasonography after resolution of clinical and inflammatory findings, and FNAB should be recommended to all patients with suspicious nodules.

New aspects in the pathogenesis and management of subacute thyroiditis

“…US is mandatory for SAT diagnosis, FNAB recommended in all doubtful cases [ 64 ] 2. Possible co-presence of DTC – tumours not visible in US due to SAT inflammatory lesions [ 76 , 77 ] 2. US monitoring of SAT patients is required …”

“…The authors underlined that SAT can significantly obscure coexisting PTC when inflammatory hypoechoic regions are present [ 76 ]. Gül et al confirmed the diagnosis of PTC in even higher percentage of SAT patients, reaching 4.4% [ 77 ]. Thus, US re-examination after resolution of SAT-related thyroid lesions should always be performed.…”

Thyrotoxicosis with concomitant thyroid cancer

“…Endocrine-Related Cancer in older female and the tumors' size occurred in subacute thyroiditis varies from 0.05 cm to 1.2 cm (Gul et al 2018). The prevalence of PTC occurring in subacute thyroiditis is 4.4% regarding a study with 137 patients, which may be much higher than previous finding of 0.43% (5/1152) (Nishihara et al 2008, Gul et al 2018.…”

“…Swelling with pain in the thyroid gland are the clinical finding in patients of subacute thyroiditis associated with DTC. Elevated C-reactive protein, erythrocyte sedimentation rate, FT 4 , and decreased TSH are commonly found (Nishihara et al 2008, Gul et al 2018. Not or poorly visualization thyroid in thyroid scan, as well as low RAIU are helpful to confirm the diagnosis of subacute thyroiditis (Fatourechi et al 2003).…”

Impact of Computed Tomography Scans on the Risk of Thyroid Disease in Minor Head Injury Patients: A Population-Based Retrospective Cohort Study

“…There are different types of noncancer thyroid diseases, all of which have been adequately studied as risk factors of thyroid cancer. In their observational study, Nurdan et al demonstrated a higher prevalence of differentiated thyroid cancer in patients with subacute thyroiditis [20]. Chen et al revealed the risk of thyroid cancer in a population with Grave's disease in a nationwide cohort study [21].…”