Diagnostic cytological features and differential diagnosis of subacute granulomatous (De Quervain's) thyroiditis

Cytodiagnosis of subacute granulomatous thyroiditis (De Quervain's thyroiditis)-A report of four cases

Subacute granulomatous thyroiditis (SGT)/De Quervain's thyroiditis is a rare self-limiting inflammatory disease, accounting for 3% of all thyroid disorders. Most commonly seen in middle aged women, it shows a characteristic triad of pain in the anterior cervical region, increased ESR and recent history of viral upper respiratory tract infection. The cytomorphological features are not pathognomonic and can also be seen in Hashimoto's thyroiditis, granulomatous infections, sarcoidosis, and papillary thyroid carcinoma. We report four cases of SGT, diagnosed on fine needle aspiration cytology (FNAC). Familiarity with cytomorphology of SGT and awareness of the clinical setting is essential for making an accurate diagnosis.

Granulomatous thyroiditis-A rare case and the diagnostic approach

The presence of well‐formed granulomas, multinucleated giant cells containing colloid, and degenerative changes in thyroid follicular epithelium are the key diagnostic features of granulomatous (subacute, de Quervain's) thyroiditis. Fine needle aspiration cytology is a confirmatory test that is helpful in cases without any clinical suspicion and to exclude differential diagnoses.

The Old and the New in Subacute Thyroiditis: An Integrative Review

Subacute thyroiditis (SAT) is the most common cause of neck pain and thyrotoxicosis. Although this disease was recognized already by the end of the 18th century, new concepts regarding pathogenesis have emerged in recent years. Moreover, in the last two years, literature on SAT has increased significantly due to articles describing the possible connection with coronavirus disease 2019 (COVID-19). This integrative review depicts old and new concepts of this disease, proposing a detailed overview of pathogenesis, a practical approach to diagnosis and treatment, and a thorough description of the latest discoveries regarding the association of SAT with COVID-19.

Vaccine-Induced Subacute Thyroiditis (De Quervain’s) after mRNA Vaccine against SARS-CoV-2: A Case Report and Systematic Review

De Quervain’s thyroiditis, sometimes referred to as subacute thyroiditis (SAT), is the most common granulomatous disease of the thyroid, typically found after a viral infection in middle-aged women. The mRNA encoding for the angiotensin-converting enzyme-2 (ACE-2) receptor is expressed in follicular thyroid cells, making them a potential target for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Besides infection, SARS-CoV-2 vaccines have also been implicated in SAT pathogenesis. We present a case of a woman developing SAT following vaccination with Comirnaty by Pfizer Inc. (New-York, USA). We performed a systematic review of similar cases available in the literature to provide a better understanding of the topic. We searched the databases PubMed and Embase and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Patient records were then sorted according to the type of administered vaccine and a statistical analysis of the extracted data was performed. No statistically significant difference between mRNA vaccines and other vaccines in inducing SAT was found, nor was any found in terms of patient demographics, symptoms at presentation, initial, or follow-up blood tests. In our case report, we described the possible association between SARS-CoV-2 mRNA-based vaccine Comirnaty and SAT.

The Evaluation of Low- and High-Dose Steroid Treatments in Subacute Thyroiditis: A Retrospective Observational Study

OBJECTIVE

The optimal steroid regimen in the treatment of subacute thyroiditis (SAT) is controversial. This study aims to compare low- and high-dose steroid regimens in the treatment of SAT.

METHODS

A single-center, retrospective observational cohort study with up to 1 year of follow-up was conducted. A total of 44 patients in the 16-mg methylprednisolone (MPS) group and 47 patients in the 48-mg MPS group were enrolled. Clinical and laboratory findings from the time of diagnosis to 1-year of the follow-up were assessed. Treatment response, recurrence, and hypothyroidism (HPT) rates were evaluated.

RESULTS

Clinical symptoms, sedimentation rates, C-reactive protein, and thyroid hormone levels of the patients were similar in the 2 groups. Recovery was achieved in all patients at the end of the treatments; however, treatment duration needed to be extended for 6 (13.6%) and 1 (2.1%) of the patients in the 16-mg and 48-mg MPS groups, respectively. The 48-mg MPS group had a higher SAT recurrence rate than the 16-mg MPS group (P = .04). Logistic regression analysis suggested that a lower thyroid-stimulating hormone level at the end of the treatment was a predictor of recurrence (β = -0.544, P = .014, 95% CI: 0.376-0.895). While the transient HPT rate was 10 (21.3%) and 10 (22.7%) in the 48-mg and 16-mg MPS groups, respectively, a permanent HPT developed in 5 (10.6%) of patients in the 48-mg MPS and 3 (6.8%) in the 16-mg MPS group. The permanent and transient HPT rates were determined to be similar in the low- and high-dose groups (P > .05).

CONCLUSION

Low-dose steroid therapy may be sufficient to achieve a complete recovery and better outcomes in SAT.