Spectrum of thyroiditis types: clinical, cytomorphological, and radiological findings

Thyroiditis encompasses a range of inflammatory conditions affecting the thyroid gland. Lymphocytic thyroiditis (LT) is a common form of thyroiditis, with acute suppuration of the thyroid, while tuberculous thyroiditis is relatively rare. Fine-needle aspiration cytology (FNAC) remains a safe and cost-effective tool for diagnosing thyroid-related diseases, especially when paired with ultrasound (US) and clinical examination.

This is a cross-sectional study including 21 cases. The cases were reported as thyroiditis on US and FNAC, and the findings were correlated with patient clinical history, symptoms during presentation, and serological profiles.

The cases of thyroiditis encompassed the more common forms, LT and subacute granulomatous thyroiditis (SAT), as well as relatively rare forms like tuberculous thyroiditis and thyroid abscess. Cases of follicular neoplasms (FN) arising in the context of LT also are included in this study. The case of tuberculous thyroiditis presented as a bulky thyroid gland that appeared heterogeneous on US with extensive necrosis on FNAC. The cases of thyroid abscess and SAT presented with painful neck swellings, with granulomas in the latter cases. US features of LT showed an array of appearances ranging from pseudonodular to an atrophic thyroid gland. All cases of FN showed a lymphocytic background.

Thyroiditis is a commonly encountered condition that needs to be sub-categorized accurately into acute, subacute, and chronic types for appropriate clinical management, as they can sometimes show overlapping features. Though rare, acute suppurative and tuberculous thyroiditis are often encountered and warrant immediate care and treatment.