RESUMO
INTRODUCTION: De Quervain's Thyroiditis (DQT) is a self limiting inflammatory disease of the thyroid gland that presents with pain and sore throat. Although the diagnosis is usually made clinically, Fine Needle Aspiration (FNA) may provide assistance, particularly in excluding other thyroid lesions. AIM: The objective of this study was to reveal the cytological characteristics of DQT. MATERIALS AND METHODS: We retrospectively reviewed the clinical and FNAC findings of 20 cases of DQT to find the most reliable features for a confident cytological diagnosis. RESULTS: Among the cases reviewed, the common cytological features present in all 20 cases were follicular epithelial cells with degenerative changes and dirty background comprising of cellular debris and mixed inflammatory cells (lymphocytes and macrophages and occasional polymorphs). The next common finding observed was Multinucleated Giant Cells (MNGCs) seen in 19 cases followed by epithelioid cell clusters in 15 and colloid in 13 cases. CONCLUSION: Presence of follicular epithelial cells, large MNGCs and dirty background of cellular debris, mixed inflammatory cells with predominance of lymphocytes and macrophages were the most striking and consistent features for diagnosis of DQT in cytological smears. The above findings in consideration with the clinical history will help us to reach a definitive diagnosis. FNA also proves to be a useful tool in excluding other thyroid lesions with similar clinical presentations.