The meaning and predictivity of Hürthle cells in fine needle aspiration cytology for thyroid nodular disease

Aims. The significance of Hürthle cells in thyroid nodule fine needle aspiration cytology (FNAC) samples remains uncertain. This study aims to clarify the meaning and the predictivity of this kind of cells. Methods. One hundred and ten patients with Hürthle cells in FNAC of thyroid nodules were reviewed. Histopathology was correlated with cytological findings. Results. The density of Hürthle cells in FNACs ranged from 20 to 100%. Eighty-nine patients had benign nodular disease (Hürthle cell or follicular adenoma), and 21 patients had malignant tumours. The presence of more than 50% Hürthle cells in FNAC correlated with benign or malignant Hürthle cell neoplasm. Hürthle cell carcinomas displayed more than 90% Hürthle cells in FNAC. Conclusions. Surgery is indicated for all nodular lesions with more than 50% Hürthle cells in FNAC.