Thyroid FNAC containing hürthle cells and hürthle-like cells: A study of 128 cases

J Cytol. Oct-Dec 2016;33(4):214-219. doi: 10.4103/0970-9371.190447.

Abstract

Aim: It is a diagnostic challenge to differentiate benign and malignant cytology in the presence of Hürthle cells. In our previous study, it was determined that in fine needle aspirations (FNA), the malignancy outcome of the Hürthle cells containing group tend to be papillary thyroid carcinoma (PTC) in a higher percentage. The most common misinterpretation is caused by PTC cells with large cytoplasm-like Hürthle cells. The aim of this study is to predict histologic outcome of the nodules, which have Hürthle cells in FNA according to cytological, clinical features, and BRAFV600E mutation status.

Materials and methods: Detailed cytological features of 128 cases were compared with histopathological diagnosis. The analysis of BRAFV600E mutation of the PTC cases were performed by real-time polymerase chain reaction.

Results: The neoplastic outcome was increased statistically significantly with younger age (P = 0.020), increase in cellular dyshesion (P = 0.016), presence of nuclear budding (P = 0.046), and granular chromatin (P = 0.003). Nuclear budding (P = 0.014), granular chromatin (P = 0.012), and hypoechoic nodules in ultrasonography (P = 0.011) were significant independent factors for the increase in the malignancy risk. Increased lymphocytes (P= 0.015) and colloid were related to non-neoplastic outcome. According to the surgical outcome, more than half of the malign cases were PTC (74%). BRAFV600E mutation was detected in 27.8% of the PTC cases.

Conclusion: PTC cases containing Hürthle cell-like cells may lead to diagnostic errors. Nuclear budding and granular chromatin of Hürthle cells are significant, remarkable findings to predict the outcome of neoplasm and malignancy.

Keywords: Hürthle cell; fine needle aspiration; thyroid.