Galectin-3 and Cyclin D3 Immunohistochemistry and Tumor Dimensions Are Useful in Distinguishing Follicular Oncocytic Carcinomas from Oncocytic Adenomas of the Thyroid.

Aims. Oncocytic (Hurthle) follicular cell tumors (OTs) of the thyroid are both adenomas (OAs) and follicular carcinomas (OCs). The routine diagnosis of these tumors can be problematic even after an accurate sampling and histological examination. Beside preoperative evaluation due to the tumor's dimension several studies have been performed to find markers able to distinguish malignant from benign follicular tumors in the thyroid, with Galectin-3 being one of the most effective. Recently, some authors suggested cyclin D3 as adjunct to the diagnosis of the oncocytic lesions of the thyroid. Methods and Results. In this paper we assess the role of Galectin-3 and cyclin D3 in a well-selected group of follicular oncocytic tumors (14 OCs and 26 OAs). The diameter of each lesion was also evaluated. The combination of Galectin-3 and cyclin D3 has a good specificity (81%) and sensitivity (100%). Moreover, the maximum diameter (in cm) of OCs is greater than OAs (4.1 versus 2.3). Conclusions. We believe that the use of Galectin-3 and cyclin D3 in OTs of the thyroid can be a helpful panel in daily practice when histology is doubtful.