Diagnostic Feasibility of Galectin-3 for Suspicious Malignant Thyroid Nodule in Preoperative Fine-Needle Aspiration Cytology

ABSTRACT

PURPOSE: Fine Needle Aspiration Cytology (FNAC) is considered as the most feasible preoperative diagnostic tool for thyroid lesions. However, the false results of FNAC are not uncommon, and so we need a development of novel supportive preoperative diagnostic modality. In previous studies, galectin-3, a beta-galactosidase-binding protein, was expressed preferentially in thyroid malignancies. In this study, we analyzed whether the galectin-3 immunohistochemistry (IHC) is useful as a preoperative diagnostic tool. METHODS: 79 patients who underwent a definite surgery for thyroid nodule were analyzed. The preoperative routine stained cytology and galectin-3 IHC for fine-needle aspirates and the galectin-3 IHC for postoperative specimen were performed. Individual results were compared with the final diagnoses. RESULTS: Of 79 specimens, 28 (35.4%) were malignant. The false negative rate (FNR) of galectin-3 IHC in the surgical specimen was 10.0%. The FNR of galectin-3 IHC for the fine-needle aspirates was 50.0% and the FNR of routine cytology was 20.5%. However, the FNR of galectin-3 IHC in the fine-needle aspirates was lowered up to 20.0% in thyroid lesions obtained by using ultrasound-guided aspiration. Among the 14 cases reported as suspicious in routine cytology, 13 cases were revealed the accurate correlations in galectn-3 IHC. CONCLUSION: It appears that galectin-3 IHC in preoperative FNAC alone had a little accuracy. However, preoperative galectin-3 IHC in thyroid lesions obtained under the ultrasound guidance could be diagnostic. Especially in suspicious group in FNAC, galectin-3 IHC could be critical method in differentiating malignant lesions from benign lesions of thyroid.