Diagnostic value of galectin-3 as a marker for malignancy in follicular patterned thyroid lesions

Background. The determination of malignancy in follicular patterned thyroid lesions is based on postoperative histologic findings. Therefore, affected patients are referred for surgery, although only 20% will have a final diagnosis of malignancy. The aim of this study was to investigate the potential of galectin-3 as a marker of malignancy in these lesions. Methods. Fifty-four tissue specimens of follicular patterned thyroid lesions were immunohistochemically stained for galectin-3. Area and intensity scores were recorded. Results. Significant differences were found between the benign and malignant lesions. The sensitivity, specificity, positive predictive values, and negative predictive values of galectin-3 staining were 82%, 68%, 75%, and 77%, respectively (p = .0002). Significant differences were also found between the subgroups of benign and malignant lesions (p ≤ .05). Conclusions. Galectin-3 staining is highly sensitive for malignancy in follicular patterned thyroid lesions. Diagnostic problems may arise in the presence of Hürthle cell proliferation or minimally invasive follicular carcinoma.