Intensity and distribution of immunohistochemical expression of galectin-3 in thyroid neoplasms.

The aim of the study was to assess the intensity and distribution of galectin-3 expression in benign and malignant thyroid neoplasms by immunohistochemical method. Immunohistochemical expression of galectin-3 was analyzed in surgical thyroid specimens from 82 patients with histopathologic diagnosis of follicular adenoma (n = 32), Hürthle cell adenoma (n = 10) and papillary carcinoma (n = 40). Results of intracytoplasmatic and intranuclear expression of galectin-3 were scored using a semi-quantitative scale for intensity. Intracytoplasmatic expression ofgalectin-3 was positive in 18 (43%) benign neoplasms and in all 40 malignant neoplasms. The accuracy, sensitivity and specificity of intracytoplasmatic expression of galectin-3 as a malignant marker in thyroid neoplasms were 78.1%, 100% and 57.1%, respectively. Intracytoplasmatic expression of galectin-3 was positive in 10 (31%) cases of follicular adenoma and 8 (80%) cases of Hürthle cell adenoma. The accuracy, sensitivity and specificity of intranuclear expression of galectin-3 as a malignant marker in thyroid neoplasms were 84.1%, 100% and 69%, respectively. There was no strong intensity of either intracytoplasmatic or intranuclear expression ofgalectin-3 in benign thyroid neoplasms, and no weak intensity of either intracytoplasmatic or intranuclear expression of galectin-3 in malignant neoplasms. There was no statistically significant difference between intracytoplasmatic and intranuclear expression of galectin-3 in benign thyroid neoplasms. The results of our study indicate that the immunohistochemical expression of galectin-3 is a highly sensitive marker of malignancy, with low specificity in differentiating malignant from benign thyroid neoplasms. The analysis of intensity and distribution ofgalectin-3 expression could improve the specificity of the method.