English

Abstract

BACKGROUND Thyroid carcinoma is the most common endocrine malignancy. Galectin-3 has been implicated in malignant transformation and metastasis of cancer cells and it has received notable recognition for its usefulness as a diagnostic marker for thyroid cancer. We wanted to evaluate the expression of Galectin-3 on thyroid neoplasms, establish its diagnostic accuracy and also differentiate between benign and malignant thyroid lesions. METHODS A total of 54 thyroidectomy specimens were studied over a period of 3 years (2016 - 2019) which included 20 benign and 34 malignant thyroid neoplasms. Histopathologic evaluation of H & E stained sections was done and immunohistochemistry (IHC) staining for Galectin-3 was performed for all neoplasms with the polymeric method using lyophilized mouse monoclonal antibody. (Path n Situ) and grading based on intensity of Galectin-3 expression were noted. RESULTS Galectin-3 expression was significantly higher (P < 0.001) in malignant thyroid neoplasms in comparison to the benign neoplasms. Galectin-3 expression for malignant neoplasms showed sensitivity of 88.23 %, specificity of 95.0 %, positive predictive value (PPV) of 96.8 % and negative predictive value (NPV) of 82.6 %. Galectin-3 expression in Papillary thyroid carcinoma showed a sensitivity of 95.83 % and PPV of 88.2 %. While comparing the neoplasms showing follicular pattern, Galectin-3 expression was more in the malignant neoplasms (follicular carcinoma and follicular variant of papillary carcinoma thyroid) than benign neoplasms (follicular adenoma). CONCLUSIONS Galectin-3 is a useful marker in differentiating benign and malignant thyroid neoplasms. Galectin-3 is sensitive for Papillary thyroid carcinoma (PTC) and among the follicular patterned lesions, Galectin-3 is sensitive for follicular variant of papillary carcinoma and follicular carcinoma. Thus Galectin-3 protein expression evaluated using immunohistochemistry technique acts as an adjunctive ancillary technique in thyroid cancer diagnosis. KEYWORDS Galectin-3, Immunohistochemistry, Thyroid Carcinoma, Papillary Thyroid Carcinoma