Diagnostic utility of CK19 and galectin-3 in differentiating papillary thyroid carcinoma from nonneoplastic lesions of thyroid.

ABSTRACT

Background: Thyroid neoplasm is one of the most common endocrine neoplasms. The diagnosis and the distinction between malignant and benign neoplasms can be difficult, but it has clinical, therapeutic, and prognostic significance. Hence, it is necessary to make precise diagnosis by using biomarkers. Materials and Methods: This is a laboratory observational study considering histologically diagnosed cases of papillary thyroid carcinoma (PTC) and nonneoplastic thyroid lesions. Immunohistochemistry (IHC) staining was done on tissue sections of all cases for CK19 and galectin-3 using appropriate positive and negative controls. The expression of immunomarkers was evaluated by a semi-quantitative method as negative, weak positive, moderate positive, and strong positive. The data were entered in Microsoft Excel sheet and were analyzed using SPSS 22 version software. Results: A total of 52 cases were considered for the study, of which 26 cases each were PTC and nonneoplastic lesions of thyroid. Among the 26 PTC cases, 6 were classical variant of PTC (CVPTC) and 20 were follicular variant of papillary thyroid carcinoma (FVPTC). Among 26 nonneoplastic cases, 13 each were nodular hyperplasia cases and lymphocytic thyroiditis. There was a statistically significant (P < 0.01) association of CK19 and galectin-3 expression between CVPTC and FVPTC. There was no statistically significant association (P = 0.271) of CK19 expression between PTC and nonneoplastic cases. There was a statistically significant association (P = 0.003) of galectin-3 expression between PTC and nonneoplastic cases. Conclusion: Galectin-3 expression can be used to differentiate PTC from nonneoplastic lesions of thyroid in ambiguous cases. Galectin-3 and CK19 expression can be used to classify PTC into CVPTC and FVPTC.