Histomorphological study of malignant thyroid neoplasm in a tertiary care center and evaluation of Galectin 3 expression in papillary thyroid carcinoma

Galectin-3 is a beta-galactoside binding animal lectin, which is frequently associated with tumour progression and metastasis. In recent years, overexpression of Galectin-3 has been reported in various human cancers and more frequently in thyroid neoplasms. The aim of this study was to analyze the histomorphological characteristics of malignant thyroid neoplasms, subtype them according to the established classification system and to evaluate the expression of Galectin-3 immunostaining in papillary thyroid carcinoma. A total of 30 cases were included in the study, out of which 28 cases were papillary thyroid carcinoma and its variants and one case of medullary and anaplastic carcinoma. Majority of the papillary thyroid carcinoma cases were positive for Galectin 3 immunostaining (25/28 cases – 89%) in our study. We conclude that galectin-3 is consistently expressed in papillary carcinoma thyroid; however, there are few false-negative cases in this study and also other studies have reported Galectin 3 overexpression in non-papillary tumors. Hence, we cannot depend on Galectin 3 expression alone as a single diagnostic tool to detect papillary thyroid carcinoma.