Galactin-3 Protein Expression in Follicular Adenoma, non-invasive Follicular Tumor with Papillary Nuclear Features and Follicular Variant Papillary Thyroid Carcinoma

Background: Galectin-3 (Gal-3) is a cytoplasmic beta-galactoside-binding protein that is implicated in a many biological processes, including tumor growth, cellular transformation, apoptosis, and cell proliferation. Gal-3 has a diagnostic value in malignant thyroid lesions. Gal-3 is weak or nonexistent in benign or normal thyroid tissue, but overexpressed in some forms of thyroid carcinomas, particularly PTC. Thyroid tumors rank as the tenth most prevalent cancer globally. In Egypt, thyroid cancer makes up around 30% of all endocrine cancers. It ranks the seventeenth malignant tumor among males and the sixth among women. It was crucial to distinguish benign tumors such as follicular adenoma (FA) from follicular variant of papillary thyroid carcinoma (FVPTC) and non-invasive follicular tumor with papillary nuclear characteristics (NIFTP). Objectives: Evaluation of Galactin-3 expression in FA, NIFTP and FVPTC cases, and correlate its expression with clinicopathological parameters of those cases. Patients and methods: 48 cases of FA, NIFTP, and FVPTC were histopathologically evaluated using a standard H&E stain and assessed immunohistochemicaly for Galactin-3 protein expression. Results: There was a significant association in Gal-3 expression between FA and FVPTC (p-value <0.001), where 91.67% of FVPTC cases had high GAL-3 compared to complete absence in FA cases. No significant association in Gal-3 expression between FA and NIFTP was detected (p-value = 0.327). Conclusion: Gal-3 was significantly higher malignant compared to benign thyroid neoplasms