Diagnostic role of galectin-3 immunohistochemistry in thyroid lesions

Background: Galectin-3 (Gal-3) is a good diagnostic marker for thyroid cancer. Evaluation of diagnostic accuracy of this marker complements the morphological assessment of a particular thyroid lesion. The aim of this study was to evaluate the immunohistochemical expression and diagnostic role of Gal-3 in various surgically resected thyroid lesions. Materials and Methods: Surgically resected thyroid specimens from 50 patients with hematoxylin and eosin (H and E)- and Gal-3-stained sections were studied. Results: The age of the patients ranged from 14 to 64 years. Of the 50 patients, 12 (24%) were male and 38 (76%) were females. Various histopathological diagnoses included were inflammatory lesions 8 (16%), hyperplastic lesions 15 (30%), and benign 2 (4%) and malignant 25 (50%) lesions. On quantitative analysis of Gal-3 immunostaining, 16/16 (100%) of the papillary thyroid carcinoma (PTC) cases showed a positive expression. In the rest of the malignant cases, 5 (20%) of follicular thyroid carcinoma, 3 (12%) of medullary thyroid carcinoma, and 1 (4%) of anaplastic thyroid carcinoma showed a negative expression. The PTC cases showed a statistically significant difference from the rest of the benign lesions (P = 0.000). In PTC cases, the sensitivity of Gal-3 came out to be 100%, specificity was 64%, positive predictive value was 75.3%, negative predictive value was 100%, and accuracy was 82%. Conclusion: The data thus obtained indicate that Gal-3 is a valuable marker for differentiating classical PTC and its common variants (follicular variant and microcarcinoma in our study) from the other benign and malignant lesions. Gal-3 as a diagnostic marker for thyroid cancer can lead to improved outcomes for individuals diagnosed with equivocal or suspicious lesions.