Expression of Galectin 3, HBME1 and CK19 in Benign and Malignant Thyroid Lesions

Background: The accurate diagnosis of well differentiated thyroid tumors is very important for clinical management of patients. Circumscribed lesions having follicular pattern of growth like encapsulated papillary thyroid carcinoma (follicular variant) and microinvasive follicular thyroid carcinoma can cause lots of diagnostic problems in their distinction from benign lesions as follicular adenoma and hyperplastic thyroid nodules with abnormal nuclear features. Aim: To assess the utility of the immunohistochemical markers (CK 19, HBME 1, and Galectin 3) either used singly or in combination to differentiate benign and malignant thyroid lesions, especially well differentiated papillary and follicular carcinoma from follicular adenoma.Material and Methods A total of forty specimens were retrospectively reviewed in this study, including 33 thyroidectomies, 4 neck lymph node excisional biopsies showing metastatic deposits and 3 core tissue biopsies from bone metastatic deposits. Four (5 microns thick) sections were prepared from each tissue block, one stained with hematoxylin and eosin and the others were subjected to the three immunohistochemical markers (CK 19, HBME 1, and Galectin 3).Results: CK 19 stained positively 95% of papillary carcinomacases 40% of follicular carcinoma cases and 50% of follicular adenoma cases. HBME 1 stained 90% of papillary carcinoma cases, 50% of follicular carcinoma cases, and only 10% of follicular adenoma cases. Galectin 3 stained positively 100% of papillary carcinoma cases, 20% of follicular carcinoma cases and 20% of follicular adenoma cases. These results proved that HBME1 is the most valuable marker if used alone in the differential diagnosis of papillary carcinoma versus follicular adenoma.Conclusion: These results proved that a panel of CK 19,HBME 1 and Galectin 3 is very useful in differentiatingpapillary thyroid carcinoma from follicular adenoma especiallyin problematic cases when the nuclear features can not be conclusive alone.