RESUMO
BACKGROUND AND OBJECTIVES: The diagnosis of thyroid nodular diseases is critical in clinical management. Fine needle aspiration cytology and ultrasound-guided core needle biopsy are widely considered as diagnostic techniques in assessment of thyroid nodular diseases. Because of the histological similarity of follicular patterned thyroid lesions, the differential diagnosis between some thyroid lesions is often difficult to determine, even with permanent sections. For this reason, we assessed diagnostic usefulness of immunohistochemical staining for the three potential markers of malignant thyroid nodule, Galectin-3, MUC1 and EGFR (Epidermal growth factor receptor) in the tissue obtained by surgery. SUBJECTS AND METHOD: The immunohistochemical expression of galectin-3, MUC1 and EGFR was evaluated in 76 thyroid lesions obtained by surgery to assess their potential as markers in differential diagnosis of thyroid nodule. The following were studied: 20 cases of papillary carcinoma, 16 cases of follicular carcinoma, 20 cases of follicular adenoma and 20 cases of adenomatous goiter. RESULTS: The expression of Galectin-3 was stronger in malignant thyroid nodules, especially in papillary carcinoma, than in benign thyroid nodules. However, there were no significant differences in the expression rates of MUC1 and EGFR between malignant thyroid nodules and benign thyroid nodules. The expression of MUC1 and EGFR was weaker in follicular neoplasm than in other thyroid nodules. CONCLUSION: Galectin-3 was a reliable marker for papillary carcinoma. The expression of MUC1 and EGFR was increased in the papillary carcinoma and goiter, so if we could selectively identify cytoplasm MUC1, we could distinguish papillary carcinoma from the goiter.