Expression of Galectin-3 and Its Diagnostic Utility as Preoperative Diagnostic Marker for Thyroid Nodule

Kang, Jin Wook; Kim, Chan Jong; Nam, Soon Yuhl

Abstract

BACKGROUND AND OBJECTIVES
Thyroid cancer is the most common endocrine malignant disease, but making a preoperative diagnosis of this disease remains a challenge. Fine-needle aspiration biopsy (FNAB) is the most accurate and cost-effective method for the preoperative diagnostic method of thyroid nodules, but not for differential diagnosis between thyroid follicular adenoma and follicular carcinoma. In this study, we assessed the usefulness of immunohistocytochemical staining for the potential marker of malignant thyrocytes, galectin-3. SUBJECTS AND METHOD: From October 2001 to January 2003, the preoperative expression of galectin-3 was examined immunohistochemically in 178 cases of fine needle apsiration biopsy (FNAB). All patients had then undergone therapeutic thyroid surgery and a permanent biopsy was obtained from each of them. The biopsy showed 30 adenomatous goitor, 105 papillary carcinoma, 30 follicular adenoma, 11 follicaulr carcinoma, 1 anaplastic carcinoma and 1 papillary carcinoma combined with follicular carcinoma. We compared the preoperative galectin-3 expressions in FNAB with the results of postoperative permanent pathology. RESULTS: The immunoghistochemical staining results showed galectin-3 expression in the preoperative FNAB in 14 cases of 30 adenomatous goitors, 76 cases out of 105 papillary carcinomas, 11 cases out of 26 follicular adenoma, 8 cases out of 11 follicular carcinoma, no case out of anaplstic carcinomas and 1 case out of papillary combined follicular carcinoma. The preoperative galectin-3 staining for differential diagnosis of follicular cell carcinoma from benign follicular lesions showed that sensitivity was 73%, specificity 43%, positive predictive value 28%, and negative predictive value 88%. CONCLUSION: This study found that the integration of galectin-3 immunostaining with conventional cytomorphological and clinical diagnostic procedures did not serve well in properly identifying preoperative thyroid carcinomas and thyroid follicular carcinoma. Galectin-3 has some limitation in differentiating benign from malignant thyroid follicular lesions. Specific immunostaining features of galectin-3 or follicular cell carcinoma specific molecules have to be investigated more in the future.