Abstract
PURPOSE: Fascin, an actin-bundling protein, is markedly upregulated in several epithelial tumors and its expression often correlates with high-grade, extensive invasion, and distant metastasis. However, reports about fascin expression in endocrine tumors remain rare. The aim of the present study was to assess the diagnostic significance of fascin in thyroid neoplasms. METHODS: Thyroid samples from 177 cases were examined for fascin and Ki-67 expression by immunohistochemistry. RESULTS: Fascin immunoreactivity was negative in normal follicles and nodular goiter. Fascin immunostaining was positive in 62.1% (41/66) of thyroid carcinomas and 26.4% (19/72) of thyroid adenomas; the difference being significant (P < 0.0001). In thyroid papillary carcinoma, upregulation of fascin was associated with both the Ki-67 labeling index and the occurrence of lymph node metastasis. CONCLUSION: Fascin may be a novel marker to distinguish thyroid carcinoma from benign lesions and may be involved in the proliferation and metastasis of papillary carcinoma.