SPARC Expression in Thyroid Follicular Adenomas and Carcinomas

Kim, Chung Yeul; Cho, Seong Jin; Kim, Min Kyung; Chae, Yang Seok

Abstract

SPARC, secreted protein acidic and rich in cysteine, is a extracellular matrix-associated protein implicated in the modulation of cell adhesion, migration, cell cycle regulation, and angiogenesis. SPARC is expressed in fibrocytes and endothelial cells involved in tissue repair and invasive malignant tumors in the gastrointestinal tract, breast, lung, kidney, adrenal cortex, ovary, and brain. This study was aimed to characterize the different expression of SPARC in the thyroid follicular adenomas and follicular carcinomas. Immunohistochemical staining was performed in paraffin-embedded tissues of 25 follicular adenomas and 15 follicular carcinomas of the thyroid gland. Immunohistochemically, SPARC was not expressed in the 19 follicular adenoma and 2 follicular carcinoma but highly expressed in the 6 follicular adenoma and 13 follicular carcinoma. These findings suggest that SPARC is a potential diagnostic marker of follicular carcinoma and is helpful to distinguish follicular carcinoma from follicular adenoma without vascular or capsular invasion.