Immunohistochemical expression of pl30cas in papillary thyroid carcinoma

pl30cas is a multifunctional protein that is involved in many aspects of cellular physiology, including adhesion, migration, and regulation of the cell cycle, and can be regulated by a variety of stimuli. We immunnohistochemically examined pl30cas, cytokeratin 19 (CK19), and epithelial membrane antigen (EMA) expression in 37 cases of papillary thyroid carcinoma (PTC), 11 cases of Hashimato's thyroiditis with papillary carcinoma-like changes, and 17 cases of nodular hyperplasia. All PTCs were immunoreactive for pl30cas. We showed no positivity in normal thyroid follicles adjacent to the tumor. However, we observed focal positivity in thyroid follicles in association with heavily lymphoplasmacytic infiltrate or degeneration away from the tumor in 19% of PTCs and in 18% (3/17) of nodular hyperplasias. This is the first study of expression of pl30cas; these finding suggest that pl30cas may have a role in tumorigenesis and its expression may contribute to the diagnosis of papillary carcinoma.