Significance of CK19, TPO, and HBME-1 expression for diagnosis of papillary thyroid carcinoma.

OBJECTIVES To evaluate the expression and significance of CK19, TPO, and HBME-1 in the differential diagnosis of papillary thyroid carcinoma (PTC) and nonmalignant nodules. METHODS Tissue samples were obtained from 257 patients with PTC and 149 patients with nonmalignant thyroid specimens, and immunohistochemical staining for CK-19, TPO, and HBME-1 was performed. RESULTS The expression of CK-19, TPO, and HBME-1 was 96.3%, 12.0%, and 85.3%, respectively, for the PTC group. For nonmalignant thyroid lesions group, the expression of these markers was 40.4%, 86.2%, and 37.2%, respectively. Further, the expression of CK-19 and HBME-1 in PTCs was much higher than that in the benign thyroid lesions (P < 0.05). However, the positive expression of TPO in PTC specimens was much lower than that in the nonmalignant specimens (P < 0.05). CK-1 had the highest sensitivity (96.30%) for PTCs. The combination of the positive expression of CK-19 and negative expression of TPO had the highest sensitivity (98.50%), while that of the positive expression of HBME-1 and negative expression of TPO had the highest specificity (92.90%). CONCLUSIONS The combination of positive expression of CK-19 or HBME-1 or negative expression of TPO can improve the specificity of the diagnosis of PTC.