Expression of CK-19, cErbB2, galectin-3, and p53 in papillary thyroid carcinomas

Aim: To determine the immunohistochemical expression of CK-19, cErbB2, galectin-3, and p53 in papillary thyroid carcinomas (PTC). Materials and methods: In this study immunohistochemistry was performed on 23 papillary carcinomas (PCs) and 20 papillary microcarcinomas (PMCs). The extents of staining and intensity were scored semiquantitatively. Results: Of the PC cases 56.5% and of the PMC cases 15.0% were stained strongly by cErbB2. The extent of 2+ staining by galectin-3 was 47.8% in PC, whereas it was only 10.0% in PMC (P=0.003). All PMC cases were stained by CK-19 and 21 cases of PC expressed positivity in varying extent of staining. No nuclear immunostaining was detected by p53 in PC and PMC. However, 65.2% of PC and 55.0% of PMC cases showed cytoplasmic reactivity. Conclusion: Both PC and PMC cases showed similar staining extent and intensity by CK-19. This may conclusively help in identifying the papillary carcinoma cases. The majority of PCs stained diffusely and strongly by galectin-3 and expressed strong reaction by cErbB2, which might suggest a relation with the size of the tumor as PMCs stained less diffusely and strongly. As no nuclear staining was detected by p53 in 43 papillary carcinomas, we support the idea that p53 expression is a late event in thyroid carcinogenesis.