Abstract: Objective To explore the expression and significance of CD26/DPPⅣand galectin-3 in papillary thyroid carcinoma. Methods Expression of CD26/DPPⅣ or galectin-3 in 68 papillary thyroid carcinomas and 36 thyroid adenomas were determined with EnVision immunohistochemical technique respectively. Results CD26/DPPⅣ and galectin-3 were higher expressed in most of papillary carcinomas but absent or lower expressed in most of all thyroid adenomas. With CD26/DPPⅣ as means to detect papillary carcinoma, the sensitivity, specificity, diagnostic accuracy were 86.8%, 97.2% and 90.4%, and with galectin-3 the respective figures were 97.1%, 91.7% and 95.2%. There were not any statistic significance within the intrathyroidal and extrathyroidal invasion, without and with lymph node metastasis, low and high dangerous prognosis groups about positive expression of CD26/DPPⅣ or galectin-3 in papillary carcinomas. Conclusions Both CD26/DPPⅣ and galectin-3 are potential markers of papillary thyroid carcinoma. CD26/DPPⅣ or galectin-3 immunohistochemical staining can be used as a supplement for conventional pathological diagnostic approach to differentiate thyroid papillary carcinomas from adenomas, while their uses to assess the invasion , metastasis and prognosis of papillary thyroid carcinomas are out of value.

Key words: papillary thyroid carcinoma, CD26/DPPⅣ, galectin-3, metastasis, prognosis