Abstract: Objective Hyalinizing trabecular tumor (HTT) is often mistaken as thyroid papillary carcinoma(TPC), which shares some morphological features with TPC. The aim of this study is to investigate HTT and TPC with immunohistochemical methods. Methodswe detected the expression of the three Immunohistochemical index((CK19, HBME-1,MIB-1) in thirteen cases HTT and twenty cases TPC. ResultsIn HTT samples, CK19: three of the thirteen were positive and focal positivity（1+）; HBME-1: None of the thirteen samples was stained. MIB-1: ten in thirteen cases were stained in nucleus. In TPC samples, CK19: all of the twenty samples were intensely stained; HBME-1: nineteen of twenty samples were intensely stained; MIB-1: all of the twenty samples were stained in nucleus. The sensitivity and specific degrees of CK19 and HBME-1 combination to diagnosis HTT and TPC were 90.0% and 69.2%. Conclusion Our research could provide potent aid to differential diagnosis of HTT and TPC. The combination of CK19 and HBME-1 are adequate to identify HTT and TPC.

Key words: Hyalinizing trabecular tumor, Papillary carcinoma, CK19, HBME-1, Immunohistochemistry