Uroplakin II Is a More Sensitive Immunohistochemical Marker Than Uroplakin III in Urothelial Carcinoma and Its Variants

Objectives: Uroplakin (UP) II and UPIII are highly specific immunohistochemical markers for urothelial differentiation. Here we studied the sensitivity of UPII and UPIII in conventional and variant urothelial carcinomas (UCs). Methods: Immunohistochemical staining for UPII and UPIII was performed on tissue microarray slides, including 105 conventional bladder UCs (BUCs), 90 upper urinary tract UCs (UUTUCs), and 47 micropapillary, 16 plasmacytoid, 22 small cell carcinoma, and 41 sarcomatoid UC variants. Results: UPII expression was significantly higher than UPIII expression in conventional BUC (44 % vs 17%, P <.001) and UUTUC (67 % vs 46%, P =.045). UPIII expression was significantly higher in UUTUC than in BUC (P <.001). In UC variants, UPII expression was significantly higher tha