Purpose To investigate the expression of DSG3,MAC387 and p40 in urothelial carcinoma with squamous differentiation and their diagnostic significance. Methods Immunohistochemical of En Vision two-step staining for DSG3,MAC387 and p40 was carried out on a series of 18 cases of urothelial carcinoma with squamous differentiation,12 cases of squamous cell carcinoma and 15 cases of urothelial carcinoma. Results DSG3,MAC387 and p40 expressions in urothelial carcinoma with squamous differentiation were 15( 83%),17(...