[Comparison of ultrastructural and immunohistochemical studies on renal cell carcinoma and human embryo kidney].

26 cases of renal cell carcinoma (RCC) were studied by both light microscopy and electron microscopy, accompanied with 9 cases of human embryo kidney as control. 20 cases of RCC in different degree of cell differentiation, 4 cases of human embryo kidney and 1 case of adult human kidney were studied with immunohistochemical methods. The results indicated that the histostructures and antigen expression of RCC were rather complicated and the ultrastructures and antigen expression changes of RCC seemed very similar to those of the developing embryonic kidneys. This indicated, that RCC might have originated from nephroblastoma cells.