[Histogenesis of renal cell carcinoma]

Immunomorphological characteristics of 27 renal cell carcinomas--18 clear cell, 6 granular, 2 chromophobic, 1 sarcomatoid--as well as 1 oncocytoma were analyzed. The investigation was performed on cryostat sections with indirect immunoperoxidase technique using monoclonal antibodies to intermediate filaments-cytokeratin and vimentin--and renal differentiation antigens--CD10 and CD24. All carcinomas, with the exception of chromophobic type, showed cytokeratin/vimentin coexpression together with strong CD24 and weak (or absent) CD10 staining indicating at primitive cells with initial differentiation toward proximal tubule epithelium as most probable site of origin. In chromophobic cells only cytokeratin and CD24 antigen presence was observed, pattern similar to that seen in oncocytoma. It could be supposed that those two tumors have closely related histogenesis, originating from more differentiated cells with tendency to develop toward distal tubule epithelium.