[Classification, histogenesis, and prognosis of renal cell carcinoma and renal oncocytoma]

Typing of renal cell tumours according to cytomorphological criteria results in different basic cell types, i.e. the clear cell type, the chromophilic cell type, the chromophobic cell type, the oncocytic cell type and the cell type of Duct-Bellini-Carcinoma. Each basic cell type exhibits a typical spectrum of cytological variability including eosinophilic (granular) variants. Antigenic properties of the proximal tubule can mainly be detected in clear cell and chromophilic renal cell carcinomas, whereas antigenic properties of the connecting tubule and collecting duct can be found especially in the chromophobic renal cell carcinoma and oncocytoma as far as in Duct-Bellini-Carcinoma. These different phenotypes of epithelial renal cell tumours are possibly due to various histogenetic pathways. Prognostic factors in renal cell carcinoma include staging, grading and to a less extent cytological and histological parameters which are summarized in a new prognostic score. From this score, three significantly distinct prognostic groups evolved with a correct prognosis of over 80% on the average for an individual case, which suggests a great prognostic potential.