534 CANCER-SPECIFIC SURVIVAL NOMOGRAM FOR RENAL TUMORS WITH VENOUS EXTENSION:INTERNATIONAL RENAL CELL-CARCINOMA-VENOUS THROMBUS CONSORTIUM

benign oncocytomas. As reference to FISH analysis we carried out array-CGH for all analyzed tumors. RESULTS: The correlation of FISH findings with histopathological data revealed that histological subtypes were correct in 100% (26/26) of ccRCC cases, in 80% (8/10) of pRCC, 100% (13/13) in chRCC and in 33% (4/12) of oncocytomas. Two tumors classified as papillary according to histopathological features were grouped to ccRCC on the basis of genetic pattern detected by FISH and CGH analysis. In 8 oncocytomas we found either no genomic alterations or alterations in less than 10% of scored nuclei. Array-CGH and CGH analysis demonstrated no alterations or atypical chromosomal changes in these tumors. CONCLUSIONS: The current study demonstrates that the developed multicolor FISH assay allows an accurate identification of the most frequent renal cell tumor subtypes and increases the diagnostic accuracy of RCC. It represents a robust and rapid method for routine diagnostics in cases of uncertain diagnosis by histopathological evaluation and helps to overcome the limitations of pathological classification. Currently we are working on a second set of probe composed of centromeric probes of chromosomes 2 und 6 and a translocation probe for chromosome 11 allowing the precise differentiation of some ambiguous cases of chromophobe RCC and oncocytomas as well.