RBPJ::ALK : a novel fusion gene amplified in a metastatic sarcomatoid chromophobe renal cell carcinoma

Using Fluorescence in situ hybridization (FISH), Comparative genomic hybridization on array (aCGH) and Targeted RNA sequencing (RNASeq), we observed a novel fusion of ALK with RPBJ that was amplified and immunohistochemically overexpressed in both the small sarcomatoid component of a chromophobe renal cell carcinoma (chRCC) and in its lymph node metastasis. The amplified RBPJ::ALK fusion was not detected in the chromophobe component of the primary tumour that harbored chRCC-typical losses of chromosomes 1, 2, 6, 10, 13 and 17. In contrast, the same mutations of PTEN, TP53 and TERT promoter were observed together in the three analyzed samples from chRCC, sarcomatoid component of the chRCC and metastasis. screening of 3 samples ofa chromophobe renal cell carcinoma by SNP array with affymetrix platform