[Atypical metastasis of renal cell carcinoma. Contribution of comparative genomic hybridisation to diagnosis].

In patients younger than 40 years, renal cell carcinoma and metastases to the bladder are rare. Comparative genomic hybridisation (CGH) may be useful to differentiate between metastatic renal cell carcinoma and secondary malignancies of the genitourinary tract, which can occur in all histologic types. We report the case of a 35-year-old patient with renal cell carcinoma in whom only CGH could help differentiate between a second primary malignancy in the bladder and an atypical bladder metastasis.