The Natural History of Small Renal Masses

There is a rising incidence of incidentally detected small renal tumours due to improved imaging techniques. Traditionally, patients diagnosed with these small renal masses undergo surgery and therefore there is limited data about the natural history of these tumours. Several small series have reported that most of these small masses grow slowly and might not require early intervention and that only some masses grow rapidly requiring immediate surgery. Presently, the investigators have not been able to identify prospectively which masses are going to grow slowly. The investigators plan to use computed tomography (CT) and Magnetic Resonance Imaging (MRI) parameters, microsatellite analysis and tissue analysis to determine which masses will behave more aggressively. Additionally, the observations on the natural history of small renal masses need to be validated with a multicentric and systematically followed cohort.