In this study, a score based on glycosaminoglycan (GAG) profiling in subjects with suspicion of renal cell carcinoma (RCC) is hypothesized to distinguish malignant masses when early actionable clinical decisions are desirable. For example to screen population at risk or to distinguish benign masses from RCC before patient is referred to surgery. To this end, the plasmatic and urinary GAGs will be measured in prospectively enrolled subjects and the resulting scores correlated to the post-surgical definitive diagnosis and eventual RCC size. A positive significant correlation is suggestive that GAG profiling can be used to guide clinical intervention in a subject at risk or referred to nephrectomy because of suspicion of RCC. The biomarker in patients with high risk RCC will be monitored to observe its correlation with disease progression. Also, the biological significance of this positive correlation will be evaluated using gene expression profiling. This data may also be used to improve further the diagnostic accuracy of the proposed biomarker.