Imaging of renal masses and staging of renal tumours

• Renal masses are a common, often incidental finding on cross-sectional imaging.• Ultrasound can readily characterize a mass as solid or cystic.• The Bosniak classification is based on CT but can equally well be applied to MRI or contrast-enhanced ultrasound.• CT is the main method for staging renal cell carcinoma (RCC), with MRI used in specific indications, such as to assess the extent of venous involvement.• Most solid renal masses are assumed to be RCC, although approximately 20% of masses under 3 cm will be benign.• The seventh edition of the American Joint Committee on Cancer TNM staging for renal cancer has been presented.• An overview of the therapeutic options for renal cancer is discussed.Renal masses are commonly encountered in adult radiological practice, with a range of appearances from entirely cystic to solid. Characterization of more complex cystic masses is a challenge, to which the now considerably refined Bosniak classification has been applied. The Bosniak classification will be discu...