A 75-year-old woman with a right renal oncocytoma presenting as a hypovascular mass secondary to cystic change and haemorrhage. a Unenhanced axial CT image shows an exophytic right renal mass, which is iso-attenuating to the normal kidney (arrow). b The corticomedullary phase of the axial CE-CT shows the mass to be low attenuation (arrow). c The nephrographic phase demonstrates thin enhancing septations (small arrow). d The delayed phase shows the mass to be heterogeneous (arrow). e (Low magnification) Oncocytoma, cystic pattern, tumour cells predominantly arranged as cystic structures (C) with haemorrhage (arrow).