57 year old male patient with history of a left renal mass. ABDOMEN:LIVER, BILIARY TRACT: No significant abnormality noted.SPLEEN: No significant abnormality noted.PANCREAS: No significant abnormality noted.ADRENAL GLANDS: No significant abnormality noted.KIDNEYS, URETERS: There is a 4.1 x 3.9 x 3.4 cm exophytic mass arising off the interpolar region of the left kidney. The mass demonstrates a peripheral hypointense T2 rim and heterogeneous internal T2 signal. Although there is internal T1 hyperintensity, there is no significant susceptibility on in and out of phase imaging; it is unclear if this represents proteinaceous material or hemorrhage. There is the suggestion of stellate enhancement within the lesion on subtraction imaging.Multiple subcentimeter hypointense lesions within the bilateral kidneys are too small to characterize. There is an exophytic left renal cyst. No evidence of hydronephrosis.RETROPERITONEUM, LYMPH NODES: No significant retroperitoneal lymphadenopathy.BOWEL, MESENTERY: No significant abnormality noted.BONES, SOFT TISSUES: No significant abnormality noted.OTHER: No significant abnormality noted.
Left renal mass with encapsulation, low T2 signal, and perhaps a stellate configuration of enhancement; this may represent an oncocytoma vs a renal cell carcinoma. 