ABSTRACT
Widespread use of abdominal imaging has increased the number of incidental tumors found in the greater than 38 000 renal masses diagnosed in the United States in 2006.1 Thirteen percent of all renal tumors were discovered incidentally in the 1980s. By the mid 1990s incidental lesions accounted for 60% of all renal masses.2 These incidental lesions present at a lower stage, grade, and likelihood of metastasis, and have improved survival outcomes compared to tumors detected in symptomatic patients.2-4 A significant number of these lesions will ultimately prove benign, but this diagnosis is difficult to obtain preoperatively. Imaging techniques are unable to consistently predict pathology and percutaneous renal biopsy is unreliable with an accuracy of only 76 to 80%.5
