Pursuit of the renal mass. Is ultrasound enough?

The accuracy of ultrasonography in evaluating renal masses was assessed retrospectively in 260 renal lesions detected by intravenous urography in 242 patients. The ultrasonographic diagnosis was confirmed by cyst puncture, surgery, or autopsy. Of the lesions, 168 were benign cysts, and all were diagnosed correctly by ultrasonography. The remaining 92 lesions were renal carcinomas, and 90 were diagnosed correctly by ultrasonography. In retrospect, it was clear that the two missed cancers did not fulfill all the ultrasonographic criteria for a cyst. An algorithm is presented for the differential diagnosis of renal masses primarily by ultrasonography, and the arguments in favor of operative diagnosis of renal masses are rebutted. With the approach described, invasive studies such as cyst puncture and arteriography will be required for a definitive diagnosis in fewer than 10 percent of patients, and the morbidity and expense of the diagnostic approach will be minimized, with no decrease in accuracy.