Ultrasonic assessment of renal transitional cell carcinoma: preliminary report.

The value of ultrasound in determining the etiology of nonopaque filling defects seen in the renal pelvis at intravenous urography is under study. The ultrasound findings in three patients with proven transitional cell carcinoma of the kidney were similar and consisted of separation of the central renal echo complex by a region of low-intensity echoes. This pattern is distinct from characteristically echogenic nonopaque renal calculi and anechoic hydronephrosis. Renal collecting system blood clots may have an echo pattern similar to collecting system tumors, but can usually be distinguished by their mobility and transitory nature. Further investigation into the specificity and sensitivity of the ultrasonic diagnosis of renal collecting system masses is underway.