Abstract
Since August 1989, we have seen 4 patients with leukoplakia of the renal pelvis associated with a longstanding renal stone. In 2 of them, excretory or retrograde pyelography revealed multiple filling defects in the left renal pelvis as well as a renal stone, although urine cytological examination was negative. One of the other 2 patients underwent extracorporeal shock wave lithotripsy (ESWL) for the renal stone, but this was not followed by the passage of stone fragments. The renal stone in the remaining patient was associated with staghorn calculi. For stone extraction as well as endoscopic evaluation of the intrapelvic lesion, percutaneous nephroscopy was performed. A small to large amount of tissue-like white debris in sheets characteristic of leukoplakia was found in the renal pelvis with stones embedded in it and was removed directly by forceps or suction and then by irrigating with saline. We propose that 1) the endourological approach should be recommended for patients with renal pelvic lesions associated with longstanding renal stones or for patients who show difficulty in passing stone fragments after ESWL and 2) this entity of leukoplakia should be kept in mind for the differential diagnosis of renal pelvic lesions associated with renal stones.