Intraductal tumor involvement and renal parenchymal invasion of transitional cell carcinoma in the renal pelvis.

Surgical specimens obtained from 21 patients with renal pelvic cancer, in which the tumor was located on the side of the renal parenchyma, were reviewed with special reference to tumor involvement with renal collecting ducts and/or renal parenchyma. Four distinct entities were found: 1) 4 tumors that involved the collecting ducts without invasion of renal parenchyma, 2) 4 tumors that involved the collecting ducts with microscopic invasion of renal parenchyma, 3) 5 tumors that invaded the renal parenchyma by less than 5 mm. and were microscopically identified as being without ductal involvement and 4) 6 tumors that exhibited extensive renal parenchymal invasion. The patients with intraductal tumors had good prognosis as did those with microscopic invasion except for 1 who died of lymph nodes metastases. Conversely, 6 patients with extensive invasion had a poor prognosis, 5 (88%) of whom died of recurrent tumor or distant metastases. The differences in these 4 entities may be important, especially if large numbers of patients are examined, and they may ultimately be shown to have a different prognosis.