ABSTRACT
PURPOSE: It is difficult to differentiate urothelial tumours of the renal pelvis, invading the renal parenchyma, from renal cell carcinomas, invading the renal pelvis or calyx. The purpose of this study was to assess the differences between the two conditions. MATERIALS AND METHODS: We retrospectively reviewed the medical records, and imaging studies, of 17 patients who underwent nephroureterectomy with bladder cuff excision for urothelial tumours of the renal pelvis, with parenchymal invasion, and of 30 patients who underwent radical nephrectomy for renal cell carcinomas, invading into the renal pelvis or calyx. We assessed the differences in clinical symptoms, urine cytology, intravenous urography, and CT findings between the two conditions. Pearson chi-square tests, with continuity corrections, were performed for statistical analyses. RESULTS: Renal cell carcinomas showed gross hematuria in only 10 cases (33%), positive findings of urine cytology in 1 case of 9 cases (11%). CT scans demonstrated contour bulging in 25 cases (83%), preservation of reniform shape in 5 cases (17%), peripheral location of tumour in 25 cases (83%), and abnormal CT nephogram in 1 cases (3%). In contrast, urothelial tumour of the renal pelvis showed gross hematuria in 13 cases (76%), positive findings of urine cytology in 9 cases of 15 cases (60%). CT scans demonstrated contour bulging in 1 cases (6%), preservation of reniform shape in 16 cases (94%), central location of tumour in all cases (100%), and abnormal CT nephogram in 10 cases (59%). There was no significant difference between renal cell carcinomas and urothelial tumours of the renal pelvis in blood chemistry or IVP. There were no cases of renal cell carcinoma concurrently with bladder tumour, while 2 cases (12%) of urothelial tumour of the renal pelvis had bladder tumours at the same time. CONCLUSIONS: The presence of gross hematuria, positive findings in urine cytology, the presence of bladder tumours, and tumour location, renal contour changes and CT nephogram in CT scans may be helpful in distinguishing both disease entities.