URETEROSCOPIC BIOPSY OF UPPER TRACT UROTHELIAL CARCINOMA: IMPROVED DIAGNOSTIC ACCURACY AND HISTOPATHOLOGICAL CONSIDERATIONS USING A MULTI-BIOPSY APPROACH

Abstract

Purpose: We assessed the diagnostic accuracy of a ureteroscopic multi-biopsy approach to upper tract urothelial carcinoma compared with subsequently resected surgical specimens. Materials and Methods: From 1990 to 1998, 45 upper tract lesions were ureteroscopically evaluated and biopsied with 3Fr cup forceps and/or an 11.5Fr resectoscope before nephroureterectomy or ureterectomy. A definitive diagnosis of urothelial carcinoma was made by biopsy in 40 lesions (89%). Each tumor was histopathologically graded but only staged if the lamina propria were uninvolved (Ta), and if the lamina propria were invaded by tumor (T1+). Results: Of the 40 urothelial tumors 16 (40%) were in the renal pelvis, and 8 (20%) in the proximal and 16 (40%) in the distal ureter. Of the lesions 95% were papillary and 65% were grade 2. Ureteroscopic biopsy grade matched surgical pathological grade in 31 of the 40 cases (78%), and was less than surgical pathological grade in the remainder. Lamina propria was detected in 27 of the 40 biopsies, including 21 of the 34 cup (62%) and all 6 resection loop (100%) biopsies. Ureteroscopic biopsy staging in 27 cases revealed Ta and T1+ disease in 22 and 5, respectively. In the 5 cases in which ureteroscopic biopsy stage was T1+ surgical pathological stage was also pT1+ (range pT1 to pT3). Tumors were pathologically up staged to pT1+ (range pT1 to pT3) in 10 of the 22 cases (45%) in which ureteroscopic biopsy stage was Ta. Tumor location did not affect diagnostic accuracy. Conclusions: This multi-biopsy ureteroscopic approach provided the tissue diagnosis of urothelial carcinoma in 89% of cases and predicted exact histopathological grade in 78%. Although it is not accurate as a staging modality, multi-biopsy ureteroscopy may assess lamina propria invasion in two-thirds of cases.