Ureterorenoscopy for upper tract urothelial carcinoma: how often are we missing lesions?

OBJECTIVE: To determine the ability of ureterorenoscopy (URS) to identify the precise number and location of all lesions as compared with pathologic review of nephroureterectomy specimens, which have not been previously determined. Upper tract urothelial carcinoma (UTUC) comprises 5% of all urothelial malignancies in the United States. With advances in endoscopic equipment, there has been a move toward using flexible ureteroscopes to perform URS as part of the diagnostic evaluation and management.

METHODS: We identified patients who had undergone URS with biopsy before radical nephroureterectomy for UTUC. Operative reports for each procedure were reviewed and compared with the surgical pathology reports.

RESULTS: URS correctly identified the number and location of lesions in 57 of 76 patients (75%). The most common locations for missed lesions were in the ureter (9 patients) and renal pelvis (8 patients). Carcinoma in situ was missed on the initial biopsy for 9 patients. Three of 11 patients (27%) with a solitary lesion in the distal ureter visualized by URS had a missed lesion in the renal pelvis. URS with biopsy accurately predicted the grade of UTUC lesions in 79% of cases, whereas 65% of patients were upstaged on final pathology.

CONCLUSION: URS with biopsy can accurately map UTUC in the majority of patients. However, up to 25% of patients will have missed lesions, and nearly 50% of these patients will have a missed carcinoma in situ lesion. Undergrading and understaging of UTUC lesions remain shortcomings with potentially severe consequences.