Safety and diagnostic accuracy of percutaneous biopsy in upper tract urothelial carcinoma.

ABSTRACT

OBJECTIVE: To assess the diagnostic accuracy and safety of percutaneous biopsy for upper tract urothelial carcinoma (UTUC). PATIENTS AND METHODS: From 2002 to 2013, 26 upper tract lesions in 24 patients (20 men; median [range] age 67.8 [51.7-85.9] years) were percutaneously biopsied. Analysis was separated based on lesion appearance (i) mass infiltrating renal parenchyma, (ii) filling defect in the collecting system, (iii) urothelial wall thickening. We tracked immediate complications and tract seeding on follow-up imaging. RESULTS: Of the 26 upper tract lesions, 15 (58%) were masses infiltrating the renal parenchyma (mean [range] size 5.4 [1.1-14.0] cm), six (23%) were urothelial wall thickenings (mean [range] size 0.8 [0.4-1.1] cm), and five (19%) were filling defects within the renal pelvis or calyx (mean [range] size 2.7 [1.0-4.6] cm). Definitive diagnosis of UTUC was made by biopsy in 22 of 26 lesions (85%). Biopsy characterised 14 of 15 infiltrative masses and five of five filling defects; biopsy characterised three of six cases of urothelial wall thickening. CT follow-up was available for 19 patients (73%) at a median (range) of 13.6 (1.0-98.9) months. Three patients (11%) developed recurrence in the nephrectomy bed at 5.6, 9.7, and 29.0 months after biopsy; none were attributed to tract seeding after independent review, because recurrence was remote from the biopsy site. CONCLUSION: Percutaneous biopsy is effective for diagnosis of UTUC, providing tissue diagnosis in 85% of cases. While case reports cite a risk of tract seeding, no cases of recurrence were definitely attributable to percutaneous biopsy. Thus, for upper tract urothelial lesions, which are not amenable to endoscopic biopsy, percutaneous biopsy is a safe and effective technique.