Clinical Utility and Concordance of Upper Urinary Tract Cytology and Biopsy in Predicting Clinicopathologic Features of Upper Urinary Tract Urothelial Carcinoma

Abstract

5% of urothelial carcinoma occurs in the upper urinary tract (UUT), a challenging location to biopsy. We aim to evaluate concordance between biopsy, cytology, and resection specimens in a large upper tract urothelial carcinoma (UTUC) cohort.117 UTUC resections with UUT biopsy and/or cytology specimens from 2000–2016 were retrieved; pathologic material was re-reviewed, evaluated for concordance, and correlated with clinical information. 14% pre-operative biopsies, including 8 from renal pelvis and 6 from ureter, lacked neoplastic diagnoses. 77% diagnostic biopsies included subepithelial tissue; 11% demonstrated reclassification of grade and 30% demonstrated reclassification of invasion status. 26% of renal pelvis UTUC and 36% ureter UTUC were invasive only on resection. Of 18 UTUC reclassified from noninvasive high-grade papillary urothelial carcinoma (HGPUC) to invasive HGPUC, 39% had prior radical cystectomy (versus 8% invasive UTUC and 11% noninvasive UTUC with concordant biopsies). Most high-grade UTUC (88%) and some low-grade UTUC (58%) resections had abnormal cytology results. Biopsy-resection pairs with concordant invasion status and pairs with discordant invasion status showed similar rates of recurrence (38% versus 38%) and metastasis (25% versus 27%). 14% of UUT biopsies lacked diagnostic neoplastic material. Grade concordance between biopsy and resection was high (89%), but 30% of cases showed invasion only on resection. Subepithelial tissue was less commonly present in ureter biopsies, particularly from mid or proximal ureter. UTUC in patients with prior cystectomy were more likely to show invasion on resection but not biopsy.