Clinical utility and concordance of upper urinary tract cytology and biopsy in predicting clinicopathological features of upper urinary tract urothelial carcinoma.

Five percent 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. One hundred seventeen UTUC resections with UUT biopsy and/or cytology specimens from 2000 to 2016 were retrieved; pathologic material was re-reviewed, evaluated for concordance, and correlated with clinical information. Fourteen percent of preoperative biopsies, including 8 from the renal pelvis and 6 from the ureter, lacked neoplastic diagnoses. Seventy-seven percent of diagnostic biopsies included subepithelial tissue; 11% demonstrated reclassification of grade and 30% demonstrated reclassification of invasion status. Twenty-six percent of renal pelvis UTUC and 36% of ureter UTUC were invasive only on resection. Of 18 UTUCs reclassified from noninvasive high-grade papillary urothelial carcinoma to invasive high-grade papillary urothelial carcinoma, 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%). Fourteen percent 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 the midureter or proximal ureter. UTUC in patients with prior cystectomy were more likely to show invasion on resection but not biopsy.