Transurethral resection of bladder and radical cystectomy: Concordance of histology. Are we good enough?

Abstract

Urothelial carcinoma (UC) is heterogeneous, and variant histologies (VH) are more frequent than initially reported. Reporting VH is recommended by several guidelines because of prognostic and therapeutic implications. We evaluated the concordance of VH between the first transurethral resections of the bladder (TURBs) and the following radical cystectomy (RC). This paper is the first to compare VH with a central pathology review between TURB and RC. In this retrospective study, we only included those patients who underwent TURB with VH and then RC between 01/2010 and 12/2013 at our institution. The presence of VH in both TURB and RC was assessed and compared according to the 2016 World Health Organization (WHO) classification by a central pathology review. Among 110 patients who had the initial TURB/RC, 54 (49.1%) were diagnosed with VH, 48 (43%) had a single pattern, and six had (5%) multiple histological patterns. Squamous differentiation was the most common single VH (31%). Twenty patients with UC (18%) showed discordance between TURB and RC, especially in micropapillary versus nested (n=3) cases. Concordant histology between TURB/RC was seen in 82% of the cases. Discrepancies can be seen between TURB and RC when reporting VH, which can be problematic for selection of therapy and management. TURB alone might be insufficient to evaluate the presence of VH, especially in VH with heavy therapeutic implications, such as micropapillary carcinomas. Nevertheless, concordance with a central review by an experienced uropathologist when applying the WHO 2016 classification is 82%.