Pathological staging of bladder cancer

Accurate pathological staging of bladder cancers on transurethral resection specimens provides essential information to the urologist on how to manage the patient. Literature has shown substantial differences among pathologists in the interpretation of invasiveness of bladder cancers in these specimens resulting both in down- and up-staging. Technical issues (e.g. cautery artefact, lack of orientation), inadequacy of the resected specimen, tumour location (e.g. bladder neck, diverticulum) and factors intrinsic to the tumour histology all may hamper an unequivocal pathological staging. Moreover, urothelial carcinomas with a variant histology may pose their own challenges for adequate staging. In this review we try to clarify and detail most of the above-mentioned factors which may compromise optimal bladder cancer staging. Given the highly variable disease course of patients with a pT1 bladder cancer, several attempts have been made to provide additional information by the distinction of pT1 substages. We will here also discuss the two main concepts underlying such attempts to perform pT1 substaging.