pT1 urothelial carcinoma of the bladder: Criteria for diagnosis, pitfalls,and clinical implications

One of the challenging areas in genitourinary pathology is the recognition of early invasion in urothelial neoplasia, Not uncommon, the patterns of in vasion into lamina propria are subtle because a desmoplastic response is ab sent. Tangential sectioning due to inability to orient transurethral resect ion of bladder tumor specimens, crush and cautery artifacts further compoun d this problem. This review is presented to familiarize surgical pathologis ts with the criteria and different patterns of lamina propria invasion by u rothelial carcinoma. Problems and pitfalls associated with the recognition of invasion and the clinicopathologic significance of lamina propria invasi ve urothelial cancer are also discussed.