[Histological variants of urothelial carcinoma with diagnostic, prognostic and therapeutical implications].

Most of urothelial carcinomas (UC) have a pattern of histological growth of papillary or solid type; nevertheless, in some cases there are histological types that significantly differ from these habitual patterns In this paper we have selected those UC variants that by its diagnosis difficulty and therapeutical or prognosis implications have to be perfectly identified and known by pathologists and urologist. The variants that we have considered of greater clinical and pathological interest have been: tubular and/or nested UC, microcystic UC, micropapillary UC, lymphoepithelioma like UC, plasmacytoid UC and sarcomatoid UC. A revision of the literature has been made of each one of these patterns evaluating the criteria diagnoses, clinical behavior and the present therapeutic options. In addition, we suggest that these UC variants must be explicitly reflected in the pathology report, due to its clinical implications.