Variant forms of bladder cancer: basic considerations on treatment approaches.

Variant forms of bladder cancer are non-urothelial neoplasms or urothelial carcinomas mixed with other histologies. Compared to pure urothelial carcinoma, they all present with a high stage and grade. Prognosis is variable and there is a lack of evidence regarding the ideal treatment approach, because of their relative infrequency and the noninclusion in bladder cancer randomized trials. Despite this, basic recommendations can be extracted from case series. In the present report, existent literature about variant forms of bladder cancer is reviewed with focus on the most frequent: squamous cell, adenocarcinoma, small cell, micropapillary, sarcomatoid, and lymphoepithelioma-like.