Mixed signet-ring and transitional cell carcinoma of the bladder. Report of a case.

A case of transitional cell carcinoma of the bladder displaying prominent signet-ring cell features is reported. Despite combined therapy, the patient died within a few months of the diagnosis, thus confirming the poor prognosis of this tumor. We understand this entity could be considered as an example of neoplastic-associated metaplasia and therefore propose that it should be distinguished from genuine adenocarcinoma.