Nephrogenic adenoma of the bladder: metaplasia or embryologic alteration?

To present a new case of nephrogenic adenoma of the bladder and to review the current concepts on the etiopathogenesis of this lesion. Seventy years old female with repetitive haematuria who was diagnosed as having a nephrogenic adenoma of the bladder which was extirpated by cold biopsy forceps. No tumoral relapse was detected after 16 months of follow up. In the light of the present knowledges, the origin of nephrogenic adenoma is a phenomenon of urothelial metaplasia due to a chronic irritative stimulus wich would lead a cellular proliferation with potentialities to originate mesonephric tissues and which starting point could be on not completely involutioned mesonephric cellular rests and/or on de-differentiated mature urothelial cells.