Nephrogenic adenoma of the urinary bladder is a rare benign lesion. It is usually induced by a variety of inflammatory triggers like recurrent urinary infections, recurrent urinary tract calculi, intravesical therapy, radiotherapy and chemical agents.
This lesion can easily be misdiagnosed as a number of malignant lesions of the urinary bladder.
Nephrogenic adenoma of the urinary bladder tends to present with irritative bladder symptoms. Rarely it can presents with macroscopic hematuria.
A 67 years old man with a history of pelvic radiotherapy 5 years before for a prostate adenocarcinoma presented in the follow up visit with the complaint of macroscopic hematuria, without any other complaints. He´s PSA was 0,3.
He´s cystoscopy revealed polypoid formations involving the left bladder wall. A transurethral resection was made and the histology revealed a nephrogenic adenoma. Follow up for 1 year without any new lesions.
The clinical presentation and endoscopic characteristics of nephrogenic adenoma of the urinary bladder are nonspecific. The diagnostic is made by histological features.
Despite is not considered malignant it is associated with a high recurrence rate. Long term follow-up by cystoscopy examination should be undertaken in order to identify and treat recurrent tumors and to identify early the few recurrent tumors that may undergo malignant transformation.