Nephrogenic Adenoma of the Urinary Bladder: Our Experience and Review of the Literature

Abstract

Objective: To assess our experience in the treatment and clinical outcome of bladder nephrogenic adenoma (NA) updating and reviewing the literature concerning this issue. Patients and Methods: From September 1976 to June 1999, bladder NA was diagnosed in 8 patients: 6 men and 2 women with a 3:1 male ratio, aged 26–80 (mean 58.3) years. Follow-up ranged from 4 to 194 (mean 93.5) months. Results: NA was associated with transitional cell carcinoma in 3 cases. Predisposing factors were assessed in all patients. Previous surgery of the lower urinary tract was detected in 5 cases: ureterocystoneostomy in 2, partial cystectomy in 1, repair of vesicouterine fistula in 1, and multiple urethroplasties in 1. Previous endoscopic treatments were carried out in 2 patients, transurethral resection of the prostate in 1 and repeated transurethral resection of the vesicle in the other. A history of intravesical instillation of bacillus Calmette-Guérin was assessed in 1 case. Patients complained of irritative voiding symptoms in 6 cases and hematuria in 2. Endoscopically, the lesions appeared polypoid and multifocal in 5 patients, and flat and single in 3. The lesions were removed endoscopically, providing relief of symptoms in all cases. Histopathology assessed the diagnosis of nephrogenic adenoma, detecting focal atypic cells in 1 case only. Five patients (63%) relapsed 2–24 months after management. Recurrences were also treated endoscopically. Conclusions: Clinical and endoscopic features of bladder NA are not specific, simulating urothelial carcinoma or chronic cystitis. Endoscopic management allows accurate histological diagnosis and provides long-lasting relief of symptoms. NA needs careful and long-term follow-up, because of the high risk of recurrences and the potential neoplastic degeneration of the metaplastic urothelium.

Recurrent nephrogenic adenoma in bladder diverticulum:case report and literature review

“…5 It could be recognized in most of cases within the bladder, but reports indicated it could also rarely be detected in other sites, such as the renal pelvis, ureter and bladder exstrophy, urethral diverticula, in an ileal conduit and in the bowel portion of an augmented bladder. 1 In our case, bladder diverticula are essentially pseudodiverticula formed by mucosal herniations through areas of acquired weakness in the muscular bladder wall as a result of increased intravesical pressure secondary to bladder outlet obstruction. Carcinomas arising in diverticula account for about 0.8% to 10% of all carcinomas arising in the bladder.…”

“…1 The latter is our case, as the patient underwent a TURP and multiple episodes of endoscopic urethrotomy.…”

“…They were mostly localized on the bladder wall; this is generally limited to lesions less than 1 cm and up to 7 cm, and are rarely reported as a burden disease. 1,10 The macroscopic appearance of the lesion varies, but is generally highly vascularized, which justifies the appearance of the disease with hematuria microor macroscopic. 10 However, our patient represents a rare case of incidental diagnosis of such a condition, as he was totally asymptomatic.…”

“…1 Nephrogenic adenoma (also named nephrogenic metaplasia) is a benign entity and a common mimic of adenocarcinoma; this presents a diagnostic challenge in the interpretation of bladder biopsies. 2 Davis issued the first report in 1949.…”

“…1,12 In the literature, a high recurrence rate (37.5% to 75%) of nephrogenic adenoma has been found during long-term follow-up of pediatric patients. 10,13 Our patient confirms this; he experienced three recurrent episodes over 24 months.…”