Nephrogenic adenoma: A rare bladder tumor in children

Nephrogenic adenomas of the urinary bladder are rare benign tumors in children. The purpose of our study was to obtain information about the sex distribution, presenting symptoms, intravesical locations, therapy and recurrence rates in pediatric nephrogenic adenomas.

The records of 3 children with nephrogenic adenoma of the urinary bladder diagnosed between 1990 and 1997 were reviewed to evaluate the initial symptomatology, diagnostic examinations and findings, therapeutic procedures and clinical outcome and recurrence rates. Furthermore our data are compared to the findings of all children reported in the literature.

Including the 3 cases reported by us, the data on 18 children with nephrogenic adenoma of the bladder could be analyzed. There was a significant predominance of girls compared to boys (5:1); the medical history in all cases was remarkable for previous bladder surgery 3 months to 7 years prior to tumor diagnosis. Most children presented with unspecific symptoms of gross hematuria, dysuria and bladder instability and in all cases the final diagnosis was established after cystoscopy and histopathologic review of a tumor biopsy specimen. Therapy consisted of transurethral resection in 15 cases, partial cystectomy and open excision in 2 and 1 case, respectively. Tumor recurrence developed in 80% of the children with a latency period of 4 years.

Nephrogenic adenomas represent an epithelial response of the urothelium to chronic inflammation or previous trauma resulting in urothelial metaplasia and the development of papillary lesions. Current treatment of choice consists of transurethral resection and fulguration of the base of the tumor and periodic cystoscopy.