Nephrogenic adenoma in the prostatic urethra and in the ureter: Urothelial lesions associated with chronic infections and injures in the urinary tract - Abstract

Purpose: To report our findings on urothelial lesions diagnosed as nephrogenic adenomas and determine the importance of a correct clinical and anatomopathological interpretation.

Materials and Methods: We report the surgical and anatomopathological findings for 3 cases involving nephrogenic adenoma into the urothelium. One case was in the prostatic urethra of an 84-year-old male who underwent suprapubic prostatectomy due to benign prostatic hyperplasia. Another one was microscopic, and in the lumen of a 4 cm proximal ureteral stenosis of a 30-year-old man due to a ureteral perforation during an ultrasonic ureterolithotripsy 18 months prior. After repeated (6) transureteral endoscopic manipulations, always stented with a double-J ureteral catheter, we finally performed an excision of the ureteral stenotic segment and end-to-end ureteroureteral anastomosis. The final case was in a 5-year-old female, exhibiting recurrent urinary infections and renal lithiasis, who presented with a polypoid lesion in the proximal ureter that we detected and resected by ureteroscopy.

Results: In the oldest male patient, who underwent surgical manipulation with repeated vesical catheterizations and experienced recurrent urinary infections, the microscopic exam revealed benign prostatic hyperplasia and an incidental lesion 1 cm in diameter in the prostatic urethra with pathological characteristics of nephrogenic adenoma. In the youngest male, the nephrogenic adenoma was incidentally found as a microscopic lesion in the ureteral fibrotic lumen. In the child’s case, she underwent an ultrasonic percutaneous nephrolithotripsy due to a voluminous renal calculus, which later resulted in residual obstructive renal calculi at the pyeloureteral junction that necessitated ureteroscopy for nephrocutaneous fistula. It was then that a 0.8 cm polypoid lesion was observed in the proximal ureter during implantation of a double-J ureteral catheter, which was resected and diagnosed as nephrogenic adenoma.

Conclusion: In areas of the urinary tract that have experienced recurrent urinary infections or traumas, or have undergone surgical manipulation, polypoid lesions can develop or appear microscopically. These lesions do not promote such chronic alterations but could result from them, likely due to cellular implants of renal tubules in areas of the urothelium in which the implantation is suitable and are recognized by microscopy as benign urothelial processes. Although such findings are rare, they likely occur more frequently than believed.

KEYWORDS: Nephrogenic adenoma, urothelial lesion, recurrent urinary infections, ureter, prostatic urethra

CORRESPONDENCE: Ricardo Leo Roberto Felts de la Roca, MD, Jardim Paulista, São Paulo, SP, 01424-000, Brazil ( )

CITATION: UroToday Int J. 2012 October;5(5):art 52.

DOI: http://dx.doi.org/10.3834/uij.1944-5784.2012.10.11