Nephrogenic adenomas of the urinary system: a clinicopathologic analysis of 30 cases

Objective: Nephrogenic adenomas (NA) are benign lesions that may occur in several sites throughout the urinary tract, from the renal pelvis to urethra, and especially in the bladder. They are strongly associated with urinary tract irritation, chronic inflammation, previous urologic surgery, and intravesical instrumentations. Our study aims to evaluate and present the clinicopathologic characteristics and findings of cases that were diagnosed with nephrogenic adenoma accompanied by relevant information from the literature.Material and Methods: Our study includes 30 patients who were pathologically diagnosed with NA from February 2005 to November 2017.Results: Among these patients, 63.3% were males and mean age was 60 years. The most common site of occurrence was the bladder (86.6%), followed by the ureter (6.7%) and the urethra (6.7%). Most patients presented with hematuria (36.7%). History of concurrent bladder cancer was present in 26.7% of patients, but there were no cases of de novo bladder cancer diagnosed after NA. Recurrence of NA after initial resection occurred in only 10% of patients who underwent follow-up cystoscopy. Nephrogenic adenoma is a rare lesion associated with nonspecific symptoms and endoscopic features. Definite diagnosis must be made after histological analysis of resected specimens.Conclusion: Nephrogenic adenoma is a rare lesion associated with nonspecific symptoms and nonspesific endoscopic features. A definite diagnosis must be after histological analysis of resected specimens. Keywords: nephrogenic adenoma, urothelial lesion, bladder, ureter