title: Nephrogenic Adenoma: Clinical Features, Management, and Diagnostic Pitfalls.
abstract: OBJECTIVE
  To review the diagnosis and management of nephrogenic adenoma (NA), an uncommon benign lesion found in the urinary tract. This lesion arises from a proliferation of implanted renal tubular cells. Although more common in adults, it can occur in all ages. NAs can recur and cause significant morbidity in patients. NAs are also a potential diagnostic pitfall as they can clinically and histologically mimic malignancy in the urinary tract.
  
  
  METHODS
  We performed an Institutional Board Review approved search of our surgical pathology database from 2005 to 2015 for cases of NA. A retrospective chart review was performed with a focus on the clinical, pathologic, and radiographic findings in these patients.
  
  
  RESULTS
  We identified 32 cases of NA in 31 patients. Lesions were most common in Caucasian males (male-to-female ratio of 2:1) with an average age at diagnosis of 55 years (range 25-77). Bladder was the most common site of occurrence (81.2%), followed by ureter (9.4%), urethra (6.3%), and intrarenal collecting system (3.1%). Most patients (72%) were symptomatic and presented with hematuria (41%), lower urinary tract symptoms (28%), pelvic or flank pain (6%), hydronephrosis (19%), or urinary incontinence (13%). NA was asymptomatic and identified incidentally in 9 (28%) patients. One patient (3%) had a renal transplant and 8 (26%) patients had diabetes mellitus. Twenty-six (84%) patients were managed with endoscopic resection of their tumors.
  
  
  CONCLUSIONS
  NAs are benign lesions that may cause significant morbidity and mimic malignant tumors. There should be increased suspicion in patients with predisposing factors.
authors.affiliation: University of Alabama at Birmingham, Department of Pathology, Birmingham, AL; University of Alabama at Birmingham, Department of Urology, Birmingham, AL. Electronic address: jgordetsky@uabmc.edu.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Gordetsky
authors.affiliation: University of Alabama, School of Medicine, Birmingham, AL.
authors.forename: Kyle H
authors.initials: KH
authors.lastname: Gennaro
authors.affiliation: University of Alabama at Birmingham, Department of Urology, Birmingham, AL.
authors.forename: John P
authors.initials: JP
authors.lastname: Selph
authors.affiliation: University of Alabama at Birmingham, Department of Urology, Birmingham, AL; University of Alabama at Birmingham, Department of Radiology, Birmingham, AL.
authors.forename: Soroush
authors.initials: S
authors.lastname: Rais-Bahrami
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000628:therapy*; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014571:Urologic Neoplasms / Q000175:diagnosis* / Q000628:therapy*