title: [Bladder nephrogenic metaplasia: circumstances of discovery, predisposing factors, and clinical course in 7 cases diagnosed between 1988 and 2000].
abstract: BACKGROUND
  Nephrogenic adenoma (NA) or nephrogenic metaplasia is a rare, benign urothelial tumour.
  
  
  METHODS
  This retrospective study evaluated the circumstances of discovery, predisposing factors, and clinical course of seven patients with nephrogenic adenoma diagnosed between 1988 and 2000. The mean age of these patients was 55.7 years (range: 16 to 88 years). The mean follow-up was 24 months (range: 4 to 108 months).
  
  
  RESULTS
  There are no specific endoscopic findings and the lesion was sometimes flat or papillary with an appearance that can be identical to that of bladder tumour. The diagnosis was always based on histological findings. Suggestive clinical signs were nonspecific and comprised: haematuria, dysuria, or urgency. Treatment was surgical with transurethral resection or electrocoagulation of the lesion, combined with elimination of the factors irritating the urothelial mucosa. In our experience, recurrences were observed in 28.5% of patients and occurred during the year following the initial treatment.
  
  
  CONCLUSIONS
  Nephrogenic adenoma is a rare, benign urothelial tumour most frequently situated in the bladder. The presenting clinical signs are completely nonspecific and usually related to predisposing factors (infections, inflammation, bladder tumour). Only histological examination can provide the essential proof of the benign nature of this lesion. Endoscopic resection therefore has two objectives: diagnostic and therapeutic. The clinical course is characterized by recurrences.
authors.affiliation: Service d'Urologie-Transplantation, CHRU d'Amiens, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Ducrocq
authors.forename: Alexis
authors.initials: A
authors.lastname: Bruniau
authors.forename: Carole
authors.initials: C
authors.lastname: Cordonnier
authors.forename: Manuel
authors.initials: M
authors.lastname: Demailly
authors.forename: Jacques
authors.initials: J
authors.lastname: Petit
authors.forename: Fabien
authors.initials: F
authors.lastname: Saint
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015984:Causality; D006801:Humans; D008297:Male; D008679:Metaplasia / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery; D008875:Middle Aged; D012189:Retrospective Studies; D001743:Urinary Bladder / Q000473:pathology* / Q000601:surgery