Nephrogenic adenoma: a form of adenomatous metaplasia of the bladder. A clinical and electron microscopical study

Our plain-English summary of Nephrogenic adenoma: a form of adenomatous metaplasia of the bladder. A clinical and electron microscopical study, by E.A. Molland, P.A. Trott, A.M. Paris, et al (British Journal of Urology, 1976).

The study

• Authors: E.A. Molland, P.A. Trott, A.M. Paris, J.P. Blandy
• Journal: British Journal of Urology
• Published: 1976;48(6):453-62
• Type of article: Case report
• Cited by: 48 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

3 additional cases of "nephrogenic adenoma" of the bladder are added to the 20 previously reported cases. Light and electron microscopic studies of the first 2 cases support the hypothesis of urothelial metaplasia. The name "adenomatous metaplasia" should replace "nephrogenic adenoma". Malignant change occurred in the third case, suggesting that this ought to be regarded as a potentially dangerous from of metaplasia. In the absence of malignant change, ileocaecocystoplasty with subtotal cystectomy afforded symptomatic cure in 2 cases: radical cystectomy was performed in the third because of malignant adenocarcinoma.

In plain English

This article, not about asbestos, reported on a bladder condition called 'nephrogenic adenoma.' The authors described three men, aged 36, 34 and 41, against 20 published cases. All three had earlier urinary tract disease: kidney stones, a ureteric stone, or treated tuberculosis. In the first two, the lesion was mistaken for cancer at cystoscopy; biopsies gave the diagnosis. Electron microscopy of these two cases showed tubules without the specialised features of kidney tubules; features typical of normal bladder lining were not identified, though the authors noted these could have been missed through sampling error. In the third, whose bladder was left in place after urinary diversion, the lesion lay beside an adenocarcinoma invading the bladder wall. The first two men were reported symptom-free after subtotal cystectomy with ileocaecocystoplasty. In one, symptoms worsened after earlier cystodiathermy, which the authors said appeared only to make matters worse. The authors concluded that their findings supported the view that the lesion is a metaplasia of bladder lining, that 'adenomatous metaplasia' is a more appropriate name, and that it may progress to carcinoma.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case series of 3 patients with light and electron microscopy, reviewed alongside 20 previously published case reports
• Who was studied: Three men treated at The London Hospital and the Institute of Urology, London. Case 1 was a 36-year-old Arab-Sudanese soldier with recurrent kidney stones. Case 2 was a 34-year-old white man with a ureteric stone. Case 3 was a 41-year-old white man with treated tuberculosis and urinary diversion. The article does not give dates of treatment.
• Exposure: Not applicable. The article does not discuss asbestos or any fiber exposure. It studied a bladder lesion in patients with prior urinary tract disease and operations.
• Main results:
  • On electron microscopy (Cases 1 and 2), the tubules had none of the specialised features of any part of the kidney's nephron.
  • The tubule cells showed no desmosomes but had tight junctions. Features characteristic of normal bladder lining (urothelium) were not identified, though the authors noted these could have been missed by sampling error.
  • In Cases 1 and 2 the lesion resembled carcinoma at cystoscopy. The authors stated that multiple biopsies were the only way the diagnosis could have been made.
  • In Case 3, frank carcinoma was found in the cystectomy specimen. It was a poorly differentiated adenocarcinoma next to the adenomatous metaplasia, invading the bladder wall.
  • In Case 2, symptoms were not relieved after cystodiathermy and grew worse. The authors said the treatment appeared only to make matters worse.
  • After subtotal cystectomy with ileocaecocystoplasty, Case 1 reported no symptoms after a year, and Case 2 was without symptoms at 2 months.
• The authors' conclusion: The authors concluded that their findings supported the view that the lesion represents a metaplasia of urothelium, and that 'adenomatous metaplasia' is a more appropriate name than 'nephrogenic adenoma'. They also concluded that the evidence suggests the change may progress to carcinoma, which must influence treatment.
• Limitations the authors state:
  • The urothelial features the authors did not find (the trilaminar surface membrane and typical tripartite junctions) could have been missed through sampling error.
  • Treatments in published cases were difficult to evaluate because 11 reported cases had no follow-up.
  • The cause of the lesion could not be determined from the available evidence.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Adenocarcinoma.

Related studies

• Nephrogenic metaplasia (adenomatoid tumors) of bladder — J.A. Kaswick, J. Waisman, et al. (1976)
• Nephrogenic adenoma of bladder — E. Kaany, S.L. Werner (1974)
• Nephrogenic adenoma of the bladder in children — S.R. Nold, W.J. Terry, et al. (1989)
• Nephrogenic metaplasia of the bladder — E.B. Sussman, M. Brice, et al. (1974)
• Nephrogenic adenoma of bladder — S.I. Tannenbaum, S.A. Kramer, et al. (1980)
• Occupational cancer of the urinary bladder in dyestuffs operatives and of the lung in asbestos textile workers and iron-ore miners — G.M. Bonser, J.S. Faulds, et al. (1955)

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