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nephrogenic adenoma

Friday 28 September 2007, by JA

Nephrogenic adenoma (NA) is a rare benign lesion of the urinary tract. Although its histogenesis is still debated, several reports suggest that the lesion has a renal tubular cell origin or differentiation.

Nephrogenic adenomas demonstrate a variety of morphologic patterns that may occasionally be confused with malignant processes, including urothelial and prostatic carcinoma.

Nephrogenic adenoma is a benign lesion that may occur at any site of the genitourinary tract, usually in association with previous urothelial injuries.

Although its pathogenesis is still debated, recent studies seem to confirm its derivation from renal tubular epithelium, rather than from a metaplastic process of urothelium.

Variants

- fibromyxoid nephrogenic adenoma

  • admixture of the classic tubular form of nephrogenic adenoma with spindled cells and fibromyxoid tissue
  • compressed spindled cells
  • fibromyxoid background
  • rare tubular and cordlike structures

Immunochemistry

- S-100A1 is a reliable marker in distinguishing nephrogenic adenoma from prostatic adenocarcinoma. (#19384190#)

  • S100A1 is a specific and sensitive immunohistochemical marker to differentiate nephrogenic adenoma from prostatic adenocarcinoma. (#19384190#)
  • AMACR immunostaining does not seem to be a useful marker in distinguishing between these 2 lesions. (#19384190#)

- CK7
- PAX2
- MUC1 r

- NA has the differentiation of distal renal tubules.
- AMACR can be used as a reliable marker for distinguishing NA from prostate cancer.

Differential diagnosis

In addition to its uncertain origin, there can be diagnostic difficulty in distinguishing nephrogenic adenoma from prostatic adenocarcinoma, particularly with lesions arising in the prostatic urethra. (#19384190#)

As NA can be difficult to distinguish from malignant conditions such as prostate cancer, there is a need for reliable markers. Unfortunately, it has been reported that NA cells also stained positive for the prostate cancer marker alpha-methylacyl-coenzyme A racemase (AMACR).

AMACR can be used as a reliable marker for distinguishing NA from prostate cancer.

See also

- renal adenomas

References

- Revisiting the Immunophenotype of Nephrogenic Adenoma. Fromont G, Barcat L, Gaudin J, Irani J. Am J Surg Pathol. 2009 Nov;33(11):1654-8. PMID: #19730362#

- S-100A1 Is a Reliable Marker in Distinguishing Nephrogenic Adenoma From Prostatic Adenocarcinoma. Cossu-Rocca P, Contini M, Brunelli M, Festa A, Pili F, Gobbo S, Eccher A, Mura A, Massarelli G, Martignoni G. Am J Surg Pathol. 2009 Apr 18. PMID: #19384190#

- Hansel DE, Nadasdy T, Epstein JI. Fibromyxoid nephrogenic adenoma: a newly recognized variant mimicking mucinous adenocarcinoma. Am J Surg Pathol. 2007 Aug;31(8):1231-7. PMID: #17667548#

- Expression of alpha-methylacyl-CoA racemase (P504S) in nephrogenic adenoma: a significant immunohistochemical pitfall compounding the differential diagnosis with prostatic adenocarcinoma. Skinnider BF, Oliva E, Young RH, Amin MB. Am J Surg Pathol. 2004 Jun;28(6):701-5. PMID: #15166661#

- Derivation of nephrogenic adenomas from renal tubular cells in kidney-transplant recipients. Mazal PR, Schaufler R, Altenhuber-Müller R, Haitel A, Watschinger B, Kratzik C, Krupitza G, Regele H, Meisl FT, Zechner O, Kerjaschki D, Susani M. N Engl J Med. 2002 Aug 29;347(9):653-9. Erratum in: N Engl J Med 2002 Oct 24;347(17):1390. PMID: #12200552#

- Metanephric adenoma, nephrogenic rests, and Wilms’ tumor: a histologic and immunophenotypic comparison. Muir TE, Cheville JC, Lager DJ. Am J Surg Pathol. 2001 Oct;25(10):1290-6. PMID: #11688464#

- Metanephric adenoma. Clinicopathological study of fifty patients. Davis CJ Jr, Barton JH, Sesterhenn IA, Mostofi FK. Am J Surg Pathol. 1995 Oct;19(10):1101-14. PMID: #7573669#