Home   Chapter Home   Jobs   Conferences   Fellowships   Books



Nephrogenic metaplasia / adenoma

Reviewers: Sean Williamson, M.D., (see Reviewers page)
Revised: 24 August 2012, last major update July 2012
Copyright: (c) 2002-2012, PathologyOutlines.com, Inc.


● Rare, associated with stone or other irritation of the mucosa
● Nephrogenic adenoma: similar histologic findings, but presenting as a mass
● For nephrogenic adenoma, mean age 52 years, range 15 to 94 years (entire urinary tract), M/F = 2:1; ureter is rare site (4% of all urinary tract tumors, Mod Pathol 1995;8:722)

Micro description

● Proliferation of tiny mucin-containing microcysts, medium-sized tubular structures (resembling renal tubules), and small exophytic papillary structures
● Lined by cuboidal cells similar to renal tubular epithelial cells
● Basement membrane around tubules may be appreciable but not prominent
● Tubules/cysts often have eosinophilic or basophilic secretion
● Generally mild cytologic atypia, characterized by enlarged vesicular nuclei and prominent nucleoli
● No mitotic figures
● May have transmural involvement and appear infiltrative, (Mod Pathol 2002;15:765, Am J Clin Pathol 1983;80:92)

Micro images

Cross-section of ureter

Tiny microcystic structures superficially resembling signet ring cells and larger tubular structures in the lamina propria of the ureter

Higher magnification of microcysts surrounded by a thickened basement membrane

Small elongated tubular structures lying in a fibrous stroma

A cystically dilated tubule contains mucin and is lined by hobnail cells


Positive stains

● CK7, AE1-AE3, mucin, PAX2, AMACR

Negative stains

● CEA, p53, Ki-67 (<5%), p63, HMWCK (34betaE12)

Electron macroscopy description

● Epithelial cells with sparse microvilli and thick basal lamina

Molecular description

● In renal transplant patients with opposite sex donor, FISH reveals the donorís sex chromosomes within the lesion, suggesting implantation and proliferation of shed renal tubular cells into injured mucosa (N Engl J Med 2002;29:347)

Molecular images

FISH and H&E in transplant patients

End of Ureters > Nephrogenic metaplasia / adenoma

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at [email protected] with any questions (click here for other contact information).