Urinary System

Kidney, Papilla, Epithelium - Hyperplasia

Narrative
Comment:
Hyperplasia of the surface epithelium of the renal papilla can range from thickening of the epithelium (Figure 1, arrows) to variably sized outgrowths of the epithelium with clear spaces amid the cells (Figure 2). Sometimes, these spaces contain eosinophilic material or cells. This lesion is commonly observed with advanced chronic progressive nephropathy (see Kidney - Nephropathy, Chronic Progressive ).
Recommendations:
Hyperplasia of the renal papillary epithelium should be diagnosed and given a severity grade whenever present.
Related Links:
Kidney - Urothelium - Hyperplasia
References:

Frazier KS, Seely JC, Hard GC, Betton G, Burnett R, Nakatsuji S, Nishikawa A, Durchfeld-Meyer B, Bube A. 2012. Proliferative and non-proliferative lesions in the rat and mouse urinary system. Toxicol Pathol 40:14S-86S.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/22637735

McInnes EF. 2012. Wistar and Sprague-Dawley rats. In: Background Lesions in Laboratory Animals: A Color Atlas. Saunders Elsevier, Edinburg, 29.

Abstract: http://www.sciencedirect.com/science/book/9780702035197
  • Image of papilla epithelium hyperplasia in the kidney from a male F344/N rat in a chronic study

    Kidney, Papilla, Epithelium - Hyperplasia in a male F344/N rat from a chronic study. The epithelium is thickened (arrows), and there are large clear spaces within the hyperplastic epithelium.

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<p>Kidney, Papilla, Epithelium - Hyperplasia in a male F344/N rat from a chronic study. The epithelium is thickened (arrows), and there are large clear spaces within the hyperplastic epithelium.</p>

Kidney, Papilla, Epithelium - Hyperplasia in a male F344/N rat from a chronic study. The epithelium is thickened (arrows), and there are large clear spaces within the hyperplastic epithelium.
<p>Kidney, Papilla, Epithelium - Hyperplasia in a male F344/N rat from a chronic study. A small focus of hyperplastic surface epithelial cells lines the renal papilla (arrows).</p>

Kidney, Papilla, Epithelium - Hyperplasia in a male F344/N rat from a chronic study. A small focus of hyperplastic surface epithelial cells lines the renal papilla (arrows).

Authors 

John Curtis Seely, DVM, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC

Amy Brix, DVM, PhD, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC

Reviewers

Kendall S. Frazier, DVM, PhD, DACVP, DABT
Director, Cellular and Molecular Pathology, Safety Assessment
GlaxoSmithKline
King of Prussia, PA

Gordon C. Hard, BSc, BVSc, PhD, DSc, FRCPath, FRCVS, FAToxSci, DACVP
Expert Consultant
Tairua, New Zealand

Susan A. Elmore, MS, DVM, DACVP, DABT, FIATP
Staff Scientist, NTP Pathologist
NTP Pathology Group
National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC