Urinary System

Urinary Bladder - Pigment

Narrative

Comment:

Pigment is rarely reported in urinary bladders of rodents. The most common pigment is hemosiderin (Figure 1). Pigmentation of urothelium has been observed with administered dye compounds.

Recommendations:

Pigment should be diagnosed and given a severity grade. With the exception of Prussian blue staining for hemosiderin, definitive pigment identification is often difficult in histologic sections, even with a battery of special stains. Therefore, it is recommended that a diagnosis of “pigment” (as opposed to diagnosing the type of pigment, e.g., hemosiderin or lipofuscin) is more appropriate. The pathology narrative should describe the morphologic features of the pigment.

References:

Jokinen MP. 1990. Urinary bladder, ureter, and urethra. In: Pathology of the Fischer Rat: Reference and Atlas (Boorman GA, Eustis SL, Elwell MR, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, 109-126.

Abstract: http://www.ncbi.nlm.nih.gov/nlmcatalog/9002563

All Images

Pigment-a focal area of hemosiderin from a female F344/N rat in a chronic study.

Authors and Reviewers

Authors

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

Abraham Nyska,  DVM, Diplomate ECVP, Fellow IATP
Expert in Toxicologic Pathology
Visiting Full Professor of Pathology
Sackler School of Medicine, Tel Aviv University
Timrat Israel

Reviewers

Samuel M Cohen, PHD, MD
Professor
Havlik-Wall Professor of Oncology
Director of Pathology Residency Program
Nebraska Medical Center
Omaha, NE

David E. Malarkey DVM, PhD, DACVP, FIATP
Head, National Toxicology Program Pathology Group
Cellular and Molecular Pathology Branch
Division of the National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC