Urinary System
Urinary Bladder - Edema
Narrative
Comment:
Edema is usually seen with other lesions, particularly inflammation, and is typically noted as an amorphous, slightly eosinophilic fluid in the subepithelial connective tissue (Figure 1). Edema has to be differentiated from artifacts produced by inflation of the urinary bladder with fixative solutions (Figure 2).
Recommendations:
Since some edema is seen with inflammatory and/or vascular lesions, edema should not be diagnosed unless it is a major component of the lesion.
References:
Hard GC, Alden CL, Bruner RH, Frith CH, Lewis RM, Owen RA, Krieg K, Durchfeld-Meyer B. 1999. Non-proliferative lesions of the kidney and lower urinary tract in rats. In: Guides for Toxicologic Pathology. STP/ARP/AFIP, Washington, DC, 1-32.
Artifactual edema-like change (arrow) from inflation of the bladder with fixative, from a female F344/N rat in a 14-day study.
All Images
A focal area of edema in the urinary bladder submucosa from a female B6C3F1 mouse in a chronic study.
Artifactual edema-like change (arrow) from inflation of the bladder with fixative, from a female F344/N rat in a 14-day study.