Urinary Bladder - Angiectasis

Image of angiectasis in the urinary bladder from a female B6C3F1 mouse in a chronic study
Angiectasis. Dilated blood vessels within a fibrous stroma in the urinary bladder submucosa from a female B6C3F1 mouse in a chronic study.
Figure 1 of 2
Image of angiectasis in the urinary bladder from a female B6C3F1 mouse in a chronic study
Angiectasis. Dilated blood vessels in the urinary bladder submucosa from a female B6C3F1 mouse in a chronic study.
Figure 2 of 2
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comment:

Focal blood vessel dilation in the urinary bladder may be diagnosed as angiectasis ( Figure 1image opens in a pop-up window and Figure 2image opens in a pop-up window ). These lesions are typically reported as spontaneous lesions but have been reported with vasodilating chemicals. Angiectasis is commonly noted in the submucosa as a focal or multifocal finding that tends to be irregular and not well circumscribed

Angiectasis must be differentiated from hemangioma. The distinction is not always obvious: hemangiomas tend to be well circumscribed, unencapsulated masses composed of tightly packed dilated vascular spaces, each enclosed and lined by a single layer of normal-appearing endothelial cells aligned on a thin collagenous stroma.

recommendation:

Angiectasis should be diagnosed and given a severity grade.

references:

Gaillard ET. 1999. Ureter, urinary bladder and urethra. In: Pathology of the Mouse: Reference and Atlas (Maronpot RR, Boorman GA Gaul BW, eds). Cache River Press, Vienna, IL, 235-258.
Abstract: http://www.cacheriverpress.com/books/pathmouse.htm