Epididymis - Amyloid

Image of amyloid in the epididymis from a male B6C3F1 mouse in a chronic study
Epididymis - Amyloid. Amyloid deposits in the interstitium (arrows) in a male B6C3F1 mouse from a chronic study.
Figure 1 of 2
Image of amyloid in the epididymis from a male B6C3F1 mouse in a chronic study
Epididymis - Amyloid. Higher magnification of Figure 1. Amyloid deposits in the interstitium (arrows) in a male B6C3F1 mouse from a chronic study.
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comment:

Amyloidosis is an age-related, incidental background finding most commonly seen in mice. It is generally a systemic condition, but the epididymis is a common site for deposition. It appears as pale, eosinophilic extracellular material that has a green birefringence under polarized light when stained with Congo red.

recommendation:

Amyloid should be recorded and graded and should be discussed in the pathology narrative if the incidence and/or severity appear to be related to chemical administration. Associated or secondary lesions need not be diagnosed unless warranted by their severity.

references:

Radovsky A, Mitsumori K, Chapin RE. 1999. Male reproductive tract. In: Pathology of the Mouse: Reference and Atlas (Maronpot RR, Boorman GA, Gaul BW, eds). Cache River Press, Vienna, IL, 381-407.
Abstract: http://www.cacheriverpress.com/books/pathmouse.htm