Esophagus, Muscularis - Degeneration

Esophagus, Muscularis - Degeneration in a male F344/N rat from a chronic study. Decreased muscle fiber size (arrow).
Figure 1 of 4

Esophagus, Muscularis - Degeneration in a male F344/N rat from a chronic study (higher magnification of Figure 1). Note the decreased muscle fiber size (arrow).
Figure 2 of 4

Esophagus, Muscularis - Degeneration in a female Sprague-Dawley rat from a chronic study. There are infiltrates of macrophages amid the muscle fibers (arrow).
Figure 3 of 4
comment:
Degeneration is characterized by decreased fiber size ( Figure 1



recommendation:
Whenever present, degeneration of the tunica muscularis should be diagnosed as "esophagus, muscularis - degeneration" and graded based upon the extent of the lesion. It should be noted in the narrative whether the pathologist considers this lesion to be due to chemical exposure or a gavage error.references:
Brown HR, Hardisty JF. 1990. Oral cavity, esophagus and stomach. In: Pathology of the Fischer Rat (Boorman GA, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, CA, 9-30. Abstract: https://www.ncbi.nlm.nih.gov/nlmcatalog/9002563
Valentine BA, McGavin MD. 2007. Skeletal muscle. In: Pathologic Basis of Veterinary Disease, 4th ed (McGavin MD, Zachary JF, eds). Mosby, St Louis, MO, 973-1039.
Web page last updated on: November 18, 2014