Da. Stoffregen et al., A FIBROSARCOMA IN THE SKELETAL-MUSCLE OF A CAPYBARA (HYDROCHOERUS-HYDROCHAERIS), Journal of wildlife diseases, 29(2), 1993, pp. 345-348
An 8-yr-old male capybara (Hydrochoerus hydrochaeris), a resident of a
n urban zoological collection in upstate New York (USA), had a mass po
steroventral to its left stifle; it was of unknown duration. The mass
was a fibrosarcoma based on invasive sheets of interwoven spindle-shap
ed neoplastic cells with moderate associated extracellular matrix comp
osed of collagen fibers. Supportive immunohistochemical staining was p
ositive f or vimentin but negative for cytokeratins, desmin, and myogl
obin. The animal subsequently died of unknown causes. This is the firs
t known report of a neoplasm in a capybara.