title: A fibrosarcoma in the skeletal muscle of a capybara (Hydrochoerus hydrochaeris).
abstract: An 8-yr-old male capybara (Hydrochoerus hydrochaeris), a resident of an urban zoological collection in upstate New York (USA), had a mass posteroventral to its left stifle; it was of unknown duration. The mass was a fibrosarcoma based on invasive sheets of interwoven spindle-shaped neoplastic cells with moderate associated extracellular matrix composed of collagen fibers. Supportive immunohistochemical staining was positive for vimentin but negative for cytokeratins, desmin, and myoglobin. The animal subsequently died of unknown causes. This is the first known report of a neoplasm in a capybara.
authors: New York State College of Veterinary Medicine, Department of Pathology, Cornell University, Ithaca 14853.
authors: D A
authors: DA
authors: Stoffregen
authors: A W
authors: AW
authors: Prowten
authors: H
authors: H
authors: Steinberg
authors: W I
authors: WI
authors: Anderson
mesh_terms: D000818:Animals; D001706:Biopsy / Q000662:veterinary; D005354:Fibrosarcoma / Q000473:pathology / Q000662:veterinary*; D007150:Immunohistochemistry; D008297:Male; D012376:Rodent Diseases / Q000473:pathology*; D012377:Rodentia; D012983:Soft Tissue Neoplasms / Q000473:pathology / Q000662:veterinary*