title: Humeral chondrosarcoma in a Hokkaido brown bear (Ursus arctos yesoensis).
abstract: Humeral chondrosarcoma was found in an 18-year-old male Hokkaido brown bear (Ursus arctos yesoensis). Necropsy revealed a large firm mass under the left superficial pectoral muscle at the axillary region. The mass involved the left shoulder joint and peripheral muscles, and connected to the head of the humerus with osteolysis. Histopathologically, the mass was composed of irregularly shaped myxomatous to cartilaginous tumor lobules. The tumor cell showed moderate nuclear atypia with a relatively high mitotic index, especially in the edges of the myxomatous lobules. The tumor cells were positively immunostained with vimentin and S-100 protein. Based on these findings, the tumors were diagnosed as chondrosarcoma. Metastases were found in the left axillary lymph node, lungs, liver and kidney.
authors.affiliation: Laboratory of Veterinary Pathology, Department of Basic Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Murakami
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Shiori
authors.initials: S
authors.lastname: Chiba
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kurauchi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Motoki
authors.initials: M
authors.lastname: Sasaki
authors.forename: Takane
authors.initials: T
authors.lastname: Matsui
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000473:pathology / Q000662:veterinary*; D002813:Chondrosarcoma / Q000473:pathology / Q000662:veterinary*; D017809:Fatal Outcome; D006652:Histological Techniques / Q000662:veterinary; D006811:Humerus / Q000473:pathology*; D007564:Japan; D008297:Male; D009418:S100 Proteins; D012782:Shoulder / Q000473:pathology*; D001503:Ursidae; D014746:Vimentin
chemical_list: D009418:S100 Proteins; D014746:Vimentin