title: Cutaneous extraskeletal mesenchymal chondrosarcoma in a cat.
abstract: A 4-year-old, male cat was presented with a fixed, subcutaneous mass in the lumbosacral region. A histopathological examination revealed a well-defined but nonencapsulated neoplasm characterized by a proliferation of predominantly spindle cells, with high mitotic activity. Interspersed between these cells were single cellular elements with chondroid differentiation. Large areas of cartilaginous tissue with foci of endochondral ossification, necrosis and myxoid tissue were also observed within the neoplastic parenchyma. A diagnosis of extraskeletal mesenchymal chondrosarcoma was made based on the histological pattern - characterized by the coexistence of cartilaginous islands and undifferentiated mesenchymal cells, results of Alcian blue staining at various pH, immunohistochemical reactivity against vimentin and S-100, and the absence of skeletal involvement or other primary tumour sites. Clinical history of the cat excluded traumas, vaccinations or other types of subcutaneous inoculation. Six months on from surgical treatment, neither recurrence nor metastases have been detected.
authors.affiliation: Department of Comparative Biomedical Sciences, Faculty of Veterinary Medicine, University of Teramo, Piazza Aldo Moro, 45-64100 Teramo, Italy.
authors.forename: Mariarita
authors.initials: M
authors.lastname: Romanucci
authors.forename: Laura
authors.initials: L
authors.lastname: Bongiovanni
authors.forename: Lucio
authors.initials: L
authors.lastname: Petrizzi
authors.forename: Leonardo
authors.initials: L
authors.lastname: della Salda
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D002415:Cats; D018211:Chondrosarcoma, Mesenchymal / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D016896:Treatment Outcome