title: Fibroblastic osteosarcoma in a lion (Panthera leo).
abstract: This report describes a case of spontaneous fibroblastic osteosarcoma in the humerus of a lion from a private park in Perugia, Italy. The tumor had an irregular, smooth, brown surface and a generally firm, rubbery consistence with gritty to hard areas interspersed. The mass was poorly vascularized with areas of necrosis at the periphery. The cut surface showed a multilobulated mass that had breached the humeral cortex, with periosteal production of reactive bone. The mass invaded the epiphysis, the synovial membrane, the joint capsule and ligaments. A mild hemorrhagic effusion appeared in the joint space. Clinical signs, gross and histopathologic findings are described in this rare case of a malignant bone tumor.
authors.affiliation: Dipartimento di Scienze Biopatologiche e Igiene delle Produzioni Animali e Alimentari, Università degli Studi di Perugia, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Leonardi
authors.affiliation: Dipartimento di Scienze Biopatologiche e Igiene delle Produzioni Animali e Alimentari, Università degli Studi di Perugia, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Lepri
authors.affiliation: Dipartimento di Patologia, Diagnostica e Clinica Veterinaria, Università degli Studi di Perugia, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Nannarone
authors.affiliation: Dipartimento di Patologia, Diagnostica e Clinica Veterinaria, Università degli Studi di Perugia, Italy.
authors.forename: O
authors.initials: O
authors.lastname: Olivieri
authors.affiliation: Dipartimento di Scienze Biopatologiche e Igiene delle Produzioni Animali e Alimentari, Università degli Studi di Perugia, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Mechelli
keywords: Bone tumor; Fibroblastic; Humerus; Osteosarcoma; Panthera leo