Ghasem Farjanikish - Department of Pathobiology, Faculty of Veterinary Medicine, Lorestan University, Khorramabad, Iran
Omid Dezfoulian - Department of Pathobiology, Faculty of Veterinary Medicine, Lorestan University, Khorramabad, Iran
Hossein Mohammadi - Department of Pathology, School of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran

A four-year-old male Persian cat was referred with three weeks history of progressive lameness due to a rigid osseous mass with ۳.۵۰×۲.۵۰×۲.۰۰ cm in dimensions in his left arm. In the histopathological evaluation of bone biopsy, two distinct populations of cells including multinucleated giant cells and oval cells which embedded in a fibro-osseous stroma and surrounded by lamellar bone trabeculae were observed. At necropsy, multiple metastatic nodules with different sizes unveiled in the liver and spleen. Microscopically, those tumor cells which already described in the bone lesion were also infiltrated to the liver and spleen. The neoplastic cells had no immunoreaction to CD۶۸, desmin, alpha smooth muscle actin, S۱۰۰, CD۲۰, CD۳ and pancytokeratin, but only a few cells had reaction to vimentin were similar to fibroblasts.

Giant cell osteosarcoma, Immunohistochemistry, Metastasis, Persian cat