An Unusual Case Report of Primitive Jejuneal Canine Osteosarcoma

Extraskeletal osteosarcoma (also called extraosseous osteosarcoma or soft tissue osteosarcoma) is a rare primary malignant mesenchymal neoplasm arising in soft tissues with histologic features resembling primary osteosarcoma of bone but without any direct relation to bony structures. It is much rarer than either soft tissue sarcoma or skeletal osteosarcoma. It can produce osteoid, bone or chondroid material. The pathogenesis of this tumor is still uncertain and in humans they are considered both clinically and therapeutically distinct from primary osseous osteosarcoma. In previous studies canine extraskeletal osteosarcoma accounted for 6.09% of all cases of osteosarcoma and was seen only in mammary glands. Very few cases of primary intestinal osteosarcoma have been described in dogs and other species of animals. This report describes a case of primary intestinal osteosarcoma in Cocker Spaniel dog.