Osteosarcoma: issues of life and limb

摘要

Canine osteosarcoma (OSA) is a common malignancy of dogs with over 10,000 new dogs affected each year. It is by far the most common primary bone cancer. It generally occurs in large breed (> 20 kg), middle aged dogs with a slight predilection for males over females. Seventy five percent affect the limbs with 60 percent in the front leg and 40 percent in the back leg. Metaphyseal sites are most common with only rare involvement of the bones of the elbow. Histologic varieties occur (osteoblastic, chondroblastic, fibroblastic, and telangiectatic) but no proof exists that these variants have a different biologic behavior or response to therapy. Radiographic features are generally of a mixed pattern (lytic and blastic change). Many tumors can be tentatively "diagnosed" on signalment, history, and radiographs but a needle core biopsy (Jamshidi) is generally recommended. If limb sparing is contemplated, the biopsy technique and position should be carefully planned.