Chondrosarcoma of the radius with distant metastasis in a dog

A 9-year-old castrated male Doberman Pinscher was admitted for evaluation of lameness of the left forelimb. Radiography and examination of biopsy specimens revealed a moderately differentiated chondrosarcoma of the proximal portion of the radius. The dog was treated by local excision of the neoplasm, which involved resection of the radial head and proximal portion of the radius. Despite the large size of the dog and the weight-bearing forces exerted on the cubital joint, major problems with ambulation did not develop after surgery. Functional use of the limb returned slowly; however, substantial limb use was observed despite the development of mild degenerative changes of the joint and migration of the humeroulnar articulation. Six months after surgery, metastasis of a widely disseminated, poorly differentiated chondrosarcoma to the subcutaneous tissues and thoracic and abdominal cavities was diagnosed. Local redevelopment of the chondrosarcoma in the area of the cubital joint was not detected. Resection of the radial head and proximal portion of the radius may be considered a viable, alternative, limb-sparing technique. The biologically aggressive nature of this chondrosarcoma of the appendicular skeleton indicated that additional information was needed before a reliable prognosis could be established for this dog with this tumor type. Reports of low rates of metastasis have been based on insufficient numbers of dogs to adequately or accurately determine the long-term prognosis of dogs with chondrosarcoma of the appendicular skeleton.