Haemangiosarcoma of the bone is a rare malignancy, accounting for less than 5% of bone tumours. It affects middle-aged to elderly animals of different sizes, but in dogs it is more common among Boxers, Great Danes and German Shepherd dogs. It probably derives from the supportive connective tissue of the bone marrow. It is a very aggressive tumour, metastasising to numerous organs including the lungs, liver, spleen, heart, muscles, kidneys, brain and bone. Affected dogs tend to manifest macroscopic metastatic lesions within 6 months of diagnosis.
Affected sites in the appendicular skeleton include the metaphysis and diaphysis of the humerus and femur: the lesions are strongly lytic with a minimal periosteal reaction and can give rise to pathological fractures (Fig. 1). These tumours are often confused with telangiectatic osteosarcoma when the histological diagnosis is made on small specimens. Haemangiosarcoma can also develop in the ribs, vertebrae and flat bones.1 Very often both the primary and metastatic lesions are multiple. Tumour staging must, therefore, include X-rays of the chest (for lung metastases) and skeleton (for bone metastases) and ultrasonography of the heart and abdomen (for cardiac and abdominal lesions).
The prognosis is poor: even animals with a solitary, non-metastatic bone lesion subjected to complete surgical excision of the tumour have only a 10% possibility of being alive 1 year after diagnosis.2-4 Small improvements in survival rates have been reported for non-skeletal forms following treatment with doxorubicin, cyclophosphamide and vincristine.
Haemangiosarcoma of the bone has also been reported in the cat, but little is known about the biological behaviour of the tumour in this species.
References
- Bingel, S.A., Brodey, R.S., Allen, H.L., Riser, W.H., 1974. Haemangiosarcoma of bone in the dog. Journal of Small Animal Practice 15(5),303-22.
- Dernell, W.S., Ehrhart, N.P., Straw, R.C., Vail, D.M., 2007. Tumors of the skeletal system. In: Withrow, S.J., Vail, D.M. (Eds.), Withrow and MacEwen’s Small Animal Clinical Oncology. Saunders, Elsevier, St. Louis, MI, USA, pp. 540-582.
- Erdem,V., Pead, M.J., 2000. Haemangiosarcoma of the scapula in three dogs. Journal of Small Animal Practice41(10),461-4.
- Jennings, Jr P.B., Andersen, G.L., Mathey, W.S., Okerberg, C.V., 1990. Bone haemangiosarcoma in a young Belgian malinois. Journal of Small Animal Practice 31(7),349-352.