Biologic Behaviour
•HSA is a malignant neoplasm that arises from the endothelial cells
•HSA account for 4% of all primary bone tumors
•HSA should be differentiated from telangiectatic OSA
•breed predisposition: GSD ± Boxers and Great Danes
•sex predisposition: males
•43% HSA occur in the appendicular skeleton and 57% in the axial skeleton
•sites: proximal humerus (most common), femur, ribs, vertebrae and scapula
•multiple lesions are relatively common
•soft tissue mass accompanies bony lesion in 50% of cases
•pathologic fracture is common
•> 88% metastatic rate with metastatic disease developing < 6 months
•metastatic sites include lungs, liver, spleen, heart, skeletal muscle, kidney, brain, and other long bones
Treatment
•survey radiographs: osteolytic with intramedullary extension and minimal cortical or periosteal changes
•ultrasonographic examination of the heart and abdominal cavity is recommended for primary lesions
•pulmonary metastatic disease is difficult to confirm as diffuse interstitial pattern mimics old age changes
•12-month survival rate < 10% even with single bone lesions
SURGICAL ONCOLOGY
SOCIETY
RESEARCH
EDUCATION
LINKS
EMPLOYMENT
HEMANGIOSARCOMA
T0
No evidence of neoplasia
T1
Tumor confined within the medulla and cortex
Primary Tumor
T2
Tumor extends beyond the periosteum
M0
No evidence of lymph node involvement
M1
Evidence of distant metastasis with site specified
Metastasis