Which canine primary bone tumor has a metastasis rate greater than 90%?

Which canine primary bone tumor has a metastasis rate greater than 90%?

• A. Osteosarcoma
• B. Chondrosarcoma
• C. Hemangiosarcoma
• D. Fibrosarcoma

Answer: (C)

Metastatic behavior is what this item is testing—the tumor with the strongest tendency to spread to distant sites, often reported as exceeding 90% in affected dogs. Hemangiosarcoma arises from the lining of blood vessels, so its cells have easy access to the bloodstream. This vascular nature drives rapid, widespread dissemination to multiple organs early in the disease, making metastasis very likely and frequently surpassing the 90% mark. That extreme propensity for systemic spread is what makes it the best answer for a metastasis rate over 90%. The other tumors are aggressive as well, but they don’t typically reach that same level of early, widespread metastasis. Osteosarcoma is highly aggressive and common, with significant metastatic potential, especially to the lungs, but its spread pattern is more organ-limited than the hematogenous, multi-organ spread seen with hemangiosarcoma. Chondrosarcoma and fibrosarcoma tend to metastasize less frequently and later, hence they are less likely to exceed the 90% threshold.

Metastatic behavior is what this item is testing—the tumor with the strongest tendency to spread to distant sites, often reported as exceeding 90% in affected dogs.

Hemangiosarcoma arises from the lining of blood vessels, so its cells have easy access to the bloodstream. This vascular nature drives rapid, widespread dissemination to multiple organs early in the disease, making metastasis very likely and frequently surpassing the 90% mark. That extreme propensity for systemic spread is what makes it the best answer for a metastasis rate over 90%.

The other tumors are aggressive as well, but they don’t typically reach that same level of early, widespread metastasis. Osteosarcoma is highly aggressive and common, with significant metastatic potential, especially to the lungs, but its spread pattern is more organ-limited than the hematogenous, multi-organ spread seen with hemangiosarcoma. Chondrosarcoma and fibrosarcoma tend to metastasize less frequently and later, hence they are less likely to exceed the 90% threshold.