What type of tumor arises from endothelial cells?

The tumor that arises from endothelial cells is hemangiosarcoma. This type of tumor originates from the cells that line blood vessels, which are known as endothelial cells. Hemangiosarcoma is particularly aggressive and is often associated with blood-filled cavities or masses due to its vascular origin. These tumors are most commonly seen in dogs but can also occur in other species, and their recognition is crucial due to the possible clinical implications, including bleeding and metastasis.

In contrast, the other tumor types listed do not originate from endothelial cells. Liposarcoma arises from adipose (fat) tissue, osteosarcoma originates from bone, and chondrosarcoma comes from cartilage. Each of these tumors has distinct cellular characteristics and behaviors based on their tissues of origin, further highlighting the specificity of hemangiosarcoma's association with endothelial cells.