Hemangiosarcoma (HSA) is a type of cancer that develops from the cells that normally create blood vessels (endothelial cells). The cause of hemangiosarcoma in most cases is unknown. However, we do know that sunlight can cause this cancer on the belly skin, inner thighs, eyelids, and eyelid membranes (conjunctiva) of patients with pale/pink skin and thin fur who live in very sunny climates.
If your dog has been diagnosed with a bone lesion most likely caused by a type of bone cancer.
An option for confirming diagnosis of this condition is ultrasound-guided fine needle aspirates of the lesion (as opposed to surgical biopsy for histologic diagnosis). This technique will provide an accurate diagnosis in 75 - 90% of patients, enabling the patient’s family to feel most comfortable when moving forward with treatment decisions. However, it is reasonable to proceed with amputation based on x-ray appearance alone, based on high likelihood of osteosarcoma as the cause of the bone lesion. Prior to radiation therapy or limb spare surgery, a cytologic or histologic diagnosis is recommended.