General Information About Hemangiosarcoma:
Hemangiosarcoma is a common, malignant cancer that arises from transformed endothelial cells (the ones that line the blood vessels). Thus, this tumor tends to bleed easily (it makes a lot of blood vessels) and spread easily (through the blood stream). The most common location of the primary tumor is within the spleen, and the most common metastatic sites are the liver and the base of the heart. This cancer is most common in golden retrievers and other large breed dogs.
Typically, there are no signs until the tumor starts to bleed. Then the patient may be very weak, panting, unable, to walk, and have pale gums. These signs are caused by bleeding into either the abdomen or the sac around the heart. It usually happens abruptly.
Radiographs confirm the presence of a mass, and ultrasound is used to determine the location and appearance of the mass. We usually do not aspirate these due to their tendency to bleed. Instead, we head to surgery for removal, followed by histopathology. We cannot tell the difference between splenic hemangiosarcoma and splenic hemangioma (a benign tumor) or hematoma (a bad bruise) based on gross appearance, so we always send out a biopsy.
Surgical removal controls the bleeding, resolving the acute emergency. Chemotherapy historically has been single-agent doxorubicin. There are some new protocols on the horizon.
Splenectomy alone yields survival of less than 6 weeks, with death resulting from the rapid growth of metastatic tumors. Adding doxorubicin increases survival to about 12 months.