Canine Multicentric Subcutaneous Hemangiosarcoma (HSA)

Last Modified: December 4, 2003


Dear OncoLink "Ask The Experts,"
My dog was diagnosed with hemangiosarcoma. She also has a history of mast cell tumor grade II. She is a 13 year old mixed shepherd. Her tail was amputated, because the tumor was on the base. She also had 4 superficial tumors removed. They all came back as Multicentric Subcutaneous Hemangiosarcoma. The tail mass came back as mast cell tumor, but the biopsy showed to be HSA. What protocols should I consider? 


Lili Duda, VMD, Section Editor of the OncoLink Veterinary Oncology Menu, responds:

The dog described has multicentric subcutaneous hemangiosarcoma (HSA), which is one of the possible presentations in dogs. This is still considered a high-grade hemangiosarcoma with the same clinical course and treatment recommendations as for visceral (e.g. splenic) HSA. The current treatment options are Adriamycin/Cytoxan every three weeks, although single-agent Adriamycin every two weeks is also being used with roughly comparable results. Chemotherapy can delay the onset of metastasis to lungs/liver/spleen and elsewhere, but unfortunately prognosis is still grim.

As far as mast cells being found on fine-needle aspirate of the tail mass, which was ultimately diagnosed as HSA – it is very difficult to comment without seeing the cytology report of the fine-needle aspirate. However, mast cells are a normal component of an inflammatory cell infiltrate, and small numbers are often present on aspirates of inflamed tissues. Mast cells can sometimes constitute a large percentage of the inflammatory cells. In addition, hemangiosarcomas can be difficult to diagnose on cytology, as the malignant cells tend not to exfoliate very well, and the aspirates are often very blood-diluted due to the vascular nature of these tumors.