Synovial cell sarcoma in dogs

Lili Duda, VMD
Last Modified: November 1, 2001

Dear OncoLink "Ask The Experts,"
I have a 7-year-old German Shepard. He just had swelling on right elbow removed, and biopsy showed synovial sarcoma (grade 1). I'm distressed and don't know what to do. My vet suggested amputating the leg - which I'm not really in favor of. Could you tell me please, what is the best course of action? Is amputation necessary or are there any other methods? What could I do to prolong my dog's life without suffering?

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

Synovial cell sarcoma is a rare tumor in dogs. It arises from the connective tissue in and around joints. These tumors are very invasive locally, and have the potential for metastasis (spread) to draining lymph nodes and lungs. Grading of the biopsy sample does have some prognostic significance, with grade I tumors being the least likely to metastasize elsewhere, and grade III tumors being very likely to metastasize. Other special staining techniques of the biopsy sample (specifically cytokeratin) might also be useful but are only available at certain diagnostic laboratories.

Wide surgical excision, which means amputation, is by far the best chance for local control of the tumor. Smaller, more localized surgeries do not work, because it is the joint that is affected, so the joint must be removed in order to remove the entire tumor. In addition, these tumors can be painful, and amputation is the best way to remove the source of pain. Radiation therapy in conjunction with pain medication might offer temporary palliation (relief) of the pain but will not provide long-term control of the tumor. For tumors that have already metastasized, radiation therapy can still provide pain palliation. The effectiveness of chemotherapy is unknown, but may provide some palliation or delay the progression of metastasis.