Canine Soft Tissue Sarcomas

Soft tissue sarcomas (STSs) consist of a variety of tumors that arise from mesenchymal cells. Tumors included in this group are fibrosarcomas, peripheral nerve sheath tumors, and hemangiopericytomas. They typically appear as firm, subcutaneous (under the skin) masses, which may be located on the extremities, trunk, or head and neck. They usually are slow-growing tumors, but may also come up quite quickly. These tumors are locally invasive, and are not likely to go to other sites (metastasize).

Diagnosis involves either cytological (fine needle aspirate) or histopathological (biopsy) evaluation. If your dog is diagnosed with a STS, the primary treatment recommendation is surgical removal of the mass. The feasibility of surgery will depend on the size and the location of the tumor. Because these tumors can be invasive, diagnostic tests such as a CT scan may help to identify the extent of the mass. We also may need to do other diagnostic tests such as thoracic (chest) radiographs prior to surgery to look for metastases. We also consult with the Surgical Service to get their opinion on the surgical options, to discuss potential complications of surgery, and to get an estimate for the surgical costs. Once the mass has been removed, histopathological evaluation offers additional information about the potential aggressiveness of the tumor, referred to as the histological grade. If the tumor appears to be aggressive, then other treatment modalities such as chemotherapy, may be recommended to prevent its recurrence or metastases. In addition, histopathological evaluation helps to determine if the tumor was completely excised. If the tumor was not completely excised, then post-operative radiation therapy or chemotherapy may be beneficial in preventing local recurrence.

As you may have noticed, there are many variables to consider. We will do our best at discussing the tumor type that your dog has, the treatment options that are available, the prognosis, and the cost associated with treatment.