Spindle cell cancer occurs in the connective tissues (such as ligaments and tendons), blood and smooth muscles of dogs. These tumours can develop in any dog, but they are more typically found in older and/or large-breed dogs.
Determining the origin of the tumours that grow within connective tissues is not always possible. The variety of originating cells explains why many names can be used to describe spindle cell tumours. These names include fibrosarcoma, schwannoma, neurofibroma, peripheral nerve sheath tumour and hemangiopericytoma.
Spindle cell tumours are typically solid, although they can be filled with fluid. Normally they appear on the legs, but they can appear anywhere on the body. Owners may notice an ulcerated or bleeding mass or lump that may become infected.
To diagnose, the lump or mass should be aspirated and the fluids examined by a veterinarian. An x-ray of the area may be taken, and a biopsy of the tissues may be performed.
Spindle cell tumours are typically excised by the veterinarian. In extreme cases, an entire limb may be amputated. Radiation may be a recommended treatment. Chemotherapy has not proven to be effective against this particular type of cancer.
Approximately 25 per cent of the slow-growing versions of spindle cell tumours will return after being removed, although most don't spread to other parts of the body. The aggressive (high-grade) tumours are rare, but when they occur, they typically return 62 per cent of the time after being removed.