Cervical Chondroid Chordoma in a Shetland Sheep Dog

SummaryA spayed female Shetland sheep dog aged 12 years was presented for examination with ataxia and hindlimb paralysis. Extradural spinal cord compression was found at the level of vertebrae C6–C7 by radiography and myelocomputed tomography. A jelly-like mass (0.6 × 1.3 cm) was removed surgically. Histopathological findings were characterized by proliferation of vacuolated polygonal cells (physaliphorous cells) in a mucinous matrix and the presence of chondroid tissue shown immunohistochemically to express S-100. The physaliphorous cells were immunolabelled strongly for vimentin and S-100, and weakly for cytokeratin. A diagnosis of canine cervical chondroid chordoma was made. This is considered to be the first report of a chondroid chordoma originating from the cervical region of the spine in the dog.