Magnetic resonance imaging, treatment and outcome of canine vertebral chondrosarcomas. Six cases.

OBJECTIVES: To report the clinical presentation, magnetic resonance imaging features, treatments and outcomes of canine vertebral chondrosarcoma.

MATERIALS AND METHODS: Retrospective review of medical records of dogs with confirmed vertebral chondrosarcoma and magnetic resonance imaging of the lesions, from four different veterinary referral institutions.

RESULTS: A total of six dogs were included in this report. In all cases, magnetic resonance imaging revealed a lobulated mass involving the dorsal vertebral compartment, markedly hyperintense with few foci of hypointensity on T2-weighted images, iso to hypointense on T1-weighted images with contrast enhancement after gadolinium administration. Intralesional surgical resection was performed in three dogs and medical management in one, two dogs were euthanased and all lesions were submitted for histopathology. Magnetic resonance imaging findings correlated with histological findings of a low tumour grade. Rapid clinical improvement was noted after surgery but two of three dogs had local regrowth.

CLINICAL SIGNIFICANCE: Chondrosarcomas show local aggressiveness and resistance to conventional radiotherapy and chemotherapy, and so prognosis depends on feasibility of en bloc resection. Magnetic resonance imaging may be helpful in establishing a presumptive diagnosis and prognosis based on the feasibility of surgical resection.