Case Report: Surgical resection of high-grade extradural thoracic vertebral chondrosarcoma in a dog

This report describes the clinical presentation, diagnosis, treatment, and outcome of a dog with an extradural, non-compressive, high-grade thoracic vertebral chondrosarcoma (CSA).

A 10-year-old, female spayed, 33-kg mixed-breed dog presented with a 96-h history of spontaneous vocalization and reluctance to use stairs. Neurological examination revealed normal ambulation without ataxia, along with marked resistance to manual ventroflexion and left lateral flexion of the neck. Magnetic resonance imaging (MRI) revealed a T1-weighted isointense, T2-weighted and STIR hyperintense, vividly contrast-enhancing mass with well-defined margins, located parasagittal to the right dorsal compartment of the T5 and T6 vertebrae, without evidence of neural invasion. Imaging and biopsy findings were consistent with vertebral CSA. Wide en bloc surgical resection was performed via a dorsal laminectomy with osteotomy of the spinous process using a bilateral paramedian approach to the T5-T7 vertebral column. Histopathological analysis confirmed a high-grade (grade III) chondrosarcoma with no histologic evidence of neoplasia at the bone margins. At the 2-week and 5-month recheck, the dog exhibited complete clinical resolution of CSA. Repeat computed tomography (CT) imaging performed 5 months postoperatively revealed no evidence of tumor recurrence.

This case demonstrates that high-grade vertebral CSA can be successfully treated with wide surgical excision, particularly in the absence of neural invasion. However, long-term tumor surveillance is required.