Synovial myxoma in the vertebral column of a dog: MRI description and surgical removal.

A 12 yr old castrated male mixed-breed dog presented with a 2 wk history of progressive tetraparesis. Neurologic deficits included a short-strided choppy gait in the thoracic limbs and a long-strided proprioceptive ataxia in the pelvic limbs. Withdrawal reflexes were decreased bilaterally in the thoracic limbs. Signs were consistent with a myelopathy of the caudal cervical/cranial thoracic spinal cord (i.e., the sixth cervical [C] vertebra to the second thoracic [T] vertebra). A mass associated with the C6-C7 articular facet on the left side was identified on MRI of the cervical spinal cord. The lesion was hyperintense to spinal cord parenchyma on T2-weighted images, hypointense on T1-weighted images, and there was strong homogenous contrast enhancement. Significant spinal cord compression was associated with the lesion. The mass was removed through a C6-C7 dorsal laminectomy and facetectomy. Histopathology of the mass was consistent with a synovial myxoma of the articular facet. A postoperative MRI showed complete surgical resection. Albeit rare, synovial myxomas should be included in the list of differential diagnoses for neoplasms affecting the vertebral columns in dogs.

Outcome of thoracolumbar surgical feline intervertebral disc disease.

OBJECTIVES: The aim of this study was to evaluate the outcome and prognosis of thoracolumbar feline intervertebral disc disease (IVDD) treated by surgical decompression. METHODS: This was a multi-institutional retrospective study evaluating the age, breed, sex, body weight, presenting complaint, neuroanatomic diagnosis at presentation, diagnostic imaging results, surgery performed and the overall outcome at discharge and at recheck. Bivariable associations between variables were assessed using the Kruskal-Wallis test (age and grade of IVDD at presentation) and Fisher's exact test (grade of IVDD at presentation and outcome). RESULTS: A total of 35 cats met the inclusion criteria for the study. The most frequently reported clinical sign was difficulty walking (54.2%). The majority of cats presented with an L4-S3 localization (57%). The most common site of intervertebral disc herniation (IVDH) was at L6-L7 (34%). The majority of feline patients that received surgery had a positive outcome at the time of discharge (62.5%; n = 20/32) and at the time of the 2-week recheck (91.3%; n = 21/23). No association was identified between the age of the patient and the grade of IVDD. No association was identified between the presenting grade of IVDD and the clinical outcome at the time of discharge or at the time of recheck evaluation. CONCLUSIONS AND RELEVANCE: Cats undergoing spinal decompressive surgery for thoracolumbar IVDH appear to have a favorable prognosis independent of the initial presenting grade of IVDD. A larger sample size and a longer length of follow-up is necessary to obtain statistical associations between the presenting grade of IVDD and overall clinical outcome.