Diagnosis and radiation therapy of an extensive myxoma in the retropharyngeal region infiltrating the cranial cervical vertebral canal in a dog

An 8‐year‐old, intact Rottweiler‐female dog presented due to an acute onset of lethargy, abnormal gait, and wheezing. Physical examination revealed stridor, cervical pain, and ambulatory tetraparesis. Magnetic resonance imaging‐examination displayed a lobulated, fluid‐filled mass extending from the sphenoid bone to C5, infiltrating the cranial vertebral canal causing extradural compression of the spinal cord and narrowing of the pharynx. An emergency debulking‐surgery around the pharynx was performed. Histopathological findings were consistent with a myxoma. The remaining tumor was irradiated resulting in stable disease 6 months later. The dog died 18 months later due to aspiration pneumonia without clinical signs of neurologic or respiratory compromise.