Features of a rare peripheral primitive neuroectodermal tumour arising from the thoracic spine in a juvenile canine patient

Peripheral primitive neuroectodermal tumours are rare tumours in juveniles. The current patient was a paraplegic 8‐month‐old Scottish deerhound with a suspected pulmonary mass. Radiographically, there was a large extrapleural mass within the mid‐left hemithorax. On MRI, the mass was mainly hyperintense on T2‐weighted images, isointense on T1‐weighted images and was heterogeneously strongly contrast enhancing with a multilobulated appearance, spinal cord compression, paraspinal musculature invasion and intrathoracic extension. Those changes were confirmed on post‐mortem, and the mass diagnosed based on immunohistochemistry.